grinding machine rings made of derlin (Polyoxymethylene)

[Robert1998]

Hi everyone. I have a grinding machine with a shaft of 12,7mm. The problem is that I want to put in it a Norton grinding wheel and its inner diameter is 32 mm. I can´t find rings for that reduction so I have thought about making them with derlin with my lathe.

Is it safe? I think the reduction ring doesn´t suffer great forces, but I´d like to be sure about that

What do you think?

Thank you

Best regards

 

[timgunn1962]

I've had grinding wheels supplied with plastic reducing bushes before (some kind of black plastic). They just worked.

I'd not expect a problem with Delrin.

 

[Lewis_RX8]

should be fine , If off center a little just true up with a grinding wheel dresser and it'll round itelf , until you unclamp it that is

 

[brightspark]

the reducers just center the wheel its the side cups that grip it

 

[Robert1998]

Thank you for your answers!

 

[Pete.]

Fine to use but make sure it's a slip-fit in the centre. If you can't push it in with your fingers then turn it smaller. I once made one that was a slightly snug fit so I tapped it in with a small hammer and the wheel cracked into three pieces. I was shocked at how little force it took.

 

[ukracer]

If using a lathe why would you not use aluminium?

 

[timgunn1962]

If it's just a spacer, why not just use whatever is to hand? In the OP's case, Delrin was presumably to hand and Aluminium probably wasn't?

Hate to be a pedant, but the side cups AND BLOTTERS are what grip the wheel. The blotters are the "blotting-paper" discs fit between the wheel and the cup to conform to the irregular surface of the wheel and distribute the load over an area, rather than only over the few high-spots where the grit contacts the cups. They are important for safety. Don't forget/ignore them. For the guys who know, this may be too obvious to mention. For those who don't, it may not be obvious at all.

 

[Maker]

blotting-paper

Aka cereal box.

 

[ukracer]

If it's just a spacer, why not just use whatever is to hand? In the OP's case, Delrin was presumably to hand and Aluminium probably wasn't?

Hate to be a pedant, but the side cups AND BLOTTERS are what grip the wheel. The blotters are the "blotting-paper" discs fit between the wheel and the cup to conform to the irregular surface of the wheel and distribute the load over an area, rather than only over the few high-spots where the grit contacts the cups. They are important for safety. Don't forget/ignore them. For the guys who know, this may be too obvious to mention. For those who don't, it may not be obvious at all.

I was more interested in if there was a "physical" reason not to use Aluminium.
I am sure someone in the know would reply if it was a bad idea.
In my case I would have Aluminium to hand but not DeLeon. (Hence my question.)

 

[brightspark]

If using a lathe why would you not use aluminium?

no need. the ones you buy are just plastic disks. its only to center them . if u only have aluminium to hand and like spending extra time messing on with it fair enough

 

[Robert1998]

Hi. Thanks for your answers.

I have made it from derlin and it works great. I don´t have aluminium in that size.

And yes, I keep the paper disk in the sides. I have a lot of respect for the grindind machine (I don´t know if in english this sentence makes sense).

 

[123hotchef]

If it's just a spacer, why not just use whatever is to hand? In the OP's case, Delrin was presumably to hand and Aluminium probably wasn't?

Hate to be a pedant, but the side cups AND BLOTTERS are what grip the wheel. The blotters are the "blotting-paper" discs fit between the wheel and the cup to conform to the irregular surface of the wheel and distribute the load over an area, rather than only over the few high-spots where the grit contacts the cups. They are important for safety. Don't forget/ignore them. For the guys who know, this may be too obvious to mention. For those who don't, it may not be obvious at all.

Thanks i never knew that about the paper

 

[Agroshield]

Thanks I never knew that about the paper

For info.:

Blotters - A Lasting Impression

Learn how to use blotters to check the state of your flanges based on contact, pressure and movement.

www.nortonabrasives.com

http://www.nortonabrasives.com/sga-common/files/document/Safety-BlotterSizeVersusFlangeSize-Norton.pdf

 

[123hotchef]

For info.:

Blotters - A Lasting Impression

Learn how to use blotters to check the state of your flanges based on contact, pressure and movement.

www.nortonabrasives.com

http://www.nortonabrasives.com/sga-common/files/document/Safety-BlotterSizeVersusFlangeSize-Norton.pdf

thats good reading. Can one purchase these blotters for grinding wheels?

 

[Brad93]

If using a lathe why would you not use aluminium?

Fretting on the shaft they quickly wear and gall

 

[Agroshield]

...Can one purchase these blotters for grinding wheels?

Just to do the recursion - see recursion thing, see:

Grinding wheel blotters

Anyone know where you can get hold of replacement paper washers for Grinding Wheels, aka Blotters?

www.mig-welding.co.uk

 

[brightspark]

a cornflake or rice crispies packet makes them quite nicely