Panic at the disco, belt modding HEQ5

[Anthonyexmouth]

 

OMG. Ok just completed my belt mod, very simple procedure. But panic ensured during testing, we'll get to that in a moment.

Have an issue, well maybe, with my RA. Got a little slop on the worm gear. Have added a video.

As for the panic. Got it together, dusted off my pristine hand controller. Used only once and then I started cheating on it with the lovely Eqmod. 

Switched everything on and warnings, both axis not responding, now I'm no newbie with repairs, disassembly and all that jazz, so I was convinced I had been careful with the plugs and not damaged anything. Half an hour later and much plugging and unplugging and a few choice words I decided to try the laptop and thankfully all is golden again. No idea why the hand controller is sulking. Anyone experienced this?

Any ideas of other mods to take this slack out of the worm gear? Do I need to do anything with it?

[vlaiv]

That part is not related to belt mod. Its backlash in worm / worm gear assembly. It can (and should) be adjusted.

I think two things can be adjusted and you need to pay attention to both - first is worm / worm gear distance - you need to get that "spot on" to minimize backlash but also to prevent seizing. There is bolt on the other side of worm gear - you need to adjust that as well to prevent any slack in worm gear.

Look into this tutorial on how to adjust it for RA (when you are at it - adjust DEC as well if there is any play in it):

http://www.astro-baby.com/heq5-rebuild/heq5-we1.htm

 

[teoria_del_big_bang]

The link above is exactly what you need. I have just stripped mine down and replaced all bearings using the guide in this link.

Be patient when setting the worm to remove any backlash as it takes a bit of a knack to do it just right. There seems to be a real fine line between eliminating backlash and binding that causes the pulse motors to stall and thus you lose position. 

Steve

[Anthonyexmouth]

A knack, need a professor of the dark arts. It's definitely better. Didn't touch the Dec as that felt alright. How did the bearing change go? Seen any results yet?

[adyj1]

57 minutes ago, teoria_del_big_bang said:

Be patient when setting the worm to remove any backlash as it takes a bit of a knack to do it just right. There seems to be a real fine line between eliminating backlash and binding that causes the pulse motors to stall and thus you lose position. 

I have heard that it is very useful to use an ammeter to measure how much the motors are working;

https://www.myastroscience.com/rowan-astronomy-eq6-belt

(see 'Adjusting the worm mesh using my new method' at the bottom of the page)

Ady

 

[Anthonyexmouth]

Does anyone know why I would get cautions with the hand controller? Either both axis not responding or usually Dec not responding. But no issues at all with eqmod. The controller is working in every other way. 

[adyj1]

2 minutes ago, Anthonyexmouth said:

Does anyone know why I would get cautions with the hand controller? Either both axis not responding or usually Dec not responding. But no issues at all with eqmod. The controller is working in every other way. 

As I understand it, this sounds like a connection issue to the mount - as long as it has power, the controller will do everything it needs to do internally without needing the mount - apart from the actual motor connection.

Your mount is working because the eqmod lead works, but your handset isn't working because it says it can't connect to one or both motors...  which suggests the lead.

Ady 

 

[Anthonyexmouth]

Just popped an old cat5 cable on and didn't get the error but trying to slew just moved it a little bit and stopped, pleased the button again and it moved a little more. Not gonna worry too much. Using the goto moved it fine

[david_taurus83]

When you adjust the worms, be sure to slew 360° a few times  to make sure theres no binding. It is a very fine line but make guiding better the finer you reduce backlash. Also worth slewing both axis at the same time to make sure the drop in voltage can still turn the motors. When I adjusted the RA on the EQ6 a few weeks ago it would slew fine on one axis but if I slew both it would bind. So had to readjust until could feel no play in the mount and no binding with both axis slewing!

[Anthonyexmouth]

I carried out a few goto moves and seemed alright, getting dark now so as it's a permanent setup outdoors I'll have a go tonight and if it's off I'll have another go adjusting it tomorrow

[Anthonyexmouth]

Well, looks like i'll have to play around with it some more. PEC showed a 2 sticking points on RA last night. 

Iv'e seen the astrobaby guide on adjusting the worm but does anyone know if theres a video guide anywhere? 

also read mixed reviews on people who have done a bearing upgrade. maybe a strip down and regrease is the best first step. 

[Anthonyexmouth]

I wish i had never thought about belt modding or building a pier, my guiding was better on the tripod. 

I need to cast a new concrete mooring block for my boat and i can foresee the pier and HEQ5 being part of it. 

[spillage]

stick with it as you will benefit from doing this. Make sure you carefully balance the scope in all three axis. Mine was out a bit and was guiding really bad last night. Just been out and rebalanced and now back to around 0.6 again.

