New ideas for tool grinding in the workshop

[Neil WyattModerator @neilwyatt]

Just musing, but that bottom photo reminds me that most larger endmills have a 'groove' behind the cutting edge to reduce the wedge angle without losing strength.

This means that the end cutting edge is far from straight – it HAS to have a quite noticeable curve in it. This is much bigger than even the noticeable striations one the edges in the photo. But as the mill actually always cuts on the flutes except when plunging all we want is a functional cutting edge and a sharp corner.

If you want a perfect finish at the bottom of a plunged hole, use a flat-ended d-bit!

Neil

[MuzzerParticipant @muzzer]

Mercans don't recognise the word "slot drill". To them, there are only 2, 3 or more flute end mills – with a choice of centre-cutting or non-centre-cutting. A good old fashioned "slot drill" would be known there as a "2-flute centre-cutting end mill".

Murray

[VicParticipant @vic]

Looks like about £20 for the drawings for the acute system, I might buy a set.

[Enough!Participant @enough]

Posted by Vic on 06/06/2015 19:05:25:

Looks like about £20 for the drawings for the acute system, I might buy a set.

I tried …. but it doesn't seem you can actually order any of this stuff at the moment.

[Clive HartlandParticipant @clivehartland94829]

What is the search name on the internet for 'acute systems', I tried but get other companies?

Clive

[Michael GilliganParticipant @michaelgilligan61133]

Here you go, Clive

It looks a very interesting idea.

MichaelG.

[Clive HartlandParticipant @clivehartland94829]

Thank you Michael.

Clive

[John HaineParticipant @johnhaine32865]

Well, I can only say that I'm amazed at the large number of responses and the ideas here! The "Acute" system looks interesting too – the pantograph-like arrangement to allow a tool to slide at a set angle anywhere on the rest plate is brilliant.

As well as a Quorn (inherited) for which I've made a new workhead to take R8 collets, I have adapted an Axminster grinding reat for shaping tangential tools – I'll take some photos of these and post them. But I still find the Quorn tedious to set up and fussy about wheels, so it gets little use. I'm thinking about a fixture to grind the end teeth of whatever we are supposed to call end mills and slot drills these days, which will be quick to set up and preferably can stay on the grinder for most of the time, along the lines of Harold's gadget. As I have a couple of angle plates and a Myford swivelling vertical slide that never get used, they may play a role!

One thought: most of us have a tool with a driven spindle and adjustable slide rest in the form of a lathe. Conventional wisdom is "never grind on the lathe" because you get abrasive dust all over the slides. But I'm wondering if the same is true if you use a diamond wheel, especially one of the electroplated ones? These seem to last a long time and most/all of the "swarf" will be metal dust. Obviously it will be hard metal dust but generally easier to pick up with a magnet. Any views on this?

[VicParticipant @vic]

Prices for the Acute system are on this page:

http://www.eccentricengineering.com.au/index.php?option=com_virtuemart&page=shop.browse&category_id=33&Itemid=3

No way to order from the UK yet though.

I think it only looks superficially like HH's version, the pantograph is the give away!

[VicParticipant @vic]

Posted by Bandersnatch on 06/06/2015 23:08:14:

Posted by Vic on 06/06/2015 19:05:25:

Looks like about £20 for the drawings for the acute system, I might buy a set.

I tried …. but it doesn't seem you can actually order any of this stuff at the moment.

I guess you need to contact the UK Distributor:

http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=17&Itemid=43

[Neil WyattModerator @neilwyatt]

You can order the stuff on the Eccentric website but oddly the description page doesn't link directly to the 'buy' page – you have to get to it through the 'shop' link.

But yes, try the UK distributor.

Neil

[Eccentric EngineerParticipant @eccentricengineer]

Hi All

Thanks for the positive comments about the Acute Tool Sharpening System.
I've been having a look through the thread and thought I'd endeavour to explain a couple of questions that have come up about the sharpener.

To try and minimise any slop in the links I have used Acetal bushes in the 6mm reamed holes in the links.
The bushes are about 0.1 – 0.2mm thicker than the link material and when you tighten the screw down on the bush it expands it enough to take out any play.
You can tweak the links this way so that they move freely but don't have any slop. It also helps to keep out grinding dust, doesn't need lubricating, and means the bushes can be replaced instead of the links if they wear over time.
Originally I tried using custom shoulder bolts and also bronze bushes. But as Neil mentions, you would have to make the parts extremely accurate as any clearance is multiplied through the four pairs of pivots.

Most of the holes in the laser cut components have been spot drilled to minimize marking out or the need for a dividing head or mill DRO. They are not through pilot drilled, just a 90 degree cone like a large centre punch mark about 2.5mm diameter done with a spotting drill.

I haven't put the drawings and kit up on the shop yet as I'm still trying to complete the DVD manual that comes with them on how to build and use the system.

I had hoped to have the DVD finished soon after returning from Harrogate, but I've been snowed under with a lot of other jobs at the moment.
Apologies to the customers who bought the drawings and kits at the show, I'll try and forward your DVD as soon as I can.

I'll put the prices for the various items on the UK distributor page as soon as they are finalised and the first batch of kits are shipped to my sister in Lancaster, she handles the sales in the UK.

