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CG-5 GOTO Help


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Hi All,

Sorry if this is a subject that has been covered before, however I am struggling to find a solid answer.

I recently purchased a Celestron C8 SGT as a replacement for my old 130P. Very happy with it so far. With one exception (yes you all know what's coming) the noise!

I have been serching the net and forums to see if there are any solutions to the noise problems, but have found nothing recent that tackles the problem. I read that in the handset firmware V4.16 there was a slew speed option added to the set up which would reduce the noise. I have managed to change speed for manual slewing, but for GOTO it still slews at full speed and am worried the neighbours are going to start throwing heavy things at me! :)

So my question is..... Is there any way to change the GOTO slewing speed? If so, where do I find such a function? Secondly, if there isn't a slew speed option, is there another known way of reducing the noise that doesn't involve wrapping a towell around the mount? Would be up for modding if there was a work around.

Any help would be much appreciated, and again I am sorry for re-heating something that has probably been discussed before.

Cheers

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As far as i know there is no way to reduce the slew speed when the mount is goto'ing to the next object. Full slew only. I wrapped towels around my motors to soften the noise a little. It helped a bit but in the end i just didn't use the mount after a certain time.

It's a real pity Celestron (Synta) haven't addressed this yet. Meade have a handy 'Quiet Slew' mode in the options for the LXD75. Makes all the difference.

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I have the CG5-GT and HEQ5 and the CG5-GT is much noisier. Out of interest the Hand Controller firmware is now at 4.19 and the Motor Controller firmware is at 5.16.

If you have HC 4.19 installed you can upgrade the MC via the handset connection, you don't have to do it via a direct connection of your PC to the mount anymore.

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Oh ok, I didn't realise that... Is it easy to update the firmware on the Hand Controller unit? Mine was supplied with 4.16.

Don't suppose this helps the noise at all does it?

Has anyone done any modifications to the mount to eliminate the noise at all?

Thanks

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Yes I'd be interested to know the answer to this too. As you say making noise in the early hours is not conducive to good terms with neighbours, and even if you've finished GOTOing, you still want to get back to Home position before you shut down.

Carole

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It is easy to upgrade. This is what I did, but you must check on line for yourself to be safe.

You need the latest software to run on your PC from Celestron's website and the lead to go from a PC comport/USB-serial adaptor to the base of your handset.

There are 2 update programs on the website, one for HC and one for MC.

Download them and install on PC.

Turn mount on whilst pressing and holding 'Undo' and 'Info' down. This puts the HC in a mode waiting for comms from the PC. Run the HC upgrade software on the PC, select your com port, select the option to download latest HC drivers from website, select the right driver then install and verify. Turn mount off.

Turn mount on and check HC version number is updated.

Now run MC update program on PC. This program grabs the HC. Select com port, let PC program download latest MC drivers from website, upload and verify. You do this twice, once for RA and once for DEC. This takes about 10mins! Make sure your mount and PC supply are not going flat!

Turn mount off/on and check MC driver version numbers are updated.

There are full instructions on the web, check them before you try the updates, don't take the above as necessarily word perfect.

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How about taking it apart and cleaning regreasing etc ...... excellent artical by Astronomy Boy: CG-5 Mount Improvements

Also noted from Jim Priors astro blog that he had much improvement in quietness of the mount after following the guide.

At maximum slew speed (Rate=9) the Dec axis in particular was previously fairly noisy and graunchy when accelerating/decelerating, whereas now it is much less graunchy-sounding, and has a much nicer smooth noise, less mechanically strained, and more servo-electronic.

Likewise the RA drive seems very much smoother, and definitely quieter at high speed, and almost silent when at sidereal tracking rate

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Interesting, it did when I did it 2 nights ago. Check the MC version numbers, there are 2 shown on the HC, mine are shown as '5.16,5.16'.

The HC version shows as one number, '4.19'.

As I said, this does nothing for the noise. Astronomy Boys site looks like the biz.

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I had the same problem with my CG-5. The grease is like glue inside making problems to tracking accuracy and noise. I followed the artical by Astronomy Boy. It looks like a difficult procedure but it isn't. You have just to start.

Also I had the same worries about neighborhoods. They hear nothing. The sound is loud for us but for the next door ... don't worry they sleep or watch tv... but can't hear you:)

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Thanks for the advice. I think I will give astronomy boys cleanup a go at some stage and see how I get on. Hoping it's not too risky...

I have also thought of buying some sound proofing material and lining the inside of the motor casing which may work. If I decide to try this I will let you know how I get on.

Thanks again!

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Why not wrap the motor boxes in sound deadening ..

before I built my obs a made two little jackets out of carpet underlay for my NEQ5.. it makes big difference from a distance... :)

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If you can afford the HEQ5, then go for it. It's better than the CG5-GT afaik.

