Wheel Dressing

This topic has 7 replies, 6 voices, and was last updated 8 September 2011 at 07:03 by Nicholas Farr.

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6 September 2011 at 15:26 #5646
Old Elan
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@oldelan
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6 September 2011 at 15:26 #74560
Old Elan
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@oldelan
I’ve searched in the normal places but can’t find much on how and what tool to use for dressing off hand grinder wheels.

There seems to be three types of dresser. The ‘old fashoned’ wheel type, the diamond point and the diamond encrusted bar on a handle.

Which is best and what is the correct way to use them?
6 September 2011 at 15:46 #74562
alan frost
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@alanfrost17805
Never used wheel types but they look hopeless. A non-diamond dressing stick is cheap and will dress the wheel quickly and sufficiently for 90% of the times you need to dress the wheel. I’ve never as aspired to anything with a diamond encrusted bar although I like most bars .

You’ll need a diamond point for the odd 10% of your dressing needs—Hmnnn–diamond encrusted bars—we used to dream about those.
6 September 2011 at 16:01 #74565
Clive Hartland
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@clivehartland94829
The ‘Star wheel’ type dresser is a must for breaking the glaze on a carborundum wheel.

Run it across the face of the wheel and it will break the matrix and expose new cutting edges of abrasive.

Diamond tools are for forming shaped wheels basically or trueing the wheel.

Lots of dust from the star dresser so be careful. You may need to press a bit hard to get it to work properly.

White wheels I dress with the diamond, particularly if they are for endmill and precision drill sharpening. ie. 4 facet.

Not many people know how to use them anyway!

Clive
6 September 2011 at 16:21 #74568
Nigel Parkinson
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@nigelparkinson39932
There are two activities which re often confused under the term dressing.

The first activity is trueing. This is done when the wheel is mounted- both before and after balancing and in service if the wheel needs to be re-shaped-for example in thread or form grinding. Off-hand grinders do not normally get trued.

The second activity is dressing. This either breaks up the glazed surface of the wheel and exposes new cutting grains, or more rarely can be used to partially glaze the surface of a wheel to reduce the agressiveness of its cutting.

Truing is an activity for a single point diamond. It should always be used trailing the rotation of the wheel by about 20 degrees and at an angle of about 20 degrees from square to the wheel face so that it doesn’t get a flat worn on the diamond point. The diamond is put into a holder on the grinder table and then traversed across the wheel by the normal grinder feed apparatus, taking cuts of about 1/2 to 1 thou (0.01- 0.02 mm) until it cuts evenly or the wheel is correctly formed.

Dressing is normally done with a star wheel or one of the multi-point diamond tools. Open the rest out from the wheel so that there is room for the hook underneath the dresser to fit between the rest and the wheel but not so far that the whole dresser is not properly supported. Hook the dresser over the edge of the rest and keep it hard against the rest. Lift the handle till the star wheels or diamonds come into contact with the grinding wheel and then traverse across the wheel. You will see when the glaze on the wheel has gone. Don’t forget to put the rest back in the right place afterwards.

Both activities produce lost of grindstone dust which is distinctly bad for other machinery!

N

Edited By Nigel Parkinson on 06/09/2011 16:24:16
6 September 2011 at 19:24 #74584
Alan Worland 1
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@alanworland1
I used to use the star type dresser, which seemed to work very well. I have also got one of those ‘encrusted’ dressers which also works well but doesn’t seem to remove as much wheel, this is the one I now use most – as the wheels last longer!

I also always do this out doors (the grinders mounted with wing nuts) as the mess can be pretty bad.

Alan
7 September 2011 at 08:57 #74609
Old Elan
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@oldelan
Posted by Nigel Parkinson on 06/09/2011 16:21:38:

The first activity is trueing. Off-hand grinders do not normally get trued.

The second activity is dressing. Dressing is normally done with a star wheel or one of the multi-point diamond tools.

I’m not sure I understand why one wouldn’t want to true an off hand wheel. My plan is to make Ggrinding rest a la HH one to do lath tools acurately.. Surely one would want as flat a face as possible?

It looks as though the bar type diamond dresser will be for me or maybe I will try a stick first as that I perceive the flat face to be able to both true and dress at the same time.

Or am I totally wrong?

Thanks for the replies.

Edited By Roy Jewell on 07/09/2011 08:58:30
8 September 2011 at 07:03 #74669
Nicholas Farr
Participant
@nicholasfarr14254
Hi, trueing and achieving a flat face on an off hand grinder can be done using a star wheel, using the mthod described by Nigel Parkinson. The star dresser should be dipped in water before and during use, as this will lubricate it and keep it cool and will help keep the dust down. The grinding rest has to be in good order of course.

Below is an extract from my abrasive wheel regulations course.

Regards Nick

Edited By Nicholas Farr on 08/09/2011 07:05:07
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