End Mill Sharpening Jig

[VicParticipant @vic]

Being able to sharpen the tip of end mills and slot drills is very handy in the larger sizes. I was gifted a number of 16mm mills and also a 20mm on a 16mm shank many years ago. All pretty unusable for one reason or another. Having just completed the Harold Hall End Mill Jig, I was pleasantly surprised to achieve more than acceptable results on my first attempt. At least cutting aluminium alloy. More experimentation to follow. I’ve also discovered I need to make some additional parts for my setup. Materials inbound later this week hopefully.
Like several others I’ve seen on YouTube, mine is not an exact copy as that documented in Harold’s excellent plans. I’ve incorporated the modifications others have suggested plus a couple of my own.

 

[duncan webster 1Participant @duncanwebster1]

TDWalshaw (Tubal Cain) recommends grinding the tips of end mills with a backed off 45 degree chamfer if you’re taking small facing cuts. I’ve done this freehand and it works, but tends to cut more on one tooth as I’m not skilled enough to get them even. I’m waiting for some clever chap to come up with an attachment, the geometry required boggles my mind

[VicParticipant @vic]

The article is here:

 

http://www.homews.co.uk/page121.html

[brickyParticipant @bricky]

There was an article in the Model Engineer in June 2004 Vol 192 No4223 by Colin Pape.It was called The Cannon A Sharpener for Milling Cutters ,I made this device and it works beautifuly but it was designed for threaded cutters only and if I ever get the time I will make a barrel to take a collet holder which would be an advantage too.The date is for the second article ,I don,t have the first one now.

Frank

[VicParticipant @vic]

I have a couple of ER collet chucks with 16mm shanks that I can use with the block I made.

[BazyleParticipant @bazyle]

Bricky, it would be nice to see a picture of your jig as I don’t have that issue.

[David George 1Participant @davidgeorge1]

This is my effort to sharpen cutter and drills.

I have made a jig which holds a collet set and I have fitted a collar with a grub screw which with a dowel with equaly spaced holes so I can set first tooth to correct position and length firstly then release the side clamp rotate to next hole and reclamp whilst holding up to face then regrind next tooth.

David

 

 

 

[Bazyle]

On Bazyle Said:

Bricky, it would be nice to see a picture of your jig as I don’t have that issue.

Yes, I’d like to see some pictures as well. 😉

[Nigel Graham 2Participant @nigelgraham2]

A selection of good ideas!

I built the Hemingway Kits ‘Worden’ T&C grinder but as designed will handle only 2- and 4- tooth milling-cutters.

It could be made with little modification to take a hexagonal body though, for 3-tooth cutters. (A triangular-section body would not give much room for larger cutters.)

It won’t sharpen helical flutes, at least not in original trim. A suitable holder might allow tap sharpening (straight flutes).

What it will do though, is sharpen lathe and shaper tools, useful particularly for critical profiles such as for screw-cutting.*

An attachment offered as an additional kit allows sharpening slitting-saws.

It’s a bit slow to use as it does not have a rapid indexing method but that’s not usually important. I also found the leadscrew arrangement could be better, so I usually disengage that and slide the table manually – one hand on each end of the table for steady control. The basic machine is otherwise fine, and it would not be too hard to make other cutter-holder arrangements for it.

……

I’ve also still to complete a Blackgates-supplied ‘Stent’ T&C Grinder, with Giles Parkes’ modification**, but am a bit unhappy about the massive overhung mass of the motor on top of the column.

……

* I recall a rather sad conversation on this site with someone puzzled how to use the ‘Worden’ for sharpening lathe tools, held in a block that sets the tool at right-angles to the main tool-slide axis for grinding the sides. The geometry somehow eluded him.  I hope he twigged it eventually.

 

** Parkes, G. Stent Modifications. Model Engineers’ Workshop, No. 108 Aug-Sept 2005, pp28-29

[VicParticipant @vic]

I sharpened a 20mm end mill the other day and had the opportunity to use it on some mild steel today. I’m very happy with the result.

