dr_hfuhuhurr

iTrader: (95)

Anyone have a good article or list of steps to ensure that a new lathe is properly setup and cutting square?

Blake

SlobbaTech

Just measure the comm with some calipers, if there is more than .002-.003" difference or taper then you need to get it fixed or replaced, the manufacturer or a machinist could do that. Then need to shim the bit in right spot so it's barely above the center of the comm.

popsracer

dr_hfuhuhurr;

A full size Lathe will always have the cutting edge of the Bit slightly below centerline.

This is the same on our miniature Com Lathes, but most of them rotate in the reverse so the bit will be mounted upside down. Try for .010 to .020 above the bearing blocks.
Mounted this way, if the Bit is installed sitting too low in the Lathe, it will hit the bearing blocks and be damaged. Just add a shim or two to clear the blocks and this should be very close.

If the Lathe was built square at the factory and the bit is sharp and set-up correctly, it should leave a nice true cut from front to rear.

dr_hfuhuhurr

iTrader: (95)

I understand how to shim the bit properly. What I am looking for is how to properly adjust the lathe so there is no taper on the comm.

rayhuang

iTrader: (5)

I sent mine to Chris Doseck to have him re-align it. I know its a lame answer-but its like a new lathe after he dialed it in.Some things in life I dont have to know how they work-as long as they work (i.e. plumbing, household wiring, my comm lathe.... )......

BIGDON18

iTrader: (72)

i have a cobra com lathe, and i had to make sure the com is cutting straight on bit during cutting. adjust the v blocks to where they are no tapering in your com cuts, and onces you get is set perfect becarefull to not let it get banged up in a pit box or else where ,, because of the chance of it getting knocked out of line again. if you just put it together they can be up to .004 off in play in the v blocks,just loosen the screws and adjust the postions of the v block to get a square cut, so i would make sure that is square,, and cutting true. also like people have post make sure the bit is cutting just above the center line in com. also make sure the lathe is truning in the right direction,, if the com seems its trying to jump out of the v block its spenning toward the bit its backwards,, the com should be spinning away from the bit,, or thats how it is on my cobra,, and it want be jumping around on you,, but for just make sure its cutting true with some old coms and calipers,, then you set,, i dont know if this helps any but maybe something will help you from my post.

BIGDON