Schmid micro boring head

In the recent time I had more and more the need for small diameter boring (below 5mm) on the milling machine.
I discovered that my Wohlhaupter UPA1 works for this application but is not ideal due to the large mass and the limitation to 1000rpm.
So I looked for a small boring head and found a used Schmid precision boring head on Ebay.
It needed disassembly and cleaning:

Another thing to deal with was the MT1 shank – On my mill, I use MT2 tooling or 10mm straightshank tooling when I deal with small tools/parts.
So I decided to modify the shank to 10mm, so I can use it in a 10mm MT2 collet, directly in the spindle of the mill.

The modification was not very complicated, the body of the boring head went into a 5C collet and was tweaked to run true (By loosening the mounting bolts of the 5C chuck and shifting it around till runount was close to 0.). Supported with a live center, I was able to turn the shank down to 10mm. In a second setup it was then also shortened, as a 10mm MT2 collet has only about 30mm length of engagement.

After reassembly it was ready to use:

Bushings for 3mm and 4mm shanked boring tools where made out of toolsteel, hardened and tempered.


The 4mm bushing has a crosspin, that allows the use of Gühring System 104 boring tools with their alignment bevel on the back.
The larger bushing shown is for the Wohlhaupter UPA1, to allow to use the same Gühring boring bars in it.

Both boring heads compared to each other: