iOptron CEM60 - a new mount design!

[blinky]

I was just doing a wee browse round the astro suppliers before heading off to work and noticed this....    

http://www.altairastro.com/product.php?productid=16708&cat=320&page=1

Not that I'm in the market for a new mount at the moment but I will be moving next year and building a new obsy......But I thought  this looks pretty interesting, an integrated USB hub and also 12v outputs right next to the mounting plate, what a great idea!  It seemingly also has optical encoders and can do PEC in real time, I assume like EQMod does?  Whats really interesting is the design though, it just looks very different to anything else I have seen - apparently it puts the payload at the center of gravity to increase stability?.  Only downside is that I assume EQMod wont work with it

Anyway better head to work now whilst trying avoiding storm force winds....

[dvb]

There has been quite a bit of discussion of this mount on Cloudy Nights.  I believe the consensus is that this is an "English Cross-Axis Mount with off-set Counter weights", although many are happy regard the "CEM" as referring to "Chinese Equatorial Mount".

I have an iOptron iEQ45 mount, which is quite good.  I understand the CEM60 will be quieter (different motors), although the iEQ45 is not especially loud. 

I'm interested in the CEM60 for its greater capacity - I have found the iEQ45 doesn't quite live up to its 45 lb. spec, especially with a longer tube. 

I will be waiting to hear how the CEM60 handles the South Meridian - I understand it may have a "flip" that would be awkward for my 10" f/4.5 Newt.

[x6gas]

I'm looking for a new mount and while the CEM-60 looks a bit awkward to me, it has forced itself in to my reckoning.

I currently use a Celestron CGEM DX and I am looking for a step up that I will notice for my £££ and the challenging bit is imaging at the native focal length of my EdgeED 1100.

The Avalon M-uno was a front runner but won't accommodate the Edge with the Celestron reducer (also a requirement); Avalon LineAR and Mesu 200 still in the running...

Anyway, anyone know the specs for the encoders on the high resolution version of the CEM-60?  I've been hugely impressed by iOptrons willingness to conduct their Beta testing in full public view and the fact that they supply a printed PE curve with each mount and are reporting <10 arcsecs peak-to-peak off the shelf with no PPEC or RPEC...

[DaveS]

I saw the CEM 60 at Astrofest and was quite taken with it, but the long offset of the dec axis was a bit worrying. I'll wait to see how those on the bleeding-edge get on.

The "Cross-Axis" mount is actually also known as the "modified English". The true "English Mount" has the OTA mounted between two long runners with PA bearings at either end. Think of a ladder pointed at the pole with the tube where the rungs would be. The Cross-Axis mount only has a single beam with the OTA on one side and a counterweight on the other, with the dec axis running through the middle.

Although a very stable mount, with no counterweight needed, the English Mount has a major disadvantage in that the pole is blocked. I think it was used for the 100" Hooker telescope on Mount Wilson. The polar problem was solved by Russell W. Porter with the Horseshoe Mount for the 200" on Mount Palomar.

[x6gas]

I saw the CEM 60 at Astrofest and was quite taken with it, but the long offset of the dec axis was a bit worrying. I'll wait to see how those on the bleeding-edge get on.

The "Cross-Axis" mount is actually also known as the "modified English". The true "English Mount" has the OTA mounted between two long runners with PA bearings at either end. Think of a ladder pointed at the pole with the tube where the rungs would be. The Cross-Axis mount only has a single beam with the OTA on one side and a counterweight on the other, with the dec axis running through the middle.

Although a very stable mount, with no counterweight needed, the English Mount has a major disadvantage in that the pole is blocked. I think it was used for the 100" Hooker telescope on Mount Wilson. The polar problem was solved by Russell W. Porter with the Horseshoe Mount for the 200" on Mount Palomar.

Yes - is it xenophobic to be interested in an English Equatorial Mount rather than a GEM?!

[DaveS]

Your point is?

I was just clarifying terminology.

