Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

For making plans I'm currently using Vectorsoft Draw - a 2-d drawing
program on PocketPC and experimenting with Google Sketch-up for 3-d
drawings. Move away from paper a couple years ago. Would like to hear
comments on what else is good.

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Thanks a lot

Ross

"djenyc" wrote in message
ups.com...
Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

It would be worthwhile, but if you're not building anything that risks life
or limb, learning by trial and error isn't bad, either.

For the examples you give there are two basic subjects you need to know:
strength of materials, and "statics." If you want to learn them, be sure to
use texts written for technical schools and junior colleges, not for
four-year engineering-school students. The former explain it in terms of
high school algebra. The latter do it in terms of calculus. If you're good
at calculus, use either one.

A basic study of these subjects will not make you a design engineer but it
may prevent some of the grosser errors. And you may find it very
interesting. These subjects provide a lot of suprises and insights into how
things work -- and how they don't.

I'd call a local community college and see if they have a program in
"engineering technology," or something like that, and ask what texts they
use.

--
Ed Huntress

djenyc sezz:
Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Look for an engineering school macine design book. It will have good
references for the section modulus of various shapes and materials as well
as the simple formulas for calculating beam deflections, etc.

One example:

Machine Elements in Mechanical Design
Mott, Robert
ISBN: 0130618853
Publisher: Prentice Hall, Lebanon, Indiana, U.S.A.
Publication Date: 2004

If a forklift crumbled when lifting your dad, maybe he should lose
some weight.

When I was building my trailer

http://igor.chudov.com/projects/Home...th-M105A2-Bed/


I use a online deflection calculator. I think that while in general,
engineering steel structures requires a lot of expertise, engineering
severely overbuilt structures requires a little less expertise.

i

Ed Huntress sezz:
For the examples you give there are two basic subjects you need to
know: strength of materials, and "statics." If you want to learn
them, be sure to use texts written for technical schools and junior
colleges, not for four-year engineering-school students. The former
explain it in terms of high school algebra. The latter do it in terms
of calculus. If you're good at calculus, use either one.

Good point. The book example I gave was used at a college in the mechanical
engineering technology cirriculum.
--
Doug

On Sep 27, 12:36 pm, Ignoramus2150
wrote:
If a forklift crumbled when lifting your dad, maybe he should lose
some weight.

I needed that forklift to carry ~150lb load, not industrial size The
part that folded was made from remains of 12 gauge mower decks ...
running low on materials at the moment


When I was building my trailer

http://igor.chudov.com/projects/Home...th-M105A2-Bed/

I use a online deflection calculator. I think that while in general,
engineering steel structures requires a lot of expertise, engineerig
severely overbuilt structures requires a little less expertise.

i

Cool, do you have a link for that calculator. I wonder how 2x4's
compare to black pipe... I'd like to overbuild, but I have a lot of
ideas and not a lot of steel.

On Thu, 27 Sep 2007 10:49:26 -0700, djenyc wrote:
On Sep 27, 12:36 pm, Ignoramus2150
wrote:
If a forklift crumbled when lifting your dad, maybe he should lose
some weight.

I needed that forklift to carry ~150lb load, not industrial size The
part that folded was made from remains of 12 gauge mower decks ...
running low on materials at the moment


When I was building my trailer

http://igor.chudov.com/projects/Home...th-M105A2-Bed/

I use a online deflection calculator. I think that while in general,
engineering steel structures requires a lot of expertise, engineerig
severely overbuilt structures requires a little less expertise.

i

Cool, do you have a link for that calculator. I wonder how 2x4's
compare to black pipe... I'd like to overbuild, but I have a lot of
ideas and not a lot of steel.


I cannot find the link, I thought I had it. It is a deflection
calculator from some mechanical society...

i

On Sep 27, 11:44 am, "Doug" wrote:
djenyc sezz:

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Look for an engineering school macine design book. It will have good
references for the section modulus of various shapes and materials as well
as the simple formulas for calculating beam deflections, etc.

One example:

Machine Elements in Mechanical Design
Mott, Robert
ISBN: 0130618853
Publisher: Prentice Hall, Lebanon, Indiana, U.S.A.
Publication Date: 2004

Doug, thanks for the book info.

So far I've found a lot of good metalworking books in pdf format on
http://www.metalwebnews.com/ed.html. I've been reading Farm Shop
Practice, US Army - Fundamentals of Machine Tools, US Navy - Machinery
Repairman Handbook, US Army - Welding Theory and Application, Aussie
Weld - The Welding Tutorial. That and some books from local library
and through inter-library loans. They were easy to read, but none went
in to design details. On the other hand, books on mechanical
engineering that I saw in local library were written for college
courses, while I was looking for a few hundred pages farmer series
type booklet . A problem with college course, imho - an overview
course will not go in to enough details to be of practical use, and
detailed courses go too far in to theory/formulas and procedures
applicable to industrial production ...not ballpark figures for hack-
jobs I'm in to I mean, may be I'm wrong, but the stuff I saw at the
library was just scary

On Sep 27, 11:39 am, "Ed Huntress" wrote:
"djenyc" wrote in message

ups.com...



Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

It would be worthwhile, but if you're not building anything that risks life
or limb, learning by trial and error isn't bad, either.

