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HEQ5 / Sirius EQ-G Strip Down Guide

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#1 astro_baby


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Posted 08 February 2009 - 07:20 AM


Apologies its been ages since I posted here, between work and my kids I had to cut down the number of boards I posted on - :crazy:

Anyway - I thought I;d post up because for the past couple of weeks I have been working a guide for taking the Synta HEQ5 / Orion Sirius EQ-G to bits and relubricating it.

I couldnt find any online guides that I was 'comfortable' with so decided to brave it and go it alone to take it to bits using ozastros guide but while I was doing the work to photograph each procedure and build a more comprehensive guide for other people like me who like the comfort of seeing pictures.

The whole process took about 8 hours to take it to bits and reassmble the whole thing while getting pics of each step - my eldest boy helped me with all the fething and carrying and picture taking.

It was then about a weeks worth of building the pages, writing it all up and verifying that the procedures were correct.

Anyway I hope people may find it useful - the guides here HEQ5 Strip Down

#2 morten


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Posted 08 February 2009 - 08:47 AM

Thank you very much for taking the time and effort to make this most useful guide. Have you noticed better tracking after having luning the mount?

#3 morten


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Posted 08 February 2009 - 08:49 AM

Sorry for the typo. I ment after you lubed the mount did you see better tracking. Any PE data?

M :bow:

#4 Charlie Hein

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Posted 08 February 2009 - 08:54 AM

This is really wonderful - a very good job!


#5 astro_baby


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Posted 08 February 2009 - 11:59 AM

I dont have any PE data - I'm afraid I wouldnt even know how to acquire it at the moment - I'm just not THAT technical I'm afraid :)

What I can tell you is that when it was stripped the mount showed none of the legnadary Synta black goop as a lubricant. It appeared to be lubricated with a heavyweight auto-grease BUT there wasn't much of it. SOme of the bearings were very dry and the worm gear appeared to have no grease at all. I also found a nasty bit of flaked off metal inside the RA worm gear and when I rubbed the oil and grease in the mount between my fingers I could detect traces of grit/swarf. I used to work with cars a lot and if this was a gearbox oil I'd be VERY worried. In fact I;d be thinking of pushing some bananas into the oil and selling it fast :)

After cleaning it all up and relubing with lithium grease and realigning the worm gear ( which is a DREADFUL job ) the mount runs smoother and when balancing the scope it feels lighter and freeer. Prior to the rebuild the mount always felt like it was pushing againts treacle inside.

I also found the worm end floats were done up way too tight causing the worms to bind badly.

The main reason for carrying all of this out was I upgraded the mount to GoTo. I was happy with the mount prior to rebuild - in fact its tracking accuracy for observational purposes was astounding (I was looking at M57 - wandered off for about 40 minutes and when I returned M57 was still perfectly centred ).
Unfortunately after the GoTo upgrade the RA axis would bind something terrible and cause motor stall and all sorts of nasty grinding noises. Probably with the standard motor running the mount at sidereal the mount could cope - running the GoTo steppers at a x9 slew obviously put more pressure on things.

After the rebuild the GoTo works perfectly well as far as I can tell with less motor noise and overall the mount ( espcially the DEC axis ) is far, far smoother.

Sorry if thats unscientific - its the best answer I can give you.

#6 western stars

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Posted 11 February 2009 - 05:07 AM

Excellent work!

#7 Timo Kuhmonen

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Posted 11 February 2009 - 03:58 PM

Thanks for the instructions, also from here...

#8 w orchid

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Posted 11 February 2009 - 07:10 PM

Thank you for the instructions.

#9 skyjim


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Posted 24 March 2009 - 05:43 AM

Wow, I dont need a re lube but getting some very small amount of play in the DEC adjustment was made easy cause of this site, Great Stuff.

#10 Trebor777



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Posted 24 March 2009 - 12:14 PM

That's very similar to the Atlas rebuild. Here and here.

Last Thursday/Friday I replaced all the bearings in my Atlas with high quality ones. The time consuming part was the final adjustments of the worm, spur and rings gears. But it was well worth it.

Good job on the rebuild page. It's alot more detailed them some others out there.

#11 geezer@gpo


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Posted 24 March 2009 - 01:57 PM

Warmest regards to you Astro Baby.

This is the best I've seen on the subject. You have done a monumental service to all of us wannabe tuner-uppers who lack the whatever to try it for ourselves. We've too many thumbs and too little smarts to go it alone, but I'd follow you anywhere.

Kim J.

#12 astro_baby


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Posted 09 April 2009 - 01:48 PM

Thanks guys - it was quite a task to do that lot. I keep hoping Synta will call me and offer me a free EQ6 in exchange for a well documented EQ6 manual.

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