# My slow speed diamond disc lapping machine, the beginning



## Janderso

I have all the materials.
The idea is to mount this 90 RPM drive motor on the 1/2” aluminum plate. There will be an 8” lapping disc that will register on a hub on the wheel. Magnets will hold the disc to the plate.
An adjustable tilt platen will allow for precise angles to grind high speed tool, carbide blades for scraping or brazed carbide cutting tools.
The discs come in grits from 250 to 2,000 grit as far as I know.
There will be an off switch and a forward and reverse switch.
I found the motor after a long search on EBay. It’s new, made in The States and I paid less than $160 delivered, I think. The keyed shaft is 5/8”. I already made the arbor flange to mount the main wheel.
Concentricity is the main focus. I think I have a good plan. We’ll see.
Thank you, Ulma Doc, aka Mike Walton and Donald Yungling for the inspiration.
I’ll post as I make progress.
I made a little progress today.
Sammy, the dog, decided to chew up some sprinkler lines. That took up some time.


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## NCjeeper

Cool project. Can't wait to see it.


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## graham-xrf

We appear to both be hooked on Stefan Gotteswinter's cute tool grinder. My motor is not as butch-looking as yours, and I will be using the 150mm discs.


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## f350ca

You'll end up using it a lot. I made one a while back using his magnet fixing idea. I bought 5 inch disks from China and run it about 300 rpm. I keep the disk wet with kerosine or it plugs up quick, but will wash off again with kerosine. Have heard of using window cleaner as a lube as well.
Moulded inserts sharpened back to the top of the edge radius will skim a thou off as easily as a sharpe HSS cutter.

Greg


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## Weldingrod1

Key trick: Recess the magnets! I had to re-set mine!

Sent from my SM-G892A using Tapatalk


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## Z2V

Looking forward to you progress updates


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## savarin

Have you looked at a gem faceting machine?
Thet have a flat slow platen with an indexable arm to hold the stone, its rotation is indexed and the angle is variable.
It may give some ideas.


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## Janderso

savarin said:


> Have you looked at a gem faceting machine?
> Thet have a flat slow platen with an indexable arm to hold the stone, its rotation is indexed and the angle is variable.
> It may give some ideas.


I’ll check it out


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## Janderso

Weldingrod1 said:


> Key trick: Recess the magnets! I had to re-set mine!
> 
> Sent from my SM-G892A using Tapatalk


That’s the plan.
I was thinking four. I would like to be able to change the discs


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## f350ca

Careful glueing in the magnets, I used epoxy and it must have expanded. Had to grind the magnets down to get them flush.
Greg


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## Janderso

I am thrilled!
I haven’t been all that successful at making concentric arbors or attaching parts to motor shafts that didn’t have some run out.
This baby runs perfect.
I’ll make the pilot/register when the diamond lapping discs arrive.
I still need to drill and tap the flange And mill the magnet pockets.
To be honest, this part was giving me anxiety. I can move on to the frame and platen.


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## pdentrem

f350ca said:


> Careful glueing in the magnets, I used epoxy and it must have expanded. Had to grind the magnets down to get them flush.
> Greg


Put a small hole in the magnet pockets to allow adhesive to bleed out the back.
Pierre


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## Janderso

pdentrem said:


> Put a small hole in the magnet pockets to allow adhesive to bleed out the back.
> Pierre


Oh good idea!


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## Janderso

f350ca said:


> Careful glueing in the magnets, I used epoxy and it must have expanded. Had to grind the magnets down to get them flush.
> Greg


If you used polyurethane glue, I can see this happening for sure.
I’m thinking locktite 603, I think. Whatever I have laying around.
Maybe epoxy is best. The pilot/breather hole should help.


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## Janderso

I decided to use JB weld. This particular product doesn’t expand much and holds extremely 
  well.
It’s an over night epoxy.


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## francist

Interested to see how this works. My experience with JB Weld and strong magnets is that it can produce some unexpected results. The iron powders in the epoxy do interesting things around the magnetic fields (remember school science and iron filings on bar magnets?) and the shape of the cured product can be quite different than what it started out as.


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## DavidR8

Interesting project Jeff. Are you modelling this after something you saw?


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## Janderso

Francist,
Now you have me worried
I checked this morning. All is stable and the magnets work well. It’s 12 hours of curing time.
These are the 6” discs.
Once I add the register it should be fine.
These small magnets pack a pull!. I had a tough time removing the disc.