For the examples you give there are two basic subjects you need to know:
strength of materials, and "statics." If you want to learn them, be sure to
use texts written for technical schools and junior colleges, not for
four-year engineering-school students. The former explain it in terms of
high school algebra. The latter do it in terms of calculus. If you're good
at calculus, use either one.

A basic study of these subjects will not make you a design engineer but it
may prevent some of the grosser errors. And you may find it very
interesting. These subjects provide a lot of suprises and insights into how
things work -- and how they don't.

I'd call a local community college and see if they have a program in
"engineering technology," or something like that, and ask what texts they
use.

--
Ed Huntress

Ed, thanks, I'll check on what books they use at community college. I
went to community college a while ago before transferring to
university, and found they courses to be more entry-level and
application oriented/ vs. more theoretical/fundamental stuff at 4 year
school. It is odd though that there are a lot of free books on line
(US Navy/Army, expired copyright, farming books, etc) about
metalworking, welding, drafting, quality control, fabrication, but
nothing on design... Even non-free selection seem to be more
production and college oriented...

"djenyc" wrote in message
ups.com...
On Sep 27, 11:39 am, "Ed Huntress" wrote:
"djenyc" wrote in message

ups.com...



Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

It would be worthwhile, but if you're not building anything that risks
life
or limb, learning by trial and error isn't bad, either.

For the examples you give there are two basic subjects you need to know:
strength of materials, and "statics." If you want to learn them, be sure
to
use texts written for technical schools and junior colleges, not for
four-year engineering-school students. The former explain it in terms of
high school algebra. The latter do it in terms of calculus. If you're
good
at calculus, use either one.

A basic study of these subjects will not make you a design engineer but
it
may prevent some of the grosser errors. And you may find it very
interesting. These subjects provide a lot of suprises and insights into
how
things work -- and how they don't.

I'd call a local community college and see if they have a program in
"engineering technology," or something like that, and ask what texts they
use.

--
Ed Huntress

Ed, thanks, I'll check on what books they use at community college. I
went to community college a while ago before transferring to
university, and found they courses to be more entry-level and
application oriented/ vs. more theoretical/fundamental stuff at 4 year
school. It is odd though that there are a lot of free books on line
(US Navy/Army, expired copyright, farming books, etc) about
metalworking, welding, drafting, quality control, fabrication, but
nothing on design... Even non-free selection seem to be more
production and college oriented...

Yeah, that is interesting. I never looked online. My own books on those
subjects are ones I bought decades ago, so I can't help you with titles.

I'll tell you what I do when I want technology books like that, though --
particularly for construction trades, welding, landscaping, etc. I find out
what the local community college is using and then I go look for them in
their library. Then I come home and order them on an interlibrary loan
through my local community library.

That is, for books I don't want to keep. I'm very cheap. d8-)

--
Ed Huntress

"djenyc" wrote in message
ups.com...

Just on the off chance that this one is still around (these texts often go
through many editions), the basic one I use is _Statics & Strength of
Materials_ by Bassin, Brodsky, and Wolkoff. Mine is the 2nd edition, 1969,
McGraw-Hill.

It should be ideal for what you need. It even includes tables of properties
for many materials, including different types of wood. But those are easy to
find on the Web. And don't forget to ask here. There is a wealth of such
information in the heads of the members of this NG.

BTW, if you *really* want to know about wood, there is an excellent and
enjoyable book titled _Understanding Wood_, by R. Bruce Hoadley (I hope I
have the spelling right). This is no text -- it's written for the
hobbyist -- but I hear it's used in technology classes, too. It's published
by Taunton Press.

--
Ed Huntress

djenyc wrote:

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course


You might want to look at Harry Parker's "Simplified Design of
Structural Steel" and "Simplified Design of Structural Timber"


Kevin Gallimore

----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
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On Sep 27, 4:20 pm, "Ed Huntress" wrote:
"djenyc" wrote in message

ups.com...

Just on the off chance that this one is still around (these texts often go
through many editions), the basic one I use is _Statics & Strength of
Materials_ by Bassin, Brodsky, and Wolkoff. Mine is the 2nd edition, 1969,
McGraw-Hill.

It should be ideal for what you need. It even includes tables of properties
for many materials, including different types of wood. But those are easy to
find on the Web. And don't forget to ask here. There is a wealth of such
information in the heads of the members of this NG.

BTW, if you *really* want to know about wood, there is an excellent and
enjoyable book titled _Understanding Wood_, by R. Bruce Hoadley (I hope I
have the spelling right). This is no text -- it's written for the
hobbyist -- but I hear it's used in technology classes, too. It's published
by Taunton Press.

--
Ed Huntress

Thanks Ed! My local library has great online feature - I can look for
books including inter-library loans from other libraries and make a
loan-request online. Saves me an extra trip and time. And they call me
up when the book is ready for pick-up, usually takes them 3-5 days. I
actually just found and put in a request for Statics & Strength of
Materials - 1988 edition and located Understanding Wood at the local
library. Will check them out.

Ross

"djenyc" wrote in message
oups.com...
On Sep 27, 4:20 pm, "Ed Huntress" wrote:
"djenyc" wrote in message

ups.com...

