Universal Joint

[Brian Rupnow]

This is something that's been coming for a long time. Every model machinist, wants deep in his heart of hearts to make a universal joint. You have to reach a certain point of confidence in your ability to machine things and be bored enough to consider a project like this. The worst thing is that one universal by itself isn't much good. To really show them working properly, you need two of the darned things working together. I'm kind of dancing from one customer to another on small jobs with free time and wait periods in between spots of real work, so I think I'll try and make a couple of these.

[crueby]

And when you have a couple made, you will need to build the boat to put them in!

[mklotz]

The PM model milling machine has two tiny ones that use small brass balls as the pivot element...



John's diorama thread...

http://www.modelenginemaker.com/index.php/topic,4170.0.html

discusses their construction in detail.

[Brian Rupnow]

Thanks Marv, that is very cool. I hadn't seen that before.--Brian

[Florian Eberhard]

Hey Brian

If you are going to build universal joints - you may consider building a shay locomotive since they use them 
(in a slightly different version though - I wonder why, probably because the ring around the two forks is more rugged than the cross??)

Cheers Florian

[Brian Rupnow]

Trains and boats don't really interest me too much. However, I'm getting so many little mechanisms built to run with my engines, that a driveshaft with two universals could connect my wonky 90 degree shaft transfer with one of the other machines.

[crueby]

Hey Brian

If you are going to build universal joints - you may consider building a shay locomotive since they use them 
(in a slightly different version though - I wonder why, probably because the ring around the two forks is more rugged than the cross??)

Cheers Florian

Check my shay build thread for that style, works really well, telescopes. The real ones were huge, the ring over a foot across. Very sturdy style, they took full load of the engine.

Posts 498-515 here:
http://www.modelenginemaker.com/index.php/topic,3778.msg88528.html#msg88528

[Brian Rupnow]

I made a start today, then got busy with a bunch of "real work" and that eat up the rest of my day. At any rate, this is the drawing I'm working from, and this is how far I got on the part. Taken down from 1" stock to 0.890" diameter, taken down to 0.562 over part of the length, drilled and reamed as per drawing, and 60 degree taper machined in, all in the same set-up.

[J.L.]

Hi Brian,
Nice progress. Good luck with your design.
The B&S milling machine Marv mentioned uses 3/16" hardened steel ball bearings as their pivot points. Telescopic tubing also makes assembly of the forks quite easy.
John

[wagnmkr]

Hmmm ... I need some of these to go in this, so I will be following along.

Tom

[crueby]

Hmmm ... I need some of these to go in this, so I will be following along.

Tom

Nice hull! Dutch tugboat?

[wagnmkr]

Atlantic Salvor ex MrDarby.

[Brian Rupnow]

So here I am, making it up as I go along. I'm working with two bars of different material so I can judge which one seems to cut best with my machinery. The one in the vice is 1045 steel, and it machines relatively well. The other one is a piece of ground and polished A36, which is not hardened in any way. The A36 doesn't machine near as cleanly as the 1045--it tends to smear and tear rather than cut cleanly.

[wagnmkr]

Brian, I have found that 12L14 steel machines very well. My machines are smaller than yours and it works great in them and my Sherline.

Tom

[Tennessee Whiskey]

I'm following Brian,  can't wait to see how you do the cups and needle bearings.

Cletus