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View Full Version : Surface grinder as TC grinder ?



TonyMoyer
05-20-2010, 08:32 PM
I have a 6X12 Harig and would like to use ot to sharpen my cutters for my Atlas horizontal mill and am not sure how to go about it, any help would be great

Tony

mmc005
05-20-2010, 09:15 PM
Well, you could use a set of centers and an expanding mandrel to hold the cutter and you need a spring finger to locate the tooth position. The finger goes into the flute opening on the cutting edge that you are currently going to sharpen. The centers and mandrel will allow about .001 runout on your cutter.
You can rough each edge first, back off your wheel at the start of every tooth to avoid wearing the wheel down to fast. Then, after each tooth has been roughed in, move the wheel about .002 and take a finish pass on each tooth.
That's how I would do it.

DR
05-20-2010, 09:27 PM
Most important is to have the correct fixtures. A nice thing about sharpening on the surface grinder is you use the mag chuck to hold the fixture.

For some grinding applications you'll likely need cup wheels rather than conventional surface grinding wheels.

I have both a surface grinder and T&C grinder. Some tool sharpening jobs I can do on either machine, others are best suited for one or the other. On the surface grinder I don't have quite the visibility of the operation as on the T&C.

I just made a couple square broaches out of hardened drill blanks. The customer supplied blanks were much larger diameter than the diagonal across the square. I circular ground the blank ends down on the surface grinder with a motorized fixture. Then switched over to the T&C to square ends to size using an indexing head.

I could have down the whole job on either machine, but the operations were more convenient on the respective machines.

oldtiffie
05-20-2010, 09:45 PM
I have a 6X12 Harig and would like to use ot to sharpen my cutters for my Atlas horizontal mill and am not sure how to go about it, any help would be great

Tony

Tony.

PM or email John Stevenson and ask for the details and costs (not much at all as I recall) of getting a copy of the very good T&C CD that his wife sells on the web.

It is well worth the cost, time and effort to get the basic principles learned and appreciated.

DR has got it right.

The principles of sharpening slab milling cutters and side and face cutters etc. for a horizontal mill are similar to those for sharpening end milling cutters for a horizontal mill.

You can sharpen all your lathe turning and screwing tools as well on your surface grinder by using it as a T&C grinder.

You are going to have to make some tools and adaptors - as well as a pair of fairly simple centres - but that is par for the course and is not difficult.

TonyMoyer
05-21-2010, 08:38 PM
Thanks for the replies I figured I would have to make fixture just not sure how I would go about it.
Tony

lazlo
05-22-2010, 09:14 AM
You want one of the Eagle Rock endmill sharpeners:

http://www.travers.com/product.asp?RequestData=CA_Search&navPath=All+Products%2F%2F%2F%2FMachine+Tool+Acces sories%2F%2F%2F%2FSharpening+Fixtures%2F%2F%2F%2FA ttribSelect%3DPrice+Range%3D%27%2475+-+%2499.99%27&eaprodid=49563-85-090-099
http://www.travers.com/images/Items/500x500/85-090-001.jpg

You can find Chinese copies for a 1/3 the price. I just did a 1/2" endmill on the surface grinder yesterday, and it came out beautifully. It just sharpens the tip, by the way...

TonyMoyer
05-22-2010, 12:00 PM
Thanks lazlo I have one of those and it works great, but I was looking for ideas for the circular type cutters used on horizontal mills.

Tony

Scishopguy
05-22-2010, 12:41 PM
Tony...Years ago my shop bought a fixture from MSC to grind the side flutes of cutters. It was not that expensive, less than $200, that was a cylinder, set in carbide bearings, that would slide back and forth as well as turn round. It had a set of collets to hold end mills or an arbor for horizontal mill cutters. It was not the fancy air bearing units that you see now for mega bucks. It worked well for occasional use. I ground several custom diameter end mills using that fixture and wish I had it today.

reggie_obe
05-22-2010, 12:41 PM
I'd suggest reading the chapters on grinding in a college level maching book or the relevant chapters in Machine Shop Practice Vol 2 or the KO Lee Tool and Cutter grinder manual. To sharpen milling cutters you need a pair of centers, arbor and toothrest. I'm not sure that it can be done on a surface grinder, the cutter is usually ground perpendicular to the wheel and I don't think the table would be wide enough.

lazlo
05-22-2010, 12:57 PM
Thanks lazlo I have one of those and it works great, but I was looking for ideas for the circular type cutters used on horizontal mills.

Doh! Sorry Tony -- didn't catch the horizontal cutter reference. Reggie has a good description of the jig you need to sharpen a circular cutter. I think you need a dish wheel tool.