Just on the off chance that this one is still around (these texts often
go
through many editions), the basic one I use is _Statics & Strength of
Materials_ by Bassin, Brodsky, and Wolkoff. Mine is the 2nd edition,
1969,
McGraw-Hill.

It should be ideal for what you need. It even includes tables of
properties
for many materials, including different types of wood. But those are easy
to
find on the Web. And don't forget to ask here. There is a wealth of such
information in the heads of the members of this NG.

BTW, if you *really* want to know about wood, there is an excellent and
enjoyable book titled _Understanding Wood_, by R. Bruce Hoadley (I hope
I
have the spelling right). This is no text -- it's written for the
hobbyist -- but I hear it's used in technology classes, too. It's
published
by Taunton Press.

--
Ed Huntress

Thanks Ed! My local library has great online feature - I can look for
books including inter-library loans from other libraries and make a
loan-request online. Saves me an extra trip and time. And they call me
up when the book is ready for pick-up, usually takes them 3-5 days. I
actually just found and put in a request for Statics & Strength of
Materials - 1988 edition and located Understanding Wood at the local
library. Will check them out.

Oh, that's a good deal on interlibrary loans. I have the rest of that, but
they make me come in for interlibrary stuff.

Well, happy reading. You'll only need some parts of _Statics..., which
you'll recognize, but you may wind up reading through _Understanding Wood_.
It's a classic.

--
Ed Huntress

I got an engineering degree 30 years ago. promptly forgot all of it.

My design criteria has always been to find something about like what I'm
building and copy it. "Shamelessly Plagiarized" is the term I use. Its worth
it do drive a ways to find something like what you're doing. Some poor
engineer has spent days designing that part, take advantage of his time.

Karl

"Karl Townsend" wrote in message
anews.com...
I got an engineering degree 30 years ago. promptly forgot all of it.

My design criteria has always been to find something about like what I'm
building and copy it. "Shamelessly Plagiarized" is the term I use. Its
worth it do drive a ways to find something like what you're doing. Some
poor engineer has spent days designing that part, take advantage of his
time.


There's the voice of wisdom. I do the same thing.

--
Ed Huntress

On Sep 28, 12:12 am, "Ed Huntress" wrote:
"Karl Townsend" wrote in message

anews.com...

I got an engineering degree 30 years ago. promptly forgot all of it.

My design criteria has always been to find something about like what I'm
building and copy it. "Shamelessly Plagiarized" is the term I use. Its
worth it do drive a ways to find something like what you're doing. Some
poor engineer has spent days designing that part, take advantage of his
time.

There's the voice of wisdom. I do the same thing.

--
Ed Huntress

How do you know that whoever built the article you are copying
actually spent time designing it?

When I was doing design work, the first thing I did was go to the tech
library and see what others had done. But you need to run a few
calculations before deciding to use some one elses design.

Dan

wrote in message
oups.com...
On Sep 28, 12:12 am, "Ed Huntress" wrote:
"Karl Townsend" wrote in message

anews.com...

I got an engineering degree 30 years ago. promptly forgot all of it.

My design criteria has always been to find something about like what
I'm
building and copy it. "Shamelessly Plagiarized" is the term I use. Its
worth it do drive a ways to find something like what you're doing. Some
poor engineer has spent days designing that part, take advantage of his
time.

There's the voice of wisdom. I do the same thing.

--
Ed Huntress

How do you know that whoever built the article you are copying
actually spent time designing it?

I don't. Maybe he copied it, too.

But I'm talking about hobby things, not production. For example, I made a
fly reel around 20 years ago (*far* more effort than it was worth), and I
just copied some of it from one I had. Same for the oscillating steam engine
I made. It probably was a 10th-generation copy. g


When I was doing design work, the first thing I did was go to the tech
library and see what others had done. But you need to run a few
calculations before deciding to use some one elses design.

If I ever build a bridge, I'll keep that in mind. g

Actually, I agree. I considered building a spaceframe sports car five or so
years ago, and I even got a simple FEA (Cadre) to analyze others' designs.
(Many commercial frames suck in a big way when you analyze their torsional
stiffness.) Then I got so caught up in studying and analyzing chassis design
that I never built one. d8-)

--
Ed Huntress

For your type of use I'd recommend something like
Architectural and Engineering Calculations Manual (Hardcover)
by Robert Brown Butler
# Hardcover: 464 pages
# Publisher: McGraw-Hill Companies (August 1983)
# Language: English
# ISBN-10: 0070093636
# ISBN-13: 978-0070093638

In spite of the broad sounding title, it has sections on sizing steel
beams, wood beams, pull out strength of screws, etc etc. And the other
sections talk about lighting levels for your shop (or whatever), pipe
sizes, etc etc. No theory, just formulas for what you need.

djenyc wrote:
Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

For making plans I'm currently using Vectorsoft Draw - a 2-d drawing
program on PocketPC and experimenting with Google Sketch-up for 3-d
drawings. Move away from paper a couple years ago. Would like to hear
comments on what else is good.