[x6gas]

Your point is?

I was just clarifying terminology.

Sorry Dave - didn't have a point - just a joke! 

[x6gas]

My CEM60-EC arrived today - very excited and can't wait to get it out under clear skies but looks like that will be a while yet.

Will start a new thread with my experiences, but for now I've posted some information on my website:

http://www.ir-astro.com/cem601.html

http://www.ir-astro.com/cem60blog.html

Cheers, Ian

[DaveS]

I'll be interested on how you get on with your new mount.

ATM I'm seriously considering either the ASA DDM60 or 85. Though the equivilent 10 Micron mounts are also engaging my attention. I'll be mounting a refractor imaging rig on them.

[x6gas]

I'll be interested on how you get on with your new mount.

ATM I'm seriously considering either the ASA DDM60 or 85. Though the equivilent 10 Micron mounts are also engaging my attention. I'll be mounting a refractor imaging rig on them.

I've been through the same thought process Dave - ASA DDM60, 10Micron, Mesu 200, Mach 1...

I don't have an observatory and so ultimately I decided to go for an intermediate mount rather than the whole hog on something like an ASA.  The ASA looks like a serious bit of kit, but I wasn't sure about the set up time and it looks to me more like something that needs to be permanently mounted.  For me it came down to the CEM60 or Avalon LineAR.

The new mount won't be up and running for a couple of weeks for various reasons but as soon as I get clear skies I'll be testing it guiding via an OAG at 2m and 2.8m focal length with a 16.5kg payload - I'm not going to get excited by flat guidegraphs using a 300mm f/l guidescope so it will be interesting to see how choppy the PHD graph is...

[perfrej]

If you're dancing DDM85 territory I would recommend a good look at the GM2000HPS.

/per

[DaveS]

As things stand I'm not doing any concrete planning until I move into the new house I haven't bought yet. But when I do I'm planning a pier under a roll-off shed affair. So perhaps a pier mounted ASA or 10 Micron and a tripod mounted CEM 60.

The GM2000 is also a possibility for the pier mount, but we'll see. I'll be looking to mount a 160mm f/6.5 oiled triplet and perhaps something shorter / faster on a dual rig, then my Meg 90 and ST80 on the CEM60, though the HEQ5 carries ithem just fine. Maybe the HEQ5 for visual / planetary with the Mak 180.

Gonna need a big garden

[x6gas]

Interested to know what the perceived advantage of the 10 Micron is over the ASA which has higher resolution encoders and direct drive...  I've done a bit of research on these mounts over the past couple of weeks but I am still almost entirely ignorant!

[perfrej]

Personal reflections around ASA include:

- Completely dead without a PC (motor control is done in the PC)

- Sky model controlled from PC (as opposed to in firmware)

- No brakes un-powered or when loosing power

- Swing freely during non-use (consequence of above)

- Reports of unreliable homing and calibration when used remotely

- Excellent unguided performance

Certainly excellent mounts, though, but i fear not in terms of reliability. If they would make a generation II series I would be interested.

Personal reflection regarding 10Micron include:

- All functionality contained within the mount (including full modeling of the sky)

- Can be used stand-alone (even with a model) with full functionality

- Sky model can be built without a PC

- Brakes and clutches

- No homing required

- No motor calibration required

- Excellent unguided imaging performance

Certainly excellent mounts and very reliable.

/per

[DaveS]

Yes, the lack of brakes / clutch on the ASA is a concern to me, as are reported problems with balance. If it's not perfect in all axes then there can be problems slewing through the zenith.

I wouldn't be operating remotely, as the set up would be in my back garden.

[x6gas]

Personal reflections around ASA include:

- Completely dead without a PC (motor control is done in the PC)

- Sky model controlled from PC (as opposed to in firmware)

- No brakes un-powered or when loosing power

- Swing freely during non-use (consequence of above)

- Reports of unreliable homing and calibration when used remotely

- Excellent unguided performance

Certainly excellent mounts, though, but i fear not in terms of reliability. If they would make a generation II series I would be interested.

