Sherline milling collet draw bar hex head conversion to 7/16"

[Russel]

This is not much of a project, but I decided to post it anyway. I had fun doing it and it will make things easier for me later.

I have a Sherline Mill. The headstock (at least it is the same as the Sherline lathe headstock) has a number one morse taper. To use a drill chuck with the  mill, you thread a MT1 adapter to the back of the drill chuck and you have a hex head cap screw to act as a draw bolt. I also have a set of three milling collets that fit into the “headstock” MT1, except the threads are larger in the back of the collets.



So, the drill chuck ends up with a 7/16” hex head and the milling collets end up with a 1/2” hex head. Keep in mind that as small as this machine tool is, the size of the hex heads are complete overkill. When I use them I very gently tighten them, you don't need any more torque than that on the little MT1 taper. So, being the lazy person that I am, I decided to machine the milling collet draw bar hex head down to 7/16” so that I would only need one wrench for both. (That and the fact that I had the rotary table already set up, so this was something else that I could do that is fun.)

OK, try not to laugh, I know this looks kind of ridiculous but it is the best that I could think of to mount the draw bar (bolt) so that I could machine the hex. I tightened the bolt into a self centering 2.5” chuck. Then, because the bolt had to go down the center of the rotary, I used some milling hold downs to hold the chuck on the RT. Here is a photo of the setup as I centered the part on the RT axis.



It's kind of funny, I usually use a milling collet to hold the DTI, but the draw bolt was in the chuck, so I had to think of the next best way. Then I remembered the WW collet set that I got (another of those “I just had to buy” items) and finally used it for the first time since I got it. (Mental note, need to think of more projects where I can put this set to good use.) It worked perfectly for the 5 minutes that I needed it!



Anyway, I machined .025” off each facet of the hex head, then decided to resurface the top. When I tried it with a wrench it seemed a little loose until I tried an actual 7/16” hex head, the one I machined was tighter. Too much measuring down to the last thousandth of an inch I guess.

So, here is the result:





I had some fun, and now I only need one wrench  (spanner) at the milling machine.

Russ

P.S. Does this take the prize for the shortest and most ridiculous project?

[bogstandard]

Very nice writeup Russ.

I think you are a little like myself. I will do tweaks like this one, just to make life a little easier, why struggle with two, when you can get away with one.

Bogs

[Gerhard Olivier]

Thanks for posting this Russel.  I think I share you and Bogs's kind of lazyness but I understand why that would have bugged you.

To me this is the very essence of being a MADMODDER.  We make things, we change things and sometimes we even improve things.

To other people making little mods please post them- you never know what somebody else learns from a post.

Gerhard

[Stilldrillin]

Very nicely done Russel! 

To me this is the very essence of being a MADMODDER.  We make things, we change things and sometimes we even improve things.

Very well put Gerhard! 

David D

[Russel]

You know the funny thing is that once you start getting the hang of using the machine tools, the wheels in your head start turning and some of the possibilities of what you can make or modify start sinking it. I'm glad you enjoyed my little project. I won't hesitate to post the little ones in the future.

Russ

[dsquire]

Russel

Sometimes its the little things that mean the most. Nice idea and even nicer that you did something about it. 

cheers 

Don

[Bernd]

Even nicer that he posted it Don. 

Bernd

[bogstandard]

Russ,

It is usually the short & sharp ones that give the most information than very long prose and piccy jobs, and are normally more relevent to more people.


Bogs