Member postings for Hirschli27

I can give a little bit of help for the disassembly of the internally geared Mikron T90 and F75 headstocks.

Starting with what you should not do: DO NOT turn those two small screws that seem to go directly into the bearings. They have flat sides at the end that go into slots in the bearings. If you turn them they either break or damage the bearing slots.

You also do not habe to remove the bearings (unless you have to adjust for radial play). Realigning them to the spindle is somewhat time consuming when you put them back.

The spindle comes out at the front. There are two rings around the spindle at the front side. The first is partly hidden and has a small screw. This screw ends in a slot on the spindle and prevents it from rotating. It should not be tightened as it should be moving along the spindle. If it is tightened just loosen it a little (it does not have to be out completely).

The second ring is a nut screwed on the spindle and it is for adjusting the axial play. Remove the screw. Under it appears a small piece of bronze which on the bottom has the same threading as the ring. DO NOT touch this bronze piece - you will never get it back in at the right angle if you move it.

After removing the screw it should be possible to turn the ring somewhat. On the opposite side of the screw there is a hole that is useful if you have to use some force to move the ring in the beginning. But be careful not to insert any rod into the threaded hole to get the ring moving. Also be aware that the ring is rather soft and the also unthreaded hole can be easily ruined with to much force. The ring should move easily - do not use force and stop before it touches the pulley. If the ring is turned to move towards the back of the headstock the hole will be partially covered by the pulley. It is not necessary to screw it that far to the back now. Just leave it where it is for the moment.

Moving to the pulley: You must loosen the screw with the square hole. This screw locks the pulley to the spindle for turning without the internal gearing. If you use the internal gearing the spindle and the pulley turn at different rpm (3:1) and so this screw must be unlocked for this purpose. The other screw on the pulley is for oiling and can stay where it is.

At the backside of the pulley is another ring with two screws on opposite sides. They have pointed ends and fix the ring to the piece underneath. Before you remove those screws check if one of them and the threaded hole in the ring are marked (punched dot or x or similar). If this not the case you really should mark one of the screws, the matching hole, and also the piece under the ring. If you do not you risk that when putting it back together in a wrong combination the internal gearing will block completely (I can tell!). Both screws must be removed. Now the ring should turn freely. Do turn it 90° and look into the threaded hole: underneath has appeared another screw in each of the holes. Unscrew these, too. Now the pulley should be able move a little. You can now can gently turn the second ring at the front to unscrew it from the spindle. It should move to the back along with the pulley and the spindle can be drawn out at the front as soon as the ring reaches the end of the threads on the spindle.

Be careful when you lift the pulley after the spindle is out: The internal gearing drops out very easily if it is not too dirty.

I have two of these internally geared Mikron headstocks. With one this procedure has worked perfectly well without the use of any force - so I can tell it is the way to do it. With the second headstock I followed the same procedure - and the pulley does not move. I think it is stuck because of dirt or hardened oil.

Kind regards, Kaspar

As a Swiss and an owner of a Schaublin lathe I can give you the answer:

We have four official languages and MANY dialects - so it is no surprise that there are several correct answers. Also Schaublin is a family name that is spelled in two different ways: Schaublin and Schäublin (with the two dots on the a, if it cannot be displayed correctly)

- in the german speaking part of Switzerland many people pronounce the name show(er)-bleen. This is the correct local pronounciation if the name is written "Schaublin" (which it is in most sales literature, manuals etc.)

- in the german speaking part of Switzerland also many people pronounce the company name as shoy-bleen (a little bit like soy-bean but with a sh in the beginning and an additional l). This is the correct local pronounciation if the name is written as Schäublin (with the two dots on the a). And that is what the company does sometimes (or at least did). In some sales literature the company called itself not Schaublin S.A. but Schäublin AG (with the two dots).

- to make matters more complicated: The name has its roots in the german speaking part but the company itself is situated in the french speaking part of Switzerland. There the name is pronounced similar to the name of the composer Chopin (if pronounced in french). As close as it gets in English would be sho(rt)-bl(ue)-un where "un" is pronounced like the french word for one.

Hope this helps.

Like the other two slots it is a V-slot that helps with alignment of the accessories of the Mikron F75 (vise, dividing heads etc.). The slots and the bottom Vs of the accessories were scraped for a perfect match and that makes alignment in both directions very quick.