Welding Tips and Tricks

Need some advice and this is the general outline of my project. I’m building a welding turntable that will be 12”x12”x12” using a 1 1/2 shaft. The lathe chuck is 7 ¾ and the motor is a 30 RPM gear drive with a 30 tooth 5 inch chain sprocket already installed. I have a Dart Speed control that can vary the Primary Motor speed from 1-30 RPM. See the pictures to get a general ideal of what I’m working with. I’m trying to figure out the gearing ratio I should use. Maybe 5 RPM Thanks for any ideals.

30 RPM is pretty fast for something like that, 5 seems more reasonable to me.

Just curious, but what type of motor are you using with the speed control? I tried to put a speed control on a split phase lathe motor, but I couldn't get it to work.

Other Steve

Gene wrote:Need some advice and this is the general outline of my project. I’m building a welding turntable that will be 12”x12”x12” using a 1 1/2 shaft. The lathe chuck is 7 ¾ and the motor is a 30 RPM gear drive with a 30 tooth 5 inch chain sprocket already installed. I have a Dart Speed control that can vary the Primary Motor speed from 1-30 RPM. See the pictures to get a general ideal of what I’m working with. I’m trying to figure out the gearing ratio I should use. Maybe 5 RPM Thanks for any ideals.

I'd think 6:1 would work out well. This gives you 5 RPM max(12 seconds for a full circle, for, say, something under 2" dia.) and a min. of 1/6 RPM or 60* per minute for larger diameters.

You might also consider adapting a belt drive from a cheapo harbor freight drill press, which would give you a very wide range of adjustment with the selectable ratios.

Just two cents from someone who's never built one...

Steve S.

Thanks and you are right. I'm going to use a 6 to 1 belt drive and with the Dart speed control I have a variable speed. The shaft is at the machine shop and is being machine to have a pulley on the end. I'll post picture's when it finished,

Gene wrote:...I'll post picture's when it finished,

Please do! I'd also like to know how the speeds work. All my thoughts on 6:1 were based on what I think I'd want if I were to build one.

Steve S

I'll be watching with vested interested as this project is on the list to complete soon. We all appreciate any build pics you take, and any problems you run in to

Hey Gene any update on your turn table yet?

Welding positioners are a great tool but at work I find myself putting my Health Miles pedometer on it all night long to get some extra steps in while I sit at my welding table.

This is a quick update on my progress on the Turn table. I want to bring up the point this project is being done on the cheep I had a friend turn down a hot rolled 11/2 inch round stock to go though the bearing blocks. It wasn't running very true but by tack welding the plate on to the shaft it run out was reasonable. Total cost so far is $125.00 for two pulleys and a pair of bearing blocks and a lathe chuck. The paint job is primer to keep it from rusting as this is all recycled plate. The speed is around 6 RPM before speed control. I have to build covers and work on the speed control placement and maybe a foot control plug setup and a stand to rotate on.

I just ordered an AC 250V 15A On Off Control Foot Pedal Switch TFS-302 on E-Bay. Somewhat cheep coming slow boat from china. I Plan on mounting it on a HF engine stand that I'm going to modify. I'll post new picture just as soon as I get the mounts all welded up and the table mounted. Gene

Interesting project - I'll definitely watch this build

I always wondered if one of those cheap 7x12 mini lathes would be a good starting point for a positioner since they have a variable speed control already.

Reading this I'm thinking if it was slowed down with a belt setup like yours it might work.

Gene,
Do you have anymore updates/pictures of the final product?

Looken good so far.

That chuck actually adds a lot of $$$$ to the build...you could have made a "cat's paw" with 3 or 4 bolts and a disc attached at the end of the pipe.

ScubaSteve wrote:That chuck actually adds a lot of $$$$ to the build...you could have made a "cat's paw" with 3 or 4 bolts and a disc attached at the end of the pipe.

They can be had dirt cheap if you find a rookie machinist learning to part off pieces. Small cracks or a little wobble wont matter for this use.