I have steel ramps, but they are very short and suitable for my [low]
trailer only.

I am considering making ramps from wooden boards. Specifically,
picture a ramp that looks like a letter I in cross section. The wide
part of the I is a 2x8. On the top and bottom of the I, there would be
2x4s. The "I", of course, would be laid flat for use.

Here's the ascii graphic:

.. .
|==========|
~ ~

The 2x4s would be screwed to the 2x8 with wood screws, and reinforced
with glue.

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

thanks

i

Ignoramus20839 wrote:
I have steel ramps, but they are very short and suitable for my [low]
trailer only.

I am considering making ramps from wooden boards. Specifically,
picture a ramp that looks like a letter I in cross section. The wide
part of the I is a 2x8. On the top and bottom of the I, there would be
2x4s. The "I", of course, would be laid flat for use.

Here's the ascii graphic:

. .
|==========|
~ ~

The 2x4s would be screwed to the 2x8 with wood screws, and reinforced
with glue.

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

It is simply a 3x3-1/2 beam for estimating purposes. You can forget the
2x8 in the horizontal as it is conservative to do so.

I don't have a link ottomh, but a google will find any number of beam
deflection engines.

Use SYP or fir for higher modulus and, of course, be sure it is
defect-free timber.

Depending on length and weight desired, going w/ 2x6 tapered some for
the ends might be more suitable at the expense of a little more
weight/heft/bulk...

--

"Ignoramus20839" wrote in message
...
I have steel ramps, but they are very short and suitable for my [low]
trailer only.

I am considering making ramps from wooden boards. Specifically,
picture a ramp that looks like a letter I in cross section. The wide
part of the I is a 2x8. On the top and bottom of the I, there would be
2x4s. The "I", of course, would be laid flat for use.

Here's the ascii graphic:

. .
|==========|
~ ~

The 2x4s would be screwed to the 2x8 with wood screws, and reinforced
with glue.

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

thanks


Two thoughts...

Why not just take the 2 X 8's and test them. Put them on a block of some
kind on the ground and roll whatever you plan to use them for onto them and
observe the deflection. This would be simple and just cost the price of a
couple boards.

I have seen a number of ramps that have a metal end on them specifically
designed for a ramp. I think that would be much more compace and work better
than your proposed 2 X 4 ends. I don't know where to purchase them, but
they are out there because I have seen them in use many times.

On Thu, 25 Oct 2007 11:45:15 -0400, "Lee Michaels"
wrote:


"Ignoramus20839" wrote in message
...
I have steel ramps, but they are very short and suitable for my [low]
trailer only.

I am considering making ramps from wooden boards. Specifically,
picture a ramp that looks like a letter I in cross section. The wide
part of the I is a 2x8. On the top and bottom of the I, there would be
2x4s. The "I", of course, would be laid flat for use.

Here's the ascii graphic:

. .
|==========|
~ ~

The 2x4s would be screwed to the 2x8 with wood screws, and reinforced
with glue.

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

thanks


Two thoughts...

Why not just take the 2 X 8's and test them. Put them on a block of some
kind on the ground and roll whatever you plan to use them for onto them and
observe the deflection. This would be simple and just cost the price of a
couple boards.

I have seen a number of ramps that have a metal end on them specifically
designed for a ramp. I think that would be much more compace and work better
than your proposed 2 X 4 ends. I don't know where to purchase them, but
they are out there because I have seen them in use many times.



Even your local borg will probably have aluminum "ramp ends" for 2x8
and 2x10 lumber. They can be secured to a trailer or truck tailgate
by means of holes in the aluminum pieces and pins that go through
those holes and into matching holes you drill in the trailer or
tailgate. The 2x8 version has worked fine for me with 8 foot lumber
for lawnmowers and snow throwers (heaviest item is about 160lbs). I
never drilled holes in the tailgate of my 18 year old truck and I
don't plan to drill holes in the tailgate of the new truck either ;-)

Just FYI, the 1989 Nissan pickup was better built (both assembly and
design) than the 2008 Tacoma is. The wind noise was lower (after 18
years) than the new one and the speedometer was more accurate. The
Tacoma reads 5% high (factory spec is +/- 7%). That 5% error will
take away 5% of the warranty coverage (3000 miles of a 60000 mile
warranty). It's all drive-by-wire and the only physical correction is
a slightly larger tire size (70 series - 80 series is 5% increase).
The dealer hasn't done anything yet, except the usual "Im sorry. What
would make you happy?" and then not following up. The dealer will get
one more chance at fixing it, then I'll file a "Lemon Law" complaint
(also covers things that reduce the value of the vehicle) - which they
must respond to in writing. At least the error will be documented for
any future warranty claims...

