eq5 pull down and bent axle worm fix find :) Youtube vid added :)

2stroke (Jay) · #1 13-12-2012, 08:25 PM

Heya guys just doing a pull down and re grease eq5 atm http://www.astronomyboy.com/cg5/ra_new.shtml . My wife picked this up with the PST she bought and i thought i might as well fix this up for a spare mount. This is the new version with bearings on the RA which really is needed and could probably be done alot better.

It looks like it has being tipped over by the last owner and the axle which has the spur gear has being bent on the DEC axis. Well theres great news just remove the worm and replace is good side in

The worm is symmetrical thank god , so don't bother bending the brass shaft and wreaking your worm.

I have found a fair bit of fillings mixed with the cheap poor grease they use so its something you would consider a must for any AP work to do. There hasn't being any casting dags or defects found with my mount though it has being a slap bang job on the assembly line. There is to much backlash and the think glue like grease makes scope balance impossible.

A few findings for people who wish to do this;
* Use carby cleaner in a spray can to make fast work of removing grease
*Don't do this near carpet or anything of value your nice $100 pair of jeans
* Wind the set screws out so there just above the thread or totally remove if you wont loose them. I could get one backed off and stripped some thread a tad bah.
*Things fall off so work in a tray ect so you don't loose things.
* There was 3 lots of set screws in the RA axis and only 2 in the DEC with my new model eq5
*Use baggies and label parts after clean and remove, saves parts getting dirty once cleaned, lost or used on the wrong section.
*Don't put carby cleaner on your sealed bearing, it will remove the lube from them and cause them to fail.
*Carby cleaner makes light work of things and it will do the same for plastic parts so don't get it near plastic.
*Buy a bag of rags, this grease is think black and there lots of it.

Heres a few photo's, i'am not writting a guide because Astronomy boy already has. If you get stuck I might have some limited skills to help you out though they are limit to bugger all experience

torana68 (Roger) · #2 13-12-2012, 08:51 PM

carb cleaner does work good but you should try and find something that wont kill you. Carb cleaner is one of the nastier ones.

2stroke (Jay) · #3 13-12-2012, 09:55 PM

Quote:

Originally Posted by torana68

carb cleaner does work good but you should try and find something that wont kill you. Carb cleaner is one of the nastier ones.

True though being under pressure it just blows the gunk off. Kero would be another good option though i just want this done quick lol. Still in the middle of camera modding so don't have to much time to spend on this mount.

2stroke (Jay) · #4 14-12-2012, 11:39 PM

Well i think i have found a great solution to making the eq5 100% better while looking at the RA setup. The stock roller bearing only removes friction from the downward force, the force pushing back into the housing relies on the plastic washer. You could add a spacer to force the ra to use the stock roller bearing by moving the bearing up a fraction so the ra isn't riding on the plastic washer. But these bearings arn't made for a force to be placed on a side axis so why not put a tapered roller bearing in

By doing this i believe its will make a dramatic change to force need to move the ra and also add to higher loading of the mount.

If i get time ill drop into skf and see what the guys can come with, if not ill return to this at a later date as i have to many projects on the go. I really can't believe synta didn't do this to the mount to start with, though i guess cost and not wanting a mount that was going to preform that good it may set people off buying there more expensive mounts. Havent even checked out the bottom end yet, maybe a tapered could also be fitted there, i can't see why not?

torana68 (Roger) · #5 15-12-2012, 08:17 AM

replace the washer with a thrust bearing maybe?

2stroke (Jay) · #6 15-12-2012, 08:56 AM

Quote:

Originally Posted by torana68

replace the washer with a thrust bearing maybe?

There's only 1.5mm to play with approximately, believe it or not a thrust bearing is used on the back end lol. You could use a thrust but the clutch section would be out a bit and may end up scoring it. I might do a quick youtube video to explain whats going on, its very strange they used a thrust bearing at the end and it rides on a plastic washer.

Maybe the mount has be machined out to much and it was meant to ride on the roller bearing? Though if this was the case they would have fitted a tapered and the original revision had no bearings at all. I think with the new revision the bearings were meant to only aid balancing of the scope and not RA drive because remember the DEC has no bearing at all.

2stroke (Jay) · #7 15-12-2012, 10:38 PM

Well didn't make skf though made a space aka washer to raise the clearance so the whole RA rides on the bearing. What can i say but WOW!! this thing could balance down to 50grams or less its that smooth and free. The DEC axis though didn't go so well and has resistance due to the grease, it requires about a 35% more force over stock heq5 i guess roughly. I might redo this later on and use oil over a grease though keep grease for the worm of course.

I used motor oil for the RA clutch and white lithium race mix for worm, thrust, plastic bushes and metal on metal. The real key is not to go crazy with grease and use minimal. For the thrust bearing i used 1/20-1/30 of a rice grain on each ball in the bearing. On plastic bushes i put a rice grain each side then moved the bush between my index finger and thumb. Running this around twice between my finger and thumb i ended up with 1 1/4 rice grains waste. A light smear was used on metal to metal and waste removed.

I haven't tested the mount yet though looking at the glue like grease i removed along with a heap of fine fillings i know things are going to be way better. I was the impressed by the RA i can't wait to do the HEQ5 because the improvement is mind blowing.

Lol will do a youtube vid i think and see if that 50grams is an exaggeration or not

2stroke (Jay) · #8 15-12-2012, 11:26 PM

Well here's a youtube video of the mount with a BD 8" reflector stock accessories on apart from the bintel right angle finder. I have put 300grams give or take a few at 1ft from center of balance. I know this isn't perfect due to using 1 far end at the finder so its means it should be less then 300grams. Here is the vid enjoy and happy modding people.

Click here to load the video

volume needs to be up lol iphone

lol well i guess you can do the maths were 50grams would tip it