Advanced Grinding Rest (Harold Hall)

[Kim]

Well, its been a while, but I’m finally ready to start on my new project!  I’m going to be building the Advanced Grinding Rest as described in Harold Hall’s book “Workshop Practice Series #35: Milling a Complete Course.”

I originally got the Workshop Practice Series, book #38: “Tool and Cutter Sharpening”, which I found quite instructive.  It had plans for a simpler grinding rest, but refers to a more advanced version in the other book.  The two grinding rests are very similar, but the ‘advanced’ rest has dovetail slides and screw adjustments for X and Y.  So I decided to get that book and make the more advanced one.  Here’s a picture of what it will look like when done:


Both books contain the exact same plans for several additional accessories that you can use with the rest to sharpen lathe tools, slitting saws and end mills.  Here’s a picture from one of the books of the end mill sharpening accessory:


I’ve spent my spare time over the last few weeks converting the plans from metric to English, incorporating the mods from his website, creating a BOM list of bars stock and HW that I’ll need (plus a few more tools, of course ), and ordering it all and getting it in.  And I think I’m ready to start on the tool rest this weekend!  And it’s a long weekend in the US (Labor Day) and I have nowhere else to be than home, in my shop!
 
And best of all, my wife just called and told me that my shipment from Speedy Metals just came in!  So I’m all set for fun and games all weekend!

What could possibly be more fun? 

Here’s a parting shot of the tool rest and attachments setup to sharpen an end mill.  I’ll be able to do this in a few months!


Undoubtedly, I’ll run into a plethora of situations where I’ll need help and guidance on this project and I welcome your input, whether I ask explicitly for it or not (I might not even know I need help sometimes!).

There are several new wrinkles for me in the project that I already know about: it's made almost exclusively with steel, something that I've only used sparingly on my previous projects.  Also, it had a couple of dovetails, which I've never done before.  I’m certain that I’ll run into more as I progress.  So, this should prove to be a nice challenge for me!

Thanks,
Kim

[Johnb]

That looks like  a good project. I'll be following along.

[Don1966]

Nice project Kim and I don't think you will have trouble with the dovetails. You will need to buy a dovetail cutter or make one. Making one is a good practice run for you and a learning experience. I will be following you what ever you decide. Getting the pop corn and beer ready.

  

Don

[Kim]

Thanks John and Don,

Yeah, maybe I should have made the dovetail cutter, but I decided to buy one for this build.  Sharpening has always been a bit of a black art to me.  I always feel a little trepidation when stepping into that area.  I've been able to get by, but that's about it.  So I'm hoping that with this new tool I can become more confident in the sharpening department.  And then NEXT time I need one, I' might be able to make my own cutter and sharpen it so it has a slightly better edge than a butter knife!

Kim

[Arbalest]

Look forward to the build Kim. What spec dovetail cutter did you get?

[Kim]

Hi Arbalest,
I bought a 60 degree, HSS, 3/4" dovetail cutter (3/8" shank) from Victor Machine for $18.80.  It looks like it ought to do the job!

Kim

[Kim]

Today I started cutting steel on my new project!

Since the Dovetails are a big focus for me, I decided to start with those.  So first off, I'm doing a pair of parts that Harold has named the "Slide Swivel Pieces".  These are the recessed half of the x/y dovetails.

I started by cutting two ~5/8" slabs of 2" square 12L14 steel.  I was worried about how long this would take my little HF saw, but it didn't take very long at all, maybe 4-5 minutes or something?  Not bad!  And the faces came out pretty straight too.

Here are the raw sliced parts - one's fitted in the vise ready to square up one of the cut faces.


I got a new TiN coated end mill to use on the steel, and it seemed to work well.  Of course, this is 12L14, so it ought to machine well!

Here's both parts, cleaned up and finished to the correct thickness. This picture makes the faces look quite corrugated, but in fact, they are very smooth to the touch.


Next, I used a roughing mill to cut most of the slot for the dove tail.


Then cleaned up the sides and bottom to the correct dimensions using my TiN 3/8" end mill.


With the dove tail cutter in place, I found the bottom of the slot, then started cutting the dovetail 15-20 thousandths at a time.  This shows the 60 degree edge about half way done.


I kept cutting in, and as I got close I started taking passes of 5 thou.  And the last few were only 1 thousandths.  But this way I got the dovetail to come out the correct width.


Performed the same operation to the back side of the slot:


And here's one of the Slide Swivel Pieces with the dovetail completed!


Now one more dove tail slot to go, and then a bunch of holes & threading and I'll be done with my first piece of this grinding rest!

Thanks for looking in on my new project,
Kim

[RMO]

This is looking good, I like the project.  I will be following along.

Mike

[steamer]

Have at it Kim!....


I want to take a look at the end mill spindle!.


Dave

[arnoldb]

Good start Kim 

I'll also follow along 

Kind regards, Arnold

[Don1966]

Good going Kim and the dovetail came out great. You made it look very easy. 


 

Don

[fumopuc]

Hi Kim, I am following along. Tool grinding is something on my list too.

[Kim]

Thanks for the comments Mike, Dave, Arnold, Don, and Achim.

Have at it Kim!....

I want to take a look at the end mill spindle!.

Yeah, I'm kinda looking forward to that one too! The end mill fixture will be the first accessory I make after I get the main grinding rest completed.

Good going Kim and the dovetail came out great. You made it look very easy.

Interestingly, (maybe predictably, as with many of these kinds of things) it wasn't as hard as I was picturing it.  I just took it a step at a time and worked through it.  It would have probably been more difficult if I had have both sides of the tool buried at the same time.  Luckily, that was not the case here!

Kim

[Dave Otto]

Neat project Kim!

I will be following along with your progress. What will you be using for the grinder part?

Dave

[Kim]

Hi Dave, Thanks!

For the grinder I'll just be using a standard bench grinder with a cup wheel.  If you look in the last picture in my first post, you can see what I expect it to look like.  I'll be mounting it on a base with a couple inch spacer under it, to give it some additional height to line up with the grinding rest better.

I'm considering just using an inexpensive Harbor Freight 6" grinder.  Those only run $40-45.  Very affordable!  Is there any reason to get a more expensive grinder?  A name brand bench grinder can run $400-500 and I'm not sure I can justify spending that much on it. What would be the added benefit? Better bearings maybe? But 10x better?

Kim