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Thanks a lot

Ross

On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five or so
years ago, and I even got a simple FEA (Cadre) to analyze others' designs.
(Many commercial frames suck in a big way when you analyze their torsional
stiffness.) Then I got so caught up in studying and analyzing chassis design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Dan

wrote in message
oups.com...
On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five or
so
years ago, and I even got a simple FEA (Cadre) to analyze others'
designs.
(Many commercial frames suck in a big way when you analyze their
torsional
stiffness.) Then I got so caught up in studying and analyzing chassis
design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Yes, we should print that and hang it on our walls.

--
Ed Huntress

On Thu, 27 Sep 2007 22:49:17 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


wrote in message
roups.com...
On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five or
so
years ago, and I even got a simple FEA (Cadre) to analyze others'
designs.
(Many commercial frames suck in a big way when you analyze their
torsional
stiffness.) Then I got so caught up in studying and analyzing chassis
design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Yes, we should print that and hang it on our walls.

Indeed. I came to the realization several years ago that I wasn't
really a woodworker, I was merely an "enhanced tool collector". Ayup,
I'll work wood and metal and plastic on occasion, but I'm more of a
tool collector these days. sigh

'Course, that new Karcher/Honda pressure washer I bought netted me a
$2,200 job which I just finished today, so I'm using a lot of the
tools, too. 2k+ s/f of concrete cleaned, primed, and opaque-stained in
3 coats. She chose the first color (which turned out too light), then
a second color (which I called "50s Pink"), and then the final color,
one of the trim colors on their interior. It was juuust right. 300 s/f
x3. Then on to the front porch/walk, then on to the lower porch and
walkway, complete with 20 concrete steps & 4 landings.

--
Exercise ferments the humors, casts them into their proper channels,
throws off redundancies, and helps nature in those secret distributions,
without which the body cannot subsist in its vigor, nor the soul act
with cheerfulness. -- Joseph Addison, The Spectator, July 12, 1711

On Thu, 27 Sep 2007 21:11:20 -0500, RoyJ
wrote:

For your type of use I'd recommend something like
Architectural and Engineering Calculations Manual (Hardcover)

I was going to suggest an architectural reference or an architectural
structures course as well. I helped my daughter a bit with her course
and it integrated statics and structural design, as opposed to my
engineering courses where statics, strength of materials and
structures were spread across four or five courses.

Another good practical book is Blodgett's "Design of Weldments,"
published by Lincoln. And a bargain at $15.
https://ssl.lincolnelectric.com/foun...dnum=DW&PID=16

--
Ned Simmons

"Larry Jaques" wrote in message
...
On Thu, 27 Sep 2007 22:49:17 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:


wrote in message
groups.com...
On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five
or
so
years ago, and I even got a simple FEA (Cadre) to analyze others'
designs.
(Many commercial frames suck in a big way when you analyze their
torsional
stiffness.) Then I got so caught up in studying and analyzing chassis
design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Yes, we should print that and hang it on our walls.

Indeed. I came to the realization several years ago that I wasn't
really a woodworker, I was merely an "enhanced tool collector". Ayup,
I'll work wood and metal and plastic on occasion, but I'm more of a
tool collector these days. sigh

That's not such a bad thing. It's better than collecting stamps.


'Course, that new Karcher/Honda pressure washer I bought netted me a
$2,200 job which I just finished today, so I'm using a lot of the
tools, too. 2k+ s/f of concrete cleaned, primed, and opaque-stained in
3 coats. She chose the first color (which turned out too light), then
a second color (which I called "50s Pink"), and then the final color,
one of the trim colors on their interior. It was juuust right. 300 s/f
x3. Then on to the front porch/walk, then on to the lower porch and
walkway, complete with 20 concrete steps & 4 landings.

And...you have the start of a new pressure-washer collection, doubtless the
first in your neighborhood.

--
Ed Huntress

djenyc wrote in
oups.com:



Thanks Ed! My local library has great online feature - I can look for
books including inter-library loans from other libraries and make a
loan-request online. Saves me an extra trip and time. And they call me
up when the book is ready for pick-up, usually takes them 3-5 days. I
actually just found and put in a request for Statics & Strength of
Materials - 1988 edition and located Understanding Wood at the local
library. Will check them out.

Ross


My library does this also, works out great since we homeschool our kids and
frequently need all kinds of reference books. Nothing like getting online
with a list of recommended books for whatever the curriculum we are
currently using, be able to get them from just about anywhere in the state
and have them delivered to our local branch. Only thing better would be if
they could deliver them directly to our door, then again that would negate
the weekly trip to the library for the kids and in my opinion nothing beats
wondering around a library as you never know what might catch your fancy.

Bill

On Thu, 27 Sep 2007 23:54:13 -0400, with neither quill nor qualm, "Ed
Huntress" quickly quoth:

wrote in message
I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Yes, we should print that and hang it on our walls.

Indeed. I came to the realization several years ago that I wasn't
really a woodworker, I was merely an "enhanced tool collector". Ayup,
I'll work wood and metal and plastic on occasion, but I'm more of a
tool collector these days. sigh

That's not such a bad thing. It's better than collecting stamps.

Ain't dat de trufe?


