14.5" Starmaster with ServoCat and Argo Navis 1966 Unitron 4" Model 152 EQ Tec 140 TV NP101 f/5.4 APO Telvue .8 Focal Reducer FLI ML8300 and CFW-2-7 filter wheel Astrodon Gen2 RGBL 2" filters Baader 2" Narrow Band Filters Borg 50mm Guide Scope/ATIK Titan Guide Camera AstroPhysics AP900 Losmandy GM-8 Gemini
17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha. Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
Quote:I also noticed that when I took a mchinists level to the disk that actually applies the pressure there was a significant low spot in the center. What this meant was I was getting pressure applied from basically the outer 1" of disk. I took a bodywork file and carefully worked the disk over till it was nice and flat.
Quote:I am curious if you ever use the mount for push-to operation since your mod and if you've noticed more stiction in its motion? I ask because I recently designed and built a mount using a PTFE disc sandwiched between aluminum plates (similar to DiscMount), and I'm interested in the results of similar setups with different surfaces in contact for braking/clutching action.
Quote:The design tolerance surely allows for that center depression in order to compensate for flexure as the clutch parts are pulled together via the main axial shaft, and to keep the hob gear from deforming under axial load on its unsupported center portion.
Quote:Breaking the smooth, hard anodized surface with a file is most likely why your mount is clutching tighter now, since raw aluminum is known to have drastically lower lubricity than class III anodizing. This can be an advantage if you're strictly using it for GOTO operation with near maximum loads. Unfortunately, a microscopic layer of aluminum oxide smut constantly builds up on all unprotected aluminum surfaces and gets pushed around by anything in contact, increasing wear rate of all the parts.
Quote:I'm glad the tune-up is working well for your application. I hope you'll keep us posted on its performance when more of your great images start coming in!
Quote: I never was unable to tighten the clutch enough to prevent un-intended movement of the scope. Putting levers on the tension knob made it easier.