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Hallo Allemaal,

Ik schreef een klein tutorial over wat ik van Juraj leerde.
Hij paste zelf ook nog wat aan. Allemaal lezen !
Voor onze internationale mede frezers/broeders maar in het Engels gedaan.
Volgt hieronder en als doc attachment.

I wrote a small tutorial about lessons learned from Jurai.
He did write himself also a part. Read all !

See below and also attached as a doc file.
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Lessons I learned form Juraj,

Fine-tuning the spindle (e.g. on the Y-axis).

Before starting:

Make sure that the wheels of the axis you are going to adjust are fitted with well some pressure to the rails (with the help of the eccentric wheels). Some pressure is absolutely necessary to reduce vibrations in the future.
When tightening the centric (no typo: I really mean the centric) wheels, make sure that AT THAT MOMENT the eccentric wheels are NOT tightened ! Have a sharp look at the ecccentric wheels. they can be positioned with the "triangles" in a light or a strong tightening position towards the rails. Think and look before mounting !

Addition from the Maestro himself:

"Better explained: There is always a set of two centric and one eccentric wheel that are used to make a tension on the profile. Eccentric wheel can be placed in two ways on it’s place. So that the when the tension plate (small triangle like plate) is turned to one side that the eccentric pert of the wheel is going towards the centric wheels or from them. Logically it doesn’t take much sence that by moving the plate you release the tension with the eccentric wheel. You must give pressure. If pressure cannot be achieved this means that either the plate or the wheel has to be turned by 180°

Centric wheels must be locked before you start adjusting the eccentric wheel. Otherwise you don’t have the support to make the tension. Use the key to prevent the wheels turning while locking the screws.

When moving the tension plate the eccentric wheel mustn’t be locked with a screw. Otherwise you won’t be able to adjust anything. Once you gave more tension, lock the tension plate with the small locking screw and then lock the eccentric wheel into it’s place. Now you can test if there is enough pre-tension on the moving system. If the result is OK, alignment is done otherwise unlock the eccentric wheel, unlock the tension plate and give more tension to the wheel. Lock everything as described above, and test again".

The absolute basis for fine tuning is the teflon ring around the spindle. Check that the screw thread of spindle and the screw thread of the ring are fitting right together.
Check and double check if the spindle is absolutely straight. If not, that wil reduce the maximum speed of the mill axes and give more vibrations. This ca make the cutting less stright and reduces the maximun veklocity of the mill.
Put lots of grease between them several (!) times. Move the ring several (and several...) times over the spindle, spreading the grease.
Adjust the teflon ring with the spindle with the two bolds to the lower part of the bridge.
Tighten it firmly. This position will be the (absolute) position which determines all other positions of the spindle (at the ends).

The other positions are of course the motor on one side and the ball-bearing on the other side.
Fit the spindle in the bear-ring and turn the screws.

At this moment the position is determined by the teflon ring and the bear-ring in the end !

Fit the motor and the coupling rot. Make sure that the coupling rot is free of motor parts. E.g. put it 1 mm from the utmost position it can take to the motor. Adjust the srews of the coupling rot at the other side.

Make always sure that there is NO tension between the position of the spindle in the coupling rot and the position of the spindle (and the bolds) at the teflon ring. If unsure, loosening and again tightening of the screws can solve this.

Start Colidrive and put in the editor window, a small but endless program which drives the Y-axis endless from e.g. 0 till 7000 and back and again, back and again, back and again.....

PA 0, 7000
PA 0,0

Make sure "File transfer" is ON (asterisk). Set repeat on a number you want e.g. 10 or 20.
Mind that "7000" in the "program" above are Plotter Units = about 17 cm on the Y axis.
The axis now moves continuous forward and back on the Y-axis !

Now put the milling machine in a 45 degrees side position with one arm (you need strong arms or some help). Adjust now the screws for the motor continuous during this procedure. Make small adjustments. You can feel and hear vibrations and so it's possible to determine the best position of the motor. The screws will "follow" this position when they are fixed in steps more and more.

Be sure, be sure, be sure NOT to damage/bend the spindle during any of this procedures ! This can make you cry for years ..... !

The procedure for the other axes is in principle the same.
On trick could be important to have a better adjustment of the Z-axis.
The painted back plate in the Z-axis (MP100005) can be a few microns to long, caused by the paint at the top (as seen in position on the mill/Z-axis housing). So I mean the surface which is about 80 x 2 mm at the top of the long side. Remove the paint here with a chisel or a sharp knife. Now it fits better and forces the Z- spindle in a better position when the cap plate is mounted again.

Happy fast and vibration-less milling !

Hessel