Author Topic: Dished grinding wheels  (Read 811 times)

Offline NormanV

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Dished grinding wheels
« on: October 17, 2017, 08:41:47 AM »
I have been searching online, to no avail, to find a stockist of dished grinding wheels for a tool and cutter grinder. I need the type that have a tapered edge for sharpening the cutting faces on the teeth of an involute gear cutter. Can anyone give me a lead please?

Offline ozzie46

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Re: Dished grinding wheels
« Reply #1 on: October 17, 2017, 09:00:30 AM »
Are you using the word "dish" in your search? The proper word should be "cupped grinding wheel , I think.

Ron

Offline Spurry

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Re: Dished grinding wheels
« Reply #2 on: October 17, 2017, 09:13:55 AM »
RDG tools seem to have quite a selection, there may be something that would suit.
Pete

Offline John Rudd

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Re: Dished grinding wheels
« Reply #3 on: October 17, 2017, 09:23:09 AM »
Something  like this might be suitable?


http://www.arceurotrade.co.uk/Catalogue/Diamond-Tools/Diamond-Grinding-Wheels/Diamond-Grinding-Wheels---15-Tapered-

( I bought some wheels from RDG and found that they were way out when running....didnt want to risk truing them up because of the amount of runout would have thinned them too much..)
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Offline NormanV

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Re: Dished grinding wheels
« Reply #4 on: October 17, 2017, 11:41:26 AM »
Thanks for the replies. Sorry, I should have made it clear, I am looking for a silicon wheel as I fear that trueing a diamond wheel wouldn't be possible.
The angle of a cup wheel is too steep to fit in between the teeth of the cutter. What I am looking for is the wheel that is almost flat with a little dishing and a tapered edge.
I found one on Ebay but it was 150mm I need 125mm.

Offline gerritv

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Re: Dished grinding wheels
« Reply #5 on: October 17, 2017, 12:10:39 PM »
I think you are looking for Type 21 wheels. The ones from ArcEuro trade match that pretty closely.
I need one for my early 1900's Cincinnati Universal grinder to grind home made gear cutters, thank you for the link.

Banggood also has a few listed.

Gerrit

Offline Doc

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Re: Dished grinding wheels
« Reply #6 on: October 17, 2017, 01:18:09 PM »
George

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #7 on: October 18, 2017, 05:01:57 AM »
I've sent a detailed PM to Norman about what I believe refers to his version of Harold Hall's  grinder and doesn't appear to need anything other than a  common or garden plain wheel.

I agree that for many other grinders that there is certainly a use for dished/ cup whatever wheels.

Mr Hall in his reply to me suggested a WA60KV  wheel for grinding hss tools

Another N







Offline NormanV

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Re: Dished grinding wheels
« Reply #8 on: October 18, 2017, 05:35:35 AM »
Here's a photo of one of the cutters that I need to sharpen. As you can see from my dreadful sketch I need a grinding wheel with a thin rim to get down in between the teeth.

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #9 on: October 18, 2017, 06:03:05 AM »
It's becoming clearer and the normal way to recondition involute gear cutters is 'between centres'

However, in Harold Hall's web site there is a video of how slitting saws are reground with a plain wheel'


Cheers

N
« Last Edit: October 18, 2017, 06:38:06 AM by Fergus OMore »

Offline NormanV

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Re: Dished grinding wheels
« Reply #10 on: October 18, 2017, 07:02:00 AM »
Norman, I've just had a look at that video. He grinds the tips of the teeth on a slitting saw, I need to grind the face of the teeth in order to maintain the profile.
What do you mean by "between centres"?

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #11 on: October 18, 2017, 07:19:29 AM »
Between centres is simply as in a lathe- one centre at each end and holding the cutter on a 1"(?) mandrel.

You index each tooth with a bit of spring steel- ex Woolworth's old alarm clock spring :ddb:

There are fancier set ups but this is OK

Cheers

N

Offline gerritv

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Re: Dished grinding wheels
« Reply #12 on: October 18, 2017, 07:27:02 AM »
I built a functional clone of the Cincinnati No2 fixture to grind the face of teeth. I have not yet bought a correct wheel though, hence my interest in this thread. I do have a wheel that is quite narrow and already dressed to a similar angle. It might work in a pinch.

The manual for No2 grinder has a good description of its use.


Offline NormanV

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Re: Dished grinding wheels
« Reply #13 on: October 18, 2017, 08:52:13 AM »
Harold Hall's grinding jig set up to do slitting saws but with the correct, i.e. dish shaped, wheel will do the job for me. Where do I find the correct wheel?