'Course, that new Karcher/Honda pressure washer I bought netted me a
$2,200 job which I just finished today, so I'm using a lot of the
tools, too. 2k+ s/f of concrete cleaned, primed, and opaque-stained in
3 coats. She chose the first color (which turned out too light), then
a second color (which I called "50s Pink"), and then the final color,
one of the trim colors on their interior. It was juuust right. 300 s/f
x3. Then on to the front porch/walk, then on to the lower porch and
walkway, complete with 20 concrete steps & 4 landings.

And...you have the start of a new pressure-washer collection, doubtless the
first in your neighborhood.

Nonononononono! We don't need that. Now I have to build a secure shed
in which to store it (and the mowers.)

--
Exercise ferments the humors, casts them into their proper channels,
throws off redundancies, and helps nature in those secret distributions,
without which the body cannot subsist in its vigor, nor the soul act
with cheerfulness. -- Joseph Addison, The Spectator, July 12, 1711

On Sep 27, 10:34 pm, " wrote:
On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five or so
years ago, and I even got a simple FEA (Cadre) to analyze others' designs.
(Many commercial frames suck in a big way when you analyze their torsional
stiffness.) Then I got so caught up in studying and analyzing chassis design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Dan

Thanks guys, I'll feel better now about hacking without a definite
plan, even if I have to go back and redo it a bunch of times ... will
stay away from SolidWorks and AutoCad, just back of a napkin
sketch .

Although, reading-up on basic differences in strength between building
materials should help.

Ross

On Sep 27, 11:29 pm, Ned Simmons wrote:
On Thu, 27 Sep 2007 21:11:20 -0500, RoyJ
wrote:

For your type of use I'd recommend something like
Architectural and Engineering Calculations Manual (Hardcover)

I was going to suggest an architectural reference or an architectural
structures course as well. I helped my daughter a bit with her course
and it integrated statics and structural design, as opposed to my
engineering courses where statics, strength of materials and
structures were spread across four or five courses.

Another good practical book is Blodgett's "Design of Weldments,"
published by Lincoln. And a bargain at $15.https://ssl.lincolnelectric.com/foun...dnum=DW&PID=16

--
Ned Simmons

Roy, Ned - will check those books. Thank you for recommendations.
Ross

"djenyc" wrote in message
oups.com...
On Sep 27, 10:34 pm, " wrote:
On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five
or so
years ago, and I even got a simple FEA (Cadre) to analyze others'
designs.
(Many commercial frames suck in a big way when you analyze their
torsional
stiffness.) Then I got so caught up in studying and analyzing chassis
design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Dan

Thanks guys, I'll feel better now about hacking without a definite
plan, even if I have to go back and redo it a bunch of times ... will
stay away from SolidWorks and AutoCad, just back of a napkin
sketch .

Although, reading-up on basic differences in strength between building
materials should help.

Oh, yeah, lots of interesting and often surprising stuff there. For example,
plywood stacks up well against foam-core fiberglass composite, and it's
stronger and lighter than uncored fiberglass-cloth/polyester composite
layups. And aluminum has no strength advantage over steel on a
pound-for-pound basis if the loads are strictly in tension or compression
(it's better in bending). And so on.

--
Ed Huntress

"djenyc" wrote in message
oups.com...
On Sep 27, 10:34 pm, " wrote:
On Sep 28, 2:37 am, "Ed Huntress" wrote:

Actually, I agree. I considered building a spaceframe sports car five
or so
years ago, and I even got a simple FEA (Cadre) to analyze others'
designs.
(Many commercial frames suck in a big way when you analyze their
torsional
stiffness.) Then I got so caught up in studying and analyzing chassis
design
that I never built one. d8-)

--
Ed Huntress

I also get caught up in studying and analyzing and often don't ever
get around to doing any actual building. The things that I design and
don't build always are perfect. The things I actually build often are
not prefect.

Dan

Thanks guys, I'll feel better now about hacking without a definite
plan, even if I have to go back and redo it a bunch of times ... will
stay away from SolidWorks and AutoCad, just back of a napkin
sketch .

Although, reading-up on basic differences in strength between building
materials should help.

Oh, yeah, lots of interesting and often surprising stuff there. For example,
plywood stacks up well against foam-core fiberglass composite, and it's
stronger and lighter than uncored fiberglass-cloth/polyester composite
layups. And aluminum has no strength advantage over steel on a
pound-for-pound basis if the loads are strictly in tension or compression
(it's better in bending). And so on.

--
Ed Huntress

I trust that you will come to appreciate that credible structural analysis
consists of rather a lot more than plugging numbers into formulas and hoping
for the best.

For example:

- Measuring, calculating, guesstimating the loads and the uncertainty
thereof.

- Determining the interaction effect of multiple, simultaneous loads.

- Determining whether loads are constant (static) or fluctuating, and if
the latter,
characterizing that fluctuation numerically.

- Considering less obvious sources of loading (e.g. earthquake, snow
loads, steady
wind loads, wind gusts flowing fluid loads, people clambering on your
baby).

- Determining whether a 2D analysis is adequate to describe a 3D
situation
(or when nothing short of a valid finite element computer analysis is
required or
when the situation is so complicated that an established empirical
approach (e.g.
lugs)or outright experimental load testing of a prototype is called
for).

- Determining how loads distribute themselves among redundant structural
elements
(such as multiple fasteners).