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## Janderso

DavidR8 said:


> Interesting project Jeff. Are you modelling this after something you saw?


David,
A friend whipped one together for our scraping class, this design is modeled in part, after a design I recently saw.
There are several of these on YouTube that are DIY projects


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## francist

Janderso said:


> Now you have me worried


Sorry, didn’t mean to cause you grief. Looks like you’re good to go, maybe the volume wasn’t sufficient enough to be able move around. I just remember being totally baffled trying to figure out why my epoxy was climbing uphill! Glad it worked for you Jeff


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## Janderso

francist said:


> Sorry, didn’t mean to cause you grief. Looks like you’re good to go, maybe the volume wasn’t sufficient enough to be able move around. I just remember being totally baffled trying to figure out why my epoxy was climbing uphill! Glad it worked for you Jeff


I cut the pockets over sized and left about .010" in depth for epoxy. Between the pocket pilot hole and the sides of the magnet, I hope to have enough holding power for the life of the tool.

Thinking about the table size and the tilting method. I draw it in a doodle first then clean it up.
I call it my CAD program. You know, Conceptualize, Adjust and Dream it up. 
I know there's probably a dozen or more ways to do this. I'm concentrating on the pivot point. My gut tells me it should be just off the face of the disc. Of course the table will be able to slide in and out but I'm designing it with this idea in mind. 
Aluminum and heavy sheet metal.


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## Janderso

I decided to use a piece of .250" structural plate I had laying around for the platen.
I have most of this design in my head. I'll get something done over the weekend, I hope.
Rain on Sunday, that will help.


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## ghack

Nothing new about magnets my old leonard grinder uses magnets to hold the disk. got to be 70 years old.


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## Janderso

Finished the hub and disc plate.
I was shooting for concentric = no wobble.
I think I achieved it. This was challenging for me. I learned a few things. The expanding arbors and turning between centers really has improved my game a bit. IMHO


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## Janderso

Had to take a break. I got in that mood where I tried to get too much done.
A hobby machinist needs to be precise and take his/her time.
I made some mistakes this afternoon. I was surface grinding the platen and moved the wheel in the wrong direction. Ugh, I’ll fix it tomorrow.
The project will recover and the parts will be ok but it’s a good reminder.
I’m learning.


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## Just for fun

It looks real good Jeff,  looking forward to the fineshed product.

Tim


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## DavidR8

Looking really good Jeff. 
Nice work there.


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## Janderso

Cut the bevel and clearance on the table.
I placed the pivot on center line as my little brain conjured.
I’m hoping this allows full motion while maintaining a close fit on the diamond disc. I am planning on having an adjustable frame.


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## Janderso

Sunday was a good day.
We had some rain!! We don't see that anymore. It's going to be another terrible fire year!
Made some good progress today. Haven't set the pins but it is looking good.
Plenty left to do. It feels good to get this far. The rest is fine tuning, allowing for an adjustable platen that locks up solid.
I need to pull out the 12" rotary table to cut the radius for adjustments.
The platen side supports will be mounted on a sliding frame for fine tuning.


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## Janderso

A little progress this weekend.
Mom had a stroke. She is improving.

A friend suggested I add a sheet of stainless to the platen.
With the diamond abrasive it really chews up the aluminum.


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## DavidR8

I hope your mom is doing ok Jeff. 
My mom had a stroke and unfortunately it confined her to bed for the balance of her days.


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## 9t8z28

Subscribed to see more.  I have this on my to-do list.


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## Janderso

Made a little more progress today.
I’m showing my rotary table alignment method. It’s close enough for this operation.
I need a 3.725” radius slot for the table tilt.
It came out perfect.
Now to clean up the edges, Threat each piece as a work of art, then move on to the flywheel pilot bushing, mounting system, housing and electrical.Whew, lots to do yet.
I’m in no hurry.


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## jwmelvin

Looking good. I like the registration tools and features for the rotary table and pallet.


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## DavidR8

The St Patrick's Day bolts are a cool touch 
Looks really good Jeff!


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## Janderso

DavidR8 said:


> The St Patrick's Day bolts are a cool touch
> Looks really good Jeff!


If you have a John Deer tractor dealer near you, check out their bolt selection.
In my farming town, the dealer sells by the pound.
We are talking pennies on the dollar compared to Ace hardware or Home Depot.
Those green bolts are grade 5, the blue ones are grade 8.
I’ll go in and buy dozens of bolts, nuts and washers for less than $10.
It would be $50 anywhere else.


