Gear rattle on HEQ5 accelleration

[great_bear]

Does anyone else's HEQ5 have gears that rattle briefly (but loudly) when accellerating / decellerating from full-speed slewing?

[Euan]

It's a problem with both the HEQ5 & EQ6. It's mainly down to the transfer gear on the motors, here are a few links to solutions (including mine):

Usual disclaimer of course

DeepSpacePlace - EQ-6 Noise removal procedure

EQ6 - Transfer gear fix - IceInSpace

Hypertuning the EQ6: Stepper Motors « Scottish Astro

[brianb]

Does anyone else's HEQ5 have gears that rattle briefly (but loudly) when accellerating / decellerating from full-speed slewing?

Yes. Doesn't seem to do any harm though. (Famous last words?)

[Euan]

Yes. Doesn't seem to do any harm though. (Famous last words?)

Aye, only get stuck in if you are more serious about reducing backlash and / or the noise is a problem

Otherwise, it's not doing any damage

[Astro_Baby]

Mine do even after tuning - I used the approach in the first link. The basic problem with hypertuning is that the basic engineering just isnt high enough tolerance. Thats not a council if despair, these are amazing mounts for the money, but there are limits as to how much tuning you can do to get a real advantage. A decent bit of gear tuning will help for sure though.

[jgs001]

Yep mine do, but only on a high speed slew... it's fine at any other speed.

[great_bear]

Thanks everyone for the great replies.

I'll probably not bother (although by co-incidence I was just tweaking anyway as there was a DEC slop that was annoying me.

Glad to know it's a diagnosed issue with a solution

[Astro_Baby]

Even the mighty EQ6 suffers from it. I spent ages trying to tune the start up rattle out the gears. I managed to tune it out of the RA entirely and mostly out of the DEC but it still does it in one direction for the DEC. After 3 days of effort I gave up and just decided to live with it.

Besides what seems noisy in the lounge is nothing at all out in a field where the mount is so quiet I sometimes forget its actually running at all.

[Euan]

I'm just trying mine out for the first time after the hypertune and it's much, much quieter and smoother than it was before

I'm doing drift alignment then I will see what the auto guiding is like

[great_bear]

Besides what seems noisy in the lounge is nothing at all out in a field where the mount is so quiet I sometimes forget its actually running at all.

Hmmm... Well I do remember last year in the early hours in the morning at Kelling Heath, my wife whispered: "Do you think we're the last ones up?" - and then far in the distance:

"WeeeeeeeeBUZZZZeeeeeeiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii"

"Guess not..." I said...

[lukebl]

Mine do too, and I was about to post a query about it myself. Slightly reassuring to know that others have the same issue.

[Astro_Baby]

Great Bear - that sounds like someone with a CG5 or maybe a Meade Skywatcher mounts are much sweeter. Mine whispers in gentle turbine breaths

[beamish]

My HEQ5 Pro 's the same- tho having read this thread and followed the links, I replaced the rubber compression washers for the teflon washers in the transfer gears and the mount runs sweet tho a wee bit of backlash is still there and I can live with it -but it's nice not have wobbly transfer gears anymore

[great_bear]

When people say "backlash" here do they really mean "slop"?

Backlash is when the mount springs back slightly in th opposite direction when stopping - a common problem when pushing an Alt-Az mount for example - but it's hard for me to see how an HEQ5 could suffer a similar problem.

My HEQ5 *still* has a little bit of annoying slop on DEC... Will have to have another shot at that soon...

[Astro_Baby]

I would define backlash as the effect that when gear A is pushing gear B and there is clearance ('slop') in the system the effect is that when you reverse the motion gear A will turn a little before taking up the slack and moving gear B. So theres a small delay before gear B starts to turn.

Thats how its defined as far as I know for the HEQ5 backlash compensation and its what I always understood by backlash when referring to gear systems.

[Euan]

From Wiki...

In mechanical engineering, backlash, sometimes called lash or play, is clearance between mating components, sometimes described as the amount of lost motion due to clearance or slackness when movement is reversed and contact is re-established. For example, in a pair of gears, backlash is the amount of clearance between mated gear teeth.

[great_bear]

What word should I be using for what I previously described as "backlash"?

(the tendancy of an alt-az mount to spring back in the opposite direction during positioning)?

[Astro_Baby]

duff engineering

[sgazer]

mine has the noise briefly at the start of a fast slew, but nothing compared with a CG5-GT coffee grinder! Ha, just realised what the CG stands for....."Coffee Grinder" :D

Althought the CG5 was silent when tracking, the HEQ5 goes like this;

swiiiiiii....swooooo......swiiiii......swooooo

anyone elses do that?

[great_bear]

Yes - very faintly - like distant radio interference. I like it for some reason.

[Michael1971]

I know its an old topic but my fairly new mount had the same sound.

I also had a little slop in my RA axis and found the courage to actually fiddle with it.

I used astro_baby's site (thumbs up) Worm Engagement for RA Axis http://www.astro-bab...ld/heq5-we1.htm to adjust it and now its completely gone.

Really amazing.