- Determining all the possible modes of structural failure and which is
the critical one
(e.g. excessive deflection, non-linear deflection, permanent
deformation,
tension/compression/shear failures, ductile rupture, brittle fracture,
fatigue
cracking, stress-corrosion cracking, hydrogen embrittlement, creep,
elastic buckling,
elastic/plastic buckling, plastic buckling, delamination).

- Locating the appropriate properties for the material in the condition
pertaining to its
planned use (e.g. Tensile yield strength, in the direction of the
grain, of Southern
yellow pine, air dried, at a moisture content in equilibrium with its
worst-case
planned environment).

- Statistical variability and possible directionality of material
properties.

- Environmental degradation of material properties over time (e.g. wood
decay, sunlight
and atmospheric effects on PVC).

- Materials that behave as composites (e.g. concrete slabs with rebar).

- Estimating the effects of material imperfections (e.g. holes, knots,
notches, changes
in section thickness, corrosion penetration) and whether this is
relevant to the
critical failure mode.

- Understanding how joints and support points affect stress distributions
(and whether
that's relevant to the critical failure mode).

- Understanding the assumptions and simplification inherent in the
derivation of strength
formulas (even the most sophisticated analyses contain simplifying
assumptions, such
as, for example, linear material behavior) and recognizing situations
in which these
assumptions are simply not tenable.

- Considering how serious are the possible consequences of a structural
failure.

- Are there liability issues associated with structural failure (anbody
but you going
to go near it) ?

- Knowing when established codes or standards should be (or must be)
applied (e.g.
residential/commercial building codes, AISC structural steel design
codes, timber
design codes).

- Considering all the things that I forgot to mention in the absence of a
specific
design problem.

- Given all of the above, determining the appropriate factor of safety to
apply
Note: The appropriate FS arrived at logically by an engineer is often
much greater
than one the layman might choose and feel to be adequate.


All that said, some references a

Roark, Formulas for Stress and Strain

Baumeister & Marks, Standard Handbook for Mechanical Engineers

AISC Manual of Steel Construction (ASD)

http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm


http://trs.nis.nasa.gov/perl/search?...pe=ALL&authors
%2Feditors=&authors%2Feditors_srchtype=ALL&year=&_ satisfyall=ALL&_order=byti
tle&_action_search=Search

http://www.knovel.com/knovel2/Toc.jsp?BookID=589

http://www.efunda.com/materials/mate.../materials.cfm

http://www.matweb.com/index.asp?ckck=1

http://www.knovel.com/knovel2/Toc.jsp?BookID=754


David Merrill




"djenyc" wrote in message
ups.com...
Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

snip...

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Thanks a lot

Ross

On Sep 28, 5:53 pm, "David Merrill" wrote:
I trust that you will come to appreciate that credible structural analysis
consists of rather a lot more than plugging numbers into formulas and hoping
for the best.

For example:

- Measuring, calculating, guesstimating the loads and the uncertainty
thereof.

- Determining the interaction effect of multiple, simultaneous loads.

- Determining whether loads are constant (static) or fluctuating, and if
the latter,
characterizing that fluctuation numerically.

- Considering less obvious sources of loading (e.g. earthquake, snow
loads, steady
wind loads, wind gusts flowing fluid loads, people clambering on your
baby).

- Determining whether a 2D analysis is adequate to describe a 3D
situation
(or when nothing short of a valid finite element computer analysis is
required or
when the situation is so complicated that an established empirical
approach (e.g.
lugs)or outright experimental load testing of a prototype is called
for).

- Determining how loads distribute themselves among redundant structural
elements
(such as multiple fasteners).

- Determining all the possible modes of structural failure and which is
the critical one
(e.g. excessive deflection, non-linear deflection, permanent
deformation,
tension/compression/shear failures, ductile rupture, brittle fracture,
fatigue
cracking, stress-corrosion cracking, hydrogen embrittlement, creep,
elastic buckling,
elastic/plastic buckling, plastic buckling, delamination).

- Locating the appropriate properties for the material in the condition
pertaining to its
planned use (e.g. Tensile yield strength, in the direction of the
grain, of Southern
yellow pine, air dried, at a moisture content in equilibrium with its
worst-case
planned environment).

- Statistical variability and possible directionality of material
properties.

- Environmental degradation of material properties over time (e.g. wood
decay, sunlight
and atmospheric effects on PVC).

- Materials that behave as composites (e.g. concrete slabs with rebar).

- Estimating the effects of material imperfections (e.g. holes, knots,
notches, changes
in section thickness, corrosion penetration) and whether this is
relevant to the
critical failure mode.

- Understanding how joints and support points affect stress distributions
(and whether
that's relevant to the critical failure mode).

- Understanding the assumptions and simplification inherent in the
derivation of strength
formulas (even the most sophisticated analyses contain simplifying
assumptions, such
as, for example, linear material behavior) and recognizing situations
in which these
assumptions are simply not tenable.

- Considering how serious are the possible consequences of a structural
failure.

- Are there liability issues associated with structural failure (anbody
but you going
to go near it) ?

- Knowing when established codes or standards should be (or must be)
applied (e.g.
residential/commercial building codes, AISC structural steel design
codes, timber
design codes).

