Advanced Grinding Rest (Harold Hall)

[Kim]

Thanks Don!

Next on the list are the Collets.  These will, of course, have a taper matching that of the spindle.

I'll be making quite a few collets, but this post will cover my first one, which I chose to make 3/8".  This seemed like a nice middle size so I just went for it.

Using a length of 7/8" round 12L14 bar I drilled a center hole just over 2" deep.  The size of the hole was selected for a 10-32 tap, which is what will be used for the draw bar.


Next I drilled about 1.5" deep to a size just under 3/8".  I wanted to leave some room to bore the hole straight, then use a 3/8" reamer for final size.  Here I'm skimming the hole with my smallest boring bar.  This will be a complication for smaller collets, not sure I'll be able to bore them, I may just have to assume the drill went straight...


Then reamed it to 3/8".


Using that nice hole, I supported the piece with the tail stock and turned it down to the maximum diameter of the tapered part, then started cutting the taper:


Here is the taper, completed:


Next I turned the rest of the length down to where it would fit inside the spindle.  I wasn't able to test fit this part, so I measured the inside bore of the spindle carefully, and turned this to about 1/2 thou under the spindle bore, hoping that was about right.  The problem is, if I get this size wrong, I won't know it till after I cut the part off the parent stock. And I don't know how to hold it for additional turning after that!  So I measured VERY carefully!  Several Times!


Using the parting tool, I marked the beginning and ending of the waist of the collet.  This is to give the collet the ability to more easily in order to clamp the part.


I used the parting tool to make successive cuts to remove the bulk of the material.


Then cleaned it up to the right diameter with right and left hand tools.


Finally, part it off from the parent stock.


After this, I checked  the fit of the collet in the spindle and was a nice fit.  Maybe a touch snug, but  I can clean that up if needed. At least it wasn't sloppy loose!  That would have been worse

One of the final operations for the collet is to cut the slits so that it can clamp down during tightening.  I did this on the mill using a hex 5C-collet block.  Again, my problem with the 5C collets came up.  The diameter I'm trying to hold (18mm=0.709") is about 10 thousandths smaller than a standard 23/32" collet (23/32"=0.719".  My solution was to use a piece of 0.004" brass shim stock and wrap that around the collet where I want to hold it.  This worked out wonderfully giving a nice snug fit even before tightening! You can see the shim in the 5C collet in my setup shot here:


I needed (wanted?) to bring the slit all the way back to the base of the collet.  Unfortunately, the slitting saw I have is 3" in diameter, and I couldn't get in any closer that this without damaging the far side of the collet (the one I'm making).


This probably would have been enough of a slit, but I wanted it to go all the way back.  My solution was to use a 1/16" mill and mill the remainder of the slot.  I'd considered using the mill for the whole slit, but the front of the collet is too thick for the 1/16" bit.  So ended up doing both.  You can also see that I had to mount the hex collet block 30 degrees off from the way it was when I used the slitting saw.  But that wasn't too hard to figure out.


And here we are with all three slits completed:


And this shows what it looks like in the spindle, holding a 3/8" item in the collet.  I used a random 10-32 bolt for the draw bar and it held that drill bit tight! How cool is that?!


Now I'm going to make a half dozen more collets - all the eighth-inch increments and maybe some select sixteenth increments too.

Kim

[Don1966]

Now that's a nice collet, I need to try my hand at that one day...........

 
Don

[zeeprogrammer]

Just finished reading the thread.
This is an excellent thread. I really appreciate the time you've put into posting it.
It's one thing to show a setup...it's even more useful to show a video and seeing how it was used.
This thread is chock full of learnings for me.

[Kim]

Thanks Don and Zee, I appreciate the comments!

