CG-5 mount advice needed

[Inimbrium]

Hi

I'm new here, but have been reading these forums for advice for ages, just never needed to ask something, until now.

I've had telescopes for years, but small fry, nothing substantial, entry level stuff, until the ebay god gave me the opportunity to buy a Skywatcher 10" (250mm 1200mm) for £175! Just the OTA, rings and some basic 1.25" eyepieces and barlows, mind you, still, a bargain me thinks.

So now the project is to build it bit by bit, and buy the necessary parts, crucially, all to be done on a budget. I'm a firm believer that deep sky observing/imaging can be done on a budget, proof is the price of the OTA (which BTW is in good condition) all I need is patience. I've waited years to find a bargain large reflector and I can wait a few more months for the missing parts.

I have and EQ2 and as soona s I saw this behemoth telescope in person I realised it's obviously not up to the task, so the ebay god smiled upon me again and granted me a CG-5 head for £62! Ok so it's missing the tripod bit, and the counterweights and the polar scope (I think) and RA motor lol but still, cheaper than £300 or whatever they cost complete.

The problem is that Idon't really know that much about this mount or any mount, and information online is rather sketchy, probably because it's an old mount, I don't know. This is where you guys come in. I'm gonna post some photos of this CG5 mount head, and perhaps if you'd be so kind you can tell me more about it, what parts it's missing, and any general advice and experience you feel like imparting

Also, that tripod thing with the hole in the middle that the head fits in, what is it called? Searching for it as simply a 'tripod' gives me millions of matches. Does it have a specific name?

Thanks

[Inimbrium]

Hmm, I don't seem to be able to edit the post so I'm replying..

I wanted to add that I have a Nikon D3100 and plan to do astrophotography, so I require a RA motor, but I can't find one. I can only find goto kits, which are very expensive. I actually like setting up the scope and manually navigating from object to object so I just need a cheap and decent RA motor.

As for astophotography, I will ask more questions another time regarding that topic.

[CraigT82]

Looks like you need counterweights (probably 3x5kg with that scope) and tripod to get started, polar scope can come later if you need it. First light optics sell motors (the EQ5 motor fits straight on) and counterweights.

It will also fit on an EQ5 tripod which are fairly easy to come across, try astrobuysell.co.uk.

Be aware that that scope is going to be pushing that mount right to the very limit! I have a 200/1200 reflector on a CG5 and its just about usable

Sent from my iPhone using Tapatalk

[RobertI]

I have three CG-5s (!) so have a bit if exprience. My first comment would be that the 10" Newt is probably beyond the sensible limit of the mount for astrophotography unless you keep focal length short and the exposures brief. You can help stability a lot by purchasing the tripod with the 2" legs:

http://www.rothervalleyoptics.co.uk/celestron-heavy-duty-2-cg-5-stainless-steel-tripod.html

The mount will fit directly onto the tripod, no other attachments necessary. Do NOT get the lightweight cheap aluminium tripod.

The mount is mechanically almost identical to a Skywatcher EQ5, so motors from that mount should fit the CG5. If you want to keep the cost down I suggest the dual axis motor kit:

http://www.rothervalleyoptics.co.uk/skywatcher-eq5-enhanced-dual-axis-motor-drives.html

It has a built in autoguider port, so you can autoguide once you get a guide camera, etc. I autoguided very successfully with a similar setup although the scope was a small refractor.

Counterweights for a an EQ5 will fit and are widely available.

Hope that helps.

Rob

[Inimbrium]

Thanks for the prompt replies!

I'll look into it

[RobertI]

I've also discovered this software which can give any EQ5/CG5 with a suitable handset such as that described above a simpe GOTO capability, which I like the look of.

[Inimbrium]

I've also discovered this software which can give any EQ5/CG5 with a suitable handset such as that described above a simpe GOTO capability, which I like the look of.

How much is it?

I've found the eq5 motor on first light optics, but they're £68 each for each axis!! That's more than I paid for the mount lol. I'm going to try and find one second-hand as it's a bit too much for my budget and I don't want costs to spiral out of control. Obviously the goto will cost more, but it offers a lot more, so I'm more flexible with justifying a higher price.

As for the weight of the OTA, I just weighed it, and it's 15kg! I'm considering trying to find a 250mm carbon tube, but they're not cheap. Maybe I can get a cheap one from china or something.

[brantuk]

Try UK Astro Buy Sell website for spares for the CG5 - there's usually a tripod there (or a S/W EQ5 one will do). Should be able to get one in good nick for £40-£50. Weights come up from time to time as well. To counter the 250 I reckon you'll need at least 2 x 5kg weights (you're quite a bit over the mount capacity there). Hth

[astrofox]

Dont discount a Vixen Great Polaris, Its the same mechanically as the CG5/EQ5 but much smoother. After all cg5 and Eq5 are copies of the original Vixen GP. I fitted skywatcher goto to mine

[ecuador]

Wow, that is too much scope for the mount. You went a bit overboard It reminds me some 10" newtonians sold in the 80's with the same mount as the 4.5" version. If you bought the 4.5" you were happy with the mount, the 10" was wobbly as hell. In any case, while the eq5 motors will fit, they are not rated for this much weight, so I doubt they would last long. Also, when you say astrophotography, I hope you don't mean deep space prime focus with the 10", as that will be impossible even if the motors don't fail. For reference, a CG5 can do astrophotography with up to a 6-7kg load, while your OTA alone should be around twice that.

I agree that you can do good things on a budget, however you have to be careful a bit, for example you went for an OTA that will require a heavy mount if you are not to get frustrated trying to use it. If you did not want to go less than 10", then perhaps a dobsonian would have been a better choice (often you get them for around £200 complete on astrobuysell) - as I said astrophotography is out of the question for this OTA without a solid mount. You could do some planetary photography though and if you remove the OTA and attach just the camera with the lens on the mount, a simple RA motor will do fine for long exposures as long as you manage a polar alignment.