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## Janderso

More progress.
A friend who inspired me to make this cut an access slot to remove the diamond discs.
Very convenient.
Love it when I hit my numbers. Those elusive dimensions are not as difficult as they use to be.


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## Janderso

DavidR8 said:


> I hope your mom is doing ok Jeff.
> My mom had a stroke and unfortunately it confined her to bed for the balance of her days.


Sorry David,
Thank you for asking.
She unfortunately will not be going home.
We are on the hunt for the right assistive living arrangement


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## Janderso

There are plenty of ways to do this and this is my take.
I am choosing to go above the centerline.
I’ve seen similar set ups.
The brass guide can lock into 5,7,10, 20,30 and 45 degrees.


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## rabler

@Janderso, I'm hooked on this idea. Very eager to see how this works out for you.


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## Janderso

rabler said:


> @Janderso, I'm hooked on this idea. Very eager to see how this works out for you.


It's getting to be lots of fun at this point.
I want to be able to slide the table up and back as needed. Maybe 3/8" or so.
I'm thinking of using stout sheet metal. Basically, the table and supports are a contained unit.
The trick is attaching the aluminum to the 1" square tubing I'm using for the side supports.
The sheet metal I'm going to use is 3/16". Pretty stout.
If you guys have some ideas on attaching the aluminum plates to the 1" risers that would be great.
I choke when it comes to creativity.
I was thinking of drilling and tapping 1/4 -20 in the aluminum sides, drilling clearance holes in the 1" tubing. How in the heck am I going to tighten the nuts? =slowly.
The 3/16" plate will be under the 1" tube. I'll weld it.


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## Janderso

I think I got it.
Simple really. Drill and tap the aluminum as discussed.
Drill through the 1” tubing to access allen cap head screws that will fasten the tubes to the side supports.


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## DavidR8

Janderso said:


> I think I got it.
> Simple really. Drill and tap the aluminum as discussed.
> Drill through the 1” tubing to access allen cap head screws that will fasten the tubes to the side supports.


Yup, that's what I was writing


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## rabler

I'll be interested in how you like this for honing HSS tools.  Especially with how easy it is to swap grits.  I don't mind rough grinding on a grinder but honing a fine edge on them is not my forte.  Of course being able to touch up carbide is a nice benefit too!


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## Janderso

rabler said:


> I'll be interested in how you like this for honing HSS tools.  Especially with how easy it is to swap grits.  I don't mind rough grinding on a grinder but honing a fine edge on them is not my forte.  Of course being able to touch up carbide is a nice benefit too!


I think 2,000 grit would put a mirror finish on hss.
You mentioned, easy to swap grits/discs.
In my mind I have two levers that are timed to easily loosen the table, pull it back, swap the discs and Bob’s your Uncle.
We’ll see if I can pull it off.


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## Janderso

I’m still pondering what to do with the inside bolt head. It needs to be self locking.
I should have milled a slot while I had it set up in the rotary table.
The thing about being a dumb ass............
I may put pin locks in the side plates for pre measured angles in the vertical plane.


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## Braeden P

You should Improve it and make it easy to manufacture and has a local shop make them, then sell them because accu-finish stopped making the their carbide hones I think there will be a big market if they cam be under 300 bucks lots of people will buy them, just some thoughts


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## Janderso

Braeden P said:


> You should Improve it and make it easy to manufacture and has a local shop make them, then sell them because accu-finish stopped making the their carbide hones I think there will be a big market if they cam be under 300 bucks lots of people will buy them, just some thoughts


Well let's see, the shop would have to work much faster. At the current pace, I should be lapping/honing by Christmas.
With Accufinish haulting production of the Glendo, surely there has to be a market.
Those things were just cost prohibitive. Kind of like a Biax.
<$300 would involve China or India.


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## rabler

Are the square tubes running the full length there as stiffeners?  I envision doing something like a couple of male dovetail tracks on the top of them, with aluminum uprights slit and clamped, so they could be slid on and off the dovetails.


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## Janderso

rabler said:


> Are the square tubes running the full length there as stiffeners?  I envision doing something like a couple of male dovetail tracks on the top of them, with aluminum uprights slit and clamped, so they could be slid on and off the dovetails.


