CEM70 connection questions - Forums

Topic starter

Oct 31, 2021

I have a CEM70 on the way and while waiting I’m trying to get all my cabling squared away. Does anyone know if I can power/control my Celestron focus motor through the CEM70 iport connection on the saddle? Or will that only work with an ioptron focuser?

Also, if possible I’d like to connect my camera (QHY268M) power and Astrozap dew heater/controller power to the the 12v DC outlets on the saddle. One is 5a and there’s a pair that are 3a combined. The camera is 12v 3a and the dew heater is 12v 8a for 4 channels but I’m only using one channel, so just 3a I think. Is that doable and which to which?

Thanks!
Scott

Sean van Drogen

Oct 31, 2021

Dont own the mount myself yet i am also waiting on mine.
But as it understood it the two 3a power outlets on the saddle come from the direct mount power.
The 5a power outlet is the one that you can separately supply with power through the connection on the RA Axis.

For my plan i will power my UPBv2 through the 5a connection power with a separate matching supply. This will have my dew straps and camera on it.
Ill power my rotator and focuses on the two 3a connections
Ill have a third power supply for my capture PC on the scope.

My plan is to run a USB3 cable through the saddle for all the connections to PC.

I would assume controlling the celestron focuser through the USB hub on the saddle should not be a problem, but not familiar with that type of focuser.

Regards,
Sean

Supportive

Andy Brown

Oct 31, 2021 · Edited: Oct 31, 2021

Hi Scott,

I'm running power to my camera (ASI533MC-Pro) and NUC from the two DC outputs on the saddle and also using the USB connections on the camera to power an EAF (focuser) and EFW (filter wheel). I also have my guide camera (ASI290MC) connected to the USB on the saddle. The power connection at the back of the iPolar is the power input which supplies the saddle outputs and the USB input connects to the USB ports on the saddle. I'm not sure what current this draws but works fine. One power cable and one USB going into the mount, everything else connected through the saddle!!.

Clear skies for when your mount arrives.

Andy

Helpful Respectful Concise

Scott Badger

Topic starter

Oct 31, 2021

Thanks Sean and Andy! Here are all the connections I'm thinking of.....

Saddle:
-- 268M camera power to one of the 12v power outlets. Does it matter whether it's the 5a or one of the 3a outlets? My filter wheel is powered and controlled via the camera.
-- Dew heater controller to one of the 12v power outlets.
-- 268M data to the non-powered USB port
-- Guide camera data/power to one of the powered USB ports
-- Celestron focuser data/power to either the second powered USB port, or to the iport/aux port. I use the aux port on my CGEM to power/control the focuser now and wasn't sure if it it's possible to use the iport/aux port on the CEM70 in the same way. And if it is possible, is there any advantage to using that port instead of one of the powered USB ports?

Back of RA:
-- 12v DC power to the back of RA to provide power to the 5a 12v output on saddle.
-- laptop to USB port on back of RA for USB ports on the saddle

Mount main panel:
-- 12v DC for mount and the two saddle 12v 3a connections
-- HBX to hand controller
-- USB to laptop

Please let me know if I've got something wrong or any better configuration....

Cheers,
Scott

Helpful Respectful

Dick Bakker

Oct 31, 2021

I have the same setup and it works sometimes..

most nights I get disconnects from the cameras or mount unfortunately. After two months of trying almost everything I ordered a dedicated 13. 8 v stabilized power supply 30A and hope it will solve these issues.

So yes the setup with 2 power cables one to mount and one to RA back and one Usb3 is all you need in theory. That's why I bought it too.

Perhaps I got a bad sample. will receive new ra board from ioptron soon, so fingers crossed.

Scott Badger

Topic starter

Oct 31, 2021

Thanks Dick! And good luck with the fixes! I've seen some similar comments/issues in the forums, but hard to know if it's just a few having issues and lots of happy campers, or not so many on the happy side…. Have to admit, simple availability was a significant factor in my choice and since some, at least, say it's god's gift I'm hoping I've built up enough karma credit with my #$@!% CGEM to get a pass this time….: )

Cheers,
Scott

Stjepan Prugovečki

Oct 31, 2021

During the cooling, the 268M pulls more than 3A (at least mine does). Therefore connecting it to power connection on DEC saddle might not be the best option, as it might cause mount instability. Connecting camera to RA power connection (using the power supply that comes with the camera is perhaps safer option. I have the same as Dick Bakker : One 30A power supply and I made splitter cable, one "branch" goes to supply the mount, the other goes to RA and supplies camera and heaters.

