Universal D-bit grinder (Deckel clone) spindle question

[durableoreo]

Trying to figure out how to mount wheels on a D-bit grinder. The shaft is straight, not tapered.

First, is this a real problem? The included cheap-o diamond wheel has radial slop on the arbor of +/- 0.002. The spindle itself, even with the belt on and turning it by hand, has TIR of a few tenths. And when I lean on the spindle, it flexes about 5 tenths.

What's a fix? Should I purchase a new grinder from Shars?

Maybe I could make straight adapters but mark the hub and arbor. If I lap the hubs to a close fit and mount them with the same clocking each time, wouldn't that solve my problem?

 

[benmychree]

Radial slop (clearance) on the arbor should make no difference in operation, the only thing that matters is runout on the face of the wheel.

 

[C-Bag]

The shaft is straight, not tapered.

This makes no sense. AFIK the clones(which I have one) all have a tapered shaft. That’s what the adapter mounts to.

Do you think you’ve got the adapter off?

It would be great to see a pic.

 

[durableoreo]

kes no sense. AFIK the clones(which I have one) all have a tapered shaft. That’s what the adapter mounts to.

Do you think you’ve got the adapter off?

Yeah, that's what I thought. Never imagined I'd get bamboozled on such a basic feature.

You asked for pictures. Here's the big-picture view of the machine, to get yourself oriented.


Here's the end of the arbor. I've had this in and out of the machine and it looks like that pulley is pressed on the shaft. There's a nut and spacer that come with the kit.


I measured the shaft at both ends and found very little variation.



Here's a photo with the diamond wheel on. Both wheels are a loose running fit on the arbor.


There is a small hole in the end of the arbor. I poked around in there and came to the conclusion that it's just a hole for a center. It's not large enough to get a hex key in there...

 

[durableoreo]

Radial slop (clearance) on the arbor should make no difference in operation, the only thing that matters is runout on the face of the wheel.

Right. But even so, I don't want to measure or fuss with the run-out every time I change the wheel. Is there any other solution other than interchangeable wheel adapters?

Also, I did run a little test today. My wheel is +/- 0.002 and it is noticeable. There's a pattern in the grinding sounds. Sure, it cuts. Maybe that's OK for most people. But I'd like to hear from someone who knows what is typically considered acceptable.

 

[durableoreo]

benmychree, I misread your comment. Yes, when I use a face wheel, it will not be a problem. That will be the majority of the time, I suppose. But when I'm using a cutoff wheel...

 

[durableoreo]

What to do?

I'm still not sure if this is a problem that needs solving. Do other D-bit grinders have tapered a shaft?

 

[pontiac428]

Mine has a tapered shaft and uses 1.25" hubs. Vitreous wheels take some dressing to true up, and CBN et al. are a (fairly) precision fit, but once dressed and mounted they can be removed and switched without re-dressing. I don't imagine that a straight shaft will be so user friendly. If one were to feel in a bind over the limitation, I would think that turning a new, tapered spindle shaft for the grinder could be a possibility.

 

[sdelivery]

When working on the face, radial runout of a few thousands is irrelevant to the process.

 

[durableoreo]

After thinking about it for too long, I decided to buy the Shars unit. I already have so many projects. I could probably take apart the spindle and figure out how to grind the right taper... but maybe not.

It was an expensive mistake, for sure.

I contacted the seller to see if we can come to some kind of understanding. I don't have much of a leg to stand on because I purchased it 8 months ago, completely disassembled the machine, and then started complaining.