malc-c

Nick, could cause the belt to wear a bit I guess, could there be a clearance issue ?

Brilliant project, executed superbly.

Well done,

Thank you

And as I have said before in my own thread.....

Everyday I look at it or I am inside,

I can say

"I BUILT THAT"

:D:D:D:D:D

Wayne

Wayne, that is oh so true. There's not a day goes past without me doing the same at least once (normally more ) in the day.

It's also the look on peoples face when they are informed (normally by the wife) that I built it and not a professional builder

it's just taken me best part of 2 hours to read this entire thread, and wow... I'm really impressed and very envious!

You have given me some ideas, we have a very under used 4m x 4m decking area at the bottom of our garden........................

Thanks for the comments and glad it has given you some ideas, and look forward to reading your build thread

Chris, don't go giving me ideas

I then parked the scope up and resynced the steppers and created a new point list, after the first 3 stars I got every slew in the centre of the crosshairs on the QHY8. Slewing accuracy has definitely improved with the belts so a big plus there for the conversion.

Nice report George, and for the above reason alone it makes sense to do the belt conversion IMO

I must admit I do keep a tidy ship Helen

Just need a clear night now to see if the PC can drive them both with all the apps running for real.... PHD does seem to be quite demanding

One small update:

I became so frustrated trying to juggle all the apps around on the monitor, I thought I would treat myself to a little upgrade

Now I have no problem having CdC, APT, EQMod, and PHD open all at the same time

Well, my machinist has worked his magic and i have everything back and ready. Now where is that extra small allen key...er....that really small easy to lose Allen key....oh darn it.

And none of the shops have one that small..

I hate mechanical thingies...

LOL - try RC model shops.

Thanks again from a EQ6 user for EQmod and all the secondary programs that run with it

Second that... and more so for the ongoing and free support via this forum...

Thanks Chris...

Is the 0.018 arc seconds a lot in the scheme of things ? - I polar aligned my scope using the built in alignment part of EQMOD, and then used the dSLR drift method (produces V trails if out of alignment) to try and dial it in.

@gina and nick - glad you guys like this... all these numbers and nice graphs look good, I'm failing to grasp this and make sense of it all.

Chris, thanks for that. I'll go through it in detail later as I'm off to work in a few moments. One thing I noticed is that the trend value through the 200P was zero, where as the ST80 gave a value suggesting a miss-polar alignment. Am I right in thinking that due to longer focal length the tolerance would be tighter on the 200 than the ST80, and thus would be more sensitive.

Could it be that the ST80 isn't mounted 100% true in all axis to the 200P's optical axis ? - If the 200P is out of alignment, in which direction is it out (i.e alt what set of bolts need adjusting)

Thanks for your help on this Chris

Sounds good... and thanks you.

At least I'm hoping to use this as a comparison for when I eventually sort out a suitable belt drive system for the HEQ5. If I choose the same star I can then have a direct comparison.

Sorry to somewhat hijack George's thread, but it is kinda related

I've just spent this evening gathering data as follows:

1Hrs running PHD with the QHY5 connected to the ST80

1Hrs running PHD with an SPC900 through the 200P.

Target star was Altair

I've attached the log files which I would love to have analyzed (Chris if you have time I would welcome your comments). However, looking at the attached screen shot it's obvious that I have quite a few problems, unless I've some how entered the incorrect information when importing the file ?

ST80.txt

200p.txt

Chris, I've been running now for 40min through the ST80.... If I get chance I'll also try it with a webcam in the 200P for an hour and then post up the results later. I would apreciate your input which hopefully will confirm how well or poorly aligned my scope is, and how much PEC I now have after the re-build of the drive train

Thanks for the input Chris. I use a QHY5 with an ST80 for guiding, is the QHY5 supported by perecorder or is it just webcam only

Chris, I'm going to ask a numpy question here. How to you obtain unguided data from PHD, and if it's unguided, does that mean I could simply let the mount run for an hour in the day time to get the data needed ?

I've just downloaded Chris's PEC application and dumped the PHD logs from previous guiding sessions (not had a chance to test since I re-meshed the gears). Not having a clue if this is right but this is what the application gives me... I assume by having small bumps in the graphs the mount is within tolerances ??

Wow - Nice graph.

Ahhh I see.

Its up to you - you can either stick with the same ratio (if you can source the 47 toothed gear) or you can go for a 5:1 ratio

For a 5:1 ratio on an HEQ5 you would need to set EQMOD up with the following parameters:

Total Steps = 8640000

Worm Steps = 64000

Tracking offset = -28

For a 4:1 ratio on an HEQ5 you would need to set EQMOD up with:

Total Steps = 6912000

Worm Steps = 51200

Tracking offset = -211

However with the 4:1 ratio you would be operating a long way away from the original values the mount is designed around and you may find that the max slews at a much faster top rate (this isn't controlled by EQMOD - the mount makes its own mind up how fast to go when slewing to a target and of course it doens't know you've changed the gearing!)

[Edit] Just for completeness I'll give the HEQ5 6:1 values

Total Steps = 10368000

Worm Steps = 76800

Tracking offset = 80

Chris.

Chris, I've opted for the 5:1 ratio... but a tad confused

In Georges post above the two values for RA and DEC are different

Is this the same on the HEQ5 or are both RA and DEC ratios 705:1 ?

The top of the shaft has a hole in that I though was a grub screw, but it had no hex form to it so the alley key just spins round... but it does look as if the shaft has a step turned at the end and the cog is fixed (probably by cooling the shaft first)

I don't want to force it so that I risk damage to the motor or gear, juts in case i need to return to gear drive

Neil, here ya go... not a grub screw in sight

On the stepper shaft gear there are 2 hex grubs, just loosen off and it should come easily, if not wrap something soft round it and wiggle free with grips......same with worm shaft gear.

Alternatively have a gander on Astrobabys site

Had a gander at that site, but can't see any mention of removing the gear. On the HEQ5 motors there are no grub screws, and it would appear that the shaft is stepped to take the cog

Not sure how to pull the cog off without damage (bear in mind I may need to return to factory settings should the belt drive not work)

Without giving too much away (you never know who might be reading this forum)..

CCTV cameras covering the back gate and observatory. PIR operated security lights, flood the garden with light should anyone enter the garden. ROR bolted down by turnbuckles on the inside. 5 lever mortise locks on the door, with blind hinges. 129db alarm system, which will give anyone hearing damage if near the sounder for too long. Security marking of the costly stuff....

Oh and if they think they can get through that... the ultimate deterrent.... a 4yr old German Shepherd who not only raises the alarm when she senses something is not right, will, like one of the other posters will protect the household if released. Any would be thief wanting to take her on would have a screw loose !