I have a "What's New" page on the website so if anyone wants to find out any new information about the sharpener, other new products, or content on the website, they will be added to there. Just click our ad on the right hand side of this screen and click "What's New" in the menu at the top of our website.

Cheers
Gary
Eccentric Engineering

[VicParticipant @vic]

Thanks for the update Gary, most helpful.

Are there any plans to show a video of the unit in action to further tempt buyers?

[Enough!Participant @enough]

Posted by Vic on 07/06/2015 10:30:51:

Posted by Bandersnatch on 06/06/2015 23:08:14:

I tried …. but it doesn't seem you can actually order any of this stuff at the moment.

I guess you need to contact the UK Distributor:

http://www.eccentricengineering.com.au/index.php?option=com_content&view=article&id=17&Itemid=43

Not really, Vic – I'm in Canada

[VicParticipant @vic]

Oh dear!

[AjohnwParticipant @ajohnw51620]

On the Acute I would like to see examples of it sharpening various tools – lathe, mill etc. I manage by hand as far as lathe tool bits go.

Noticing an earlier comment about touchy with wheels that is an area that concerns me. While it's possible to buy all sorts of wheels and many have a max speed rating I see little signs of optimum speeds against the materials being ground. Maybe there is something some where but I haven't found it in a usable fashion. Take diamond wheels for instance – % diamonds and usually the size and thickness of part that actually has them are often quoted. I did ask one supplier of a small watch maker sized wheel and had the reply 2,800rpm. Frankly I don't believe that given it's size and the fact that watch makers grind on the lathe. This was a specialist diamond tool supplier too or reckoned they were. The other aspect is that surface speed should be the main factor not rpm.

Some one mentioned grinding on the lathe. I have come across several old lathes that had probably spent many years lying around in the corner of some factory eventually going to scrap. They often have white wheels in their cupboards so at one time I feel grinding tools on the lathe was fairly common. The wheels were generally white and some what coarser than a typical tool grinder sharpening grit wheel but would still give a decent finish. Some were too fragile for actually shaping tools. I'd guess people just covered the lathe.

John

–

[VicParticipant @vic]

I sharpen most of my tools on a belt sander.

[JasonBModerator @jasonb]

Slow speed seems to work fine on grinders like the Tormek and their is a diamond option for that, My DMT stones also work well when moving the tool back and forth by hand and that must be very slow. Same with the diamond coated drills I often use for work work best about 400rpm in a cordless and thats a 6mm dia bit.

J

[VicParticipant @vic]

I've sharpened carbide inserts on a cheap Aldi diamond bench stone, the square type with four different grades on it. I've also used it to true up small hand stones.

[Clive HartlandParticipant @clivehartland94829]

Diamond wheels are resinous or rubberoid matrix, the matrix is only a carrier for the diamonds and if you push too hard you will smell the matrix burning. The amount you take off on a diamond wheel is very small and if you run them fast they will not cut as well when used at the right speed. Along with this if you are say, grinding up an engraving tool the size of the tool quickly lends itself to over heating. The amount taken off is half a thou, never free hand grind on a diamond wheel, it will dig into the matrix and ruin the diamond wheel very quickly. They are expensive take care with them.

Clive

[SteveIParticipant @stevei]

Jason,

Do you have a link to the Tormek diamond wheel option?

Thanks,

Steve

[JasonBModerator @jasonb]

**LINK**

**LINK**

Not tried one myself just the standard wheel that comes on it.

About 200sfm and bonded with nickle

 

J

Edited By JasonB on 08/06/2015 19:14:59

[Michael HornerParticipant @michaelhorner54327]

Here is something I made from the junk box. I needed to touch up the cutting edge on a few tools. You can get 360 degrees on 3 axis. so should be able to get the angle you want, I think it can be improved upon time and brain power permitting.

Cheers Michael

[John Stevenson 1Participant @johnstevenson1]

Posted by Clive Hartland on 08/06/2015 17:53:15:

Diamond wheels are resinous or rubberoid matrix, the matrix is only a carrier for the diamonds and if you push too hard you will smell the matrix burning. The amount you take off on a diamond wheel is very small and if you run them fast they will not cut as well when used at the right speed. Along with this if you are say, grinding up an engraving tool the size of the tool quickly lends itself to over heating. The amount taken off is half a thou, never free hand grind on a diamond wheel, it will dig into the matrix and ruin the diamond wheel very quickly. They are expensive take care with them.

Clive

Diamond wheels can also be electroplated and these are a different animal altogether.

You can remove quite a bit of metal with them and no reason not to grind freehand. Speed isn't critical on them as many are designed to run at 12,000 rpm.

This is a 16mm square brazed tipped tool used for chamfering weld prep.

Becase the plates are laser cut they have plenty of hard spots in them and the result is as above, those chips are about 1/32"

The results of about a minutes worth of grinding on an electroplated wheel mounted on an angle grinder, which it was designed for and all done free hand.

[Clive HartlandParticipant @clivehartland94829]

Agreed John, different matrix's for different purposes. My thoughts are from my own use of diamond wheels in the matrix I mentioned and as yet have only used a plated diamond disc a few times. I have a disc mounted on an arbor all mounted on a board and driven by a mains motor and I know it will take metal off at high rates.

Clive

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