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View Full Version here: : How to adjust focusser ?


Ukastronomer
13-05-2019, 12:17 AM
Any ideas appreciated.

The 72mm scope is good but with all the weight the focusser slips, any ideas appreciated

thank you

Oh any advice on an alternative focusser also

Paullus
13-05-2019, 07:23 AM
I found running the "flat" surface of the focuser tube on a whetstone/sharpening stone improved the weight capabilities of my focuser. I generally followed this guide. It's a slow process but worthwhile:
https://agenaastro.com/optimizing-your-gso-crayford-focuser.html

and this is good for the general assembly of crayford focusers (screw number and placement seem to vary between manufacturers):
https://teleskop-austria.at/information/pdf/Justieren_Adjusting_Crayford_focuse r.pdf

xelasnave
13-05-2019, 09:32 AM
Maybe get rid of the diagonal and use an extension tube in its place...you would reduce weight and have one less surface in the optical path.
Alex

raymo
13-05-2019, 04:29 PM
All the crayford style focusers I have had were equipped with a locking screw
which enabled me to use heavy 2" eyepieces and/or a DSLR without any
problem.
raymo

sil
14-05-2019, 03:20 PM
.....so... rtfm is called for? find the model number of the focuser unit and a manual which may show screws for tuning as opposed to merely holding it together as well as an online search for adjusting/tuning/maintaining that model focuser to find others that have had similar issues and what actions can be taken. You may even find out there is nothing to be done with that model except replace it totally but at least you might find a definitive answer. Regardless souns like a good time to learn about cleaning and inspecting and regreasing the gear teeth . Make sure you aren't lubricating with something thin or inappropriate like wd40. A good grease can provide "sticktion" to help parts stay in the position you put them. Poor greases can change composition over time with use and changes in weather etc. I use SuperLube from a tube exclusively for mechanical lubrication and its never let me down or altered over the years. Others will have their own preferences though.