tool cutter grinder

[mark smith 20Participant @marksmith20]

[mark smith 20Participant @marksmith20]

Ive had this chinese endmill grinding thing for a while whic was going to be used for another project ,which was abandoned. I believe it only is for cutting flutes of end mills not the ends. I also have just salvaged this 1/4hp dc motor with kb electronics speed controller.

Can anyone explain to me what i could make in order to sharpen blunt endmills/slot cutters(dont have to be perfect just usuable for roughing. I get thoroughly confused about what range of movements i need to do what at first looks quite simple. I have an er32 collet chuck that will fit the Chinese tool spindle.

Also have this swiveling vice base which could be adapted to allow the chinese thing to swivel. Not sure about raising the height of the chinese thingy or the motor.

Anyone have any suggestions. Do i need some sort of xy table?

Thanks

[Thor 🇳🇴Participant @thor]

Hi Mark,

I used a xy table when I made a cutter grinder, see here. Have you checked out Harold Hall's website?

Thor

[BazyleParticipant @bazyle]

No need to overcomplicate things by trying to make it too 'universal'.
For endmills and slot drills you need to be able to index around the 4 or 2 teeth so

a) make a disc to fit the spindle with 4 holes or slots to do the indexing and a spindle clamp that holds.

Next you need to control the movement longitudinally into the grinding wheel while allowing it to be withdrawn to prepare then fed in to make the cut but no deeper. This needs to have control to a thou, and be repeatable as you index round the 4 (2) cutting edges.

b) make your disc above true and concentric and be able to move it in to a screw stop that can be adjusted to a thou. eg a 40tpi thread with dial of 25 divisions. (see alternative later)

You need to set the cutting edge angle. Just go with 10 degrees and don't make it adjustable.

c) The simplest way to do this is to make a 1/4 inch metal plate that the is tilted by having a bar screwed to one edge to lift it up.

You want to traverse the cutting edge across the face of the grinding wheel although the first stage you can just screw your slide to the plate and do a plunge grind only.

e) fit a thin bar <1/4 in thick under the base of the 'thing' you already have at right angles to the spindle axis, such that it bears against the edge of the angled plate (c) and guides it across the plate at a fixed distance from the grinding wheel.

As an alternative to b you could put 2 screws through the bar (e) to bear against the plate which would then give depth control and tilt if you didn't remember to set them the same length.

[mark smith 20Participant @marksmith20]

Hi Thor, yes ive read the Harold Hall stuff and watched his videos on Youtube, Your cutter grinder looks nice,although i found the Quorn and Bonnell grinders extremely over complicated to understand.

Bazyle , thanks for your suggestions which im trying to read though but without diagrams/quick sketches im a bit lost.

The gear from a harrison lathe fits the chinese spindle ,its 80 teeth but a heavy chunk of metal for simple indexing of a milling cutter.

[mark smith 20Participant @marksmith20]

I also have several of these motor well 3 motors and two controllers ,anyone have a novelle idea what i could use them for . They were expensive laboratory pump motors but only 1/6 hp so maybe too low power for a tool grinder of some sort. .I have one at the moment adapted with a foredom flexible shaft and handpiece. They are geared down at the front end but i removed the end for the flexishaft adaption. Which leaves a 8mm splined shaft which i also had to alter for the flexishaft .

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