Jump to content

Stargazers Lounge Uses Cookies

Like most websites, SGL uses cookies in order to deliver a secure, personalised service, to provide social media functions and to analyse our traffic. Continued use of SGL indicates your acceptance of our cookie policy.

stargazine_ep28_banner.thumb.jpg.b94278254f44dd38f3f7ee896fe45525.jpg

Sign in to follow this  
The Admiral

Some thoughts on the new iOptron GEM45

Recommended Posts

Posted (edited)

I recently took delivery of this mount, having until now only used an Alt-Az mount for imaging. So this is a whole new experience, and as such I’m not really in a position to give a meaningful performance review. Nevertheless, here are my first thoughts.

I wanted a mount that could be set up for each session, and light enough to allow my ageing frame to be able to carry it from inside the house to outside. It also had to be able to successfully carry a load currently around 6-7kg without complaint. So this is what attracted me to the GEM45. I bought the version with the case and tripod, non-EC. I don’t guide it as yet, so I can’t quote chapter and verse on its guiding performance.

Here's the set up raring to go! I've left the tripod trousers on!

682695110_GEM45withAltair104mm.jpg.a944af092318b2b212137d5622f84ae4.jpg

 

First impressions.

It seems a solidly built, well finished, precision machine, unlike what one would expect from a mass-produced object. The axes move smoothly and I haven’t noticed significant backlash either by ‘free play’ or other than instant response to commands when lining up objects. However nice the looks, performance is everything of course, though it does give confidence.

The first thing I needed to do was to swap the latitude adjustment from the low position to the high position, as I live in the UK. It is worth noting that for where I live, ~51° N, I need to wind back the altitude to ~40° with the altitude adjuster (not re-set the setting from high to low, fortunately), each time I need to get the mount into the foam cut-out of the case.

Initially I had trouble locating the bolts with which to bolt the mount onto the tripod, the Azi Locking Screws. Thanks to FLO that was simply resolved, but I found that one of the bolts was slightly bent, enough to bind a bit in the thread, again resolved by the excellent services of FLO. Also, these bolts are meant to be used with the provided washers, but only one could be located. These are little perishers, as it’s easy to drop them when assembling the mount, as I discovered. My wife’s eagle eyes managed to spot it on the patio; try doing that in the dark! It’s a pity that the bolts don’t have a winged- or star-head for finger tightening to make life easier with repeated setting up, but there isn’t room beside the mount to allow that.

P1030412.jpg.63e5df43fea32682bebc5183e99b0be6.jpg

The bolt shown here is a make-shift arrangement and is not the proper bolt and washer.

The same could be said for the Lat Locking Screws, since they have to be slackened off and re-tightened before and after setting up/Polar aligning. However, these could reasonably be replaced with hand operated bolts, rather than rely on the Allen key, as there is ample room.

A note re. the tripod, is that it has an alloy top plate and I do wonder how resilient it will be to the repeated attachment of the mount. However, I also bought the Mini-Pier and the threads on this are inserts pressed into the alloy and look to be made of a more bolt friendly material. I plan to leave the Mini-Pier on the tripod.

Tracking

As I said I don’t guide so I can’t offer any figures. So the best I can do is provide some subs from my recent tests. You’ll need to bear with me on this as I’ve not many examples to date. My first examples are of M3 showing different sub durations of 90s, 120s and 150s. Unfortunately I was having trouble with my optical train and have got out of shape stars towards the edges anyway so that may confuse. Here they are for what they are worth:

90s

90s.thumb.jpg.4e9eefa8fea28d108f10731b4be6fb3b.jpg

120s

120s.thumb.jpg.ff35e7690b1108173c7dddb81f60f643.jpg

150s.

150s.thumb.jpg.2aacbc4d34dc73b5645222e1b79f54a0.jpg

 

My second offering is a sub from an attempt at M81 shot at 90 seconds:

2018551412_LightframeM8190s.thumb.jpg.ab13bcd67d3eeb8b6cb78d6c8732e7b2.jpg

 

The full image is posted here https://stargazerslounge.com/topic/352345-m81-m82-with-gem45-unguided/.

In summary then:

Pros

  • The iPolar is a doddle to use, though does need a laptop to be set up for the alignment process, but that can be put away afterwards. Far better than kneeling on the floor and craning one’s neck.

