D-bit Tool Cutter Grinder R8 to 5C work head conversion

[petertha]

I have a the typical Chinese TCG purchased from Accusize here in Canada a few years back. Sadly not getting the attention it deserves, but I aim to change that.

2301-1007, MY-30A Universal Cutter Grinder with Standard Accessories, 110v, 60hz

When you choose Universal End Mill Cutter Drill Bit Grinder Sharpener, it works as the following tools (and solutions): Universal End Mill Cutter Drill Bit Grinder Sharpener, etc.

accusizetools.com

But having buyers remorse. Its R8 collet work head. At the time that was desireable because most were the Ux Dekel format which were pita to source. I already have a full set of good quality 5C collets, limited selection of R8. I could go out & buy R8 set but having tough time justifying. I don't really use them all that often in the mill or other applications. Maybe it was around the same time but Shars offered their 5C model.

Universal End Mill Cutter Drill Bit Grinder Sharpener

www.shars.com

I inquired with Shars if I could buy the 5C work head separately. Thinking (hoping) it will likely fit my dovetail, since these machines look generically similar & come in R8, 5C & original Ux flavors. The answer is yes, comes with the pivot for some reason. Not cheap, but maybe inline with collet set.

End Mill Sharpening Attachment

www.shars.com

Then I went lurking on AliExpress & Ebay. Rather confusing & still waiting on some replies but possibly I can get 5C head via that avenue, example pic

My question is, have any of you swapped out a head? Any issues I should be aware of? Shars mentioned one of the flute attachment guide accessories wont fit the same, of no real consequence.

 

[petertha]

I had this idea pop in my head that I could use my R8-ER20 collet chuck. Just plop that in the TCG work head & that would give me some continuous gripping range vs an extensive incremental (guessing 1/32") graduated set of R8 collets. Alas, some disappointment. The collets slide in but not the chuck arbor. Turns out they left the set screw a bit long inside the barrel & its scraping my shallower toolholder groove. I had this same issue on my mill, but I was able to locate the head under the quill cover ring & just back off the screw. On the TCG it looks like some major disassembly to gain access. And judging by its brother, the end mill flute accessory quill, they thread it in permanent, maybe some tap peeing & grind it off all purdy like with disc grinder :/

For reference, Accusize came back with a firm NO via their supplier. No 5C heads available.
Still trying to communicate with the other sellers. To be continued.

I'm actually scratching my head about these grinders in general. Back in the Deckel days, did they really have a full suite of collets? Or maybe say a handful of standard sizes & they just matched the shanks? I had hopes of sharpening drills & changing geometry & custom cutters with any kind of shank - hence my perceived requirement for an incremental set. I'm not even sure R8 are supposed o be squeezed down that much? For example if say 0.015" below nominal, well then even a 1/32" increment set wont really span continuous diameters. My 5C set is 1/64" increment. Grrrr...

 

[Larry$]

I've got the Shars 5C T&CG but my set of collets is by 1/32s. So I can't do all the drill sizes. But even with 64s collet sets closing on small sizes is less than ideal if they don't fall very close to the nominal size. The drill sharpening attachment is a lot less than ideal. Also because the thread that pulls the collet in is driven by a closed crank handle, I cant pass work through the handle. Going to see if I can make it more like my collet blocks with a pass through hole. Another mod is going to be a way of easily locating the pivot point so radius corners can be easily done.

 

[Eyerelief]

I have the shars 5c version as well. I also have a 5C-ER16 collet chuck that I use occasionally. The problem with the ER set up is it extends the nose of the collet out over an inch from the head. Doesn't seem like much but it severally limits the rotation of the head towards the wheel. As a result, in some situations a proper grind angle can't be achieved. For instance I can't rotate an end mill up close enough to grind the shallow angles found on the bottom of a center cutter. I would think the added capacity of an ER20 would only magnify this limitation.

 

[Toolmaker51]

I recall Deckel's well, a mold shop afterall. The collets we had were common shank diameters; it's not a true T&C grinder.
Use biggest collet you have, with shopmade headed split bushings. Best not to split both sides; if you do, the head preserves axial and radial runout as made.
That'll keep stickout just as designed for the work envelope.

 

[petertha]

I have the shars 5c version as well. I also have a 5C-ER16 collet chuck that I use occasionally. The problem with the ER set up is it extends the nose of the collet out over an inch from the head. Doesn't seem like much but it severally limits the rotation of the head towards the wheel. As a result, in some situations a proper grind angle can't be achieved. For instance I can't rotate an end mill up close enough to grind the shallow angles found on the bottom of a center cutter. I would think the added capacity of an ER20 would only magnify this limitation.

That's exactly what I was wondering to myself. Even with a low profile nut, I think the stick out would be problematic in many cases.
I also considered a straight shank ER holder. The shank OD could standardize on common R8 ID & might improve stick out slightly if it could be pushed in a bit more. But now you have something holding something else holding the stock. Not good. This is collectively what drove me to the conclusion the best plan of action is replace the work head to 5C because I have the full collet set. Another potential plus is 5C offers square & hex whereas R8 does not. Not sure I'd use it but something to ponder.

I got the work head off last night & spotted many Yeesh factors that I'll have to fix up. Fully spray painted dove tails, machining burrs that were dragging on the ways, misaligned parts that explained lack of movement. I was kind of prepared for this having watched a few YouTubes including Stefan.G & Rob.R. I'll save that for another post. First things first.

 

[Larry$]

I can get 5C head via that avenue

The shipping is a killer! The game of a low price and make it up in shipping.

 

[petertha]

Yes, an ordinary day for a Citizen of Kanuckistan. Always have to factor shipping cost & currency FX & other potential dinger fees. The irony is shipping this part from China is probably the same cost as USA to here. Potentially cheaper. Shars is quite a bit more for the base part, possibly how they have it configured with the bottom swivel assembly. And its not in stock so moot point. But I'm not over the hump with AliExpress yet,, language & communication issues. Sometimes what they call 'color' means part number. They show the collet style as being available but so way I can see to select it & be sure, so proceeding with caution.

I'm not 100% sure if the work head casting is identical between the various collet versions & the difference is confined to the tube which is inserted & somehow retained within the casting hole. I had thoughts of disassembling my R8 head & turning a 5C tube, but... lots of fiddly parts & might be some mystery assembly techniques that would bite me. Pressed in vs. glued in vs. .....?

 

[petertha]

This is what I mean about the insert collet tube (yellow) & presumably matching end thread tightening handle (green)

 

[Toolmaker51]

I had this idea pop in my head that I could use my R8-ER20 collet chuck. <<<<<snipped>>>>>>I'm not even sure R8 are supposed o be squeezed down that much? For example if say 0.015" below nominal, well then even a 1/32" increment set wont really span continuous diameters. My 5C set is 1/64" increment. Grrrr...

Generally speaking, collets that pinch have diameter 'tolerance' are more cylinder like, with longer slots and proportionally shorter tapers and classified 'work holders'.
ER's and similar combine the traits but collapse lengthwise over a significant range and hold either quite well. Tools are straighter, rounder and more concentric to their function than material.
R8 and the like are tool holders, with closed ends for drawbars or knock out bars, not conducive for holding material. BUT, in home shop environment R8 collet blocks would answer a need, bridging a gap before outlay and committing to 5C. Like this.....