Disc grinder/sander WIP

[Kevin Powers]

I already showed this in another thread but figured I'd update with changes in design and such.
first incarnation was a tilting table design and it looked good on paper but then once it was all completed there was an apparent design flaw. As you tilt the table the table pulled away from the disc due to the pivot bolt being lower than the table surface.

I also wasn't happy with the table height and the fact that the brackets would be in the way to utilize the disc unobstructed.

Back to the uh.... Plasma board?
This time I decided I want sliding arms that will bring the table closer when tilted, up closer to the actual center of the wheel in height, and can be completely removed to allow for true flat grinding. So we widened the width of the face mount to allow for slots to act as keepers of the sliding arms, and height to allow for enough clearance to do long plunge cuts.

Cut out and cleaned up. I had to clean up the bolt holes and slots with my mill.

So now this design ran into some areas of trouble.
First, the swivel brackets contact the face plate mount as we did not build a new table.
Second is that since the swivel mounts are so big, the sliding arms don't slide much.

After cutting and sliding the table closer to the wheel and nipping the corner off the faceplate I realized no matter what I do, it isn't going to function correctly unless I make the swivel brackets shorter.

Getting there, this will actually function fine as is, but I want to have more articulation in the table to do crazy angles and what not.

So back to the drawing board to shorten the swivel brackets and play around with different nestings to see how big of a piece you'd need to get one cut. Turns out with the new modifications this could be water or laser cut out of a piece of 1/4" that's 11.5" x 17.79" We also changed the cutouts in the face plate to use the tabs that form the slider mounts.

 

[Kevin Powers]

Here's a plasma version on the left(low tolerance) and an indexed water jet version on the right(high tolerance). Once I have one water jet cut and confirm it works right, I will share the file with the knife community. The working prototype that I have been using in my garage is literally just tacked together and it works extremely well.

 

[elementfe]

Interesting design problem, thanks- I'll be following this one!

 

[Frank Niro]

Sometimes these things turn out to be unexpected challenges. Disc grinders are a tool all into themselves. The outside of the disc moves faster than the inside. Now as for a table I sure would think that could be a great tool to have. I did hear that Lee Valley had one for sale but I couldn't find it in there many catalogues. I'll bet you make a good one!
Frank

 

[Kevin Powers]

Sometimes these things turn out to be unexpected challenges. Disc grinders are a tool all into themselves. The outside of the disc moves faster than the inside. Now as for a table I sure would think that could be a great tool to have. I did hear that Lee Valley had one for sale but I couldn't find it in there many catalogues. I'll bet you make a good one!
Frank

Thanks Frank, this project was mostly about trying to give back to the community and to hopefully save some people time or money or both. I wanted the table to do bevels on scales and to also help do some profiling. The first version was a problem because it had tabs out in front of the disc. Now with the latest version it is completely unobstructed which the tools spends most of its time. Now that I have the disc I haven't touched my belt in a while. I'm just about finished with my first dagger and it was done completely on the disc.

 

[Kevin Powers]

I also sent the file to Salem so hopefully he will chime in and give some feedback

 

[tim37a]

I'm putting together a disc sander right now and would be very interested in a file so I can have a local water jet cutter cut it out for me. Waiting on tether hooks....

Tim

 

[Lo/Rez]

That's very generous of you to share the plan. Thank you very much.

 

[Josh Rider]

That's very generous of you to share the plan. Thank you very much.

I agree, thanks so much!

 

[Kevin Powers]

so bringing back this one from the dead. Today I was able to cut a newer version of the disc table, still on a plasma, but a much nicer and more accurate one. (new job) I was also able to use much better material. This design actually works extremely well and I have been using the previous version almost daily since I built it. The tabs that the table arms bolt to don't need 2 bolt holes, In all actuality I only bolt one side down. I have never even put bolts in the degree slots either. I just use countersunk allens and my 1/4" drive cordless impact to do all adjustments and for removing the table. The slotted and tabbed design allows all welding to be done on the bottom of the mounting plate to help prevent distortion. The table tilts from about -10* all the way to more than you'd ever need.
I will be sending this to design to a few different knifmakers for some beta testing. I will let you all know their impressions.

 

[Scoli Forge]

That looks like a really good design. I especially like how you remove the table and can keep your angle.

 

[Kevin Powers]

That looks like a really good design. I especially like how you remove the table and can keep your angle.

That comes in handy more than you'd believe. Once the table is removed, the disc is operational without and obstructions. The sides of the mounting plate are also low enough for guys that like to cut their plunge lines with the edge of the disc.

 

[Scoli Forge]

I recently made one, but didn't make it with a tilting table. Do you have any intention of selling the plans for that rest? I'd be interested if you did.

 

[Kosa_PL]

You know, the best method is to start cutting from the center of hole...
And if you cutting outer shape, start out of the shape..
(if you do this like on photos, in my friend company you could get fired..)

 

[Kevin Powers]

You know, the best method is to start cutting from the center of hole...
And if you cutting outer shape, start out of the shape..
(if you do this like on photos, in my friend company you could get fired..)

Sure do but I am trying to learn the new program. Sheet cam is doing it automatically and I haven't figured out how to fix it yet. This table uses Sheet cam to generate the G-code and Mach 3 to run the plasma, and it is really giving me fits.

 

[Brian Avila]

Looks excellent! Great work!

 

[Kevin Powers]

I got home and bolted the table I welded up today to check the articulation. It's got a big range of motion and it also made me realize I welded the dang pivots in the wrong spot lol. So when the table tilts down it goes below center. So imagine the table recess an inch higher if the edge of my pivot meets the wheel side of the table.
-15* plenty of movement for lock faces and what not

76.5* for those extreme bolster angles.

 

[PEU]

Hi Kevin, can you share the blueprints? I already have the motor, vfd and plate and this comes like just in time manufacturing. Will touch it here and there so it fits my motor. My email is pablou at gmail

one degree taper

Thanks!


Pablo

 

[Kevin Powers]

Hi Kevin, can you share the blueprints? I already have the motor, vfd and plate and this comes like just in time manufacturing. Will touch it here and there so it fits my motor. My email is pablou at gmail

one degree taper

Thanks!


Pablo

The taper shouldn't matter. If I had a tapered disc I'd just glue some 60 grit on and push the table into the spinning wheel to true up the table and keep the gap tight. I can send you the file the next time I'm at work.

 

[PEU]

The taper shouldn't matter. If I had a tapered disc I'd just glue some 60 grit on and push the table into the spinning wheel to true up the table and keep the gap tight. I can send you the file the next time I'm at work.

That would be fine, I'm in no hurry at all. Thanks!!


Pablo