  • I’ve found tracking to be good enough for me up to about 1½ minutes, though possibly beyond that to 2 minutes or more, without guiding, with a FL of ~560mm and load between 6-7kg. Depends on how purist one wants to be about ‘round stars’.

  • It’s quiet whilst tracking but slewing is by no means silent. I’m always concerned about disturbing neighbours so perhaps I’m being unduly critical. It’s quite difficult to judge how loud these things are in the middle of the night when you are standing next to the source. Then again, I’ve not used other mounts to compare it with.

  • The hand controller seems fairly logical to use.

  • Assuming I’m setting up everything correctly, I’ve found that the homing in on alignment stars to be somewhat ‘out’, and have always needed a significant correction to align. I do a 3-star align and I find this to be the case for each star. However, when I come to align on my target I found that it centred the object very well. May be I have significant cone error which will only be corrected for after the 3rd align, if I understand correctly.

Cons

  • The need to reset the altitude setting to around 40° in order to replace it into the case.

  • Fiddly washers beneath the mounting bolts which are easy to lose. A touch of grease might help them to be retained by the bolt.

  • Having to use the Allen key on the Lat Locking Screws.

  • When aligning, the stars offered are in magnitude order, which from one point of view is logical, but is a bit of a pain when one wants to find particular stars. It would be good to be able to change your preference on star order.

That's it for now, and I hope that it's been of some use.

Ian

Edited by The Admiral
  • Like 4
  • Thanks 1

Share this post


Link to post
Share on other sites

Good write up, awaiting the next instalment.

  • Thanks 1

Share this post


Link to post
Share on other sites
On 19/04/2020 at 21:35, The Admiral said:
  • Fiddly washers beneath the mounting bolts which are easy to lose. A touch of grease might help them to be retained by the bolt.

  • Having to use the Allen key on the Lat Locking Screws

Great initial write up Ian, there always seems to be some flaw in design that could be made better, in any mechanics.

A suggestion for fiddly washers, would flanged bolts be ideal?

A suggestion for the lat locking screws, would screws that have a deeper head to incorporate incremental holes, on the grippy bit where a metal rod/pin can be inserted to tighten them up, help?

Just a couple of ideas, that’s all. Obviously you will know best having it right in front of you.

Richard

  • Like 1

Share this post


Link to post
Share on other sites
40 minutes ago, Autoglassman said:

A suggestion for fiddly washers, would flanged bolts be ideal?

I don't think so as the washers are the same diameter as the head. I think their purpose must be to allow some slippage so that the mount can be adjusted for Az against the pin.

42 minutes ago, Autoglassman said:

A suggestion for the lat locking screws, would screws that have a deeper head to incorporate incremental holes, on the grippy bit where a metal rod/pin can be inserted to tighten them up, help?

I'm not quite sure I follow, but using the Allen key of itself isn't really a problem, it's just that for operations which have to be repeated each time the rig is set up it would be less fidly and more convenient if they could be tightened by hand. You always run the risk of dropping the Allen key in the garden too! All the more so as in order to put the mount back in its case they have to be slackened off again so as to allow the altitude setting to be reduced to ~40°. Note that these bolts have a shaped shank, they are not straight bolts.

You are right about minor flaws though, if they can be called flaws. Perhaps I am just being picky. But thanks for the suggestions anyway.

Ian

Share this post


Link to post
Share on other sites

Seems a step backwards my old iEQ45 has proper knobs that tighten by hand with Allen key centres to tweak them up, on altitude and azimuth the only problem was when tightening the dec adjustment it shifted Polaris so I fitted shims in the gaps between the castings.

Hand controller is annoying as it doesn't scroll if I hold the button down so have to keep pressing and letting  go and pressing etc etc.

Dave

Share this post


Link to post
Share on other sites
25 minutes ago, Davey-T said:

Hand controller is annoying as it doesn't scroll if I hold the button down so have to keep pressing and letting  go and pressing

I don't have any problem on that score.

Ian

Share this post


Link to post
Share on other sites
1 hour ago, The Admiral said:

it's just that for operations which have to be repeated each time the rig is set up it would be less fidly and more convenient if they could be tightened by hand.

Sorry, I misread the context, yes I can see how that would be a pain each time.

