Home built welding carousel

Has anyone built their own carousel?

I have been throwing around in my head, and the biggest problem I have is how to insulate the rotary shaft from the bearings.

Rich C.

I have not made one but I would think you could easily accomplish this by using a plastic (non-conductive) coupling and use a "brush" along the edge of the positioner's edge for grounding purposes.

That way you avoid the bearings getting in the way.

I may not be understanding the "carousel" term correctly but as a rotating welding fixture I use a crappy old mini lathe which has plain spindle bearings (steel spindle on cast iron bearings) with earth clamp anywhere on the bed.

Not sure if I have ever lubricated the bearings but I have certainly whacked some amps through it.

regards

Brian

We used to use non conducting grease on our welding cable reels and had no problems,did a fair amount af gouging also.Built them with front auto spindle.


Ken

Hub photos

Here's a few pictures to ponder.

http://www.practicalmachinist.com/v...ontact hub shots/th_P1030741.jpg[/IMG][/URL]


These pictures are from an All Fab weld positioner.

I had intentions of building one but a job came up that allowed me to cost this piece into the job.

Good luck on your project.

Tom

I built my positioner out of odds & ends I had in the shop....here's a pic of the grounding solution.........ain't real pretty, but it's had 300amps through it with no issues.


Rex

I like the engine stand useage . Nice setup.

Positioner

I have a small unit that I built from scrap materials. I used a pair of Ford starter brushes mounted to press against the mounting plate for a four jaw chuck used on the unit. The plate has a copper ring attached to the back of the plate. It has worked well for over 20 years.

JRW

That is a nice setup Bjorn.. very handy looking.

I am planning on building something similar soon. I was able to get a few electric motors and reduction boxes for free from a friend.. just need to free up some shop time to work on them.

The two up top came out of old grocery conveyors, the other small motor and gearbox are out of a Dayton plastic wrapping machine.

Here are some pics of mine taken as it was being built. You rotate the table with your feet.





The weight of the ground cable presses the copper ground against the bottom of the table. The copper is an old EDM electrode. The piece it sets in is slotted and the electrode can rock to keep it flat on the bottom of the table as it wears.



The pivot is insulated with a fiberglass pivot shaft and plastic washers.

Bjorn - you say 'it's not pretty' - your right - it's beautiful - thanks for several good ideas there...what is black box on the left insultaed from frame with boat trailer rubber ??- speed control or on-off pedal operated by hip action??
TriHonu - Also love your foot powered model

kgize said:

Bjorn - you say 'it's not pretty' - your right - it's beautiful - thanks for several good ideas there...what is black box on the left insultaed from frame with boat trailer rubber ??- speed control or on-off pedal operated by hip action??
TriHonu - Also love your foot powered model

Click to expand...

The black box is the speed control. I was lucky to find the Bodine 20RPM DC motor and the compatible speed control on Ebay within a couple of days of each other...and for Cheep. It's mounted on the remains of a Jotto Desk mobile laptop stand.

Here's a pic of the control and the speed chart:







I also added an adjustable arm rest so I wouldn't cramp up trying to hold the torch steady.






Rex

crij said:

Has anyone built their own carousel?

I have been throwing around in my head, and the biggest problem I have is how to insulate the rotary shaft from the bearings.

Rich C.

Click to expand...

Here's one I started last winter: Positioner



Ran out of time but my intent is to fill the groove I cut in the chuck backplate with braze and run a gang of carbon brushes against it. I did use it a bit this summer by just clamping the welder ground to one of the chuck jaws.
I built a plasma circle cutter a couple years ago and used the brush assembly from an old 6Volt starter. Have done some welding with my MIG by using it as a positioner and the brushes worked fine for that current.
Cutter

Trihamu, Nice one, I was also thinking about a potter's wheel like one also.

Ed, Went thought you assembly photos, but I was wondering, what is the story with the weld in the middle of your housing, did the shaft lenghten to clear the drive or was there some other reason? The trunion bearings, what were they originally, connecting rod caps? Definately like your torch circle cutter, may have to make one for A/O torch since I don't see myself getting a plasma cutter anytime soon.

One thing I am noticing, that is perplexing me, no one seems to be insulating their motors or controls. I would think 100+ amps would try to go to ground via your motor wire, thus torching everything. Is it that there is more resistance going through the motor housing then the ground cable that is preventing it (since electricity prefers the easy route)?

Thanks,

Rich C.

Hi Rich, The main reason for the 2-piece housing was to accommodate for the size of my mill vise.
The trunnion bearings are made from the caps of the crankshaft mains from an old MOPAR V8.
On the grounding for a DC welder: The motor is powered by a variable voltage AC to DC power supply. First step in that thing is a transformer that knocks the voltage down from 120V. The welders I use are a Miller wire feed, which has as the first step; a transformer that converts 230V to whatever. The other main welder around here is a Lincoln coffee grinder DC machine. First step in that one is a 3-phase motor that turns a DC generator. Many people don't realize this but one of the functions of any AC transformer is it isolates all of its output from any other voltage source in the world. Current made by a transformer is only interested in getting back to the same side of that same transformer. If you have a transformer that's making 200V @ 150 Amps, you can take the positive terminal lead from that transformer and touch it to anything you want -- big sheet of steel, pool of water, or your tongue and you will see no sparks, nor feel anything. Now take the negative lead from that transformer and ground it to the sheet of steel or hang on to it with your bare hand and you will see sparks when you touch the steel and feel juice flowing when you touch it to your tongue because it has an attraction to get back to the other side of the transformer winding. No matter which welder I may be using, the welding current flow is only interested in getting back to the other side of the device responsible for generating the current and really has no interest in going through the motor because there is nothing there that provides a path back to source. High frequency AC or high freq. pulsating DC is a different matter but since I don't TIG, there's no need to isolate the motor & controls.

crij said:

One thing I am noticing, that is perplexing me, no one seems to be insulating their motors or controls. I would think 100+ amps would try to go to ground via your motor wire, thus torching everything. Is it that there is more resistance going through the motor housing then the ground cable that is preventing it (since electricity prefers the easy route)?

Thanks,

Rich C.

Click to expand...

I was TIG welding a flange to a short aluminum tube for a guy when he tripped over my work cable and yanked the clamp off the "L" bracket near the tension spring (I clamp there to keep the ground path as short as possible), the arc stopped but the DC motor continued to rotate the chuck.

I made a call to Bodine Electric before I bought the motor and control. I wanted to be sure that TIG high frequency would not cause problems with the controller. The engineer I spoke with assured me that it would not be an issue as long as I used a 3 wire plug for the controller power input cord.


Rex

Very nice setup ! I also have two engine stands that will be used for a welding table,airplane fuselage rotiserie and who knows for what else.

bjorn toulouse said:

I built my positioner out of odds & ends I had in the shop....here's a pic of the grounding solution.........ain't real pretty, but it's had 300amps through it with no issues.


Rex

Click to expand...

Cool builds! Wish I had that kind of talent.

Or don't go around more than 360 degrees...

Check this one out!
https://www.youtube.com/watch?v=_OnF6_V28DM