Hi,
as i said some people are lucky and get good results, search around, many have problems. I have used a variety of tools over the years to analyse what is going on. I know exactly where the problems lie:
1) the bearing journals are not concentric with each other, nor with the actual worm thread...this means the worm wobbles in its bearings as it turns. Adjust backlash so it is right in one spot then the worm jams in another....)
2) the transfer gear is not round (appears to be a moulded blank that has been cut when examined under a loupe) This means that it is not possible to correctly set the spacing between the gears for good engagement)
3) the 47 tooth gear on the worm had been bored to an incorrect size so it was a very loose fit on the worm and wobbled - though we did make a collar for it in an attempt to fix this...a small amount of success.
4) because the gear ratio is not even, periodic error correction can never give good results as it does not repeat regularly (the gear ratio is 47/12=3.916666)
5) I get the well known 10.2 second error, which because of the above factors causes a 2 arc second jump every 10.2 seconds that is far too fast for an autoguider to catch - note that it was a 5 arc second jump when I started!!!!!!
What I have tried (the short list!)
new collar to fit 47 tooth spur gear accurately to worm - slight improvement
New precision bearings to hold worm - no difference
New gears from Alaska - useless as motor gear was not made accurately and wobbled on motor though others were fine - $200 down the drain
Lapping everything - no great change
Huge number of attempts to adjust everything to get tracking right - did get it working for a short time purely due to dumb luck, didn't stay right for long..
Have tried every possible option to fix it, but no luck. The stupidest decision I ever made was to sell my Bartelised EQ6 to avandonk......it was beautiful.
After 3 years with very few images to show for it, I'm sure you will understand why I am a bit peeved with it!!!! I really wish I had a good one, but I don't, time for a change......
I do have to say that Tasco gave outstanding service, replacing the original mount twice after examining my original one. they paid freight both ways and agreed with my problems. I regard their service as exemplary. The only thing they didn't do was offer me a refund! The two replacements were similar in performance to the original, so I can only conclude that there was a bad batch around when I got mine.
hope this fills in any queries..
cheers
Gary
Quote:
Originally Posted by bmitchell82
I run a 10" dob with a 114mm newt running 20 min subs with round stars. something must be amiss with yours, sure you might get one or two lemons but not one after the other when so many others get decent variants.
where about's are you in aus? maybe there is somebody that can at least look at what your doing. irrespective if you can pull this mount down in 30 minutes sometimes different eyes see different things. just a suggestion.
As bert said Leinard has his vc200l in its native format and i have accompanied him whilst this is happening. have you used PEMpro to see your errors. and whats actually happening at the time?
just trying to help as the eq6 is a decent setup until you save some dollars.
|