MadModder
The Shop => Tools => Topic started by: ieezitin on September 01, 2013, 11:34:50 AM
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peoples....
I have been trying to cut an internal taper this weekend and have been having a hard time getting it right.
when I slide the male end into the bored hole it seats but if you apply some slight pressure on it you feel a wobble, I applied a little more pressure with an arbor press and it seated well, I then returned to the lathe to bore out a hole, I made one pass checked it and it ran true ( the bored hole that is), I then took it out of the headstock, I detached the stub end from the piece and re seated it, put it back in the head stock and there was miss alignment, it did not seat correctly.
To test my fit I applied chalk to the male end and inserted into the taper hole, gave it a slight twist and then removed it, there was touch marks all over the tapered male stub, it looked pretty fine, I then ran down the tapered hole some fine emery cloth to put a decent finish on it, I did not go hog wild it was more like a buff, I did a chalk test again and got the same reading.
It’s a 2JT male end on a MT2 that I am trying to copy (the 2JT that is). To get my angle I set the piece in between centers and had a .0001 test indicator set in my tool post, I installed a needle point tip to it, I set the elevation to a dead center that I had in the tail stock, I wore x3 mag goggles to see it. I ran the compound slide up and down the male taper and eventually I got it down to 2 tenths of a thou over about 5/8 run, hell if you breathe on the lathe you will get a reading.
My question is, if I am doing anything wrong please let me know and…. How do you all do it?
Thanks in advance Anthony.
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I Bought some MT2 Reamers for the hole. Take care, it's VERY easy to go to far.
To make an MT shaft use an arbour set between centres and offset the tail stock until the arbour runs true on a dial.
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try getting a soft pencil and draw pencil lines along the length of the male taper all the way round the diameter, then wring it into the taper and see where it touches, this may give you a better idea than chalk.
Phil
UK
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Are you replacing the MT in the same place each time , I have mine marked and line them up with the back gear pin at top dead centre , as you are using a tenth of a thou DTI it could just be a bit of dust .