Offline gerritv

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Offline j1312v

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Re: Dished grinding wheels
« Reply #15 on: October 18, 2017, 09:57:12 AM »
Hi Norman,

If you have a plain wheel, dish it in the lathe. Make a mandrel or similar device to hold the wheel, use low rpms and hss.
Protect the lathe and be safe of course.

Joe

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #16 on: October 18, 2017, 10:04:14 AM »

I googled my other local stockist ie Cromwell tools for dished abrasive wheels and found a suitable 60 grit cup wheel which will go on my old Clarkson.

As  most of  my wheels are really ready to be replaced as they are - like me- probably past the expiry dates.

Worth a try?

N

Offline j1312v

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Re: Dished grinding wheels
« Reply #17 on: October 18, 2017, 10:07:39 AM »
You can also doit by hand in the grinder with a single point diamond dresser, all you need is some kind of rest and a steady hand.
You need to be more careful and have a good hand eye coordination.
Again if you are not comfortable doing something don't do it.

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #18 on: October 18, 2017, 11:08:55 AM »
Whilst I have a single point 'professional' thing to do 'funny shapes on grinding wheels, I have multi diamond thing which is probably better to do trimming wheels by hand

Yer pays yer money and yer takes yer choice.  I also use angle grinder disks but I'm really digressing

N

Offline NormanV

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Re: Dished grinding wheels
« Reply #19 on: October 18, 2017, 11:24:42 AM »
I don't have a diamond dresser but I must say I don't fancy the idea of reshaping an existing wheel. There's an awful lot of material to come off.
I will find the right wheel eventually.

Offline philf

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Re: Dished grinding wheels
« Reply #20 on: October 18, 2017, 11:49:20 AM »
Norman,

These are aluminium oxide - you said before that you wanted silicon - did you really mean silicon [carbide] or was it that you just didn't want diamond?

https://www.abtec4abrasives.com/dish-and-saucer-shaped-grinding-wheels-568-c.asp

They have 4", 4.5" and 6" but no 5". For some reason the 4.5" is much more expensive than the 4" or 6".

Phil.
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Location: Marple, Cheshire

Offline NormanV

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Re: Dished grinding wheels
« Reply #21 on: October 18, 2017, 12:25:35 PM »
Thank you Phil, that is what I am looking for. I suppose 4.5" is less common, shame it's so much more expensive.
Norman

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #22 on: October 18, 2017, 12:41:38 PM »
Norman( and other interested parties), the bedroom-workshop.com site may prove an interesting resource.

Cheers


Norm

Offline gerritv

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Re: Dished grinding wheels
« Reply #23 on: October 18, 2017, 10:23:32 PM »
I don't have a diamond dresser but I must say I don't fancy the idea of reshaping an existing wheel. There's an awful lot of material to come off.
I will find the right wheel eventually.
My link provided you with a diamond type wheel, did you look at it? Lot less grit comes off that than the others suggested. Given that you are uncomfortable with dressing the wheel I thought it might be the most suitable for you. And less money to boot.

Offline gerritv

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Re: Dished grinding wheels
« Reply #24 on: October 18, 2017, 10:26:11 PM »
You can also doit by hand in the grinder with a single point diamond dresser, all you need is some kind of rest and a steady hand.
You need to be more careful and have a good hand eye coordination.
Again if you are not comfortable doing something don't do it.
You are joking right? I wonder what kinds of gears would result. If the teeth aren't all ground equally and radially then the gear teeth will not be of the intended shape.

Offline Doc

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Re: Dished grinding wheels
« Reply #25 on: October 19, 2017, 01:15:06 PM »
The link I provided has the wheels used for the very thing you want to do also.
George

Offline NormanV

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Re: Dished grinding wheels
« Reply #26 on: October 19, 2017, 03:52:57 PM »
I did see it George but shipping from US would be expensive. Thanks anyway.

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #27 on: October 19, 2017, 04:21:39 PM »
I did see it George but shipping from US would be expensive. Thanks anyway.

If it's price then why not cast discretion to the winds and buy a cheap angle grinder and a box of thin cutting off disks?

My wee claim to fame or infamy,  is the use of one using worn disks but my purpose is to hollow grind inverted rear tool post blades.

Of course, the rounding off requires no further dressing after a bit of judicious fettling in lieu of filing the odd casting.

N


Offline NormanV

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Re: Dished grinding wheels
« Reply #28 on: October 19, 2017, 05:30:07 PM »
I already have some 1mm grinding discs ( my angle grinder is my most used tool) and have thought about it. I discarded the idea as it seemed ridiculous, maybe I should revisit it.

Offline Fergus OMore

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Re: Dished grinding wheels
« Reply #29 on: October 19, 2017, 05:44:28 PM »
People like Aldi sell  holders for angle grinders at times. Whilst I use the disks on other t and c  grinders,  it should be possible to index and  control the depth of cut/grind with a stop.

N