Put as much weight on the mount as you are going to use and slew the mount around as much as is physically possible to check for binding. I just kept adjusting till I got binding then wound it out just a touch.

[Anthonyexmouth]

1 minute ago, spillage said:

stick with it as you will benefit from doing this. Make sure you carefully balance the scope in all three axis. Mine was out a bit and was guiding really bad last night. Just been out and rebalanced and now back to around 0.6 again.

i'd like to think i can, but there must be something i've pooched along the way and cant for the life of me work out what it is. faffing about all day trying to get it running smooth and only being able to test at night is supremely frustrating, knowing that i'm basically going in blind tomorrow trying to fix something but not having a clue what.

[vlaiv]

8 minutes ago, Anthonyexmouth said:

i'd like to think i can, but there must be something i've pooched along the way and cant for the life of me work out what it is. faffing about all day trying to get it running smooth and only being able to test at night is supremely frustrating, knowing that i'm basically going in blind tomorrow trying to fix something but not having a clue what.

Are you using stock bearings on your mount? I changed all of mine for high quality SKF ones. If you are going to fiddle with your mount again (and I think you ought to) - maybe changing bearings for high quality smooth ones will be beneficial.

[Anthonyexmouth]

1 minute ago, vlaiv said:

Are you using stock bearings on your mount? I changed all of mine for high quality SKF ones. If you are going to fiddle with your mount again (and I think you ought to) - maybe changing bearings for high quality smooth ones will be beneficial.

considered that, its another expense i would happily make but really would like to know what ive done to make it so much worse than it ever was before, if i knew bearing would cure it id order some now.

do you have a link to the required bearings? 

[vlaiv]

10 minutes ago, Anthonyexmouth said:

considered that, its another expense i would happily make but really would like to know what ive done to make it so much worse than it ever was before, if i knew bearing would cure it id order some now.

do you have a link to the required bearings? 

Unfortunately no, I took mine with me, went into local hardware store - and just handed them to the guy and said I want the best, smoothest ones in these sizes that you have

I had very good reason for changing mine - one was cracked and caused very sudden jump of 5" in RA every minute or less (each time ball would go over crack in the casing, it was small bearing holding worm gear shaft).

Try following thing - take your mount and try to see if there is any play what so ever in both RA and DEC - do this with your hand - you maybe increased backlash instead of decreasing it. You should be able to feel small play that way - it will not actually move, but you should be able to sense it.

[Anthonyexmouth]

This is my graph tonight. Getting worse every night. 

 

[spillage]

Have you tried turning off Dec guiding just to see where that lies. I really am not expert but try turning RA aggression down to maybe 30 and it could be your worm gear binding causing those spikes.

with your clutches on do you have any movement in RA or Dec?

[vlaiv]

Dec actually looks pretty good. It can be better but might be such due to seeing. At 0.54" RMS it's not bad at all. RA on the other hand looks like there is much backlash in it. Whenever you see guide pulse train on one side then on another - then alternating - it just means backlash. Guide pulses just fire and don't move the mount it keeps going in same directions until they clear backlash and then guiding "over does it" - mount starts going slower and guide pulses need to clear backlash once again - hence another pulse train on the other side.

[Anthonyexmouth]

4 minutes ago, vlaiv said:

Dec actually looks pretty good. It can be better but might be such due to seeing. At 0.54" RMS it's not bad at all. RA on the other hand looks like there is much backlash in it. Whenever you see guide pulse train on one side then on another - then alternating - it just means backlash. Guide pulses just fire and don't move the mount it keeps going in same directions until they clear backlash and then guiding "over does it" - mount starts going slower and guide pulses need to clear backlash once again - hence another pulse train on the other side.

so maybe fiddle more with the backlash grub screws tomorrow. i did see a thread on here a while ago about heq5 bearings. gave a run down of ones needed and offered a cheap and expensive option. cant find it now. 

[Anthonyexmouth]

Well i just completed an 8 cycle PEC training and this curve looks, well , better?

[vlaiv]

It does look better except for those two jumps present. What does guiding graph look like now with PEC? It should be better, but I guess you'll still see pulse trains on RA.

[Anthonyexmouth]

Graph looks like the bloody alps. 

ill have another tinker tomorrow, priced RA bearings £52 for quality ones. i'd do that first. if i can sort RA then i'll move onto Dec, but that doesnt seems so problematic

[spillage]

I have the neq6 and not the heq5 but I would suggest backing off the RA worm so that you get a small amount of play, then run a 10 min guiding session and bit by bit take the play out. I find on my mount RA always has some play or else it binds, this is just how it is and why its hard to say exactly what you need to do as each mount seems to have its own characteristics.