Grinding wheel arbour

[Paul LousickParticipant @paullousick59116]

I would like to easily change the wheels on a grinder without having to balance and dress them each time and would like to mount the wheel on a steel arbour with a taper bore. Similar to that used on a Deckel D-bit grinder.

Does anyone have a drawing of the arbour ?

Paul.

[Paul LousickParticipant @paullousick59116]

[old martParticipant @oldmart]

Grinding wheels are normally held between plates with blotting paper or thin cardboard to protect them. It could be risky to have the centres located on a taper which would tend to put radial forces on the bore. A possible work round for repeatable concentricity might be a centre bush glued in with epoxy which is square to the wheel and a sliding fit on the shaft. The plates and cardboard would still be required, but the dressing each time would be minimised. A separate arbor for each wheel could be made if the bores of the wheels are big enough and the arbors held the wheels safely. How would the taper be broken when changing the wheel / arbor assembly?

[Keith LongParticipant @keithlong89920]

Paul I can't help with details of the Deckel spindle but you might get some ideas if you do a search for "Sopko grinding wheel adaptors". These are a hub unit that the wheel is mounted on and then the hub and wheel assembly is fitted to the spindle by tapers, plain shaft – whatever. The hubs for tapers usually have provision for a removal puller to be attached so that all removal forces are applied to the hub not to the wheel. McMaster Carr have them listed at around the 70$ mark so quite pricey but not ridiculously so, which suggests that they are a commonly used item. The ideas in them should be relatively reproducible for your own version.

[Clive FosterParticipant @clivefoster55965]

Paul

I doubt that an ordinary grinder would be sufficiently accurate to properly exploit an arbor system and some dressing would still be needed.

Looked into something similar with my Clarkson and eventually decided to pay careful attention to the adapter bush sizing and clamp washer accuracy. Clamp washers with mine were pressed rather than turned so possibly less than ideal. Since making new washers and ensuring that adapter bushes are nice fit on the spindle I've found that only minimal dressing, if any is needed. So far no issues with balance but that may be because I buy at least mid range wheels from known brands which seem to be pretty well balanced when made.

I'm scaredy-cat when it comes to grinding wheels so cheap and bargain wheels aren't on the menu. Never had one blow up on me, yet, and I'd prefer to keep the winning streak running.

Given a decent fit as standard I think you are better off making mechanical arrangements for fast, accurate dressing.

Clive

[David Davies 8Participant @daviddavies8]

Paul

if you search YouTube for Stefan Gotteswinter he has uploaded two videos on making slave hubs for grinding wheels to suit his Deckel clone. They may not have all the dimensions you need but may give you inspiration.

hth

Dave

[Pete RimmerParticipant @peterimmer30576]

The actual taper is largely inconsequential just make it steep enough so it's not self-locking (which is about 7 degrees IIRC). About 20 degrees will do it. Also the shallower the taper the more care you need to make sure it doesn't seat too shallow or deep on the machine.

What I strongly suggest is that you make a gauge master so that you can replicate the wheel hubs later if needed. Turn some press-fit adapters for the grinder and a master on the same lathe taper setting.

[David George 1Participant @davidgeorge1]

most surface grinders have an arbour to mount the grinding wheel on. They are mounted on a taper with a screw flange the same diameter as the paper washer to grip the wheel and a nut on the shaft to hold the arbour on to the shaft. I don't see why that system couldn't be used on any grinder as long as the shaft was substantial enough. then you can change wheels for different jobs at will.

David

[Paul LousickParticipant @paullousick59116]

Thanks for your response.

Just to clarify a few points:

Yes, I do know that the wheels are clamped between 2 pieces of paper and that they have to be dressed to make them concentric as the wheel hole is not that accurate and that the spindle on a standard grinder is also not that accurate. Which is why the wheels are mounted on a metal adaptor and then only need a slight dressing of the wheel.

A separate adaptor/arbour is required for each wheel and is located by a taper onto the motor shaft. The parallel shaft would have to be ground for a mating taper. I believe that a short morse taper is used on some grinders.

The Deckel grinder also has a jacking screw arrangement in the wheel adaptor for removing the wheels, which is the type of information I am seeking. (why re-invent the wheel).

Thanks Keith for suggesting Sopko wheel adaptors. **LINK**

Cheers, Paul

[Mark RandParticipant @markrand96270]

I don't have drawings for you, but the Sopko site does give a good idea of what you want to make.The 15° included taper on my Jones & Shipman grinder is a locking taper to the extent that I need either the jacking screw or a gentle rap on the back of the wheel to get the wheels off (bit of wood or even knuckles will do it usually).

One thing to bear in mind is to have left handed threads on the left wheel spindle and right handed threads on the right wheel spindle to prevent the nuts from loosening with vibration. This should already be the case with the current mounting nuts. That would make the arbours non-interchangeable from left to right sides of the grinder.

To get around any concerns about repeatability on the not-quite-precision spindles, there's nothing to stop you having an axial alignment pin or similar at the inboard end of the spindle tapers and a matching hole on the arbour flanges,

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