- Considering all the things that I forgot to mention in the absence of a
specific
design problem.

- Given all of the above, determining the appropriate factor of safety to
apply
Note: The appropriate FS arrived at logically by an engineer is often
much greater
than one the layman might choose and feel to be adequate.

All that said, some references a

Roark, Formulas for Stress and Strain

Baumeister & Marks, Standard Handbook for Mechanical Engineers

AISC Manual of Steel Construction (ASD)

http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm

http://trs.nis.nasa.gov/perl/search?...%2Freportno%2F...
%2Feditors=&authors%2Feditors_srchtype=ALL&year=&_ satisfyall=ALL&_order=byti
tle&_action_search=Search

http://www.knovel.com/knovel2/Toc.jsp?BookID=589

http://www.efunda.com/materials/mate.../materials.cfm

http://www.matweb.com/index.asp?ckck=1

http://www.knovel.com/knovel2/Toc.jsp?BookID=754

David Merrill

"djenyc" wrote in message

ups.com...

Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

snip...

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Thanks a lot

Ross

David,

You raise very good points.

But, nothing would ever get built if all the i's got dotted and the
t's got crossed.

It is EXPERIENCE that allows shortcuts to the desired result. Many,
many designs begin with sketches of what it should look like, along
with likely material sizes. A quick analysis then would verify the
strength of the design and allow adjustments.

Use large factors of safety, an FOS of 5 to 10 is not too much...this
is also called factor of ignorance among the initiates. :-)) Steel is
cheap and you're not building an airplane, are you?

Good judgement comes from experience, and experience comes from bad
judgement.

Wolfgang

On Sep 27, 3:20 pm, "Ed Huntress" wrote:

BTW, if you *really* want to know about wood, there is an excellent and
enjoyable book titled _Understanding Wood_, by R. Bruce Hoadley (I hope I
have the spelling right). This is no text -- it's written for the
hobbyist -- but I hear it's used in technology classes, too. It's published
by Taunton Press.

http://www.woodweb.com/knowledge_bas..._Handbook.html

I'm not sure how this compares to what you mentioned, but its free and
looks very technical. I've browsed a few sections in the past.

"Wood Handbook -- Wood as an Engineering Material
Information on engineering with wood, properties of wood and designing
with wood. September 28, 2002"

wrote in message
ps.com...
On Sep 27, 3:20 pm, "Ed Huntress" wrote:

BTW, if you *really* want to know about wood, there is an excellent and
enjoyable book titled _Understanding Wood_, by R. Bruce Hoadley (I hope
I
have the spelling right). This is no text -- it's written for the
hobbyist -- but I hear it's used in technology classes, too. It's
published
by Taunton Press.

http://www.woodweb.com/knowledge_bas..._Handbook.html

I'm not sure how this compares to what you mentioned, but its free and
looks very technical. I've browsed a few sections in the past.

"Wood Handbook -- Wood as an Engineering Material
Information on engineering with wood, properties of wood and designing
with wood. September 28, 2002"

Oh year, the Forest Products Laboratory book. Also excellent, although aimed
more at the engineer. I have a really old copy of it that I have referred to
in the past.

Hoadley's book is more for the amateur who wants a good understanding of
wood as a furniture and building material. I think Hoadley is an engineer
himself, and an academic, but he takes the point of view of a hobbyist. At
the same time, the book is very thorough and provides a lot of information
about dealing with shrinkage and expansion, etc.

It also contains excellent information on identifying species of wood from
any old plank you have lying around (You need a 15X hand lens). For me, that
alone makes it worth the price.

--
Ed Huntress

David, I see there are a lot of design factors too consider- with
major ones to not get sued or get hurt Will try to keep that in
mind when applying theory to practice

Those pdf links are great! Thanks a lot.

Ross

On Sep 28, 5:53 pm, "David Merrill" wrote:
I trust that you will come to appreciate that credible structural analysis
consists of rather a lot more than plugging numbers into formulas and hoping
for the best.

For example:

- Measuring, calculating, guesstimating the loads and the uncertainty
thereof.

- Determining the interaction effect of multiple, simultaneous loads.

- Determining whether loads are constant (static) or fluctuating, and if
the latter,
characterizing that fluctuation numerically.

- Considering less obvious sources of loading (e.g. earthquake, snow
loads, steady
wind loads, wind gusts flowing fluid loads, people clambering on your
baby).

- Determining whether a 2D analysis is adequate to describe a 3D
situation
(or when nothing short of a valid finite element computer analysis is
required or
when the situation is so complicated that an established empirical
approach (e.g.
lugs)or outright experimental load testing of a prototype is called
for).

- Determining how loads distribute themselves among redundant structural
elements
(such as multiple fasteners).

- Determining all the possible modes of structural failure and which is
the critical one
(e.g. excessive deflection, non-linear deflection, permanent
deformation,
tension/compression/shear failures, ductile rupture, brittle fracture,
fatigue
cracking, stress-corrosion cracking, hydrogen embrittlement, creep,
elastic buckling,
elastic/plastic buckling, plastic buckling, delamination).

- Locating the appropriate properties for the material in the condition
pertaining to its
planned use (e.g. Tensile yield strength, in the direction of the
grain, of Southern
yellow pine, air dried, at a moisture content in equilibrium with its
worst-case
planned environment).

