Simple Conversion of a Unimat SL to sharpen milling cutters

[DoddyParticipant @doddy]

So the bottom draw in the workshop has a few milling cutters which are a bit dull and have lost their edge. Always wanted a ToolCutter Grinder and one day I'm sure I'll make a Quorn, Stent, Worden or go and buy one. Up until now I've always though about the cost of a Tool Cutter Grinder Vs the price of a new cutter. Looking at the growing pile of blunt and chipped cutters there are a few that only require the edge "touching up" so heres my solution, yes it needs a guard and few other mods but I just made it to see if the results were OK. The only real problem is I can only sharpen the ends of Slot drills and End mills and not the sides and the diamond disk is turning down across the cutting edge rather than away from the cutting edge, but it hardly leaves a burr the block milled with a 6degree and 8degree angle and two mounting holes square to theses facessquared up an off cut of angle iron a mounted it central to the 3mm deep slotadded a stop screw and clamping boltmachined a carrier stub with 12mm x 1mm pitch threadscrewed to Unimat SL nose and machined in-situ to take the Diamond Grinding WheelDiamond wheel runs true as stub cut in postionMade a Riser Block to fit under the headstock of the lathe – this has to be 20mm thick so the Unimat Headstock clamp worksMilling cutter aligned horizontal with vernier on surface plate so as each cutting edge is sharpened in turn the are square and the stop screw ensures correct depth of cutsmall light cuts feeding the cross slide. E25 Collet Block ensures correct alignment

[DoddyParticipant @doddy]

[Thor 🇳🇴Participant @thor]

Seems to be simple to make. I have made a cutter holder with a MT 2 spindle, and mounted it on a small X-Y table. The Unimat is used to grind the cutting edges, I use an ordinary aluminiumoxide wheel though. From your pictures it should be easy to mount a diamond wheel.

Thor.

[jason udallParticipant @jasonudall57142]

It does highlight a “problem” with the SL…almost any tooling dwarfs the SL…but nice work. .neat job…guess diamond wheels also avoid shedding grit in the workshop. ..

[Ian PParticipant @ianp]

I like it!

I have an SL doing nothing under the bench so now I know why I kept it.

One questiion, where did you get the ER25 collet block? I can only find ER32 size.

Ian P

[Ian PParticipant @ianp]

Oops! I see Arc Euro do them.

I looked at their website 'New Products' page and it has them listed as ER32, its only when you go to the page that the ER25 is shown

Ian P

[Sub MandrelParticipant @submandrel]

I discovered ER25 'stephenson collet blocks' on the Arc Website a few days ago. They also sell Mr S's trusty endmill sharpening block which works like the one above, but with a surface grinder (for the lucky few who have a surface grinder).

Neil

[jason udallParticipant @jasonudall57142]

Just a thought..the SL three jaw would suffice for grinding work holding…and the indexer would also serve…use the stub mounting for that assy. And away you go….

[Ian PParticipant @ianp]

Jason

If you use the chuck to hold and index the cutter you then need another spindle/motor for the diamond wheel, also I doubt the chuck accuracy would be good enough for cutters.

The SL spindle is ideal for the grinding wheel, I'm sure with the right pulleys it would be good for 10,000 RPM so its a waste just to index with it.

Ian P

[jason udallParticipant @jasonudall57142]

No use the index unit with chuck for work holding..keep spindle as you say for wheel

[jason udallParticipant @jasonudall57142]

As to the chuck accuracy…well truw they do vary

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