The aluminum base plate is going to be cut down to size and the 1" tubing has been reduced to 7".
I'm going to add a box (I think) around the motor that will have the reverse switch and on-off.
I have a basic idea in my head. The production environment is a hunt and peck method, based on my limited free time.


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## rabler

Janderso said:


> The production environment is a hunt and peck method, based on my limited free time.


I'm retired, and still suffer from the same limitation.


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## Janderso

Made a little more progress today
Before I go any furthe, I wanted to make sure it does what I want it to do.
I’m pretty happy with it. After using it to sharpen some HSS and carbide tools, I have changed the drip pan design.
There will be a lip in the back of the tray to keep the coolant contained for easy clean up.
Also, I plan on making the motor easily adjustable and easy to remove for cleaning.
Next step, make the pan and start on the adjustable side plate mounts.
Pressed the carriage bolts into the side wings. This way I don’t need to worry about the bolt spinning while I tighten the table thumb/wing nuts.


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## Tim9

Janderso said:


> Had to take a break. I got in that mood where I tried to get too much done.
> A hobby machinist needs to be precise and take his/her time.
> I made some mistakes this afternoon. I was surface grinding the platen and moved the wheel in the wrong direction. Ugh, I’ll fix it tomorrow.
> The project will recover and the parts will be ok but it’s a good reminder.
> I’m learning.


Trying to do too much is my problem too. Plus I’m pretty damned sure that I have a case of attention deficit disorder . It explains a lot about my past behavior. Plus explains all of these 1/2 “ butt” projects that I started but haven’t finished.


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## rabler

Janderso said:


> Before I go any furthe, I wanted to make sure it does what I want it to do.
> I’m pretty happy with it. After using it to sharpen some HSS and carbide tools, I have changed the drip pan design.



How does the HP and RPM combination feel?


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## Janderso

rabler said:


> How does the HP and RPM combination feel?


Good questions.
Plenty of power for what I’ve done so far.
I’ve only used a friends diy Glendo and an Accufinish on scraper carbide blades.
I think it will be just fine.
I plan on adding another table pivot hole on each side so I can use the full diameter of the wheel.
I think a lot of the time I’ll use this free hand to touch up edges of lathe/mill tools.
I have a Baldor tool room grinder but don’t use it much for some reason.
I have a diamond wheel and a green aluminum oxide Wheel mounted right now.


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## rabler

Janderso said:


> Good questions.
> Plenty of power for what I’ve done so far.
> I’ve only used a friends diy Glendo and an Accufinish on scraper carbide blades.
> I think it will be just fine.
> I plan on adding another table pivot hole on each side so I can use the full diameter of the wheel.
> I think a lot of the time I’ll use this free hand to touch up edges of lathe/mill tools.
> I have a Baldor tool room grinder but don’t use it much for some reason.
> I have a diamond wheel and a green aluminum oxide Wheel mounted right now.


I ebay'd a gearbox motor yesterday.  Will be starting a build shortly!  Let me know if you have any thoughts on design improvements as you use it.  Where are you getting the diamond wheels from?


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## Janderso

Rabler,
On design and function, I haven’t used it enough yet to have much input there.
A friend of mine had a slot where the center pivot is. He made changes as he went along and still is.
I chose to put the table pivot above center line as I have seen some do.
When lapping with a 1,500 grit diamond disc, I can’t imagine it would make a difference if the abrasion marks were perpendicular to the part. We’ll see.
I put the stainless sheet on top. Imagine if it was aluminum how it would absorb all the grit.
I may add preset holes for table tilt, 5, 10, 15 degrees.
I will keep posting, a few members are interested.
Did you see Richard King’s post? He asked to see all the DIY carbide lapping machines since Accufinish has discontinued the Glendo design. $1,300-$2,300.
I’ll be in this less than $300


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## Janderso

Made some progress today. So many steps!
The table is now mounted to the aluminum base. I added for .250” forward and backward adjustment.
The stainless side plates facilitate this.
Next step, cut the base to size, mount the motor to the base and clean up edges here and there.
Then, use it for a while to see what I need to add or alter.


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## WobblyHand

This is a very nice build.  Someday I'd like to be able to make a low speed grinder.  Hope to use some of the ideas you have shown here.  In the past I had difficulty understanding how to make the table.  Your pictures make it clearer for me to make some progress.


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## Janderso

Hey made some progress today.
It works great!
I need to make the motor housing that will allow access for the power button and reverse switch.
I Originally started this build to polish/lap scraper blades. The 5 degree angle allows for two cutting edges.
The Sandvik carbide came out great. I still need to grind in the shape with the 600 grit.
WD 40 works great for a lubricant medium.


