Making and using a hand crank lathe for use with a plasma cutter

. We make alot of stuff out of metal and a good circle was hard for me to do freehand. Using a tool like the one we show you here makes it easy to cut circles and washers out of any metal using a plasma cutter. It could also be used for some welding or grinding applications or as a crude PTO. For safety I designed this to be operated by 2 people .One person focuses on the feed speed (the turner),and the other focuses on the plasma gun location. This current design relies on having a hole in the center of the (to be ) circle. I usually have to have a hole there anyway but I plan to experiment with magnets to hold my rough blank in place.

Step 1 Parts and pieces

You need to have a heavy base to keep the tool from walking or provide a way to clamp it down. I milled my base out of some old heavy pallet wood.

Comments

[Phil B]

The shaft on your lathe appears to be too long for one person to hold the plasma cutter gun and turn crank, too. Do you use a helper or are you able to turn the crank and hold the gun, yourself?

Thank you for your Instructable.

[drewgrey]

I opted for a 2 person tool because one person can focus on feed speed and the other can focus entirely on gun position. The same design could be scaled for 1 person operation though. Thanks,Drew

[pfred2]

Come on, put foot pedals on it. You can do it! Steal a bicycle.

[drewgrey]

Actually a slow constant speed is what I need even for thin material. If I cut 1/2" or more the rotation speed will be a crawl compared to the cut I made in the video. What inspired me to make this was an early attempt to make a circle by chucking up a piece of steel on a stick in a big drill motor. DON'T do this! It does work but when the trigger is touchy and the thing speeds up suddenly while I was cutting the hot liquid metal spun from the disk like a pinwheel and rained down ..................Is that hair burning?

[SinAmos]

You shouldn't be holding the torch. You should build a rig with the bicycle gears that not only engaged the wheel, but also activates the plasma burn. Good stuff though.;)

[pfred2]

Maybe the dog's. When I cut and weld I wear protection.

[drewgrey]

I do also but I did not have my hat on under my helmet. I have thought of attaching one of my hats to the helmet . There was no damage but the kind of reminder that warns you and then makes you laugh...best kind.

[pfred2]

I hate back lighting in my mask when I weld so I put a spare bib off a summer welding jacket over the top of my helmet. What I look like when I do that would probably make someone laugh, but I'd rather see what I was doing better.

[omnibot]

If I may suggest an improvement;
Attach a rope and weight, run it around the axle and gravity should spin the lathe nicely.

[Robot Lover]

Very cool. If you added a tool rest you could get better circles. Good instructable!

[drewgrey]

That is indeed in the future . I also want to create indexing holes for the nozzle of the gun so I can repeat exact sizes and step up in even increments. Thanks for the comment,Drew