Mounting white oxide wheels on an arbor

[chucketn]

I’m building a belt driven arbor for two white aluminum oxide wheels. The arbor will have a 1/2 “ shaft in ball bearing pillow blocks. The wheels have a 7/16”mounting hole. I will turn 7/16” x 20 tpi., left and right hand threads on the shaft. My current dilemma is how to make the cup washers for the wheels. I have some 6061 aluminum bar ends, will that be sufficient? I plan to face the end, and cut a relief about 1/16” deep for ½ the diameter, leaving a face at the inner and outer diameters, and part off at 3/16” thick. I will then mount the washers on an arbor and face the other side. What do you all think?
Chuck

 

[Dave G]

Hi Chuck, you didn't say what size wheels you are using so I will make some assumptions. Your idea for washers should be fine, just make them thick enough so they won't distort when tightening. Proper practice is to place paper blotters between the washers and the wheel on both sides. These can be made from thick paper or thin cardboard.

Make sure you ring the wheels before installing them. If you take the wheels off for some reason rering them before remounting. They should be lightly tapped with a wood handle, if the wheel rings then it is good to use, if the sound is muffled or dead discard the wheel by breaking into little pieces with a hammer. Cover the wheel with a rag before breaking to prevent flying debris. Be aware of the max rated speed for the wheels you are using and don't exceed.

My experience with grinding comes from working in a bearing factory for 30 yrs. I have seen many grinding wheel accidents and wish to see no more. I suggest making wheel guards, when a wheel explodes it is catastrophic. Stand to the side when powering up and when using the wheel. If you damage the wheel in any way discard it. Our bosses had no problem with us discarding wheels if they were suspect. Alot easier and cheaper than filling out accident reports. Wear your safety equiptment and don't be distracted when a wheel is running. I don't mean to preach but I have been taken to the ER to get stitched up from a grinding wheel. Dave

By the way, I got stitched up by a Dr Payne, go figure.

 

[MachineTom]

There are charts the show the correct size collars for mounting X size wheels. If you make the collars somewhat smaller than the blotters, say 1/4 in in 3" for will be fine. I would not use AL collars, I've not ever seen a grinder with AL collars. In the shop are 4 grinders of different sizes, none have AL collars even the one from HF.

Go to Nortons website and look at the spec's for collars.

 

[chucketn]

Machine Tom, I don't find any info on collars on the Norton website. Is it in one of their downloadable .pdf's?
Do you have a link?

Chuck

 

[kuhncw]

Hi Tom,

Why wouldn't you use aluminum for collars on a grinding wheel?

I usually see steel collars also, but suspect that is because steel is less costly and because in the case of common bench grinders, the collars are usually stamped.

I'd think an aluminum collar would work fine, assuming it was thick enough not to deform easily.

Regards,

Chuck Kuhn

 

[MachineTom]

There are PDF's aplenty on the Norton site, just have to look. I had looked for spacers suggestion for my CG and found that even a spacer should be made of steel. The MHB states that collars/Flanges should be no less that 1/3 wheel D and no more than 1/2 D of the mounted wheel, also stated is the flanges should be relieved to give annular contact.

My examples, the 7" SG has a flange D of 3" and the CG has 5" flanges on a 10" wheel, 6" tool grinder 2 1/2 D. these are 1/2hp motors, except the CG which is 1 1/2hp. Toolpost 1/3 hp 1 1/2 flange on a 3" wheel.

I suspect the AL will deform when the spindle nut is tightened.

 

[kuhncw]

Hi Tom,

Thanks for the information on flange sizes.

I think deformation is the point. I feel either aluminum or steel flanges could be used if the aluminum part was thick enough to allow proper torque on the spindle nut.

I agree, steel is best, but in Chuck's (in E TN) case he has the aluminum and this is a home shop application.

I'll leave it at that.

Regards,

Chuck Kuhn