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## Braeden P

Those sandvik blades are nice I was given one that was already ground on both sides so no I just need to make a holder.


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## Janderso

Braeden P said:


> Those sandvik blades are nice I was given one that was already ground on both sides so no I just need to make a holder.


I bought the Sandvik hand scraping handle and blade before Richard Kings class. If you are going to spend some time hand scraping, you'll want to customize the commercial varieties. Most guys like a handle with a little flex. The belly pad also helps.
I would like to hone my scraping skills before I forget I ever learned how. There is a lot to it!!


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## Janderso

All done.
I've shaped the Sandvik to a 60 degree curve with the 600 grit then polished/honed it with the 1,800 grit.
I use the angle tools in the set I bought. This pic is showing a 4 degree negative angle so I can put two edges on the blade.
This baby is awesome. I'm pretty proud of it.
I had help with the electrical wiring. I'm no electrician.
I think I have about $300 in it.


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## rabler

Nice job.  Hopefully it gives you many years of use.


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## Just for fun

Good looking job Jeff,  congrats on finishing it up!


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## dewbane

Janderso said:


> I found the motor after a long search on EBay. It’s new, made in The States and I paid less than $160 delivered, I think.


Funnily enough, I discovered your project on the same day I got a free random motor. That looks like an excellent machine to use. I've only glanced through the thread at this point, but I like the design, and I feel like I can feel it through my computer screen. It feels crisp, solid, and accurate. You did a nice job on that!

What kind of torque does your 90 RPM motor develop? The data plate on mine is illegible, and I have no clue how fast it turns, but it's probably way too fast. I would have to gear it way down, which would increase the torque considerably. That seems acceptable for something like this. I have a commercial diamond knife grinder whose wheels bog down at the slightest touch, and it would be better with more torque.

I think I have a use in mind for this free motor. Now I just need to source some free metal that's nice and rigid. Well thanks for giving me something to think about, and congratulations on a really nice build!


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## Janderso

dewbane said:


> Funnily enough, I discovered your project on the same day I got a free random motor. That looks like an excellent machine to use. I've only glanced through the thread at this point, but I like the design, and I feel like I can feel it through my computer screen. It feels crisp, solid, and accurate. You did a nice job on that!
> 
> What kind of torque does your 90 RPM motor develop? The data plate on mine is illegible, and I have no clue how fast it turns, but it's probably way too fast. I would have to gear it way down, which would increase the torque considerably. That seems acceptable for something like this. I have a commercial diamond knife grinder whose wheels bog down at the slightest touch, and it would be better with more torque.
> 
> I think I have a use in mind for this free motor. Now I just need to source some free metal that's nice and rigid. Well thanks for giving me something to think about, and congratulations on a really nice build!


Thanks,
I have plenty of torque, no worries there.
The table pulls back for access to change discs. I think I added four magnets, you only need two. The register is snug so they don’t move at all on the flywheel.
It’s great for touching up carbide lathe tools and honing to a super sharp edge.
I’m very happy with it.


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## dewbane

Janderso said:


> I have plenty of torque, no worries there.


My question about torque was more on the lines of ensuring I have enough torque. Anything I build will be a ghetto version of yours. I want to make sure it has a useful amount of torque. I will have to make mine out of table scraps, rejects, and dumpster finds, unless my employer actually gives me a 212% raise so I can keep up with inflation.


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## OCJohn

Jeff, I'm not seeing registration holes on your disc like Stefan Gotteswinter uses. Do you find your magnets are enough to keep the disc from spinning on the platen? (Are you using double sided discs? I assume that would help as well...) I hope that's the case. Seems like a PITA to have to drill the discs before they can be used...


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## Janderso

dewbane said:


> My question about torque was more on the lines of ensuring I have enough torque. Anything I build will be a ghetto version of yours. I want to make sure it has a useful amount of torque. I will have to make mine out of table scraps, rejects, and dumpster finds, unless my employer actually gives me a 212% raise so I can keep up with inflation.


Boy, no kidding about inflation.
I think about relative cost vs. income.
Example, I was making $36,000 a year in 1987. We bought our first home for $91,000. Nice 3 bed. Two bath with almost an acre in the foothills of Northern Ca.
I retired last year making about $105,000.
That same home is available for $560,000.