John

John wrote:

On Thu, 25 Oct 2007 11:45:15 -0400, "Lee Michaels"
wrote:


"Ignoramus20839" wrote in message
...
I have steel ramps, but they are very short and suitable for my [low]
trailer only.

I am considering making ramps from wooden boards. Specifically,
picture a ramp that looks like a letter I in cross section. The wide
part of the I is a 2x8. On the top and bottom of the I, there would be
2x4s. The "I", of course, would be laid flat for use.

Here's the ascii graphic:

. .
|==========|
~ ~

The 2x4s would be screwed to the 2x8 with wood screws, and reinforced
with glue.

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

thanks


Two thoughts...

Why not just take the 2 X 8's and test them. Put them on a block of some
kind on the ground and roll whatever you plan to use them for onto them and
observe the deflection. This would be simple and just cost the price of a
couple boards.

I have seen a number of ramps that have a metal end on them specifically
designed for a ramp. I think that would be much more compace and work better
than your proposed 2 X 4 ends. I don't know where to purchase them, but
they are out there because I have seen them in use many times.



Even your local borg will probably have aluminum "ramp ends" for 2x8
and 2x10 lumber. They can be secured to a trailer or truck tailgate
by means of holes in the aluminum pieces and pins that go through
those holes and into matching holes you drill in the trailer or
tailgate. The 2x8 version has worked fine for me with 8 foot lumber
for lawnmowers and snow throwers (heaviest item is about 160lbs). I
never drilled holes in the tailgate of my 18 year old truck and I
don't plan to drill holes in the tailgate of the new truck either ;-)

I didn't drill holes in my tailgate either. What I do do though, is use
cargo straps wrapped around each ramp and secured to the bumper to keep
the ramps from slipping off. It wakes you up real fast when a ramp slips
out while you're backing a riding mower out of the truck...


Just FYI, the 1989 Nissan pickup was better built (both assembly and
design) than the 2008 Tacoma is. The wind noise was lower (after 18
years) than the new one and the speedometer was more accurate. The
Tacoma reads 5% high (factory spec is +/- 7%). That 5% error will
take away 5% of the warranty coverage (3000 miles of a 60000 mile
warranty). It's all drive-by-wire and the only physical correction is
a slightly larger tire size (70 series - 80 series is 5% increase).
The dealer hasn't done anything yet, except the usual "Im sorry. What
would make you happy?" and then not following up. The dealer will get
one more chance at fixing it, then I'll file a "Lemon Law" complaint
(also covers things that reduce the value of the vehicle) - which they
must respond to in writing. At least the error will be documented for
any future warranty claims...

If the dealer hasn't done anything call the regional factory rep. The
calibration is an easy adjustment with a proper scan tool and would take
a competent tech about 5 minutes if they just go by tire measurements
and 10 minutes if they measure the actual rolling radius of the tires.

"Lee Michaels" wrote in message
. ..


Why not just take the 2 X 8's and test them. Put them on a block of some
kind on the ground and roll whatever you plan to use them for onto them
and observe the deflection. This would be simple and just cost the price
of a couple boards.

I have seen a number of ramps that have a metal end on them specifically
designed for a ramp. I think that would be much more compace and work
better than your proposed 2 X 4 ends. I don't know where to purchase
them, but they are out there because I have seen them in use many times.




Home Depot sells the ramp ends pretty cheap. They're in the Outdoor Garden
department.

--

-Mike-

Mike Marlow wrote:

Home Depot sells the ramp ends pretty cheap. They're in the Outdoor Garden
department.


I have a set of those. They work fine with 2x8's getting my 500 pound
wide cut mower in and out of my 4x4 Tacoma twice a year.

Ignoramus20839 writes:

On the top and bottom of the I, there would be
2x4s.

Might be stronger/lighter/cheaper if you attached some steel angle (hidden
at Home Depot on the electrical aisle) to the 2x8, or to slices of a sheet
of 3/4 plywood.

Ignoramus20839 wrote:

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

Using spruce pine and ignoring the 2x8, the sagulator gives a deflection
of .7" for 500lbs of load in the center of a single 8' ramp.

Chris

On 2007-10-25, Chris Friesen wrote:
Ignoramus20839 wrote:

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).

Using spruce pine and ignoring the 2x8, the sagulator gives a deflection
of .7" for 500lbs of load in the center of a single 8' ramp.


OK, this is great. What does your sagulator say about 1000 lbs load?

also, what would it say if I replaced 2x4s with 2x6s?

