CEM70G and Tri-Pier - initial thoughts

[paul]

Since October last year I had been staring wistfully at the iOptron Tri-pier in my dining room wondering when the CEM70G was going to turn up. In the middle of December it arrived.

This is a big step up from the EQ5 and HEQ5 Pro I'd been using for the last 10 years. 

The Tri-pier is fanatically rigid, simple to set up and although its not a grab and go solution I actually could see it being used as a portable tri-pod. As I have seen mentioned in other reviews, the black paintwork is easily scuffed and scratched the first time you adjust the height of the central column, it quickly looks used. (I have no idea how to address that but it is only cosmetic). The pier is at least twice the weight of the HEQ5 tripod. On its own its no problem but I wont be moving the pier and mount as one item like I did with the HEQ5.

Mounting the CEM70G onto the pier takes some practice to get the two bolts of the mount aligned to the pier but after you have done it once or twice you get the feel for it. But even after you have tightened everything down it is still possible to rock the mount vertically in the north south plane - I think this is some play between the mounting plate and the azimuth adjustment plate (once its all loaded up this should not be an issue but it was disconcerting at first).

Mount Alt-azimuth adjustments are effortless with the large knobs, the HEQ5 altitude adjustment is a trial in comparison. Combined with the integral iPolar polar alignment is very easy, very quick and accurate.

The cable arrangement on my version of the CEM70G was different to the pictures in the user guide and in other reviews. The mount USB port has moved from the main interface panel to be on the RA axis panel next to the secondary power input, which I guess reduces internal wiring (it doesn't rotate with the axis so no problem there).

The hand controller is very easy to use, after using skywatcher products for years I was concerned I would get lost but it is very easy to work out and I like it a lot. What I am not so happy about is single line of missing pixels, I shall contact the supplier to get advice. 

Balancing the OTA is a new experience, there is so little friction with the clutch disengaged that even a few grams misplaced is obvious. After a while I decided not to stress out too much - the mount is designed to handle much more than I was loading it with (at max about 15kg) and you are supposed to offset anyway to improve guiding.

I have not used the built in guide scope yet, that needs some time to get it in focus and I just haven't had enough clear nights. Also my current arrangement of equipment blocks its view of the sky (camera pointing down). I think its more suited to refractors than newts.

ASCOM just works and using the builtin GPS to sync clocks and location makes everything just smoother. 

I have had a couple of guided sessions with my 150mm newt imaging M45, guiding was under 0.6 average and that was without applying east side weighting. I've loaded up my OO 250mm and the mount throws it around effortlessly so I expect to achieve the same if not better when I get some clear skies.

I'll add more observations (pros and cons) later but so far its full of promise and I am very happy with my purchase.

 

Cheers,

Paul

 

[paul]

Cable Management

Excluding my dew heaters that currently ?  have their own supply I connect to the mount with one fat USB3 cable and the supplied 5A PSU.  I can reliably connect to and power the mount, iPolar, iGuider, DSLR (with a 12v to 8.6V adapter), ZWI EAF and external guide scope.  IMO the supplied USB cable is a little short for such a big mount (it is perhaps 120mm?). When a scope is swinging around - I need more separation! Amazon offer 6 and 9ft alternatives for not much money and they work fine. If I need more power to the head there is a secondary PSU socket on the RA panel which connects to 2 outputs on the mounting plate. You can also run extra cables through the mount if you need to.

Tidy your cables away. One thing I soon learnt is to make sure cables don't snag on fixed parts of the mount.  A USB cable is not going to stop the head rotating, (hopefully only) the cable will fail.

The 12V supply is beefy enough but the DC cable part is a little short for my liking, the PSU block doesn't reach all the way to the ground so its weight hangs on the input socket. I have it propped on another box for now but I shall have to make a permanent solution to secure it to the side of the pillar.

Star alignment

I still use the hand controller star alignment out of habit, the system provided by iOptron works well and is familiar. The pier and mount are so firm that pointing consistency is very good on both sides of the pier.

[paul]

The USB3 hub didn't power-up last night, none of the ports registered a device. Unfortunately it will be a few days before I can investigate in daylight, I need to check if the hub itself is detected in Windows, if its not then fingers crossed its just a lose cable somewhere. I hope it is designed for cold weather (it was -5 C last night)! I had to dig out an old USB2 hub ?, and was up an running again.

The iPolar and mount USB are still working fine though.

 

 

[TerryMcK]

I'm looking for a second mount to complement my HEQ5 Pro with Rowan and also am looking at the iOptron CEM70 Center Balanced Equatorial GoTo Mount with iGuider. I quite liked the idea of the 3 x USB3 + 2 x 12volt ports at the head. The blurb seems to show the capacity as being just over 30kg, not sure if that is for imaging, but even with a 1/3 off that is still 20kg. Way enough for my current needs and also gives the opportunity to have a larger scope on.

 

At the time of writing the mount is in stock at a Devon based retailer but conversely to you Paul, the tri-pier or even tri-pod are out of stock. But as I'm having some building work done at the moment so I will have to dream for the moment until more funds become available.

 

I do have one question though what diameter is the balance shaft? I may be able to mod some spare Skywatcher weights I have to fit to it. The IOptron prices for a block of iron are quite high.

[Jkulin]

Hi Terry, I have an iOptron 120EC and a 40EC and once tamed they really do produce some good results.

 

The CEM70 is a cracker and if it is anything as good as my old 60EC then it will be a winner.

 

For the money I don't think the can be beaten, give Ian a call at AA as he will often do some great deals on them, give some thought to the EC version if you can?

[paul]

On 2/24/2021 at 8:04 AM, TerryMcK said:

I do have one question though what diameter is the balance shaft? I may be able to mod some spare Skywatcher weights I have to fit to it. The IOptron prices for a block of iron are quite high.

I can confirm the diameter of the shaft is 28mm, just measured it 😀.

 

Regarding my USB3 issue, as I sort of hoped it began working again when things warmed up. I've not seen any other reports of this.

 

On another issue I'd found that the head could be rocked North-South even with everything tightened down.  But Ioptron have been very helpful in sending documents showing me how to tighten the azimuth plate to the head.

 

Aside from the USB3 issues I've been very happy with the mount.

[TerryMcK]

Thanks Paul very useful information 

[paul]

There are exercise weights advertised on Amazon with 28mm holes, along with clamps. This was something I was considering if the single weight wasn't enough for my setup. 

[paul]

On 3/1/2021 at 7:37 PM, paul said:

I can confirm the diameter of the shaft is 28mm, just measured it 😀.

 

Regarding my USB3 issue, as I sort of hoped it began working again when things warmed up. I've not seen any other reports of this.

 

On another issue I'd found that the head could be rocked North-South even with everything tightened down.  But Ioptron have been very helpful in sending documents showing me how to tighten the azimuth plate to the head.

 

Aside from the USB3 issues I've been very happy with the mount.

With more nights experience I've decided that booting the laptop up first before powering the mount ensures everything gets detected reliably.