Personal reflection regarding 10Micron include:

- All functionality contained within the mount (including full modeling of the sky)

- Can be used stand-alone (even with a model) with full functionality

- Sky model can be built without a PC

- Brakes and clutches

- No homing required

- No motor calibration required

- Excellent unguided imaging performance

Certainly excellent mounts and very reliable.

/per

Well let's see how many of these the CEM60 ticks off...

'Course it's half the cost of the ASA or 10Micron...

[lensman57]

Well let's see how many of these the CEM60 ticks off...

'Course it's half the cost of the ASA  or 10Micron...

When I told a friend of mine who runs a shop selling astro gear about some US reviews calling these a "Chinese EQ Mount" CEM, he laughed and dismissed the information, now they are being marketed over here as a "Central Equitorial Mount" . It is a variation on the Old English offset design which  itself was a take on a balanced yoke design. I have seen the smaller of these and the engineering is very good, quite pricy for the amount of the metal that you  get but it seems to work. How much is a mount worth? It does depend on how much one values this hobby in the end.

A.G

[perfrej]

Oh don't talk money like that! If we ever even consider the amount of money we spend in order to produce a few Hubble lookalikes we'd all be doing something else for a hobby, like flying real helicopters for fun or something A good mount and a decent refractor actually gets you a PPL(H) - which is aviation talk for "Private Pilot Licence (Helicopter)".  Try it, you'll like it

/per

[ollypenrice]

Money on AP??? This...

cost three times as much as this...

...but in the end, that's about right when you really think about it.

The DDM is a curiosity. I know quite a few owners and all have struggled to get it to work. Visits from ASA apply in several cases. In the end a very savvy owner who can make his work simply said, 'If you are not an electrical/electronics engineer don't even think about buying one.' I respect his opinion.

Olly

[x6gas]

When I told a friend of mine who runs a shop selling astro gear about some US reviews calling these a "Chinese EQ Mount" CEM, he laughed and dismissed the information, now they are being marketed over here as a "Central Equitorial Mount" . It is a variation on the Old English offset design which  itself was a take on a balanced yoke design. I have seen the smaller of these and the engineering is very good, quite pricy for the amount of the metal that you  get but it seems to work. How much is a mount worth? It does depend on how much one values this hobby in the end.

A.G

I think iOptron have always referred to the design as the Centre-balanced Equitorial Mount or the Z mount; I believe that the moniker Chinese Equitorial came from outside of iOptron.

As to the design, there has been a raging debate on Cloudy Nights as to whether this is a new design or not.  Afterall the GEM is a development of English Cross Axis according to this website.

[perfrej]

The stuff in my signature was more than three times my helicopter licence, so we're on par there. Wanna race?

/p

[ollypenrice]

The stuff in my signature was more than three times my helicopter licence, so we're on par there. Wanna race?

/p

Along the ground?

lly

[DaveS]

The DDM is a curiosity. I know quite a few owners and all have struggled to get it to work. Visits from ASA apply in several cases. In the end a very savvy owner who can make his work simply said, 'If you are not an electrical/electronics engineer don't even think about buying one.' I respect his opinion.

Olly

This might well make me look at 10 Micron instead as I'm not that good at electronics engineering.

I just want a mount that WORKS.

[x6gas]

This might well make me look at 10 Micron instead as I'm not that good at electronics engineering.

I just want a mount that WORKS.

Then I suspect Olly will recommend the Mesu - that's his rallying cry...

I'm actually not expecting my CEM60 to work perfectly out of the box - it's too new and they are still working on the firmware, but it's kinda cool that I have a shot at providing some feedback that might make it in to a release... and you sure don't need an engineering degree to use it!

[perfrej]

Along the ground?

lly

I need a few feet of clearance from the skids to the ground, but apart from that I consider it grounded Whooosh!

/p