A while back I replaced the focuser on my mak with a TS Optics UNC low-profile unit:
This is essentially the Baader Steeltrack focuser, and I am guessing some readers may have added similar to their SCT or Newtonians.
This is beautifully smooth and free-running, however like many Crayford focusers it tends to roll out under the weight of a heavy eyepiece. While it has a locking screw, that seems to be all-or-nothing, ie achieving smooth drag is almost impossible.
However there is a simple modification, as follows.
On the underside of the focuser are two 5mm threaded holes which originally had 5mm grub screws fitted. These are for the motor drive - but I'm not using that.
Remove these grub screws and insert two 5mm nylon screws long enough to press against the shaft inside. It only requires modest finger-force to apply drag to the shaft - enough to hold heavy eyepieces - without compromising the ability to focus. This works much, much better than the lock screw.
The two nylon screws I used are part no. SFTR-M5-20-N from ACCU in the UK:
https://www.accu.co....ry=SFTR-M5-20-N, these are visible in the attached photo.
Edited by luxo II, 24 May 2019 - 06:55 AM.