--Metalworking content: lotsa templates and jigs..
--Have been working on these puppies for waay too long; finally got
one done the other day and took a photo. Direct link:
http://www.nmpproducts.com/woodengn.htm
...and yes, those frosted areas are dust from long stretches of
project being bumped by other projects, sigh..

--
"Steamboat Ed" Haas : Better an early adapter
Hacking the Trailing Edge! : than an early adopter..
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

I think your ingenuity and workmanship are great. I am building the
Fizgig Sterling engine and although I'm making the parts out of
aluminum, the methods you use for making connecting rods give me
helpful ideas.
I wish you could find the time to reinstate the SRSMEEBBQ aka the
Santa Rosa Society of Model and Experimental Engineers.
I really enjoyed those meetings.

Engineman (John Taylor)

steamer wrote:
--Metalworking content: lotsa templates and jigs..
--Have been working on these puppies for waay too long; finally got
one done the other day and took a photo. Direct link:
http://www.nmpproducts.com/woodengn.htm
...and yes, those frosted areas are dust from long stretches of
project being bumped by other projects, sigh..

--
"Steamboat Ed" Haas : Better an early adapter
Hacking the Trailing Edge! : than an early adopter..
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

steamer wrote:

--Have been working on these puppies for waay too long; finally got
one done the other day and took a photo. Direct link:

Geee, nice con rods are a pain to do.
I have developed a method (that requires a RT) that is accurate and
quite fast:

I start with a flat big enough.
1.) Drill the two holes on both ends
2.) Drill 4 holes (a little math required) where the round outer contour
meets the staight connecting part.
2a) If you make the connecting part slim, mill it off now.
3.) Put rod on the RT with some jig to clamp coaxial with top or bottom
hole
4.) Mill the round outer contour
5.) Mill round on the other end
4a + 5a) you can make the connecting part slimmer and can mill that
radius with a radius mill.
6.) Clamp rod in vice, and with the help of some shims and 2 rods
through the bore, mill the two straights.

Last time I made a rod, I made photos, but forgot to make them for all
steps. So you have to wait until next time.

BTW:
Nice work!

Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO // Eigenbau-Digitalanzeige
http://www.yadro.de

On Tue, 14 Mar 2006 22:42:42 +0100, Nick Müller wrote:

4.) Mill the round outer contour
5.) Mill round on the other end

What's the best way to do this outer contour? Say I have a hole, and I
want an outer contour most of the way around it. I'm thinking a rotary
table on the mill, with the hole centered on it? Is there a better way?

Dave Hinz wrote:

What's the best way to do this outer contour? Say I have a hole, and I
want an outer contour most of the way around it. I'm thinking a rotary
table on the mill, with the hole centered on it?

That's how I did it.


Is there a better way?

CNC ;-))


Nick
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO // Eigenbau-Digitalanzeige
http://www.yadro.de

On Tue, 14 Mar 2006 22:54:54 +0100, Nick Müller wrote:
Dave Hinz wrote:

What's the best way to do this outer contour? Say I have a hole, and I
want an outer contour most of the way around it. I'm thinking a rotary
table on the mill, with the hole centered on it?

That's how I did it.

So holding, then, is done with a shaft the diameter of the hole, and a
larger shoulder top and bottom, and a bolt for tension, or something
else?

Is there a better way?

CNC ;-))

Ah. I'd like to revise my question to introduce a constraint of "for
the home machinist with 1960s technology" please.

Thanks, it's good to see confirmation that my guess is what people who
know what they're doing would do.

Dave Hinz wrote:

So holding, then, is done with a shaft the diameter of the hole, and a
larger shoulder top and bottom, and a bolt for tension,

Exactly. I have some of those shafts. And they get more for each
diameter missing.


Is there a better way?

CNC ;-))

Ah. I'd like to revise my question to introduce a constraint of "for
the home machinist with 1960s technology" please.

I was kidding. :-)
If you look at old connection rods, and know what means they had, it is
clear how they did it and why they look the way they look.

There are also other forms of con rods. But this is the simplest form.
If you have a RT with a table (with one axis) sitting on top of the RT,
you can mill the outer form in one go. I don't have, but maybe ...


Nick, also no CNC
--
Motor Modelle // Engine Models
http://www.motor-manufaktur.de
DIY-DRO // Eigenbau-Digitalanzeige
http://www.yadro.de

Good job!

Now to cast a metal one :-)

Martin

Martin Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
NRA LOH & Endowment Member
NRA Second Amendment Task Force Charter Founder



steamer wrote:
--Metalworking content: lotsa templates and jigs..
--Have been working on these puppies for waay too long; finally got
one done the other day and took a photo. Direct link:
http://www.nmpproducts.com/woodengn.htm
...and yes, those frosted areas are dust from long stretches of
project being bumped by other projects, sigh..


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