Does this mount sound normal? EQ6 with my new scope!

[Quetzalcoatl72]

Pardon the bad footage, phones are terrible for that. I'm testing my new RC8", I've never had a scope heavier than 5kg on this NEQ6 mount, so there's a good 10 on there and that's without full accessories. It makes a crackling sounds on start up and before it comes to a stop. Is that a problem and if so how do I fix it?

[Stuart1971]

No, that does not sound correct at all...something is wrong with the worm gears, without opening up hard to know exactly what....🤔🤔

[Quetzalcoatl72]

10 minutes ago, Stuart1971 said:

No, that does not sound correct at all...something is wrong with the worm gears, without opening up hard to know exactly what....🤔🤔

Is it the crackling I mentioned or something else? I have been struggling to get a 3min exposure with perfect guiding

[EntropyTango]

Might be time for a service if it's under warranty, or a DIY checkup

Sometimes gears slip or there are lubrication issues

[Sp@ce_d]

They do tend to sound a bit like a bag of spanner’s on start & stop but yours definitely doesn’t sound right. I can hear a regular clicking too. If it’s not under warranty and you feel competent I’d be pulling it apart & checking gears & tolerances etc. Maybe think about a belt mod while you’re in there. 

[CraigT82]

Mine makes the same graunching 'coffe grinder' noise on starting and stopping the slew, most of them do i believe. But the regular clicking during the slew doesn't sound right to me. It seems to be at about the same period as the worm gear turning so definitely something worth checking as you really don't want anything wrong with the worm. 

 

[AllanJ]

The clicking might be a balance problem - try moving your counterweights to see if that helps - it solved it for mine when I changed the scopes, etc but didn't re-balance properly. Mine seemed to be worse when counterweight axis was about horizontal.

[Quetzalcoatl72]

30 minutes ago, AllanJ said:

The clicking might be a balance problem - try moving your counterweights to see if that helps - it solved it for mine when I changed the scopes, etc but didn't re-balance properly. Mine seemed to be worse when counterweight axis was about horizontal.

It's hard to get balanced, when pointing scope diagonally down is moves straight vertical, same with scope pointing up.

[Stuart1971]

3 hours ago, CraigT82 said:

Mine makes the same graunching 'coffe grinder' noise on starting and stopping the slew, most of them do i believe. But the regular clicking during the slew doesn't sound right to me. It seems to be at about the same period as the worm gear turning so definitely something worth checking as you really don't want anything wrong with the worm. 

 

This is not right at all, I had this mount a few years back, and it was nothing like this one, it was smooth with just the hum of the steeper motors when slewing, and no noise when it stopped, I can assure you those “coffee grinder” noises are NOT normal....

[Quetzalcoatl72]

The RA sounds better imo, DEC still needs work I'm not sure what to do, i feel like the more I mess around with it the more chance I'm going to ruin a £950 piece of equipment. The humming sound is new, I don't know if that's a good thing.

[Quetzalcoatl72]

48 minutes ago, Stuart1971 said:

This is not right at all, I had this mount a few years back, and it was nothing like this one, it was smooth with just the hum of the steeper motors when slewing, and no noise when it stopped, I can assure you those “coffee grinder” noises are NOT normal....

The gears looked ok to me, nice and firm when they rotate no slipping, the grease flys off when they rotate anyway so it's not like i can get the teeth fully drenched

[CraigT82]

59 minutes ago, Stuart1971 said:

This is not right at all, I had this mount a few years back, and it was nothing like this one, it was smooth with just the hum of the steeper motors when slewing, and no noise when it stopped, I can assure you those “coffee grinder” noises are NOT normal....

I didn't say it was normal. it is common though as I've heard several EQ6s and a few HEQ5s make that sound at start and stop of slew. Granted it's not ideal and in the video above it is quite bad, but it should be relatively easy to minimise with adjustment of the spur gear mesh which may improve the guiding on its own (as seems to have been done for the RA with the new video posted). It is the ticking/crackling noise during the slew I'd be more concerned about. 

Actually just re-reading the second post by the OP which says that they couldn't managed 3 min exposures with "perfect guiding". If guiding is perfect and stars are dodgy then there is nothing wrong with the mount... differential flexure is your issue. 

[Quetzalcoatl72]

26 minutes ago, CraigT82 said:

I didn't say it was normal. it is common though as I've heard several EQ6s and a few HEQ5s make that sound at start and stop of slew. Granted it's not ideal and in the video above it is quite bad, but it should be relatively easy to minimise with adjustment of the spur gear mesh which may improve the guiding on its own (as seems to have been done for the RA with the new video posted). It is the ticking/crackling noise during the slew I'd be more concerned about. 

Actually just re-reading the second post by the OP which says that they couldn't managed 3 min exposures with "perfect guiding". If guiding is perfect and stars are dodgy then there is nothing wrong with the mount... differential flexure is your issue. 

I had to look up differential flexure, that sorta makes sense, because different objects yielded different results, m81/82 was better than m51. I was using this extension tube because I couldn't get focussed. However my new scope that i'm testing the gears on has never been used, tonight I plan to have a go and see if collimation has survived the transit and see if my workings have payed off. Currently trying to get that grinding sound out of the dec, that's all. Is the spur gear mesh method the same as loosening those 4 screws and adjusting the grubs then tightening the screws because thats what i did with RA to make it solid. DEC is even more solid with no backlash so I didn't bother with those.

Come to think of it, i was having problems until my camera fell off the scope...

Edited March 20, 2021 by Quetzalcoatl72

[CraigT82]

1 minute ago, Quetzalcoatl72 said:

DEC is even more solid with no backlash so I didn't bother with those

If it is solid you might want to loosen the worm adjustment off a little on the dec then and see if the noise disappears (the 4 bolts and two grub screws is what adjusts how tightly the worm gear is meshing with the worm ring).

Adjusting the spur gear meshing is done by removing the mother board, loosening the two screws holding the motor to the casing and lightly pressing the motor in whilst retightening the screws. Again if it's too closely meshed it can cause issues (the motor will stall during slewing). If you do this be very careful with the mother board. 

The other adjustment is the worm shaft end float which is under the round black caps with the two holes, but if you don't have any side to side play on the axis you probably don't need to touch these. 

Getting the mount to run sweetly is a real balancing act between all three adjustments and can take lot of time and testing to get right! 

[Stuart1971]

51 minutes ago, Quetzalcoatl72 said:

The gears looked ok to me, nice and firm when they rotate no slipping, the grease flys off when they rotate anyway so it's not like i can get the teeth fully drenched

The RA sounds exactly like it should now....but DEC is still not right......

[Quetzalcoatl72]

5 minutes ago, Stuart1971 said:

The RA sounds exactly like it should now....but DEC is still not right......

Thanks, at least I can leave it alone, I didn't do anything different with the DEC, but I'll try the grub adjustment.

[Quetzalcoatl72]

The grinding is gone hurray! but there's a slight knocking sound on start up and before the stop.

 

aaaaanddd it's back, it either grinds or has binding, i can't have neither 

Edited March 20, 2021 by Quetzalcoatl72

[Quetzalcoatl72]

I noticed something very interesting, when slewing to the west, there is no backlash but westerly it starts grinding