Supercharged mounts with 4-5 times better PE than normal

[g__day (Matthew)]

I was reviewing mounts with acceptable carrying, pointing and tracking capabilities to handle long duration astrophotography.

The CGE was looking interesting until I saw its raw PE is around +/- 15 - 20 arc seconds (ugh), so all its great looking design and asthetics, and its simple to use functionaility it looks like it fails the tracking test badly.

Interestingly I read about Dr Clay Sherrod of Arkansas Sky Observatories who does a 107 step "supercharge of mounts" like the CGE. The results seem to be PE of 4-5 arc seconds - or better with PEC!

http://www.arksky.org/supercharge.htm

I wonder if there is a service that can improve PE by 200% - 300% - why don't Celestron and Meade do it out of the box as part of their quality assurance program?

Anyone experienced this?

[rogerg (Roger)]

No, I haven't. It would be interesting to hear from someone who has.

However, US$575 for my LX200 would definitely not be worth it for me. PEC gets my PE down to a few arc second anyway, why bother with spending $575. Not that I've tried training PEC since all my hardware replacements recently to know if it's still so easy to achieve such good PEC.

[netwolf]

This is a great service however once you add international shipment costs its becomes a service few can afford. Wish something like this was available down here. I know Bintel do offer certain services in this area but I am not sure how they stack up against Dr Clay. It would be good if people could do a training course and become certified to do it locally.

Regards
Fahim

[g__day (Matthew)]

It would be good if the manufacturers became certified on the finishing touches for their own equipment and didn't let it our the door until it was good as it can be!

Honestly - if it there were basic and fully quality control checked gear - it would give us the option. I'd pay for a premium offer.

But the very fact his services so seriously boost performance show something very major is left lacking in the finishing department. Imagine if you bought a car and only after a special check up would its performance be boosted 300% - don't you think you be wondering that the manufacturer just didn't do an optimal job finishing his product? If my brand new car did 100km on a tank of gas, then I got it special serviced and after that ir regularily managed 400 km on a tank I'd rightly understand the manufacturers blew it on the finish!

We aren't talking a 10% or 30% lift here - his results show 200% - 300% lift of brand new moderate - high end scopes. As well as corrections to faulty gear! That screams to me that this gear is being shipped in very, very far from optimal condition. I'm stunned thinking it through why they don't just do the final checks and tuning Dr Clay does!

[Kal (Andrew)]

Meade/Celestron are manufacturers that cater to the volume market. If you want that sort of attention payed to the product then you can have it, you just have to purchase off a different manufacturer like astro-physics etc. but you will pay the $$$ to have the attention payed to the final product.

[asimov (John)]

Your expectations from this mount are a little high. If you want + - 4 or 5 out of the box, expect to have to pay a lot more than the fairly trivial amount the CGE go's for.

As usual its hit & miss, my CGE is + - 10 out of the box.

[AndrewJ]

The results seem to be PE of 4-5 arc seconds - or better with PEC!

I cant comment on the Celestrons, but as part of writing/testing my PEC editing App for Meades, i have seen quite a large no of Meade curves.
These range from +/-12 arcsec ( best ) to over +/-56arcsec
In the Meades ( GPS/RCX ) there are two major sources of PE,
when talking in the +/-10arcsec region.
The motor gearbox and the worm. The gearbox PE is very complex, but has a period equivalent to three turns of its output shaft ( hence the new PEC system they use )
Sooo, the result you get from PEC training is going to be a function of the motor as well as the worm that was fitted to "your" scope
( and the phase they are connected with )

Doc Clays supercharge effectively blueprints the scope and sets all the meshing tolerances etc
however, the result obtained for PEC training is going to be limited to what gears ended up in the scope. He will probably get the best out of whats there, but the result is still limited to the tolerances of whats fitted.

I wonder if there is a service that can improve PE by 200% - 300% - why don't Celestron and Meade do it

A program like PEMPro can create a good PE model,
Doing a train followed by multiple updates in the meade scope will also give reasonable results.
Another option is to do multiple trains and tweak them in an external app and backload ( which is what my app does ) This allows you to see how "consistent" the PEC training is. This is very illuminating.
I have NEVER seen a set of data where two trains gave similar results.
There are always non periodic phase shifts due to tooth spacing errors etc
The Meade gears are apparently flat cut, not true worms, hence there are lots of non periodic effects due to the way the gears mesh.

Bottom line
All the above methods will average this to a best fit, but the final result you achieve will be limited by what gears you got to start with.
Also, for latest GPS firmware (4.2g ) it looks like Meade have inverted the data if yr in the Sth Hemi, which doesnt help either

Andrew

[Vince G]

To improve the periodic error in RA here is what I did with an 8" LX200, and my 12" LX200GPS.
Using a high power eypiece centre a star near the zenith and watch its movement.
If you think it needs improvement then loosen the RA clutch and rotate the 'scope to face east. Re-tighten the RA clutch and slew the 'scope back to the same star.
If there is not much improvement then repeat the proceedure until you can see a tracking improvement.
If you do improve tracking significently then never loosen the RA clutch again.
With my 8", I was able to image for 4 minutes unguided. Probably a miracle.
The 12" has improved a lot from its original errors.
Give it a try it may help.
Vince G