Author Topic: 3MT Mill collet chuck  (Read 3062 times)

Offline Bezalel

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3MT Mill collet chuck
« on: April 02, 2011, 02:56:45 AM »


This is more of a record of my machine shop learning experiences.    ::)

Hopefully other beginners like me can learn from my unintended outcomes and the old timers well they might just get giggle.
                                                              :lol:

  For my first turning project I went ahead and made my first tool. which was a fly-cutter to bolt to the face plate. On an 8 inch face plate it covered a large surface. Machining up my second project (which was a much needed angle bracket)   I count both these projects a success as well as being very educational.
   


Having bought a lathe without the benefit of 20/20 hind sight I soon discovered it is difficult to mill anything on a lathe that has no T slots in the cross slide. (you'll see in later photos).  :doh:

I don't think Mrs was quite as easily convinced  :poke: but it was obvious to others, This Workshop Needs a Mill.

Of course the type of mill drill I could afford, typically comes with a drill chuck but no collet chuck
So the start of my next Project #3MT Collet Chuck
 

Now on with some milling!  What .. No T Nuts!  :scratch:

Oh well! lets make some .. on the mill?
At this point there is a song stuck in my head.

###  With what shall I hold it dear Eliza? with what? ###   :palm:

by chance I have a few Whitworth cap head bolts, (what a shame there not 5/8 I think they would fit even better) any way, if I file a few mm off each side of the head they should do nicely to hold the vice down while I mill a piece of bar to make some T Nuts (with light cuts of course, I don't want to rip a chip out of my nice new mill table)



Now where were we thats right making a #3MT Mill Collet Chuck.

The first hurdle is the #3 taper.
The book says the Taper starts at a diameter of .778 and for 3-3/8ths of an inch it tapers out 0.0502 per inch on the diameter.   :smart:
I don't know about you but as a novice I'm struggling to understand what it means let alone measure it with a ruler and calipers.  :zap:

But I have seen something that could help, on the cover of one of Tubal Cain's books. See below if Nexus Don't mind the plug



so from this example, if I mount the 3MT centre between centres ( at the head end center drill a piece of very old round bar) and then line up the side of the compound slide with the edge of the taper, it has to cut a 3MT right?



Worked out  o.k. in my head but when I went to the lathe there's two problems    :doh:
1.the edge of the compound slide is well below the center height and
2.tail stock is in the way.

If I make a parallel block (on the mill) I can sit that on the compound slide and measure the gap at both ends of the center at centre height.


 
The rest is is just threading and turning.




 :coffee:
Except the collet tightening handle and the bluing,  I'll talk about them another time.

Rob.Wilson

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Re: 3MT Mill collet chuck
« Reply #1 on: April 02, 2011, 03:51:55 AM »
Nice going bezalel   :thumbup: 

Nothing better than making ones own tooling  :med:   ,,,,,,,,,,, i like your tapper setting block ,, good idea  :headbang:  :clap: :clap: :clap:



Rob

Offline Bernd

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Re: 3MT Mill collet chuck
« Reply #2 on: April 02, 2011, 08:42:14 AM »
Ya, I kind of know how that goes. Very interesting and amusing story.  :thumbup:

Bernd
You can't fix "STUPID".