1 hour ago, The Admiral said:

I don't think so as the washers are the same diameter as the head. I think their purpose must be to allow some slippage so that the mount can be adjusted for Az against the pin.

Yes, you are quite right, they look like nylon/plastic washers? As you say, to allow necessary adjustment for polar aligning the mount

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By AstroRuz
      FLO sent me this beast of a mount for review, and after a few months use I've finished said review. If you don't want to read, then scroll to the bottom to see the video. If not, let's go.
      From the top, the dual type Vixen/Losemandy type puck, and at the back of mine it had 3 5521 type power ports for powering equipment, and 3 USB ports (2 powered) for connecting to the internal USB hub network. Whilst I didn't exactly use this network, it's still very handy to use, especially being on the puck - it means you don't have to worry about any slack on your cables and they won't pull. A handy feature. The power ports seem to be of a different type to 99% other astronomy hardware though, which means you'd need to get different connectors, a major inconvenience which still will make itself known later.
      The mount includes an iPolar system, which is absolutely awesome. Sure the UI looks like it's straight out of Microsoft Paint but it's certainly function over form as it's quick and uses plate solving to align. This means you can polar align even with a semi-obstructed view to the pole. It's powered by a USB2-B port at the back of the mount with no need for external power. There is no manual polar scope on the mount so a computer is a must for polar alignment.
      The carry capacity of 31.8kg is a hefty amount, though it's advised to not exceed 21kg for astrophotography. I never loaded it up with this much equipment however the sheer build quality and performance of this mount leads me to have no concerns whatsoever about using that much weight, or even all the weight. It's always advised to use underneath the stated maximum capacity anyway.
      The altitude adjustment knob is a hefty coarse worm gear style affair. Embossed with the iOptron logo. It's a nice way of adjusting, especially when coming from GEM mounts where you have to undo/do up two individual bolts. However on my mount it was let down by an abhorrent squeak it made when raising it whilst the mount was loaded up. When going down in altitude sometimes the gear would jump a bit and let the mount down even further than I wanted. Azimuth adjustment was fluid and great.
      The control panel includes its power port, power switch, hand controller port, ST-4 port and the USB port. The USB port can be used to control the mount via computers, and is also the other end of the internal USB network. It is USB2-B. 
      A major issue I found was the power port. It wasn't the standard type DC centre-positive tip style that all my other astro equipment used. IT's also a standard female type port, whereas I would've liked to have seen a screw type connector for this price point. But yes, the biggest gripe was the different style port, which meant I couldn't power it using my power box (without getting more cables), and had to use the supplied plug.
      The carry case is a substantial and very sturdy box. It's foam cutout and very tight in holding the equipment. All but the counterweight goes into this box and I believe it could really survive quite a harsh fall. It's very well built.
      Slewing with the CEM70 was quick and fluid, it was also quieter than I was anticipating for such a large bit of machinery. Using its own dedicated software through the laptop was intuitive and there was little to no learning curve. The axis clutches, whilst using a small switch, feel solid and substantial with a nice meaty clunk when engaged. One lock position is the EQ Home position which makes life a lot easier.
      When guiding, I was regularly getting values of 0.4-0.6" total error. This enabled me to take extremely long exposures if I so desired, though I mainly did  5 minutes, I was able to do 10 under testing. Unguided (just sidereal tracking) I was only able to achieve 2 minutes before trailing was found with my Evostar 80ED (reduced to 510mm) and ASI 071mc Pro. Now in full admittance the mount was unbalanced as the Evostar package was too light for the mount. 
      The counterweight, if moved too high up the bar, will strike the body. So you would need to buy a lighter weight if you wanted to balance a lighter load on the CEM70.
      Also when attaching it to a tripod or a tri-pier, you do need to bolt down 2 spring loaded bolts down with the supplied allen key. Now this is a bit fiddly and adds several minutes to the setup and tear down times. Though I suspect iOptron made this mount with a permanent setup in mind so if you're putting this into an observatory then this won't be a problem. For me, who setup and torn down the rig each night when using it, became a bit of a chore.
      Overall I found the CEM70 to be an extremely capable mount with a lot of features. Whilst there are niggles that detracted from the user experience; the altitude gear squeak and the non standard power ports. Other features improved the quality of life and user experience enough to vastly outweigh the drawbacks. The iPolar system is particularly capable and excellent, the carry capacity, build quality also and guided performance, as well as the internal USB hub. 
      I think this would be a nice investment if you were looking to mount larger scopes on, or decking out an observatory. I can't afford one but if I was making my own permanent setup I would severely consider buying one. 
      If you're interested you can find more information at the links below (if you did buy through these links, I'd earn a few pennies to help support these reviews).
      iOptron CEM70 w/o iGuider: https://bit.ly/CEM70
      iOptron CEM70 w/ iGuider: https://bit.ly/CEM70iGuide
      iOptron Tri-Pier: https://bit.ly/CEM-Tripier
       
