Turning thin tubing

[Cobaltcutter]

I have started fabricating/selling fishing reel repair parts made from stainless steel to prevent saltwater corrosion. The parts so far have been a cinch but a customer want me to fabricate the line winder gear cover on a inshore Penn reel. It is only 0.0312 thick and has a slot cut in the bottom. I have a piece of tubing that I was able to ream to the correct id but will have to turn quite a bit off the od to match his part. Anyone know a good way to keep if from collapsing? Thank you

 

[ddillman]

turn a slug to fit inside?

 

[Cobaltcutter]

That's an idea I hadn't thought of. A guy I work with suggested filling it will lead. Not sure which of those ideas will be best, maybe we will see a few more ideas or someone who has done it before will chime in. Thanks for your input.

 

[markba633csi]

Turn a wooden piece to fit snugly inside-a dummy arbor. There should be enough friction to hold it if you size it just right, and cut a slot in the end to give some springy-ness

 

[strantor]

 

[SLK001]

Make yourself a steel mandrel that gives you a light press fit with your tubes. Take small cuts to get to finished diameter.

 

[markba633csi]

A refinement to post #4: add a flat head screw to the end as a wedge to expand the arbor

 

[great white]

I use a wooden plug (snuggly fit) when turning od on thin tubing. Its more about the chuck not crushing the tube than the tool making chips for me.

For a little more “safety factor”, leave the portion in the chuck as “waste” and part off your good part. Be aware that parting thin tube on the lathe (for me) has always been an “iffy” proposition. Never know when its going to just break through and fall away or grab and ruin the whole part.

I’ve never personally used a madrel for thin tube, but I did watch a guy use one of those exhaust pipe “expanders” once to make a tight fitting mandrel. He inserted it, snugged it and then chucked up the part of the expander still protruding out of the thin wall. Can’t say I recommend that, but seemed to work well enough for him….

 

[talvare]

You don't say what the OD is of the part you're making, but if you have the capability, 5C expanding collets work great for this type of operation.

Ted

 

[Cobaltcutter]

After a couple of attempts, I combined the method shown in the video with a press fit plug in the unused portion of the back half. The od is .378 and I used a 3/8" er32 collet to hold it. It came out a couple thou oversized but that ended up being a blessing because I was not pleased with the finish so after polishing it, it worked fine. Nail biter though, too labor intensive to make money on vs the ones for the spinning reels I started with. Thanks to all for you advice