# Grinding Wheel Adapter(s)



## RobinHood (Oct 13, 2018)

My surface grinder came with just one wheel adapter. It has no provision for static balancing. I want to be able to balance. After watching Steve Summers and Stefan Gotteswinter make their own, I decided to give it a shot myself. I figured I would start with the easy parts first and work myself up.... Here is the result:

a) Locking Ring







This was made out of some 4140. I made a thread gauge for the 1 1/4"-16tpi LH internal thread first; the specs for it came out of the Machinery's Handbook (left pic, background). Then I cut the thread in the ring (right pic) and used the gauge to check fit.

b) Anti-Rotation Washer










This is made from 50 thou sheet stock. I used a hole saw on the mill to cut the rough shape. The ID was machined in the lathe to accept an arbour to then hold it for OD machining (left pic) and centering on the rotary table on the mill for the next step. I used a 1/8" end mill with the appropriate step-over to create the required final 1 1/4" ID with two tabs (center pic). Stefan used a TIG welder to attach the "ears". Steve did all the work with a dremel and files. I cut the little "washer" that was left out with a cut off disc in the dremel and filed the tabs to final size (right pic).

c) Balance Rings







These are made from 1/4" hot rolled plate I had on hand. The process is much like the anti-rotation washers: hole saw, ID and OD work on the lathe, and the rotary table to cut out the 270* sector on one side. I then drilled and tapped a hole from OD through to the ID (approximately where the "F" is) to accept a little set screw to allow the ring to be locked on the rear shoulder of the main body. Two of these balance rings are used in conjunction to statically balance a mounted grinding wheel. (right pic; you can just see the set screw hole).

d) Main Body
















The main body is made from a junk of mystery metal (left pic, bottom center). It has 1 1/4"-16 LH OD threads on the nose and 1"-16 RH ID threads to use a removal tool to get it off the spindle arbour (2nd pic from left). There is an internal thread relief groove behind them. It also has a 1 1/4" ground surface for the grinding wheel to sit on and a ground rear flange for the wheel to butt up against. From the rear side, there is a 3" per foot ground taper, which is center relieved (middle pic). The internal taper was finish ground using the tool post grinder and the taper attachment on the lathe. The internal features required some special tools which were not on hand. I made them from broken HSS speciality drill bits used in cabinet making. The profiles were formed on the tool and cutter grinder (last two pics).








Here is how I ground the flange face and wheel seat using the surface grinder and the cylindrical grinding attachment





Finishing off the main body (milling the anti-rotation groves and pin holes) using the dividing head on the mill. The body was mounted on the previously made balancing arbour











All done and wheel mounted ready for static balancing. (pics l-r: overview, front, rear)

None of the items are hardened. I have no real good way to do it. Would be a good challenge though.

Now to make at least four more...


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## CalgaryPT (Oct 13, 2018)

You get bonus point for great pics.


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## Everett (Oct 13, 2018)

Very cool work.  x2 for the photo documentation.


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## Dabbler (Oct 14, 2018)

very nice work!


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## LenVW (May 27, 2022)

You should get a instructor’s position at a training center !!
Excellent explanation of the details and manufacturing process.

I especially like your explanation of the two balancing rings.
See - Photo (c)
By rotating the balancing rings, your can fine tune the weight distribution precisely.


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## RobinHood (May 27, 2022)

Thanks for the compliment Len. I was a flight training instructor a long time ago - perhaps that is where that comes from…

I saw the balance ring idea online somewhere. It made sense to me and it does not involve “nibbling” away at the wheel. So I went with it.

There are of course other ways to balance a wheel/adapter assembly which work equally well.


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## Susquatch (May 27, 2022)

RobinHood said:


> My surface grinder came with just one wheel adapter. It has no provision for static balancing. I want to be able to balance. After watching Steve Summers and Stefan Gotteswinter make their own, I decided to give it a shot myself. I figured I would start with the easy parts first and work myself up....  ID with two tabs (center pic). .
> .........
> Now to make at least four more...



Awesome post! No idea why I didn't see it before creating my thread. I love many of your ideas. I especially love the photos and the explanations. I'll be borrowing some of them for sure.