Look at the number of years it would take to pay off the house with full gross earnings.
Something is broken.
Gas, food, housing, taxes,…….

Tell me about your motor.


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## dewbane

Janderso said:


> Something is broken.
> Gas, food, housing, taxes,…….
> 
> Tell me about your motor.


I'm not really given to conspiracy thinking, but the one thing whose price has remained pretty level is liquor. I admit, that makes me suspicious.

As to the motor, there isn't much to tell at this point. It's a standard induction motor of some unknown horsepower that may or may not be wired for 110V operation, with about a 5/8" shaft. The data plate is all scuffed off, and it has a bunch of wires hanging off of it, and a giant capacitor that is attached to one, but not two wires. The first puzzle is figuring out which other wire attaches to the capacitor.

A buddy of mine just showed up at random and handed it to me yesterday.


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## Weldingrod1

One important tip: recess your magnets into you backing plate.

Sent from my SM-G715A using Tapatalk


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## Janderso

dewbane said:


> I'm not really given to conspiracy thinking, but the one thing whose price has remained pretty level is liquor. I admit, that makes me suspicious.
> 
> As to the motor, there isn't much to tell at this point. It's a standard induction motor of some unknown horsepower that may or may not be wired for 110V operation, with about a 5/8" shaft. The data plate is all scuffed off, and it has a bunch of wires hanging off of it, and a giant capacitor that is attached to one, but not two wires. The first puzzle is figuring out which other wire attaches to the capacitor.
> 
> A buddy of mine just showed up at random and handed it to me yesterday.
> 
> View attachment 417333


I don't see the RPM.
If it's 1,750, you put a 2" pully on the motor and a 4" pulley on your spindle you can slow it down to 875 RPM.
That's still pretty fast.


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## Janderso

I paid $170 for this motor on ebay,
Bison 014-242-9019 gearmotor 90 rpm, 1/6 hp 115v ac.
Sold by -Nri-Industrial

Maybe they have more?
It's a great motor for this application imho.
Some may say it's too big, too expensive, too heavy.
It works great though.


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## dewbane

Janderso said:


> I paid $170 for this motor on ebay,


That motor goes for $775 new. Wowww. You got it so cheap yours must have a ton of hours on it, or someone hijacked a truck, or got caught cheating on a vindictive spouse.  

All the more reason why I should try to do something with my dumpster find. Even if I have to do multiple pulleys, like a drill press.


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## Janderso

dewbane said:


> That motor goes for $775 new. Wowww. You got it so cheap yours must have a ton of hours on it, or someone hijacked a truck, or got caught cheating on a vindictive spouse.
> 
> All the more reason why I should try to do something with my dumpster find. Even if I have to do multiple pulleys, like a drill press.


I don’t know why it was so cheap. It was new.
$775??? Holy schnikies


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## dewbane

Janderso said:


> I don’t know why it was so cheap. It was new.
> $775??? Holy schnikies


Yeah, that's what I said. Galco has it for $748. Zoro for $775. BDI for $740. I've never dealt with any of these suppliers, but $700+ seems like a reasonable price for a Bison 014-242-9019.

On the other hand, it was probably $350 two years ago, and somebody sold it for half of that price. That actually does seem plausible.

You got an extremely good deal on that motor!


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## Janderso

dewbane said:


> Yeah, that's what I said. Galco has it for $748. Zoro for $775. BDI for $740. I've never dealt with any of these suppliers, but $700+ seems like a reasonable price for a Bison 014-242-9019.
> 
> On the other hand, it was probably $350 two years ago, and somebody sold it for half of that price. That actually does seem plausible.
> 
> You got an extremely good deal on that motor!


I wasn’t aware of this until now.
That’s a lot of money man.


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## Janderso

DavidR8 said:


> The St Patrick's Day bolts are a cool touch
> Looks really good Jeff!


I just reread this. Green bolts, now I get it


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## brino

Hey Jeff,

Back in post #69 on page 7, @OCJohn asked the same thing I was wondering:


OCJohn said:


> Jeff, I'm not seeing registration holes on your disc like Stefan Gotteswinter uses. Do you find your magnets are enough to keep the disc from spinning on the platen? (Are you using double sided discs? I assume that would help as well...) I hope that's the case. Seems like a PITA to have to drill the discs before they can be used...



Thanks,
Brian


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## Janderso

brino said:


> Hey Jeff,
> 
> Back in post #69 on page 7, @OCJohn asked the same thing I was wondering:
> 
> 
> Thanks,
> Brian


I have four rare earth magnets 
It is rock solid.