      Thanks for reading everyone. What are your thoughts about this mount? I hope my review has been helpful for you  clear skies all, keep looking up and keep them cameras clicking.
    • By alexbb
      It seems that I got less active lately in this hobby, mostly due to the pandemic, directly or indirectly.
      However, I'm planning to move from where I'm living now in the close future so I started replacing my gear with lighter and better items.
      One of the items was the mount. I still have a tuned SkyWatcher AZ-EQ5 and a stock SkyWatcher EQ6-R. I used both quite a lot, I passed with them long time ago 1000h of exposure. And recently I bought an iOptron GEM45.
      The AZ-EQ5 is in the lightweight mount class, but performs quite poor for astrophotography. The original RA worm was a crappy one and I sent the mount to DarkFrame for tuning. I received it back the same, I only lost time and money. I then purchased 2 new worms from China via OVL with some help from FLO. The new one (I didn't test both) have a larger PE than the original one, but a smoother one. The p2p PE of the new worm results in a >60" deviation. When pointing close to the NCP, it guides well below <1.0" total RMS. When pointing towards the celestial equator, the performance drops significantly to 1.0"-1.8" RMS. I always need to use short exposures in PHD to guide it smoother.
      In total I spent for the AZ-EQ5 perhaps more than 1800 euros with the tuning, the new worms and deliveries. A lot pricier than stock in the end, but it still has 2 big advantages: mine came with a foldable (towards the mount) pier style tripod and it's light, I can carry the mount with the tripod folded in one hand. The mount and the tripod weight less than 15kg. The other advantage is that I can use the second saddle for the second scope. I used this combo more than a couple of times, with short focal length refractors and all went well. A SW 72ED + an ASI1600 + a finder/guider mounted as counterweight as close as possible to the RA axis, perfectly balances a SW Esprit 80 and a Canon 550D.
      The EQ6-R is a lot heavier mount. The head itself weights about 17.7kg, it has a handle, but even standalone it seems a lot harder to carry than the AZ-EQ5 assembled on the tripod. The 2" tripod for the EQ6-R weights about 8kg. Definitely I cannot carry both the mount and the tripod in a single trip for a longer distance. The performance and weight capacity are decent though. Mine has quite a large backlash on both axis, I cannot feel it at hand, but it's obvious when slewing at slow speed. It doesn't bother me for imaging, anyway, since I balance the mount a little east heavy. At most I put a single 200/1200 newtonian and camera on it or a dual setup consisting of a 150/750 newtonian and + a 102/714 refractor and camera, one on top of the other. Weight was not an issue, but a larger momentum + wind affected the guiding performance a little. Towards the NCP it guided excellent at 0.4"-0.6" RMS, but closer to the celestial equator, the performance varied and dropped for this mount too. On Orion, at times the guiding stayed below 1.0" total RMS, but many times it went worse than 1" total RMS. I believe that I never put a scope on this mount and looked through it, I only used it for AP. One thing that bothered me for a while was that the mount was stalling at times due to insufficient power. None of my domestic 12V power sources that I used for the AZ-EQ5 was good enough so I used a 15V 8A source to power the mount. I recall paying around 1300-1400 euros for the mount about 2 years ago.
      I used the SynScan app on Windows to drive the SkyWatcher mounts. The app mimics the functionality of the hand remote. The AZ-EQ5 doesn't have a polar scope and I believe I never used precisely the polar scope on the EQ6-R either. The app allows you to perform a 2/3 star align, then it figures out the polar error and you can then perform a polar alignment routine aided by the software. You can select a star for polar alignment, slew to it automatically after select, align in center, then the mount moves a little and the software tells you to adjust the altitude and bring the star in center, then it moves again and tells you to adjust the azimuth and bring the star in center. Simple as that. If you're way off initially with the polar alignment, you might need to realign once or twice again. The SynScan app + drivers are also much simpler than the EQASOM and can be used for controlling the mount from other programs via ASCOM or for pulse guiding.
