Robo welder is rotating. Not welding yet but soon.
It amazes me that tiny motor and gear box is all you need.

Here is a movie to prove it.

Just because something you are building is small does not mean it does
not take a lot of time.

I tried the rubber tubing coupler but it did no rotate smoothly.
It would wind up and then would release.
This is a special coupling nut with a 4-40 set screw.

Paul Lamar


I am getting a degree in robo welder design.

I have discovered several things. Don't use caster wheels that are
the least bit soft. It is best to make your own rollers out of
metal.

The grounding of the tube resting on the stop doesn't
work very well. I found some 4 gage wire in  an automobile hi fi
audio shop that is very flexible. A zillion tiny copper wires.
I stripped the insulation off but not entirely necessary.
The insulation is soft and flexible as well.
About 2 bucks a foot.


I will attach that to the tube with
a hose clamp and wrap several turns around the tube to be
unwrapped as the tube turns and is welded.

I found a 110 Volt synchronous motor at MaMaster Carr that rotates at
exactly 1 RPM no matter what. It has enough torque to twist your
wrist off.

It takes the speed of welding out of the equation. All you need set
is the welding current and the distance of the tungsten to the metal.
The gas flow can be near the bottom of the recommended scale to conserver
that expensive consumable.

Paul Lamar


A bit of advice from someone who has thousands of hours experience
with welding wire in a physicly dynamic environment. First, properly
size the wire for the current load. #2 for 100A give or take depending
on the insulation(bumping 1 or 2 guages here won't kill you). You
always want to size on the high side because.. it's expensive to
replace. Welding wire has many fine conductors, composed of alloys
that resist fatigue and heat crystalizing. Welding wire, is quite
properly more expensive because it handles abuse and motion.
If your robowelder only needs 360/380 degrees of rotation, get
enough length so you can perform the rotation without too much
twist per inch of wire, but always turn it back to a start index.
C. Smith


tig does not use wire. Filler rod sometimes but not needed here.
This is basically an over lapped joint.
Here is a picture of the part that is welded on to the end of the
4130 .049" wall one inch OD tube. The turned down part goes inside
the end of the tube.

Paul Lamar

You totaly misunderstood the entire paragraph. the welding wire I'm
referring to is the wire that conducts the current to and from the work, not
the filler wire. Yes, I know that TIG does not use filler wire, I have been
welding for years.
C. Smith



Your right. Sorry. I was too much in a hurry. I saw the term welding wire.
I would have got it if you had said "ground wire" :)

Never the less it worked fine with the 4 gage :)

Here are the actual tube lengths for the Tango Motor mount.
Bolt these together with the right fittings and the prop flange
automatically comes out in the center of the cowl hole :)

BTW what OS and email program are you using?
Can you just send me plain text?

Your email comes in in the form of one long line.
I have to load it into joe and reformat it.

Paul Lamar


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