Hey I was looking to use the lathe for one of my projects but wasn’t sure how to go about it. I have a 6 inch disk 1/2 thick that I need a perfectly centered 1 3/8 hole in. My plan was to use a drill press and drill as close to center as possible and then put it on the lathe and lathe it down till its perfectly centered. After this I have to create a 5 hole spider set up thats also perfectly centered. Any tips?
If the 6" disk will fit on the 3 jaw chuck, you get the advantage that it is self centering.
You can drill a hole on the lathe and then use the boring bar to open it up to the appropriate diameter. NOTE: there is a LOT of constant checking that needs to be done else you’ll oversize it. Remember that when you move the boring bar 0.001" your taking that on both side of the hole which means you’ve bored 0.002".
Alright sweet. Luckily the hold in the center does not need to be very precise just enough to clear a little cover/bumb.
If by 5 hole spider you mean 5 holes on a circle of a certain diameter, then the rotary table on bridgeport would be good, takes a bit of work to get it set up and centered (can use coaxial indicator or test indicator on arm to center rotary table then center piece on table.)
Could also just rely on the DRO instead of rotary table to drill the holes after calculating their x,y position, but that would probably have more error.
yeah, I didn’t read the part about the 5 holes. +1 on what Brandon said.
Would it be possible and easier to make a rendering and cut it out of a plate on the plasma?
That would depend upon what your tolerances are. Cutting something out is easy, but the kerf can be pretty large.
I might end up using plasma and if it doesn’t work then do it on the lathe or mill. The tolerances on the holes arnt major as long as its centered and spaced right.
What is your tolerance for error? Does it need to be balanced or will it be rotating?
What about placing the oversized disk on the laser and marking the hole centers and the outline onto the part by lasering a shallow mark for each spot and the outline.
Take the part to the drill press and drill out the 1 + 5 holes using Forstner bits, cut close to (but proud of) the outline with a band saw, then sand to the outline using the large sander.
1 Like
For that matter, you could print out a template on a paper printer, glue it to the top of the blank using spraymount, and do the same thing without even using the laser.
What I think I’m going to do it make a rendering of the shape I need with dots where the holes go so that I can line the bit up there and have the right spacing.