D-Bit Grinder Holzmann UWS3

The D-Bit grinder is not the most common machine in the average shop, but every proper machineshop I worked in so far had at least one of them, in Germany that is usually a Deckel S0 or S0E. They fulfill a variety of tasks in the shop, when you don’t have a proper tool and cutter grinder, for example relieving the shanks of endmills, grinding single lip engraving and milling cutters, form tools for the lathe, shortening pins and much more.

I was looking into buying an old Deckel grinder, but the prices for those range from high to stupid high. But then, a few homeshop machinists got together and organized to buy a bulk of Chinese single lip cutter grinders for a very good price – And I bought one too.

That’s the machine, a Holzmann UWS3:

It came with some accessories, but most of them are quite useless (Endmill sharpening attachment) or I just don’t use them (Drill sharpening attachment), so I sold most of them. I only kept the stock dividing head that takes the Deckel Style 355E collets with the S20x2 buttress thread, the diamond wheel and the collets that came with the machine.

The 355E collets look a bit like an R8 collet and range from 0,5mm to 16mm in 0,5mm steps. Officially you are only supposed to clamp the nominal diameter, otherwise you might damage the collet (Just like with 5C collets).

Unlike the Deckel S0(E) grinder, the dividing head of the Chinese grinder runs in ball bearings – Which is in my mind an improvement, the Deckel dividing head wears out over the hears, if you do a lot of cylindrical grinding.

More detailed articles on different aspects and modifications on the machine:

  • Modifications to the dividing head
  • A few examples of work that can be done with the grinder:

    Single lip cutters in different forms:

    This is an example for an very small dovetail cutter to cut the 5mm dovetail to fit a dial test indicator:

    Relieving the shank of endmills to get deeper into slots and cavities without having the shank of the tool rub – Of course you can also buy a long fluted endmill, but a relieved one is stiffer:

    Regrind front cutting edges of endmills to get more life out of them:

    Grinding the front cutting edges of shell endmills: