Pointing south and crossing the meridian.

[Devil20]

If you are using an equatorial tracking mount and it's tracking across the meridian at this poiint the counterweights are going to end up progressively higher than the scope. Additiionally, but of less importance the eyepiece (for a side firing scope) will also end up in  an unusual orientation.  How does a tracking mount deal with this? Does it do a meridan flip or can you force it to do a meridian flip or does it eventually just cockle over and wreck your scope?

--

Ian

[davefrance]

Mine does a meridian flip but I believe I have seen a tracking mount that goes through the meridian.

[Devil20]

Mine does a meridian flip but I believe I have seen a tracking mount that goes through the meridian.

Ah. I wasn't expecting that answer. Is it the norm that a tracking mount will do a meridian flip then? I'm assuming you are talking about your HEQ5 mount when you say this performs a flip.  

I'm new to astronomy and bought a cheapo Celestron 130 Newtonian reflector about 2 weeks ago. I've still not used it as it's been cloudy every night bar one when I was elsewhere and I'm already thnking of upgrading starting with an HEQ5 Pro SynScan. That seems to be a no brainer. It's only going to get more expensive. Even if I just stick it in the loft pending a decision which scope I want then that's fine for now. Got my eye on a Skywatcher 200mm Maksutov Newtonian but if I buy both at once it'll end up with me getting a severe beating and having to undergo a non-elective transgender operation without anaesthetic and with a blunt breadknife. For now I'm working on the basis that one tripod looks much the same as another to the untrained eye.

[Devil20]

Just another quick question on the back of this. Easily enough when you're at home near a socket outlet but how do you power your mount when out in the field?  

[Chris Rowland]

It varies. Some mounts will only track to the meridian, others will track for a while past the meridian.  The Celestron AVX can track for 20 degrees past (or start 20 degrees before) the meridian.  That gives about 1h 20m.  There's options in the HC to prefer one side of the other. The CG5-GT only goes 6 deg which in practice is practically nothing.

In both cases the mount does nothing automatically. When it reaches the Ra Limit tracking stops.  The limit is adjustable if there's something getting in the way before that.

I don't know about the Synta mounts, but plenty of people here do.

Chris

[SnakeyJ]

Ah. I wasn't expecting that answer. Is it the norm that a tracking mount will do a meridian flip then? I'm assuming you are talking about your HEQ5 mount when you say this performs a flip.

I'm new to astronomy and bought a cheapo Celestron 130 Newtonian reflector about 2 weeks ago. I've still not used it as it's been cloudy every night bar one when I was elsewhere and I'm already thnking of upgrading starting with an HEQ5 Pro SynScan. That seems to be a no brainer. It's only going to get more expensive. Even if I just stick it in the loft pending a decision which scope I want then that's fine for now. Got my eye on a Skywatcher 200mm Maksutov Newtonian but if I buy both at once it'll end up with me getting a severe beating and having to undergo a non-elective transgender operation without anaesthetic and with a blunt breadknife. For now I'm working on the basis that one tripod looks much the same as another to the untrained eye.

Not speculating on the operation, as it made me laugh and wince as just recovering from my own hernia op!

However, I think the EQ6 is the minimum or recommended mount for the mn190, which is quite a lumpy bit of kit. Great scope though

typed on my mobile with Tapatalk

[davefrance]

There are loads of threads on this subject here on SGL. I am still learning so best wait for more learned members to join in and give you the benefit of there knowledge. Here is one topic that might help http://stargazerslounge.com/topic/195311-how-to-predict-the-meridian-flip/

With regard to powering mount I use a Lucas 12v 22ah deep cycle AGM battery (like this one http://www.ebay.co.uk/itm/like/200785096894?hlpht=true&ops=true&viphx=1&lpid=95&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0&ff12=67&ff13=80&ff14=95) with cigarette lighter socket attached. Many on here use all sorts of Powerpacks, Leisure batteries and Jump starters.

[Devil20]

Not speculating on the operation, as it made me laugh and wince as just recovering from my own hernia op!