But if you're going to go for the EQ5, then stick to the CG5.

My two cents.

As for the noise, it's not such a big deal either. The problem is that you cant fit anything inside the plastic casing of the motors. It's full of electronics and cables, so that's a no-go i think...

Not sure what makes the noise actually. The motors themselves ? Maybe they can be replaced by better, quieter ones and compatible with the electronics ?

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I had the same mount and the same problem. Noise is a problem with that mount. some of the noise is magnified throught the OTA. like a load hailer. Dont think there is a solution to the problem. Got rid of mine because of the neighbour problem.

Neighbour is a s**t, try not to have anything to do with them, evrytime I set up ....on comes he security light grrrrrrrrrrrr. Thinking od building a platform a bit further up the gardento get away from the light.

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Hi All,

Just a quick update from me as I know a few people will be interested to know how I got on...

I have followed Astronomy Boys CG5 improvement guide. It took me 2 days to get right as the guide is based on an older CG5 model, and some of the parts are different, however I managed to dismantle, clean, sand and re grease the whole mount. I have to say that after some fine tuning of the worm gears on each axis it seems to have made quite a difference to the noise.

The mount no longer sounds like it is screaming when it moves the scope about. It is by no means silent, but a marked improvement over how it was.

Next on the list is to buy some sound proofing material used to quieten down PC internals which aparently cuts noise down considerably. My aim is to then wrap the motor in the material and potentially making a jacket out of it for the plastic casing.

Will get back and let you all know how I get on... So far so good though!!

Cheers

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That is really interesting and very productive, nice one!

I wonder with materials wrapped around whether things might get too hot? Probably not but it crossed my mind. I look forward to hearing what the progression is.

Adam

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  • 2 weeks later...

Hi All,

Another quick update from me......

So I have now soundproofed the RA Drive casing using Acoustipack soundpreefing material. It is usually used for dampening noise generated in high end PC's but looked thin enough to do the job with my mount.

AND......

I was right!! :)

So, it is a little bit fiddly. Basically I have wrapped material around the motor itself and lined the inside of the plastic casing with as much as is possible. Bear in mind that too much can make it impossible to close the casing back up again - something I learned the hard way.

The combination of the material and the sand and re grease of the gears has worked wonders. I still need to sound proof the DEC axis, but the sound is so much better with just the re-grease that I'm in no rush. I will do it though as I want to get it as quiet as possible.

One other thing I have found is that the sound vibrates from the mount into the OTA which acts almost like an amplifier. Depending on what scope you use this will differ. My C8 SGT loves to carry the sound which is a little annoying, seeing as the gears with no OTA or just a DSLR mounted are a LOT quieter than they were. I found a way to stop the OTA amplifying the sound as much which I am quite pleased with. What I did was lined the Dovetail mount (not sure if that is the right description?... basically the part of the mount that you attach the scope to) with the same sound proofing material, and it seems to dampen the vibrations to the scope. Not making it silent, but again a nice improvement.

I still need to play with the worm gears a little as the slewing noise can be louder in one direction than another, but I have managed to reduce backlash quite a bit as well. Managed 90 seconds of unguided photography on Orion nebula the other night with great results.

I will try and post some pics of the soundproofing on here when I can for anyone who wants to give it a go. It's pretty easy, but requires a bit of trial and error as not to cram too much into the casing.

If nothing else, it has kept me busy for a good few hours and still a few more to go.... and my neighbours will not be so angry with me when the warmer evenings roll in. Whenever that may be!!!

Happy to answer any questions if anyone wants to give it a go.

Cheers

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Sure no problem... The material I used is Acoustipack lite

AcoustiPack Lite Multi-Layered Material Kit (ACOUSTIPACKLITE) - dabs.com

There are 2 types, lite and ultimate I think it is. The lite is only 4mm thick and so ideal for lining the casing. The ultimate I believe is 7mm and will probably be too think.

The material has self adhesive on the back, so it just needs to be cut into shape and stuck on the inside of the casing.

I will try to post pictures as soon as I can....

Cheers

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Glad to hear that you have managed to reduce the noise from the Celestron drive

The noise that Celestron mounts (the alt azi goto and the CG-5) seem to make is one reason I opted for an Explorer scope on a EQ-5 mount. From what I've read the Celesron drives use servo motors where as Skywatcher drives appear to use stepper motors, which whilst not silent, don't appear to make the same level of noise as the Celestrons. Does the CG-5 have a lot of gearing inside the cases, or is the motor almost a direct worm drive ?

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Hi,

There isn't much complex gearing in the mount. There is a servo motor which feeds a cog which then turns the worm gear... It's a fairly simple set up.

I have found the main problem is the sound increase when the OTA is on the mount. This comes from amplification through the OTA and I'm guessing added strain on the motor from the weight

Am going to keep tweaking it until it's as quiet as it can be.

Cheers

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