Rotary Welding Positioner; The Build

[hotrodder]

Pretty much what's already been said... the carbon brush ground particually (more for long term reliabilty). I like the idea of 0-90* adjustment but can see where you're coming from- quite a bit of extra work if you rarely need that adjustability. Given the size of the frame (relative to the face plate) if you added another bearing to the shaft it'd work on it's side 'as is' though? With a roller stand that'd let you use it for longer work should the need ever arise without needing a step ladder to reach

Simple stuff aside I don't do electrics but if you going to add a torch holder how about setting it up so that the welder can start and stop the table with the arc?

 

[Shox Dr]

The table has been designed so you can run it in either plain. I was thinking using the armrest as a fixture to hold a sliding steady/ tail stock.

The ground strap, is stock braided earth cable from any motor factors, very easy to get hold of.

 

[brightspark]

sleeve the shaft with copper tube and use large carbon brush

 

[brightspark]

nice job there shox its hard to design things from scratch but a lot easier for sumone to come along and add 2 whats already being achieved

 

[Shox Dr]

nice job there shox its hard to design things from scratch but a lot easier for sumone to come along and add 2 whats already being achieved

Your right there, but I take all suggestions and criticism on board, it's why I posted it.

 

[hotrodder]

The table has been designed so you can run it in either plain. I was thinking using the armrest as a fixture to hold a sliding steady/ tail stock.

Obvious after looking at the pics again. Nice one, the two most useful positions with the minimum amount of work. A few bits of sliding fit box section etc and you'll have a modular set up, positioner and welding lathe

 

[Shox Dr]

Appartently an American Co called Jetline use the same of ground straps, on some of their positioners, and I can't imagine those been cheap


(rubs hands together, in Fiddler on the roof Stylee)

 

[astro_al]

When can I expect delivery of my prototype?

Al

 

[Dr pepper]

The roller is a steel shaft and drum with a non conductive hypalon coating.
I ave tried brass brush arrangements, various carbon brushes and a really expensive and ridiculous carbon fibre ring, non have been any good.
There isnt an issue with static shocks or paper floating away, we have anti static corona machine further down the line, the issue I have is that the bearings for the roller dont last 2 minutes, I sent one to skf for analasys and they said pretty much what I expected, electrical spark erosion premature failure.

 

[brightspark]

the only problem i can see with the strap arangement is if the welding earth is conected to the metal frame and the strap conductivity breaks down the path would be through the bearings on pillow block or gearbox bearings resulting in damage. can u not insulate the strap arangement from the frame and conect welding earth direct to the isolated strap that way if strap conductivity breaks down there isnt a return path for current to travel through the bearings

 

[Dr pepper]

A very good idea.

 

[Shox Dr]

In my first post I noted that I wasn't happy with the facility to clamp the ground to, so I'm fitting a Female Dinse connector to the bracket, to stop people trying to clamp to other parts of the frame. The frame will also be powder coated so it will be hard to ground through it.

 

[brightspark]

please corect me if im wrong but if u conect dinse plug to the bracket the bracket is atatched to the frame without isolation. so a return path is available though frame to bearings then table

 

[Shox Dr]

If you look in some of the pictures, you can just see the bracket holding the ground strap is only bolted to the frame, I did this so it could be isolated if necessary

 

[brightspark]

yes if u can insulate. that would be fine bolt on a piece of tuffnol or anything to fasten it to

 

[wyn]

I think what Shox Dr is refering to is one of these panel connectors

The ideal thing might be a male one though to match up with any spare leads which are more than likely going to be female on the free end.

 

[brightspark]

I think what Shox Dr is refering to is one of these panel connectors

correct ideal fitted to bracket with strap as long as insulated from frame

 

[Shox Dr]

That's them Wyn, And a Male would be a better Idea

 

[Shox Dr]

Male Dinse now fitted, Just need to machine an insulator up out of Delrin

 

[brightspark]

that looks real nice the only other thing i would do is make a brass sleeve to fit on shaft. better conductivity more surface aeria and can be replaced .smear with a small amout of silicone grease rs suplies do it in a small tube a few quid . it stops arcing on ht switchgear and electrical aparatus