End Mill Grinding Fixture

[Brentin]

I am looking for drawings and ideas to build my own fixture to sharpen end mills using a surface grinder

[mrb37211]

Philip Doclos wrote an article on building a '"Floating" End Mill Sharpener' for one of the Village Press magazines. Don't know which mag or which issue(s) but the article is in the book "The Shop Wisdom of Philip Duclos" pp 24 - 36. Charles

[JimGlass]

Here is one. This sharpens the ends of 2, 4 and 6 flute endmills. I bought one just like it on Ebay for $10

http://www.use-enco.com/CGI/INSRIT?PMAK ... TPG=INLMK3

Jim

[BadDog]

Can you explain how that works? I'm afraid I don't see it...

[Rich_Carlstedt]

When in the 'primary position" (almost vertical !) you grind the first angle, rotate the cutter and grind the next flute (ie 4 times).
The you tilt the block (mag table required) and grind the secondary relief angles, again one at a time (ie ..rotate,grind,rotate)

The block is not a 90 degree angle as it seems in the photo
Rich

[kapullen]

Brentin,

You can use a spin index type attachment, but you have to rig an adjustable finger at the wheel head to follow the flute.

A carbide finger works best.

You have to use the table traverse to work like this.

That is a tricky operation and guaranteed to have a learning curve.
I recommend use of a face shield when you start out.

I have a self contained fixture using a hardened, and ground, endmill holder bar with plungers like vee blocks making two steady rests to hold the bar that works ok with larger mills. That was a commercial unit that Enco, or Msc may carry.

I'll post a picture if I get a chance tonight.

A weldon air bearing type fixture works best but is pricy, the tolerances, and fits may be beyond the home shop.

Kap

[BadDog]

Thanks Rich.

So there is no indexing, you just turn it in the collet and get it close? And keeping height the same is just done free hand? Or is there a positive stop in the collet/holder for consistent depth?

[JimGlass]

The step fixture shown indexes. The secondary clearance angle is ground first then the primary clearance angle last.

It indexes via a spring loaded ball. The collar around the 5C collet is knurled for rotating by hand. There are dedents in the fixture the ball locates with. The spring loaded ball retracts while indexing then drops into the next dedent to locate the index. The endmill rotates with the fixture and the height stays the same with each index. You plunge grind each flute to the same depth. It is simple to use and works quite well.

However, I only use it when I have absolutely nothing else to do or in emergencies. New endmills are to cheap to spend valualble time sharpening used ones. But, I do use it.

Just for the record, I tried using a cheap 5C indexer to sharpen endmills and it did not work. Too much endplay in the fixture causing each flute to have a different hgight.
Jim

[kapullen]

Benton,

Here are some pictures of the Yusa Endmill Grinding Attachment.







Kap

[BadDog]

Ah, thanks Jim, that makes much more sense. It just didn't look to me like any indexing features were built in based on that pic so I wondered what the "rest of the story" might be.

[Hyper]

Here's one on ebay similar the the one Jim posted a picture of.
http://tinyurl.com/yljq7u
Only about 1 1/2 days left as of this posting. Bid is at $9.06 + about $15 shipping. Includes 10 collets.

[MikeC]

Kap, I am waiting on a Weldon ABF to arrive as we speak. Got lucky and got one for about 1/8 what they seem to typically sell for. I will undoubtedly have some questions for you if you are fairly familiar with them.