For my cutter grinder I have a preference for draw in collets. It allows me to snug them up from the back end with a knurled closer. I consider wrenches a nuisance such as for ER collets.
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For my cutter grinder I have a preference for draw in collets. It allows me to snug them up from the back end with a knurled closer. I consider wrenches a nuisance such as for ER collets.
Agreeing with old_toolmaker, but different objection. Draw in collets have a distinct advantage over those closed at the front. The nut required by the latter eats up tool length to grip [adding run out], and interference within grinding/ cutting area. 1/2"+ diameters maybe not so bad, adverse in the smaller sizes, being proportionally shorter.
PS. There are toolholdering and workholding collets; for example 5C is good at both but they are workholders first.
R8, on the other hand not a good workholder because they are blind, restricting part length.
ER and similar are terrific for tooling and work. The reason outside others mentioned, is they collapse to grip; full contact and concentricity.
Many collets only pinch, good for a specific diameter +/- a thou or 2 max.
5C and such [215, 2J, and others get a bit of range because their overall length.
I definitely agree with that.
I am currently using ER-32 collets. I plan to make or purchase a suitable set of draw in collets to fit within a 1” diameter bar.
I don’t know where to get drawings for this cutter grinder attachment, but there are numerous similar bench grinder attachment plans available. Maybe Google “Tinker Tool and Cutter Grinder”
The only working drawings I have for this are in Sketchup format, they are to scale and can be dimensioned from within if you are a user of Sketchup. These were drawn retrospectively for the post as I do not generally make drawings and work on the fly with what I can find and good old pencil and paper. I could send a zip file if it would be of use to you (too large to post here). I have since made a new top block incorporating an ER20 mounting with a click indexer for end mill and drill sharpening.
Seems the Tinker T&C grinder was a popular feature in the "Home Shop Machinist" publication; so much that castings were available by order.
I would greatly appreciate the zip files that you have offered , heck even sketchups will help. If you can just email them to me. Thanks
I would appreciate the zip files if you have the time. Please email them it is greatly appreciated
I was particularly interested to read about salvaging a cupped grinding wheel using plastic metal. What limits would be placed on a repair like this? I note that it was a diamond lapping plate, not an ordinary grit wheel.