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## brino

Thanks Jeff!


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## homebrewed

This is a good thread, thanks for sharing your work!

Here's a 0-90RPM gear motor for $99.  Nice with the speed controller, but it would need a different mounting system.  More like a stepper.

Speaking of steppers, I've been using a "spare" stepper motor + driver for a similar application (but not implemented nearly as well).  I'm generating the step pulses using a 555 timer circuit I built for the purpose.  But all the pieces now would cost more than $99, especially if you have to buy a power supply for it.  On the flip side you would get a _lot_ more flexibility in terms of the RPM range.

I've used 4,000 grit diamond to hone carbide scrapers.  It produces a mirror finish on the scraper.  Too bad my scraping results don't "reflect" the tool


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## Boxless

Janderso said:


> I have four rare earth magnets
> It is rock solid.


How does the runout perform when you switch from one grit coarseness disk to another? Still good?

Cool project BTW.


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## Janderso

Boxless said:


> How does the runout perform when you switch from one grit coarseness disk to another? Still good?
> 
> Cool project BTW.


Yeah, no difference


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## Janderso

homebrewed said:


> This is a good thread, thanks for sharing your work!
> 
> Here's a 0-90RPM gear motor for $99.  Nice with the speed controller, but it would need a different mounting system.  More like a stepper.
> 
> Speaking of steppers, I've been using a "spare" stepper motor + driver for a similar application (but not implemented nearly as well).  I'm generating the step pulses using a 555 timer circuit I built for the purpose.  But all the pieces now would cost more than $99, especially if you have to buy a power supply for it.  On the flip side you would get a _lot_ more flexibility in terms of the RPM range.
> 
> I've used 4,000 grit diamond to hone carbide scrapers.  It produces a mirror finish on the scraper.  Too bad my scraping results don't "reflect" the tool


I just saw this.
Way over my head.
4,000 grit aught to put a mirror finish on those blades


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## Boxless

Janderso said:


> Yeah, no difference


Great. I think I might try something like this. Thanks!


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## Boxless

Janderso, My project is slow moving, but I bought an aluminum disk for my project and I'm starting to think about how to affix that disk to my arbor. I have a couple questions about what you did.

First, I can see the key on your motor shaft and the associated slot in the hub you made, but I cannot see how you held the hub onto the shaft. I'm assuming there's a setscrew hiding on the back side of the hub that just never showed up in any of the pics?







And second, about the screws you used to clamp the disk to the hub... It looks like you threaded both the hub and the disk? In this pic, there are threads below the countersink?





Did you ream the threads out of the aluminum disk when you were done?


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## Janderso

Boxless said:


> Janderso, My project is slow moving, but I bought an aluminum disk for my project and I'm starting to think about how to affix that disk to my arbor. I have a couple questions about what you did.
> 
> First, I can see the key on your motor shaft and the associated slot in the hub you made, but I cannot see how you held the hub onto the shaft. I'm assuming there's a setscrew hiding on the back side of the hub that just never showed up in any of the pics?
> 
> 
> 
> 
> 
> 
> And second, about the screws you used to clamp the disk to the hub... It looks like you threaded both the hub and the disk? In this pic, there are threads below the countersink?
> 
> 
> 
> 
> 
> Did you ream the threads out of the aluminum disk when you were done?


I used a set screw on the keyed coupling. I made sure I had a tight fit for accuracy, it probably didn't need the set screw.
No, no reaming.
As said before, the slow speed output is the tough part. Trying not to break the bank.


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## Boxless

Thanks again. As for the speed, my (potentially flawed) plan is to use a DC motor to drive a belt coupled grinder arbor.


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## Harry Knutz

dewbane said:


> I'm not really given to conspiracy thinking, but the one thing whose price has remained pretty level is liquor. I admit, that makes me suspicious.
> 
> As to the motor, there isn't much to tell at this point. It's a standard induction motor of some unknown horsepower that may or may not be wired for 110V operation, with about a 5/8" shaft. The data plate is all scuffed off, and it has a bunch of wires hanging off of it, and a giant capacitor that is attached to one, but not two wires. The first puzzle is figuring out which other wire attaches to the capacitor.
> 
> A buddy of mine just showed up at random and handed it to me yesterday.
> 
> View attachment 417333


That looks a lot like a swamp cooler motor?


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