I appreciate your help . Thanks a lot.

i

Ignoramus20839 wrote:
On 2007-10-25, Chris Friesen wrote:
Ignoramus20839 wrote:

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).
Using spruce pine and ignoring the 2x8, the sagulator gives a deflection
of .7" for 500lbs of load in the center of a single 8' ramp.


OK, this is great. What does your sagulator say about 1000 lbs load?

Google "sagulator" and experiment to your heart's content...

--

On 2007-10-25, dpb wrote:
Ignoramus20839 wrote:
On 2007-10-25, Chris Friesen wrote:
Ignoramus20839 wrote:

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).
Using spruce pine and ignoring the 2x8, the sagulator gives a deflection
of .7" for 500lbs of load in the center of a single 8' ramp.


OK, this is great. What does your sagulator say about 1000 lbs load?

Google "sagulator" and experiment to your heart's content...


I thought that sagulator was a PC program. It is great! I have it
bookmarked and am now experimenting!!!

Looks like with 2x4x, the deflection of a 1,000 lbs load in the middle
will be about 2 inches, which is too much.

However, with 2x6s, the deflection will only be 0.36 inches, and 0.7
inches with 2,000 lbs center load.

So, it seems, that a ramp made to the shape of letter I, could easily
let me deal with 2,000 lbs wheeled loads. (such as a dolly on casters)

i

Ignoramus20839 wrote:
On 2007-10-25, dpb wrote:
Ignoramus20839 wrote:
On 2007-10-25, Chris Friesen wrote:
Ignoramus20839 wrote:

My question is, what would be the strength of this ramp if it was,
say, 8 ft long. Specifically, how much load could I place in the
middle for some reasonably low deflection (like 1-2 inches).
Using spruce pine and ignoring the 2x8, the sagulator gives a deflection
of .7" for 500lbs of load in the center of a single 8' ramp.

OK, this is great. What does your sagulator say about 1000 lbs load?
Google "sagulator" and experiment to your heart's content...


I thought that sagulator was a PC program. It is great! I have it
bookmarked and am now experimenting!!!

Looks like with 2x4x, the deflection of a 1,000 lbs load in the middle
will be about 2 inches, which is too much.

However, with 2x6s, the deflection will only be 0.36 inches, and 0.7
inches with 2,000 lbs center load.

So, it seems, that a ramp made to the shape of letter I, could easily
let me deal with 2,000 lbs wheeled loads. (such as a dolly on casters)

Well, when you're dealing with that kind of loads, don't forget the
supporting ends, joint strength and fasteners, point loading of a caster
on the 2x ramp, the downward force of the load back down the ramp
running over whatever is in the way, the load limit on a truck tailgate,
etc., etc., etc., ...

--

On Oct 25, 5:39 pm, Ignoramus20839 ignoramus20...@NOSPAM.
20839.invalid wrote:

I thought that sagulator was a PC program. It is great! I have it
bookmarked and am now experimenting!!!

Looks like with 2x4x, the deflection of a 1,000 lbs load in the middle
will be about 2 inches, which is too much.

However, with 2x6s, the deflection will only be 0.36 inches, and 0.7
inches with 2,000 lbs center load.

So, it seems, that a ramp made to the shape of letter I, could easily
let me deal with 2,000 lbs wheeled loads. (such as a dolly on casters)

i

While you are playing with the design, think about a couple of blocks
you could put between about the middle of the ramp and the ground. If
you had a block in the middle of the span, it would be like two 4 foot
ramps in series. And I think the capacity would be much higher. So
you could use you original design which would be lighter to set in
place.


Dan

"Ignoramus20839" wrote in message
...


So, it seems, that a ramp made to the shape of letter I, could easily
let me deal with 2,000 lbs wheeled loads. (such as a dolly on casters)


Why the "I" on the ramp? Especially at the ground end, it serves no purpose
that I can see and only makes it harder to get things started up the ramp.

--

-Mike-

Looks like with 2x4x, the deflection of a 1,000 lbs load in the middle
will be about 2 inches, which is too much.

However, with 2x6s, the deflection will only be 0.36 inches, and 0.7
inches with 2,000 lbs center load.

So, it seems, that a ramp made to the shape of letter I, could easily
let me deal with 2,000 lbs wheeled loads. (such as a dolly on casters)

i

Why not nix the idea of the 2X4's on the sides and do this instead. Make
your own metal ramp ends that you fit to the ends of the ramps and then rout
slots on the underside of the boards where you run a couple of 1/4 or 3/8
rods that are fastened to the metal ends. This way the lumber will be in
compression, and the steel will restrain the wood from flexing too much.

I did something similar to some saggy rafters and was able to jack the whole
roof straight.

--

__
Roger Shoaf

Important factors in selecting a mate:
1] Depth of gene pool
2] Position on the food chain.