I do see one offer for an eq5 pro tripod on astrobuysell that might do and alsor a CG5 tripod with CWs.

[LeeB]

The issue with the 10 on an eq5 is that it has the steel skywatcher tube and thus heavy, very heavy. I have happily used an orion optics 10 on a gp1/eq5. It may be possible to buy an ali tube, which will be alot lighter than steel and a lot cheaper than carbon. That all said first get hold of the two inch leg tripod from a celestron cq5 and balance it all well and it will still work visually. The tripod really does help. 

[Inimbrium]

Try UK Astro Buy Sell website for spares for the CG5 - there's usually a tripod there (or a S/W EQ5 one will do). Should be able to get one in good nick for £40-£50. Weights come up from time to time as well. To counter the 250 I reckon you'll need at least 2 x 5kg weights (you're quite a bit over the mount capacity there). Hth

Found this: http://www.astrobuysell.com/uk/propview.php?view=107234

But being aluminium it probably has a lot of give in it. I don't have much (or any lol) experience with big scopes, but I'm an engineer and that Al looks wobbly under 30kg (15 ota+ 15 weights).

[Inimbrium]

Wow, that is too much scope for the mount. You went a bit overboard It reminds me some 10" newtonians sold in the 80's with the same mount as the 4.5" version. If you bought the 4.5" you were happy with the mount, the 10" was wobbly as hell. In any case, while the eq5 motors will fit, they are not rated for this much weight, so I doubt they would last long. Also, when you say astrophotography, I hope you don't mean deep space prime focus with the 10", as that will be impossible even if the motors don't fail. For reference, a CG5 can do astrophotography with up to a 6-7kg load, while your OTA alone should be around twice that.

I agree that you can do good things on a budget, however you have to be careful a bit, for example you went for an OTA that will require a heavy mount if you are not to get frustrated trying to use it. If you did not want to go less than 10", then perhaps a dobsonian would have been a better choice (often you get them for around £200 complete on astrobuysell) - as I said astrophotography is out of the question for this OTA without a solid mount. You could do some planetary photography though and if you remove the OTA and attach just the camera with the lens on the mount, a simple RA motor will do fine for long exposures as long as you manage a polar alignment.

I do see one offer for an eq5 pro tripod on astrobuysell that might do and alsor a CG5 tripod with CWs.

The problem is that the EQ6 is hugely expensive.

What about those motorised goto dobsonians? Any good for astrophotography? Can I convert this behemoth with any off-the-shelf kit? Sorry for bombarding you guys with questions..

[Inimbrium]

Oh, I weighed the OTA, with the ringsdovetail and finderscope it weighs 15kg!!

I'm looking into getting a carbon fiber tube made in china and waiting on the prices. Might be cheaper than the EQ6 option...

[brantuk]

Yes that Alloy tripod with the  Sct is gonna be wobbly. You can't do much more than planetary imaging with a motorised dob - however you can get barn door tracker kits to convert to equatorial tracking. Some are cheap diy solutions and some are expensive off the shelf masterpieces. Check out Stellercat and Argo Navis systems - but I reckon they're more than you wanna spend. The DIY sections will have some kit solutions or home made ideas for you.

With a 10" dia tube - the absolute minimum you need is an EQ6 - even that will be overloaded - but with the right balancing and inside an obsy, effective equatorial tracking is achievable for imaging. In the field it would be more trouble than it's worth. A barn door diy solution may be your best way forward.

[Inimbrium]

I've been away for a while and I missed out on the EQ5pro tripod, unfortunately. And also missed out on the ad with the counterweights. I did manage to get me an eq5 tripod, and still looking for weights.

I'm still considering any ideas for making the OTA lighter. How about taking an angle grinder to the OTA? What I mean is going all out chopper style on it. This might sound ridiculous, but I have to ask

See diagram below. The holes have been exagerated somewhat in the diagram, perhaps thicker strips would be more rigid.

 

 

Raf

[RobertI]

Looks like an ambitious project to me! Not something I would embark upon myself, but if you have to (assuming you are going to remove all the components first) i would have thought drilling a number of large holes would be easier.

[Inimbrium]

On 07/08/2016 at 22:19, RobertI said:

Looks like an ambitious project to me! Not something I would embark upon myself, but if you have to (assuming you are going to remove all the components first) i would have thought drilling a number of large holes would be easier.

Genius!!

Sometimes I do overthink things and come up with elaborate and unrealistic plans. The holes method absolitely wins it. Thanks for the idea. I even have a 20mm hole cutter. I would ofc take out the optics before drilling away . However I won't do this just yet. I managed to get my hands on an EQ5 tripod from Astrobuysell, thanks for the reference, Proto Star, and I snatched a polar scope for £18 off ebay. A proper one as well, not those cheap chinese ones without any markings. So for now the 10" will be used as an observing scope, well, when I get my hands on some counterweights, as it all it's missing now.

I have another side project with an eq3 tripod, RA motorised eq2 mount ( I had someone I know made an aluminium adapter) and using a small 80mm scope on that which is swappable with a camera. I basically made the EQ2 hot swappable with a telescope and a DSLR, sort of like a Star Adventurer, but way cheaper. I still need to find counterweights and the counterweight shaft for the EQ2.. :/ If anyone has anything like that or knows someone that does, let me know please.

If you guys want to see photos of these projects you can see them here on my facebook profile:
https://www.facebook.com/rafatom/media_set?set=a.10156359080265254.1073741896.521620253&type=3&pnref=story