      Now, to the more recently acquired mount, the iOptron GEM45. I spent a lot of time researching what mount would suit my needs. Lightweight, good performance and not astronomically expensive. After many reviews read for the CEM40, I decided to go for the GEM45 as both share the same components. I only saw CEM60's and the older 45 eq. All my astrofriends' CEM60's perform better and more consistent than my EQ6-R.
      The GEM45 is supposed to have a PE resulting in an error less than 14" p2p. The graph for mine says that it's less than 10".
      The first thing that I noticed when I received the mount it was how small the box it came in was. The mount head is light at about 7kg and the tripod 5-7kg. The second thing that I noticed was what a poor design was made for mounting the mount's head on the tripod. It is unbelievably stupid compared to the SkyWatcher mounts and it's horribly difficult to mount and tighten the mount on the tripod in dark and cold.
      Again, comparing to the SkyWatcher, a minus is that you always need to disengage very carefully the gear switches and never leave them engaged. The mount does not have a friction clutch as the SkyWatcher has and hitting or pushing hard the components can lead to damaging the gears. So the mount seems very sensible to handling, it requires a lot of care and mounting the telescope(s) on the mount while holding the CW rod with the other hand can be quite damn hard sometimes. However, there is no backlash.
      After setting all the hardware, the next thing was to connect the remote control + the software. It was clear the day I received the mount. It arrived at 5PM and at 8PM I was out of the city with all the software installed.
      The iPolar was easy to use, however, you need to connect a separate USB cable for this, the mount does not have a USB hub.
      You can perform a star align from the hand controller, but not from the Commander app. You can perform a polar iterate align from the hand controller, but not from the Commander.
      Speaking of star alignment, if you choose a 2 or 3 star alignment procedure, I was used to the fact that the first star can be way off when initiating the alignment. The SkyWatcher mounts' software (hand controller or PC app) took into account the error and corrected it for the next stars. iOptron's software (hand controller only, the PC Commander can't align at all) does not. So you need to search again for the second (and third) star to bring it into the view and center it. Only then the model is taken into account. Moreover, the polar iterate align is a pain and, surprise, the polar iterate align and a retry of star alignment after polar adjustment does not take into account the model it computed at the previous star alignment so all the stars are way off if the zero position is not set very accurate. Searching automatically for zero position seems rather a poor joke. So, after being used to the SkyWatcher software, the iOptron seems soooo limited and counterintuitive.
      Due to this, I had quickly to learn to drift align with PHD when Polaris isn't visible (it my the case at home on the terrace).
      Leaving all the poor engineering and software designs, things are getting better. The mount looks very nice and rotates around both axes very very smooth. You can also pull cables through the RA and DEC axis and have them available at the DEC saddle. There's only a USB 2.0 connector on the saddle, that was rather useless for me so I needed to pull a USB 3.0 cable. However, the 12V power available on the saddle is very welcomed to power the cameras' coolers.
      As I type, I'm imaging with 2 ~70mm refractors one on top of the other + 2 mono ASI cameras. Both scopes weight about 10kg. Guiding performance is always below 1.0" total RMS, ranging between 0.4" and 0.8" total RMS, regardless of the pointing position on the sky. If I manage to convince either the mount or PHD to compensate for the PE, I believe it should perform much better as the error increases to >0.6" only when the guiding switches from East to West or viceversa. Plus, being backlash free, it responses very fast to dithering commands and settles quick and, with the small refractors, it didn't seem bothered almost at all by a mild wind.
      In the end, I'm very happy with the consistent very good performance of the mount, but still disappointed by the mount attachment to the tripod and the poor designed software and alignment procedures.
       
