Found Dreaming

I have a 1/4" precision shaft that is 3 inches long I bought for my CNC. I was told to center drill a 1/8" hole approx 3/4" Deep. Well, I tried and severely botched it. (off center) There is still one good side, If anyone has a good lathe, and a 1/8" bit how much would you charge me? I'd send it in a padded envelope with a second envelope with postage paid, plus payment.

I have a small lathe but I have never gotten the tailstock precisely aligned with the chuck, not real sure on how to accomplish this honestly and it has not been detrimental in the kinds of things I do with it.

I am curious as to why the center hole needs to be so deep? seems like once the larger bit gets in it should stay on center or is this the final hole size?

Aligning the tail stock isn't really hard to do and has to be done every so often, the vertical alignment is harder to do then side to side. the side to side alignment I use a bar with to cams on it or you can use a bar about 10 to 12 inches long and make a cut down the lenght of the bar and mic it and it will tell you which way to move the tail stock, there are adjustment screws in the base.

David

The 3/4 inch deep hole is to allow normal length bits on my spindle, There is a lack of z travel with this machine if you buy normal 1/8th shank bits as they are pretty long. So essentially since your using a 1/8” to 1/4” shaft adapter thats my collet.

Did you mic in the bar before you started ??? Or did you just pt it in the 3 jaw chuck and hope for the best If you used a 3 jaw chuck to do the job then that is more than likely the problem. the other thing could be if you used a dull drill bit, that can make it wander.

Just my 2c worth

I see, the finished hole is 1/8" diameter. When you mentioned center drilled I thought it was for further drilling the hole out to a larger diameter.

David, yes I need to learn how to set up the tailstock on the lathe. It is just one of those cheapie minis from HF and it has done pretty much everything I have needed it for though. I would be concerned about doing something like what Shadow is requesting though because this is for a chuck on his mill and will need to be very accurate to keep from breaking bits. My alignment problem is in the vertical I believe and it seems the fix is shimming up the headstock, not likely I will be doing that... as I said though it has been close enough for my needs but I can see small bits wobbling in little circles so I know it is off.

Shadow, have you considered using some old pieces from a dremel for the arbor? Might be able to find one with a burned out motor on the cheap.

have you considered using some old pieces from a dremel for the arbor? Might be able to find one with a burned out motor on the cheap.

I could post you one but it would probibly be cheaper to but one new and pull it to bits.

Nudge wrote:Did you mic in the bar before you started ??? Or did you just pt it in the 3 jaw chuck and hope for the best If you used a 3 jaw chuck to do the job then that is more than likely the problem. the other thing could be if you used a dull drill bit, that can make it wander.

Just my 2c worth

Your two cents worth was read with full attention to detail.
I used the Three Jaw becasue that was what was on the lathe at the time I did it, it was almost two in the morning when I preformed the operation, I was out to see if I could actually drill the hole not how close to center that I could come.

If I was doing it for pay of on a real part I would of put on the four jaw chuck, although an 8 inch four jaw is sorta big for a 1/4 inch diameter rod. I could of used the 9X20 and put the four jaw on it, would have to look for that one, since getting the 12 inch lathe thats the daily driver.

Or I could of used the 7X10 but I do't have a four jar for it, but I could of started with a larger rod and used the steady and dead center and turned a say 3/8 down to 1/4 then drilled it.

And all the bits I used were new usa made bits except for the 0 center drill. if I had of had one I would of reamed the hole to final size of 1/8 from 7/64 inch bit but I don't think I have a .125 reamer.

I actually have a dead dremil tool that the shaft could probably be pressed out of which would make a 1/4 inch spindle shaft with an eighth inch collet closuer on the end of.

David.

I got a friend at work to use the lathe here. (An old Navy Lathe used to bore gun turrets) Was comical watching such a large lathe drill a small hole.

I can imagine, a 1 oz part in an 800 lb chuck