Monorail focuser loose.

[Jessun]

I have a monorail focuser on the RC. It's an Orion one, but they are fairly generic I'd say.

Mine seems loose, and I can wiggle the drawtube sideways - it's like it's pivoting over the point where the rail meets the friction screw. It's a full millimetre each way, and that makes for quite a bit of angular movement for such a short draw tube... Not good.

Can this be adjusted?

Greatful for any advice!

/Jesper

[EBXL5]

Having a similar issue with my SkyWatcher 150 Dobs focuser, any help in adjustments etc much appreciated.

[Jessun]

Not too much to go on here, so I replaced it with a 2.5" Moonlite !

/Jesper

[EBXL5]

After a small bit of fiddling, I found out the two grub screws fore and aft of the focuser locknut correct this play in the system. The grub screw closest to the EP had no tension on it at all, once tightened nearly all play in the focuser was removed.

Not as nice as a 2.5" Moonlite though.

[Jessun]

Glad you got it sorted. I took mine apart and once the pinion assembly was off (four screws) another set of screws became visible, and these needed tightening. So now I have a spare :-)

/Jesper

[EBXL5]

Just retightened the grub screws after getting the right tool for the job and can confirm they are 1.5mm hex headed screws.

The focuser is now super smooth and super tight and I feel much happier trying to hang a DSLR off of it.

[Moonshane]

Resurrecting this thread as I also has severe sideways waggling on my monorail which is on my pst mod. I got fed up in the end and took it apart. I found that after removing the four small bolts that hold on the focuser knobs and housing (shown in the photo below), the problem was obvious. There's a small plate which centralises the steel runner on the drawtube. Ensuring the drawtube was squared, I tightened up the four loose screws and put the focuser knob housing back on and now all is well. Nice and tight again and working smoothly.