Author Topic: Venusberg Grinding Attachment for a lathe  (Read 329 times)

Offline eskoilola

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Venusberg Grinding Attachment for a lathe
« on: March 06, 2018, 02:28:37 PM »
Something to keep my tools sharp.

Venusberg 4-jaw drill chuck. Attach this with a rolling facility in the toolpost, rotate some grinding material in the spindle and You should have a quite versatile grinding tool with decent accuracy. The four jaw chuck enables to sharpen things that are square - as lathe tools sometimes are.

The chuck is an unused DDR oldtimer. I think that this has a Jacobs taper. I might be wrong but replicating a matching cone is a no-brainer. Just takes some patience when setting up the compound angle.

I have already made (my first) drawing of the part which is the one that is fixed to the toolpost. I would greatly appreciate feedback for that one. I tried to create a design which could be made with reasonable accuracy without milling equipment. Fortunately I have a 4-jaw chuck in my lathe. That helps.

The ring with 36 holes is one part of a spindexer. The "thing" that rotates inside this tube has a similar plate with 10 holes in it. This results theoretically in one degree accuracy.

The rolling thing inside the tube should also have some sort of a brake to make it steady. Maybe an expanding axle with cones and all - or just a simple set screw in the side. Actually I like the idea of a swelling axle - it might make a better grip and certainly be more interesting to make.

The drawing (a small PDF) can be downloaded from here.

Here are some images of the Venusberg 4-jaw chuck. Bigger ones by clicking each image.