[Martin KyteParticipant @martinkyte99762]

Putting a 45degree facet on the tips of slot drills is quite achievable by hand in the larger sizes and even more so with some kind of cutter grinder. I’m fortunate to own both a Quorn and a Union cutter grinder and prefer big slot drills and end mill ground this way for facing. It produces a better finish than sharp corners and the cutter stays sharp for longer and is more robust. You can actually buy cutters of this form.

I can recommend it.

[VicParticipant @vic]

Martin, I took the corners off a milling cutter some years ago as I didn’t want a sharp inside corner on a small part. I didn’t particularly notice how good the finish was. I’ll have to seek it out and give it a try, thanks.

[Clive BParticipant @cliveb55652]

David, That’s a really nice jig you’ve designed and made. One day I’ll get around to making a copy.

Clive

[Martin Johnson 1Participant @martinjohnson1]

Putting a 45 chamfer on end mill teeth is a good way of getting more use out when you have chipped one tooth.  Or is it just me that chips teeth?

You could do it on the OP’s jig but you need to roughly double the clearance angle due to it being at 45 to both the end and side faces.

I have ro go searching for a cutter that doesn’t have chamfer

Martin.

[VicParticipant @vic]

I sharpened a couple of slot drills the other day. As the cutting edges differ in length a slightly different approach is needed. On a couple of 12mm SD’s the difference was about 2mm so I used a piece of 2mm gauge plate to space the holder against the stop block during grinding. I’ve not actually tried a plunge cut yet but the cutters look ok. This is the setup.

Long edge first.

Then adding the spacer for the shorter one.

 

[BazyleParticipant @bazyle]

Vic, I have been warming to your ideas on the screwed plate and the slot in the guide from your earlier photo. Why did you need this alternative clamp?
Are the holes 1 in spaced or 2cm or???

[VicParticipant @vic]

Hi Bazle, I went for a 20mm grid of M6 holes in the end. The slotted stop block is not my idea. Harold Hall originally made this with four holes. Having seen the modification of a slot on a couple of YouTube videos I decided it was a better option. I saw this alternative clamp somewhere on another video and decided it may be a useful addition to the table. If not for this particular jig then perhaps for another setup. It’s surprisingly solid for a two part component. Obviously if I’d made this first then I wouldn’t have needed to slot the stop block.

[Howard LewisParticipant @howardlewis46836]

With the Worden, grinding a lathe tool in the holder at right angles to the tool slide can severely limit travel of the table before the tool holder collides with the grinding wheel, so careful positioning of the tool, and the the travel stops is necessary. It might help to modify the wheel guard slightly, as well, to gain a little more travel.

But, with the correct combination of table angle, tool slide angle, and careful setting,  a knife tool can be ground.

Using a shop made (as Giles Parkes)  ER 20 collet holder in the tool slide, End Mills and Slot Drills can be ground.

The same holder, fitted to the original HK1310 drill grinding jig, can be used to four facet grind drills.

As with End Mills and Slot Drills, the cutting edge has to be correctly aligned, Vertical for drills, and Horizontal for milling cutters. The square tool holder makes 180 degree rotation a doddle!

With a diamond wheel, it is possible to grind inserted tooth milling cutters, then the inserts have be aligned equally for every one.

Howard

[VicParticipant @vic]

This is a really good website on Four Facet Drill Sharpening, with lots of examples of shop made jigs.

https://gadgetbuilder.com/DrillSharp.html

[BazyleParticipant @bazyle]

Thanks for the info. The plate allows for a lot of potential fixtures and overall a lot simpler than the Worden.

[VicParticipant @vic]

As you may be aware, the table and its mounting brackets are based on the Accute sharpening system. I thought it may benefit from slightly thicker materials though so instead I made the brackets 5mm thick and the table 6mm thick. I also allowed for lateral movement of the table seen in this picture. This could be further refined at a later date if the need arises.

 

Edit: Not seen are two straps with M6 threaded holes for the mounting screws under the base. The screws can therefore easily be loosened and retightened from above with a ball end hex driver.

Check out this link again for some really inspirational ideas on grinding platforms and jigs.

https://gadgetbuilder.com/DrillSharp.html

My trials and tribulations with the table build are here:

https://www.model-engineer.co.uk/forums/topic/grinding-rest-3/

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