Adapting a drill chuck with a taper with tang for use in the mill

[Anko]

Hi everyone

some good day i realize that the drill chuck that came with my mini-mill was chucking the drills off center, with a closer inspection i notice that one of the three emm dogs? was more worn than the other out, so i assume that the drill chuck was a very cheap one

time for new and precise drill chuck comes

i bought a well emm jaja, cheap one, but it was all I could afford, and buy the taper too

time to go to the lathe:

this is the new drill chuck

carefully chuck in the lathe, measuring a 0.02 mm of runout in the extreme of the taper

then facing the tang and start drilling

and here is when all the project go to hell jaja ;D

i got some trouble drilling the taper, but when i put the tap to made the tread ufff the material was so strong that i have to put incredible force to the tap to make just a 1° of avdance, i feel that in every second the tap will broke, afther a couple of hours i just made a 2 or 3 treads, and give up.

the draw bar enters the taper a litlle so all my efforts will not be in vain, but i have to put a spacer in the top of the spindle to compensate the lack of the number of treads on the taper

seems to work fine, futher late i will measure the runout of the drill chuck with a bar of silver steel, but from now, i like to think that all is fine and well made :- jajaja


well, i do not recomend trying to do this jajaja i will considerate making my owns morse tapers in the future...


Saludos

 

[tel]

The main thing is that it works Anko, you don't need a lot of threads there to hold a morse taper. I too have had trouble trying to do that in the past.

 

[Deanofid]

i assume that the drill chuck was a very cheap one
time for new and precise drill chuck comes
i bought a well emm jaja, cheap one,
jajaja

So, you bought another cheap one. :big:

Who is jajaja?!

Maybe he's they guy who hardened your MT shank! It's his fault you couldn't run your tap in very far.
Should do fine, none the less. These tapers will almost stay in by themselves.

Dean

 

[jmshep]

Hi
I would have bought a threaded MT arbor to suit your chuck, they are probably cheaper than a broken or damaged tap. The only thing you have to get right is to identify the type of taper in the chuck.
I would suggest that it was not necessary to worry too much about the accuracy of your set up to face off the end of the MT as it is the taper and accuracy of the chuck that matters not the accuracy of the thread for the draw bar. Besides the real test is how accurate the chuck holds the tool in the jaws not the relationship between the outside of the chuck and the arbor.

Jacobs Chuck

JT No Large D Small d Length
0 6.350 5.802 11.112
1 9.754 8.469 16.669
2* 13.940 12.386 19.050
2 14.199 12.386 22.225
33 15.850 14.237 25.400
6 17.170 15.852 25.400
4 20.599 18.951 30.956
5 28.550 26.346 42.069
6 35.890 33.422 47.625

2*= Short



DIN Taper

Ref. Large D Small d Length Morse
B10 10.094 9.400 14.500 1
B12 12.065 11.100 18.500 1
B16 15.733 14.500 24.000 2
B18 17.780 16.100 32.000 2
B22 21.793 19.800 40.500 3
B24 23.825 21.300 50.500 3

PS I have just uploaded a "book" I have compiled that contains the infromation above in the downloads and uploads section