Flocking SkyMax 150

[catburglar]

I'm considering flocking my SkyMax and would like a bit of advice before I get any tools out.

Itlooks as though the front and rear cells are secured by small allen bolts- does anyone know if there are nuts on the inside of these to drop off and fall onto the meniscus or mirror?

Also, will I have to worry about collimationifI keep the relative orientation of front and rear cells unchanged when I reinstall?

Any advice from someone who's done this is very welcome.

[Peter Drew]

I'm sure that not all designs are the same, but some models have nuts on the inside the rear cell. If they fall off they're easy enough to recover, it's getting them back on again that's the challenge. I would advise removing the front cell only and flock from there. Make note of the orientation as you already mention. Good luck.

[JamesF]

I've not stripped a 150, but I've done my 127 which sounds like it's similar but different

On the 127 the meniscus lens assembly is threaded and screws straight into the end of the OTA, so I can't help you there. However, the backplate may well be similar. There are six bolt heads showing through the backplate on the 127. Three of those screw into a pressed steel frame that itself screws into the back end of the OTA, and the other three press against the frame. Between the six of them this allows the primary mirror to be collimated. None of them have nuts. In case it's useful, here's a picture of all the bits:

If the 150 is the same then you will need to recollimate the scope if you touch any of the screws at the back. If you can do the entire job from the front and mark the meniscus assembly so it goes back exactly the same way then you may be ok. Unfortunately the baffle tube extends well into the OTA and is covered in grease so it's hardly ideal to have in place, but the only way to remove it is to remove the backplate.

Collimation is a real pain in the neck compared with your average newt, but not beyond the realms of possibility. I did mine by eye using a bottle cap that I'd drilled a small hole through. This is what the diffraction rings look like now:

which I think is pretty reasonable.

James