- Statistical variability and possible directionality of material
properties.

- Environmental degradation of material properties over time (e.g. wood
decay, sunlight
and atmospheric effects on PVC).

- Materials that behave as composites (e.g. concrete slabs with rebar).

- Estimating the effects of material imperfections (e.g. holes, knots,
notches, changes
in section thickness, corrosion penetration) and whether this is
relevant to the
critical failure mode.

- Understanding how joints and support points affect stress distributions
(and whether
that's relevant to the critical failure mode).

- Understanding the assumptions and simplification inherent in the
derivation of strength
formulas (even the most sophisticated analyses contain simplifying
assumptions, such
as, for example, linear material behavior) and recognizing situations
in which these
assumptions are simply not tenable.

- Considering how serious are the possible consequences of a structural
failure.

- Are there liability issues associated with structural failure (anbody
but you going
to go near it) ?

- Knowing when established codes or standards should be (or must be)
applied (e.g.
residential/commercial building codes, AISC structural steel design
codes, timber
design codes).

- Considering all the things that I forgot to mention in the absence of a
specific
design problem.

- Given all of the above, determining the appropriate factor of safety to
apply
Note: The appropriate FS arrived at logically by an engineer is often
much greater
than one the layman might choose and feel to be adequate.

All that said, some references a

Roark, Formulas for Stress and Strain

Baumeister & Marks, Standard Handbook for Mechanical Engineers

AISC Manual of Steel Construction (ASD)

http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm

http://trs.nis.nasa.gov/perl/search?...%2Freportno%2F...
%2Feditors=&authors%2Feditors_srchtype=ALL&year=&_ satisfyall=ALL&_order=byti
tle&_action_search=Search

http://www.knovel.com/knovel2/Toc.jsp?BookID=589

http://www.efunda.com/materials/mate.../materials.cfm

http://www.matweb.com/index.asp?ckck=1

http://www.knovel.com/knovel2/Toc.jsp?BookID=754

David Merrill

"djenyc" wrote in message

ups.com...

Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

snip...

Are there any good books for home-workshop design /plans making? -
just basic practical stuff that can be readily applied, not looking
for Mechanical Engineering intro course

Thanks a lot

Ross

Karl Townsend wrote:
I got an engineering degree 30 years ago. promptly forgot all of it.

My design criteria has always been to find something about like what I'm
building and copy it. "Shamelessly Plagiarized" is the term I use. Its worth
it do drive a ways to find something like what you're doing. Some poor
engineer has spent days designing that part, take advantage of his time.

Karl


I got an engineering degree about 20 years ago, I remember much of it
and I keep studying the subject to learn more.

Yet I use pretty much the same design criteria when I can -- if I'm not
doing something totally unique, I start by shamelessly copying some
existing work. I'll usually do some reverse engineering and analysis on
it to make sure that the original designers knew what they were up to,
but that doesn't keep me from using existing knowledge.

Even if I am doing something totally unique, if there are parts of it
that aren't unique -- I get all shameless, and start looking for
existing designs.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html

Ed Huntress wrote:
"djenyc" wrote in message
ups.com...
Hi, I'm doing some hobby level wood and metal fabrication projects
around house - shelving, boat cradle/ boat lift / trailer implements/
carts / work tables/ bike racks etc. I'm mostly using scrap material
that I happened to come buy...

I'm not a mechanical engineer, and have no idea what load/deflection
ratings are for different materials. I've been using 2x4, steel
tubbing, angle iron ... just found 20 ft of 2" pipe another day ...
Currently, when I'm designing stuff, I just rely on limited prior
experience and eye measure. Some things turn out to be overbuilt and
sometimes things fail under load (hopefully it's not critical and I
get a chance at redesign ). For example, I built a manual forklift
last week and it crumbled while testing/lifting my dad - now I know
where to strengthen it , but is where a better way?

Would it be worthwhile to look up load ratings of common materials
like steel pipe and 2x4? Where would I find such information? Or are
this calculations so complicated, that I'd be better off continuing
with what I'm doing?

It would be worthwhile, but if you're not building anything that risks life
or limb, learning by trial and error isn't bad, either.

For the examples you give there are two basic subjects you need to know:
strength of materials, and "statics." If you want to learn them, be sure to
use texts written for technical schools and junior colleges, not for
four-year engineering-school students. The former explain it in terms of
high school algebra. The latter do it in terms of calculus. If you're good
at calculus, use either one.

A basic study of these subjects will not make you a design engineer but it
may prevent some of the grosser errors. And you may find it very
interesting. These subjects provide a lot of suprises and insights into how
things work -- and how they don't.

I'd call a local community college and see if they have a program in
"engineering technology," or something like that, and ask what texts they
use.

I took a quick tour of all the 1st-level answers to the OP's question,
and this is just about the best one, and the one that I'd recommend if
such a book exists in the area you need to know.

You may even consider going to said community college and taking the
class, if you have time. This will be particularly useful if you can
buttonhole the instructor and ask questions about specific projects
you're working on -- you'll get a design review of something you care
about, and information that pertains directly to what you're doing.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html