JMI NGF Focuser Mods?

I've searched for, but could not find, any mods related to the JMI NGF series of crayford focusers.

I have a DX3 that seems a little too stiff and a bit rough, or "bumpy". My previous DX2 had the same issues, although not as bad.

Any ideas of what I could do to smooth this out? (Upgrading to a Feathertouch or Moonlite excluded.)

Thanks,

Mark

First, make sure the roller bearings are clean. On my NGF some of the black anodize finish from the focuser drawtube would build up on the bearing surfaces over time, causing roughness. Also, check for a similar build up of material on the steel axle that presses against the flat surface of the focuser drawtube.

Second, I think I saw a website somewhere (sorry, don't have the URL) where the guy reworked the flat surface on the drawtube to make it perfectly smooth and flat. On his focuser, there were some machine tool marks leftover on the drawtube flat. I think he used a "Arkansas Stone", normally used for knife sharpening, to polish the surface flat and smooth.

Best of luck,

Ed