Glad you found some of it helpful Zee, it certainly has been quite a learning experience for me!  I've had a ton of fun building this, though I'm starting to get ready to build something that moves again

Thanks,
Kim

[Roger B]

  I've had a ton of fun building this, though I'm starting to get ready to build something that moves again

And you won't have to worry about blunt tools 

I've also enjoyed the build and hope you get good use out of it   

[Kim]

Thanks Roger! I've been getting a lot of good use out of the sharpening jig already!

It's been almost a month since my last update, but I'm still here, plugging away.  Lots of summer family things going on keeping me away from the shop, but I've managed to make some progress.

During this time, my wonderful wife got me this great South Bend MT3 keyless chuck.  I'm really enjoying it.  Don't know how I lived without it now!


So what progress has he made on the End Mill sharpening jig you might ask?  Well,  I finished 8 more collets.  I made from 1/8" to 5/8", by 16ths.  Took me a while, but I decided now was the time to do it.  Here's the whole set:


Thanks for checking in,
Kim

[Don1966]

Looks great Kim and you wouldn't regret making those collets because they will come in handy. Love the keyless Chuck  I guess I need to break down and get one.

 
Don

[Kim]

Thanks Don,
That's what I was thinking with the collets; they'll come in handy when I need them!
Kim

[Tennessee Whiskey]

Great job on the collets Kim. You are going to love the chuck.  I bought one when I first started in the hobby and it sure beats bending over or getting on your knees in the swarf to find a dropped key. Actually,  I liked it so well, I bought one with an R8 shank for the mill . Carry on.

Eric

[Kim]

Thanks Eric!  If I ever get a bigger mill, I think I'll have to get an R8 keyless chuck for that too!

This weekend I made the Indexing Collars for the End Mill Sharpening jig.  These allow you to easily position the jig for sharpening the multiple edges of an end mill.  While the plans only show a 4-way indexing collar, I also made a 6-way at the same time. These two collars will theoretically allow me to sharpen tools with 2, 3, 4, or 6 edges.

I didn't have any round stock that was 1 5/8" in diameter so used a piece of 2" square 12L14.


I took it easy bring it down to size since it was an interrupted cut.


Once down to size, I drilled out the middle then bored the hole to the required diameter.


When I had a nice tight slip fit, I parted off two 3/8" wide rings for the two collars.


I put in the 3-jaw chuck and faced off the other side to the correct width.


I decided to make a mandrel to hold the rings while I milled the indexing flats.  But to do this, I had to make a small washer and I needed to face it off.   That's the reason for this picture here.  I think this is the deepest Klot's level I've been to yet - it's got to be at least a Klotz level 4.5;

• Modifying the jaws of the chuck to
• Turn a mandrel for the indexing collar to
• Make a End Mill sharpening jig to
• Sharpen end mills to
• Make things

I only gave myself a 1/2 point for the chuck-jaw-modification project.  But still, that's pretty respectable, don't you think?

Here I'm back out to Klotz level 4 (making the mandrel):


And here's the completed mandrel, popping me back up the stack to only a Klotz level 3 (making the sharpening Jig).


Now I hold the mandrel in the 1" 5C square collet block and cut the 4-way index.


Then in the same setup, cut a pocket for a clamping screw.


Here I'm spotting the hole for the clamping screw, using my dental mirror to see what I'm doing there in the back.


With the holes drilled, I then tap the lower half of the hole (4-40).


The final step is to cut the clamping slit.


And here are the two completed indexing collars.


I'm getting down to where there's just simple pieces left!

Thanks for taking a look,
Kim

[fumopuc]

Hi Kim, nicely done. I like your soft jaws.

[Kim]

Thanks Achim,
Those are the standard soft jaws for the Taig 3-jaw chuck. You can get a replacement set for $10, so its cheap to modify them as needed.
Kim

[ncollar]

Kim
Very nice and love all the finishing touches. They will bring years of satisfaction. And they make you life a lot easier.
Nelson Collar

[Don1966]

Simple piece or not Kim still out standing work.   



 
Don

[Kim]

Thanks for the comments Nelson and Don, they are much appreciated!
Kim