      I'll come back with more reviews for cameras and telescopes that I own or owned. And images, after I manage to process them. I've more than 100h of data waiting in the queue to be processed.
       
      Clear skies and stay safe!
      Alex
    • By The Admiral
      I'm just starting to get to grips with my new iOptron GEM45 EQ mount, having spent some time cutting my teeth in astro-imaging using an Nexstar Alt-Az mount. Very much an EQ virgin!
      I decided to image M81 & M82 as these were inaccessible with my old Nexstar, so it was new territory for me. I used my Altair Wave 104 f/7 ED triplet scope, Photoline 0.79x reducer and Fuji X-T1 (effective FL 560mm). ISO400. 60 x 90s lights and flats. I did take 20 darks but I found that using some old bias frames from an earlier session gave a better result. Stacked in AstroArt 6, processed in StarTools v1.6.393 RC2, and polished in Lightroom. I've yet to get to grips with this latest version of ST, so for this image I haven't used the full gamut of controls. I like to get as much detail as I can from my images, I don't do subtle! Fans of a naturalistic look may not approve .

      At about the 9 o'clock position there is a small blue 'smudge', enlarged here. It does unfortunately reveal some trouble with my stars!

      I had originally thought that this was NGC 2976, but Astronet shows that galaxy to be too far away. Anyone any idea?

      Thanks for looking.
      Ian
    • By Geoff Lister
      I bought this mount, from FLO, at the beginning of January 2020.  https://www.firstlightoptics.com/ioptron-mounts/ioptron-smartstar-cubepro-az-mount.html These comments are after a month's occasional use.
      I already have a selection of Celestron & Skywatcher (Synta) GoTo mounts, but I wanted something smaller for a grab-and-go with quick setup. Overall I am very pleased with my choice.
      The GPS locks in a few tens of seconds, and the mount emits a short "beep" to indicate the lock (the top-right corner of the display also changes from "ON" to "OK"). Provided that the mount is pointing towards its designated starting Az & Alt positions, (see below), the automated slew to the selected target is accurate and, after final centring, tracking is excellent. It is very quick and easy for solar white-light observing when there is a gap in the clouds. The single object alignment (2 and 3 object alignment is also available) is ideal for daytime, when only the Sun is visible.
      The mount incorporates a holder for 8-off 1.5V AA cells, and there is a socket for a 12V,  2.1mm ID/5.5mm OD power jack. I have measured the current consumption. Initially (no tracking) it is between 75 & 90mA; whilst tracking, between 90 and 130mA; 2-axis slewing at maximum rate, up to 470mA; and 2-axis slewing at 128x standard rate is about 155mA (about 10mA less if only 1 axis). Generally, the standard zinc/manganese dioxide "alkaline" cells have a capacity between 1700 and 2850mAh. The manual indicates a supply range of 10V to 14V and >1.5A (the supplied PSU is rated at 1.5A - so, in theory, out of spec!).
      The mount has a 3/8" - 16 UNC internal thread (heavy duty tripod), and is coupled to the top of the tripod by a long, captive, bolt. The tripod's legs are locked in position by rotating a plastic tray (with holes for 3 off 1.25" eyepieces) similar to the Synta ones.