However, I think the EQ6 is the minimum or recommended mount for the mn190, which is quite a lumpy bit of kit. Great scope though

typed on my mobile with Tapatalk

The HEQ5 looks like it can accept the payload of the mn190 easily enough but take your point about the EQ6. The extra 200 quid is probably lost in the noise of the overall cost and might make more sense. I'd then have to consider lugging it around though. I'm fit and healthy touch wood but no point wearng yourself out uneccessarily and sweating all over your telescope and fogging it all up.

[davefrance]

The HEQ5 looks like it can accept the payload of the mn190 easily enough but take your point about the EQ6. The extra 200 quid is probably lost in the noise of the overall cost and might make more sense. I'd then have to consider lugging it around though. I'm fit and healthy touch wood but no point wearng yourself out uneccessarily and sweating all over your telescope and fogging it all up.

HEQ5 recommended max = 11kg for imaging, 18kg for visual. Mn190 OTA 10kg, by the time you add few bits and pieces + camera could be above imaging weight.

[SnakeyJ]

The HEQ5 looks like it can accept the payload of the mn190 easily enough but take your point about the EQ6. The extra 200 quid is probably lost in the noise of the overall cost and might make more sense. I'd then have to consider lugging it around though. I'm fit and healthy touch wood but no point wearng yourself out uneccessarily and sweating all over your telescope and fogging it all up.

 On paper the bare OTA scrapes it at 11kg, but when you add camera, filter wheel, dewshield, tapes and a guide scope or OAG  you are pretty much on the max visual load - then there's the windage to consider.    I'm sure it could be made to work, but I definitely feel my rig (200P and guidescope) are about the limit and will be upgrading the mount as soon as I get the chance.

[Devil20]

Im glad you told me that Dave. Although I'm new to the hobby, at some point I'd like to start dabbling in astrophotography. So, looks like if I do end up with that scope (which I shortlisted as it seems to be a particularly good scope for AP) then the EQ6 is the one to go for.  I appreciate your help. SGL is certainly the place to be for this hobby.  

[davefrance]

Im glad you told me that Dave. Although I'm new to the hobby, at some point I'd like to start dabbling in astrophotography. So, looks like if I do end up with that scope (which I shortlisted as it seems to be a particularly good scope for AP) then the EQ6 is the one to go for.  I appreciate your help. SGL is certainly the place to be for this hobby.  

Hope youv'e got some good muscles.

I would recommend making a list of desired scope, mount and any equipment you might need for both visual and imaging then total the weight. Don't forget portable power option as well, that can add a few kilos. You can then decide whether that is practical. A lot might depend whether you are going to spend most of the time at home or touring round visiting dark sites and of course mode of transport. Donkey is optional but definitely very handy with anything above EQ3

[Devil20]

I've got a couple of old series Land Rovers. I can get to remote sites and load them out the back. The bloke that eventually convinced me to get a scope was on one of out Land Rover meets when I got chance to peer through his 8' Dob at Saturn. He's on here, I recognised him on one of the posts, because he uses the same handle as our Land Rover forum.

[ollypenrice]

The HEQ5 looks like it can accept the payload of the mn190 easily enough but take your point about the EQ6. The extra 200 quid is probably lost in the noise of the overall cost and might make more sense. I'd then have to consider lugging it around though. I'm fit and healthy touch wood but no point wearng yourself out uneccessarily and sweating all over your telescope and fogging it all up.

Not the HEQ5! The MN190 is not only heavy but long, and it has full aperture glass at both ends which gives it a considerable moment working against the mount. It does need to be the NEQ6 for this OTA. If you are aiming to image with it, its focal length of nearly a metre will not be at all tolerant of vibration or guiding error. And, as above, it is a wind sail.  I would say the HEQ5 was totally out of the question for it.

Not many mounts flip automatically. They can do so under command from a PC once the slew limits have been set, but these vary with the length of the tube. Or, once you have passed the Meridian, your Go To will usually just perform the flip if applied.  Watch it slew, though, because long OTAs can collide on both sides of the mount. There are sometimes dead spells when a high object is not accesible on either side of the mount, mainly when using a tripod. A pier collides less readily.

Olly

[Devil20]

Right. NEQ6 it is then. I'll probably be splitting time at home and out and about about 50/50 I'd say.