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Last night when we was out in the night to do astro photographing I got problem with my Star Adventurer mount. The friction coupling in RA axis got stuck and I have difficulties to aim the camera to the object.
Today I have dismantled the mount to find what the problem is with it. I got to repair it, I took photos from my disassembling and repair that I think can be interesting for others to look at and read.
Here is the link to my homepage:
Have any other of you had a simular problem with the Star Adventurer mount?
So my birthday just past so money to splash on astro stuff , i will have my 1000D modded by juan at cheapastrophotography and also have ordered an autofocuser from deepsky dad https://deepskydad.com/autofocuser i know they can be done DIY but this is a neat package and costs about the same as a SW autofocuser and a hitechastro focusmaster and i`m no electronic wizard and pavel seems to have a good product and works with ascom and confirmed it works with APT i will update in a few weeks time when hopefully i will have received and tried out .
I have a Helios 200p (identical to the Skywatcher) mounted on an EQ3-2.
I know it is overloaded but I find it OK for visual provided I give it a couple of seconds to settle down at high powers.
I intend to motorise the mount using stepper motors & an Arduino. It will be tracking for visual only with a possible upgrade path to GoTo.
Since I dont need fantastic precision and having read the relevant threads on this forum, I propose to drive the RA worm directly & the DEC with a simple belt drive. By avoiding a step-down gear set I will still be able to use the manual slo-mo controls without disconnecting the motors. I think that centering the target with the slo-mo's & then switching on the tracking will be nicer than using fast-forward & fast-reverse controls.
But no step-down means no torque amplification. So how much torque do you need to drive an overloaded EQ3-2. I decided to do some quick & dirty tests.
200p with 25mm Plossl & 9 X 50 Finder, payload about 9kg.
EQ3-2 with 10kg of counterweights
Improvised wooden pulley, effective radius 0.375 inch
2 X 1kg barbell weights
piece of string
For each axis ,with the clutches locked, a 1kg & then 2kg load was hung from the pulley & released. This was repeated for the opposite direction of rotation.
DEC 1kg Torque 13.5 oz.inch Rotated smoothly at about 90 degree/minute
DEC 2kg Torque 27 oz.inch Rotated quickly at about 300 degree/minute +
RA 1kg Torque 13.5 oz.inch Did not rotate
RA 2kg Torque 27 oz.inch Rotated smoothly at about 90 degree/minute
The required torque for RA would be on the limit for a (cheap, ungeared) NEMA 14 stepper but a NEMA 17 motor with a torque of 84 oz.inch should be up to it.
So now all I have to do is order the bits & learn how to use an Arduino.
By Roy Challen
My Dad has asked me to sell this lovely Tal 100R on his behalf, I hope this is not against the forum rules. I owned this scope before him, and the condition is as it was when I had it. There are a few chips in the paint and some very small marks on the objective. There is a scratch on the inner surface of the dew shield which creates a horrible reflection on the objective, however this is not visible when observing. It comes with the original diagonal, mount, tripod and box, but no eyepieces. I do have some Tal plossls of a later vintage that could be added to make a complete package if desired. I fitted the SkyWatcher spreader plate/accessory tray as it was much better than the original, but does take away from its originality.
I'm asking £200 and collection will have to be from Watford as it is a heavy item. The link at the bottom is to my first and second light reports of this scope. It sounds a little negative but that's only because the RS is that little bit better.
If you have any questions or need additional photos, just ask.
As I am hopeless with DIY, give me a car, bike home electrics or plumbing I`m fine anything else I am rubbish. Well bought this ironing chair second hand from Ebay £9.98 came in bubble wrap on inspecting it the back is cracked and broken. For the price I am not bothered about that but could you kind people give me some ideas as to how replace it please.