Mystery Attachment, possibly for Tool & Cutter Grinder?

I recently won an auction which included a mixed bag of attachments for tool & cutter and other grinders. The auction was to clear the workshop of a closed company who had specialised in making and sharpening cutters of all kinds. Mostly carbide milling cutters and timber working cutters made on ANCA CNC grinders, but also a whole lot of old manual grinding machinery. The attachments were not kept with the machines, so it was a bit of a mess.

I know what most of the attachments are for, but not this one.

There is no name on it, but the chart seems to be written in German and says "Clearance Angle Table". That is a Google translation, so it may be incorrect.

There are some cast-in part numbers which begin with "BSG". Searching with these letters found a German company "Kaindl" who make grinding equipment, some with the model prefix "BSG", e.g. drill sharpeners. But I couldn't see anything that looked like this.


There is a main barrel with a crank handle on one end and a smaller barrel (black oxide finish with an internal morse taper) inside the main barrel.

When the locking pin on the crank handle is withdrawn, you can rotate the main part of the barrel. What is interesting however is that the smaller barrel then rotates inside the main barrel, but in the opposite direction and at roughly twice the speed.

Any ideas what this attachment is for and who made it?

Thanks for any help!

Probably for drill sharpening

Peter

Along with Peter, I'd guess an eccentric relief fixture for tap relief grinding, drill grinding etc.

freiwinkel tabelle - clearance angle table. I agree with the above.

Tom

Yup, agree as well.
Much like the drill grinder I had.

The 1:2 ratio is to drive a cam for clearance for a 2 lip drill Perhaps it is possible to change the ratio to 1:3 or 1:4
Does it come with a cam ??

Peter

I agree it is some kind of relief grinding fixture but it isn't obvious to me what it is for.
It could be for drill grinding but that type usually have a means to swivel the base while turning to take off the heal on the secondary relief of a drill similar to the Brierley shown in the video.
brierley drill grinder 11 - YouTube
I notice in picture #4 there is some thing that looks like an arm coming down from the spindle centre that prehaps would serve to provide the rocking action somehow.
I don't see any protractor on the base swivel to set the base for the point angle like on the Brierley either.
Perhaps you could try contacting Kaindl and see if they made something like this at one time .
KAINDL PROFESSIONAL SHARPENING & GRINDING MACHINES
If they didn't make it they may know who did .
I don't recognize your attachment as belonging to a Tos or older Walter ,Deckel,Saacke , or Christen machines that I have seen.
There were some companies that made cutter grinders that were adapted more for wood working tools .
Stehle was one of them that I was reminded of but it doesn't seem to be at first glance for one of those either.
stehle grinding machine - Google Search
Jim

Here are a couple of scans from a Saacke brochure from the mid 1980s that show their relief grinding and drill grinding attachments .
I have a feeling the drill grinding attachment is one they bought, copied or licensed from Brierly .

Thanks to everyone for your replies, all of them helpful.

Following Peter's comments about ratios and cams, I had another look at it today.

The ratio looks to be 1: 1.5.

One complete turn of the handle rotates the spindle 1 1/2 turns. This brings the 2nd flute of a 2-flute drill into the exact same position/location as the 1st flute was at the start. Very clever.





There is an internal cam of some sort which advances and then retracts the outer barrel once per revolution of the handle.

The cam "lift" can be adjusted by the graduated knob on top, '0' = 1.5mm stroke, '10' = 3.3mm stroke (approx.)

Photos below show the adjuster and also the advanced and retracted positions:

Jim Christie said:

I notice in picture #4 there is some thing that looks like an arm coming down from the spindle centre that prehaps would serve to provide the rocking action somehow.

Click to expand...

Jim,

The arm you noticed is a tube which is free to rotate 360*. It is a simple welded assembly and looks like a rod or bar? is made to fit inside. There is a knob on the side which could lock anything put inside the tube.



A closer shot of the base. Interesting to see there are wipers fitted.

The two large locking handles are the type you can lift (against a spring) and re-position the handle. One locks the swivel base (in photo below) and the other locks the tilt of the spindle assembly.




I fitted a short 1" drill into the spindle, but I guess it might require one of those multi-jaw chucks?

The tube perhaps is missing a piece that is meant to set the position of the cutting edge of the drill
A drill chuck with a morse taper can hold the smaller drills

Peter