Mount load capacity question

[Black Knight]

I have an Explorer 200p mounted on an EQ5 Pro. I'm toying with the idea of adding an ST80 as a guide scope at a later stage, perhaps running Skywatcher's Synguider.

Would my EQ5 cope with the weight OK, or should I be thinking about trading in the mount for perhaps an EQ6 (or some other mount)?

thanks

[simon84]

I believe the payload limit of the EQ5 is 9kgs with the weight of the 200P OTA coming in at just under that it will struggle so if you can upgrade to the EQ6 which has a payload limit of 25kg that would be better.

[Black Knight]

OK, looks like EQ5 will (eventually) have to go then. Thanks for replying so quickly.

[simon84]

No problem, if you want to image with the 200P then the HEQ5 might be an option as that can handle 15kg, ideally for imaging you want to be within 50 to 75% of the maximum payload limit.

[simon84]

Just to add the ST80 weighs in at about 1.5kg.

[Black Knight]

Yeah, I'm trying my hand at imaging with a DSLR for the moment (not without a few problems), at least until I get more experience. Funnily enough I was just looking at the HEQ5 when you posted.

Really I was just thinking about where I might like to go from here, and what I might need to get there, so to speak.

I just wish I'd known when I bought the kit (I've only had it a couple of months), that imaging was something I'd want to do. TBH, the thought hadn't really occured to me.

Oh well, never mind

[simon84]

You'll get where you want to be, it all takes time though.

I didnt have a clue about astro imaging when I started out but me being me I wanted the biggest scope I could so I got the Explorer 300P which came on the NEQ6 Pro.

Take your time, check all your options and keep asking questions.

[Black Knight]

Take your time, check all your options and keep asking questions.

Sounds like really sound advice to me!

Thanks again

[simon84]

No problem at all.

[Glider]

if you are still in the process of 'thinking' about things consider using a finderguider on the EQ5/200P, you can get a lot of experience without spending a lot of money.

[Black Knight]

Never heard of a finderguider before. So I googled it, and it returned with a thread here! Hmmm... might be worth comtemplating ....

[Glider]

You could also just get the ST80 now and use it on the EQ5 to experiment with some DSLR widefield imaging.

That way if you do get the imaging bug then you can still upgrade to an HEQ5/EQ6 later and use the ST80 for guiding the 200P.

[Black Knight]

Hmmm... for around £85 for the ST80 OTA that's actually quite tempting ...

[Glider]

Better than that, zcapp96 has one in the For Sale section for £60.

[Black Knight]

Unfortunately I can't see the for sale section :'(

I'll have to run it by Mrs Black Knight first

[cardconvict]

hi i'am experimenting at the min with the st80 for widefield imaging and it's not that bad. if you want to look at the results, imaging-deepsky and look at the thread m31.or follow my link to flickr.

[Glider]

You could pm zcapp96 direct about the ST80.

[Bizibilder]

I have put an ST80 and 200P on an EQ5 mount and it is definately overweight! - You can almost hear it groan!!! Seriously the bearings "feel" strained as you push that weight around - not forgetting the 2 skywatcher balance weights PLUS another 3-4Kg of additional weight that I had to add to achieve balance. I've upgraded to an HEQ5 and this handles the same combination easily.

When buying my own ST80 I bought one with an EQ1 mount. Two reasons really: This version has a 90° diagonal (OTA alone has 45° only) and I intend to mount and motorise the EQ1 for some "camera only" widefields when I get around to it.

[Glider]

Interestingly I've just weighed my; 200P, ST80, guide camera, imaging camera and a few other bits and the total comes to 14kg.

I've found conflicting limits for the HEQ5, some say 15kg and some say 18kg (excluding balance weights).

Though under the limit I've also read rule of thumb 50 to 75% weight limit for guiding.

How do you guys feel about this?

My bottom line experience is as per Bizibilder, it does work, but is it on the limit? Could something get bent or broken?

[simon84]

I suppose at the end of the day you want it as solid as possible, the more stress on the gearing, the more likely errors will start to appear in the tracking.

I dont suppose anything will end up broken but you will really bring your exposure times down.

[ollypenrice]

In part it depends on where you put the weight. If you piggyback the guidescope the moment is increased but if you go side by side you can keep the weight in close and it will have less effect. If your imaging focal length is short you will get away with far more than if you are working the mount hard at a long fl.

Olly

[Black Knight]

I neglected to think about extra the counterweight completely. So if I do go down the ST80 as guider route then it seems I'm definitely looking at an EQ6 rather than an HEQ5. OK. Time to revise those plans ....

Actually Bizibilder, you make a good point about the EQ1. It only costs around £30 on top of the OTA, and could prove useful at some stage too.

[Glider]

I might have confused you, the counter weights don't count towards the 15kg load capacity.

[Black Knight]

Ahhh OK