The difference a disk makes

[Jason Fry]

I sat on the judging committee for the Knifemakers' Guild inspections at Blade this year. One thing I noticed that I hadn't before was that I could tell who had a disk sander and who did not, by the fitup of their handle scales. I hadn't thought about it that way before, so I put together a little test. I took two pieces of steel and two sets of identical micarta scales. I glued them with the same glue, and used three identical spring clamps on each piece, set in the same clamping position.

One set of steel and micarta were flattened on my flat platen. The other set was flattened on my 9" disk. Watch the video and you can see the difference between the two. It's in thousandths, but there's a glue gap on the platen flattened set. For this application, I am using a flat disk, set horizontal. I also have a 1 degree vertical disk, but that's a tool for a different problem.

 

[JV Knives]

Great tip and visuals. Thanks J Jason Fry !

 

[RD_knives]

Perfect tool the disc grinder. Made one a while ago and still love it
Perfectly flat and also perfect for making facets in handles and thin knife blades after the belt grinder.

 

[godogs57]

Enjoyed talking with you prior to the show Friday morning and then the meeting.
Hank

 

[Crag the Brewer]

Ok........ So I made one, and it's wired, and it runs.
I got the feathering adhesive from the local auto body supply.


What do I do about sanding sheets? What are the good grits?
Brands? Rynowet I heard about....

Blades should be done before handles

There IS a learning curve.
My test knife.... I accidentally put a gouge near my edge because of getting fast and cocky and accidentally tilted against the outer diameter..... Grrrrrrrr!

I still don't know speeds either, so far slower than I first figured?

 

[JV Knives]

Crag the Brewer show us your setup.....im looking for someone to copy off of

 

[Crag the Brewer]

Crag the Brewer show us your setup.....im looking for someone to copy off of

I'm at work, but I'll take some snazzy pictures when I get home

 

[weo]

What do I do about sanding sheets? What are the good grits?

Whatever grits you normally use. (for example, I use: 220, 400, 800, 1500, 5000)

Brands? Rynowet I heard about....

Rhynowet.

 

[Crag the Brewer]

Whatever grits you normally use. (for example, I use: 220, 400, 800, 1500, 5000)

Rhynowet.

I'm a murderer on the knives I make, and have sold so far with my 2x72..... I use Alot of 50 grit ceramic. I have some 220, but it's too floppy for my taste on the 2x72. I need to find some with a stiffer backing.

I guess my finishes are rougher than i figured???
I don't think Ive ever even seen 1500, or 5000. Wow!


And here I was thinking of stopping after work, to see If i could find some 80?.......

 

[Mobius1]

My platen is always a tad dished so that's always a no go for me! After having a glass platen shatter in my face at 4000 RPMs (thank God I had a full face shield on!), I am forever going to stick with steel! But that means it's not the best for flattening stuff by a long shot.

All that non-flat ground stuff from AKS practically forced me to get a disc sander! Mine is a 1 degree tapered wheel. To be honest I was a little nervous about it at first and continued to lean heavily on hand filing and hand sanding, but after getting frustrated wasting hours on 64 rockwell blades I started to go to town on it and quickly got more and more comfortable.

 

[Richard338]

Pop's has 50-sheet packs of Rhynowet in many grits. They might also have some PSA discs.

 

[weo]

I don't think Ive ever even seen 1500, or 5000. Wow!

It all depends on the finish you want. I do almost exclusively damascus, thus the high grit paper.
(And I guess I should clarify that the 5000 grit is not Rhynowet, I think the highest they offer is 2000.)

 

[Jason Fry]

There's a white Rhynowet that Pops carries that has a heavier backing and is much better for disks. Plus it's cheaper than the redline.

 

[Lorien]

ordered a Brodbeck disc attachment for my 2x72, fingers crossed it'll work. Much cheaper than the real deal, and the speed is adjustable. Also ordered a reverse switch for the vfd.
only downside I can see at this point is no option for a work rest, but the main thing I need it for is to true up surfaces so it should be good for that
I have a single phase 1750 rpm motor which I bought a disc for, but it's way too fast for most things. I'm sure I'll find some use for it at some point

 

[Crag the Brewer]

ordered a Brodbeck disc attachment for my 2x72, fingers crossed it'll work. Much cheaper than the real deal, and the speed is adjustable. Also ordered a reverse switch for the vfd.
only downside I can see at this point is no option for a work rest, but the main thing I need it for is to true up surfaces so it should be good for that
I have a single phase 1750 rpm motor which I bought a disc for, but it's way too fast for most things. I'm sure I'll find some use for it at some point

I thought about doing that too
I decided I wanted mine horizontal instead

You might need to bring your grinder to the side of your bench?

Mine is in the middle, and I don't think I could use the right side (12-6) of the disk, because of the bench.

 

[Jason Fry]

I have a single phase cheap old air conditioner motor on my horizontal disk. I use a momentary switch from Harbor Freight to power it. Works well. I stole that idea from Bruce Bump if I remember correctly.

 

[Lorien]

I thought about doing that too
I decided I wanted mine horizontal instead

You might need to bring your grinder to the side of your bench?

Mine is in the middle, and I don't think I could use the right side (12-6) of the disk, because of the bench.

I have the grinder mounted to its own horse, so I can be right beside it

I have a single phase cheap old air conditioner motor on my horizontal disk. I use a momentary switch from Harbor Freight to power it. Works well. I stole that idea from Bruce Bump if I remember correctly.

never thought of mounting it horizontal, that would make it much easier to use at 1750 rpm

 

[Crag the Brewer]

Crag the Brewer show us your setup.....im looking for someone to copy off of

Here is my little dirty part of the Universe....










I don't have my drive mounted yet.

Looks bad.... someday I'll take nicer pictures when it's cleaned up

 

[JV Knives]

Here is my little dirty part of the Universe....










I don't have my drive mounted yet.

Looks bad.... someday I'll take nicer pictures when it's cleaned up

Very cool…thanks ! I have that techtop style motor on my 2x72 and am happy with it as well.

I’ll look into that drive. I’m far from savvy on motor control but I appreciate a nema 4 rating as my shop stuff, like everyone, takes a dust beating.

I’m interested in going vertical and horizontal. Been looking at a few different stands that are available, which rotate with a 56c motor…need to narrow that down.

Grats on the new toy!

John

 

[Crag the Brewer]

Very cool…thanks ! I have that techtop style motor on my 2x72 and am happy with it as well.

I’ll look into that drive. I’m far from savvy on motor control but I appreciate a nema 4 rating as my shop stuff, like everyone, takes a dust beating.

I’m interested in going vertical and horizontal. Been looking at a few different stands that are available, which rotate with a 56c motor…need to narrow that down.

Grats on the new toy!

John

I could mount mine on its side, but I think I'll like it like this better.

I still don't know what speeds are needed?
At a certain range of frequencies it vibrates. Faster and slower it doesnt.
I'll have to play with it. Maybe it needs more support? I could weld a gusset on it...