      There are a few areas with significant differences to my other Celestron and Skywatcher mounts, and other "features" of note:-
      (1) The Cube's dovetail clamp is on the right, whereas on the Synta mounts it is on the left. Thus any Synta OTA is going to be upside down on the cube. This is not a problem with most focusers, but the finder is now bottom right, and A RACI with eyepiece facing downwards, is unusable. The OTA from my Heritage 130p has the helical focuser pointing directly downwards (I believe it is possible to remove and reverse the truss tubes, but then that would make the OTA incompatible with my other mounts). The 127mm Mak from my Skymax system is right at the top end of the mount's OTA-weight range, and I have glued a second finder shoe at 180 degrees to the original, so I can use my 6x30 RACI finder. I have a Celestron C90 Mak. spotting scope, designed to go on a tripod, and this works fine with the cube - the finder moving from top left to top right.
      (2) The supplied system includes a 12V 1.5A mains PSU. This supply is a small block with a permanently-attached mains input lead. This lead has a "European" small, round-pin, (incompatible with standard UK socket) mains plug. It has similar spacing to the plugs supplied with UK shavers and electric toothbrush re-chargers, but, the pins on the supply are of a smaller diameter. I tried the plug in two plug-in shaver adapters; there was no problem with electrical contact, but it was far too easy to dislodge the plug with a small movement of the lead; easy to disconnect in the dark (leads and supply are black). I cut off the plug and fitted a UK BS1363 square-pin plug.
      (3) With my Synta AZ/Alt systems, the default starting position is with the OTA pointing North and the OTA level or pointing to the NCP (Virtuoso Dob. mount). With the Cube The default starting position is with the mount facing South, and the OTA/dovetail clamp, vertical. This makes it far more difficult to attach the OTA. With a horizontal dovetail clamp, the clamp supports most of the weight of the OTA, and just requires a gentle push to adjust the OTA's dovetail plate position in the clamp. With a vertical clamp, you have to support the full weight of the OTA + any clamp-to-plate friction. I have found a solution that seems to work for me. Unlike the Synta system, the Cube remembers the mount's position at power-down. So, at the end of a session, I slew the mount to AZ 180 degrees, Alt to 0 degrees, and then power down. The mount seems to accept this as a starting point for the next session. (I have yet to try the Az at zero [= North] end/restart setting).
      (4) The initial "South" starting point is more difficult than North, (no Polaris equivalent) and the mount has a strong stray magnetic field, so you cannot use a magnetic compass near it. I have found the best method is to use a compass to identify an object (roof/tree/pole) roughly due South, point the OTA's finder at the object, tighten the tripod's mounting bolt, swing the OTA vertical (spirit level across objective end shroud/ dew shield), and tighten the Alt knob/balance weight shaft. Remove spirit level - its a long way down to a concrete paving slab when the mount slews!
      (5) The Cube mount relies on a level tripod for its initial accuracy. However, the little bubble level incorporated in my mount was not well aligned. With a leveled tripod, using a "good" builder's spirit level, the mount's bubble was off-centre, with one edge of the bubble touching the black line. I got round this by putting a Tipp-ex white blob on the level's glass, positioned to just cover a properly-leveled bubble, and leveling is now just a game of "Hide the bubble".
      (6) Some of the advertising photos show the handset as though it is attached to one leg of the tripod. There is no way of doing this with the supplied kit. The handset has a little lanyard, and there is a small raised "button" on the North face of the Cube. The lanyard slips easily over the button, and is a reliable "dock" for the handset. However, both the lanyard and the button are black, so in the dark, it is difficult to find the button, and ensure that the lanyard's loop is open and correctly positioned. I made a tripod-leg docking clamp, similar to the ones supplied with the Synta tripods. I find the lanyard is best for daytime solar, and the (home made) docking clamp for night use.
      (7) The Alt axis drive is from a sleeve on the main Alt shaft. The coupling is performed either by the locking knob, or by the end of the balance weight shaft. In both cases, the drive is through metal-to-metal friction with the end of the drive sleeve. There is no compliance in this coupling, so a minor release movement completely unlocks the drive. I have added a thin fibre washer (of a type often used in plumbing joints) to absorb any minor changes due to temperature or a nudge on the OTA. It's still not the same as an adjustable clutch, but it seems to stop inadvertent release (and associated loss of alignment).
      When I have a few suitable photos, I will add these as an edit. Photos now added.

      90mm Mak from Virtuoso system and Ioptron-supplied 1.4kg counterweight. Note "glow-in-the-dark" tape added on mount's lanyard attachment button, handset, eyepiece tray and tripod legs. DIY docking clamp for handset - in dark, easier to use than lanyard.

      Skymax 127mm Mak and 3.5kg counterweight from SkyTee mount. Note, extra finder shoe (the black one) on OTA, so RACI finder works.
       

      127mm Mak in "zero" position. Note that you are fighting gravity when sliding the OTA into the dovetail clamp.
       

      Cosmos 90mm refractor and 1.4kg counterweight. Note upside-down position of RDF and focus adjustment shaft.
       

      Heritage 130P OTA showing focus tube facing downwards.
      Geoff
    • By Michael Hogan
      I have decided to sell my Cem-120 mount as i got a second hand AP 1100 GTO from my friend who got a new AP 1600 with encoders
      its just under a year old bought from Altair Astro so still under two year warranty is in mint cont i couldn't miss the opportunity to get
      AP 1100 GTO and let it go still waiting for pier plate for mount.
      So theirs no point in keeping two large mounts after i got my dream final mount buyer will pay shipping price is 2150 pounds.
      Altair Astro price without Ipolar Camera is 3250 pounds without Ipolar Camera which is 200 pounds total 3450 pounds
       

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.