How to make the washer without welding was a big one.

What are the Clamps you used on your rotary table? I've seen some like that at KBC and wanted to try them but they were a lot of money and I never pressed buy. Not sure they are even still in my shopping cart. I can't really make out the name on them in your photo...... 

You adopted the Sopko balancing approach. I like that too. It's especially nice to keep the grinding grit out. If I go that way, I'm thinking about making them integral to the back plate of the adapter. Of course, I'd like to do that no matter what way I actually go. 

Did you ever make 4 more?


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## LenVW (May 27, 2022)

@RobinHood - has shown a way of overcoming a dilemma associated with a precision operation. 
Just a fine example of passing on knowledge for more people to make use of . . . KUDOS to you Sir !!


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## RobinHood (May 27, 2022)

Susquatch said:


> What are the Clamps you used on your rotary table?



They are MightyBite hold down clamps. If they were not included with my BP mill, I would most likely not have gotten them either. They are, as you have discovered, pricey.

I have all the accessories for four more (washers, lock nut, and balance rings)… but not yet the main adapter bodies. The drawings are hanging from my to do board… I just have to make them… right after all the other “fires” are put out…


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## RobinHood (May 27, 2022)

LenVW said:


> @RobinHood - has shown a way of overcoming a dilemma associated with a precision operation.
> Just a fine example of passing on knowledge for more people to make use of . . . KUDOS to you Sir !!


Thanks Len!


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## PeterT (May 27, 2022)

RobinHood said:


> They are MightyBite hold down clamps. If they were not included with my BP mill, I would most likely not have gotten them either


I have the same ones & agree on price. I use them to clamp my RT onto mill table & not much else. I always assumed these would be easy to shop make once I got a close look at them, but easy is a relative word. A feature of how they work to clamp at varying heights is the curve profile of the nose & heel so tangent contact. Also asymmetrical. Not a particularly easy profile to mill. Could be water/laser cut but they are what 0.75" wide? Then you have to bill the center half-circle recess for the matching semi-circle clamp nut. And under that an elongated longitudinal slot to accommodate the stud at various angles. I guess that's why they are probably cast.





__





						BESSEY,500L BESSEY HOLD DOWN CLAMPING SYSTEM,1-820B-050,KBC Tools & Machinery
					

BESSEY,500L BESSEY HOLD DOWN CLAMPING SYSTEM,1-820B-050,KBC Tools & Machinery




					www.kbctools.ca


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## Susquatch (May 27, 2022)

PeterT said:


> I have the same ones & agree on price. I use them to clamp my RT onto mill table & not much else. I always assumed these would be easy to shop make once I got a close look at them, but easy is a relative word. A feature of how they work to clamp at varying heights is the curve profile of the nose & heel so tangent contact. Also asymmetrical. Not a particularly easy profile to mill. Could be water/laser cut but they are what 0.75" wide? Then you have to bill the center half-circle recess for the matching semi-circle clamp nut. And under that an elongated longitudinal slot to accommodate the stud at various angles. I guess that's why they are probably cast.
> 
> 
> 
> ...



Yup, the ones in my cart are Bessy Clamps. Lotta money though. So many other things I'd rather have at that price. 

Anybody ever see these (or a copy) on Ali?


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## Dabbler (May 27, 2022)

I have a pair of genuine Bessy and a pair of offshore I bought 20 - 25 years ago.  The offshore ones were still over 30$ for the pair. There is a fair amount of work in them, but the body is soft cast steel, so they can be made from fairly inexpensive materials.  A bit of work, but fairly easy to do with a mill.


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## Susquatch (May 28, 2022)

Dabbler said:


> A bit of work, but fairly easy to do with a mill.



Your skill set exceeds mine by several orders of magnitude. 

Too many other priorities. Maybe someday. For now I think stacked blocks will have to do. 

Maybe something will show up on Kijiji.


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## Proxule (May 28, 2022)

A work of art, Nice work!!


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## Dabbler (May 28, 2022)

-- I saw them in person yesterday, and work @RobinHood did is very impressive.  Now I know why the Sopko adapters are so expensive.  There is a LOT of work in them.


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