Helpful Concise

Scott Badger

Topic starter

Nov 1, 2021 · Edited: Nov 1, 2021

Hi Stjepan, the 12v 5a port on the DEC saddle will work for the 268, right? I believe it’s powered by the RA power input and like you suggested I planned on using the camera’s power supply into the RA port. Since I’m only using one channel on the dew controller, one of the 3a 12v ports should hopefully work for that so long as I don’t use the other one.

In thinking all this through again, I realized the female connection at the end of the power cord coming from the camera is probably a 5.5x2.5 connection, though I couldn’t find the specs on it, and the 12v 5a port on the saddle is 5.5x2.1……back to Amazon for more adaptors,

And I thought backfocus was complicated…. : )

Really appreciate all the feedback!

Cheers,
Scott

Respectful Supportive

Stjepan Prugovečki

Nov 1, 2021

I have a "G" version and arrangement of ports is different to non "G". You are correct for non "G" version and will work as you say. I was referring to "G" , where there are 2 12V ports on the back, next to USBs. In G version, they are powered from the mount itself and are max 3 A. In addition , there are 2 more 12 V connectors and they are powered from 12 V on RA and they are 5A (or whatever you put on RA, as there are just wires through from RA to the front of DEC saddle
And of course, it will remain mystery to me forever why they mixed 5.5x2.5 and 5.5x2.1 connectors …..

WAskywatcher

Nov 1, 2021

You never want to skimp on power to mount or cooled camera. Luckily you can easily run any additional cables you need up through the mount.

Shogun

Nov 1, 2021

I have had the mount for over a year. it is correct that the two 3A power ports are from the mount power. The single 5A is your own power you connect on the RA near the iPolar dedicate USB. The non-G version is USB 2 on the saddle with all 3 connected to the mount USB near the power switch. Only 2 of 3 on saddle are powered USB ports. Person having drops might be flooding the USB 2 bandwidth needed to control the mount too.

I ran a USB 3.0 cable in through a 3D printed RA cap replacement (though a hole in original cap will allow some cables to fit). it goes through the saddle plate top out back to my ZWO camera where my EFW and OAG guide camera are plugged in. My Celestron focuser is attached to 1 of the powered USB 2 saddle plate ports.

Helpful

Scott Badger

Topic starter

Nov 2, 2021

I'm just glad I'll have these options to sort through! The CGEM, not so much…..and to boot, super sensitive to the slightest tug/swing of the cables, or breeze–like a moth flying too close!…. : ) So living 10 miles downwind of one of the windiest spots on earth can be a bit frustrating.

Cheers,
Scott

Dick Bakker

Nov 2, 2021

Ran the mount and control it over its wifi (cem70G) since my usb is not functional and waiting for a board replacement .

guiding with a rasa8 , 60 mm guider and accessories, total 30 lbs , at. 3-.5 " rms total using asii air pro.
could not wish for much more in tracking I guess.

Scott Badger

Topic starter

Nov 2, 2021

That'll be a new world for me!.... Best I can get with my CGEM is .8 - .9, and that's with good seeing and perfectly calm, and after doing a Hypertune on it. Both axes spin much more smoothly now, so a lot easier/more accurate to balance, and nearly all of the backlash in both axes has been tuned out. Unfortunately, there remains a huge amount of DEC backlash that I finally tracked down to the DEC motor gearbox, so not much I can do about it (looked at three different replacements, and all have the same). Consequently, I guide in one direction only which works reasonably well, so long as it's calm.......

Cheers,
Scott

Helpful Insightful Respectful Engaging

Dick Bakker

Nov 2, 2021

That sounds terrible, I think you will be impressed by the tracking performance of the cem70 mount.
I am for sure. And I did not even start fine-tuning in phd or z axis balancing like some people do.

I also tried an 8 inch newton f6 from an older dobsonian mount, total weight approx. 26 lbs and despite it is a huge sail, I got around. .6 with average seeing.

good luck!

Scott Badger

Topic starter

Nov 2, 2021

Yeah, with the dew shield on, my SCT is both fat and long, and relatively light for the extra volume the DS adds, so basically a spinnaker.....

Scott

Scott Badger

Topic starter

Nov 11, 2021

The new CEM70 arrived, even a day early, and set it up for a dry run in the living room. Sorted out ports & cables and minus the focuser (it’s own issues, not the mount’s port) all worked fine—and not a single dangling cable except from the base of the mount : ) Saturday morning I set up the tripod as closely aligned with my previous mounts tripod to give myself a bit of a head start on the first PA. Then with a clear nearly moonless night forecasted for it’s first light, I managed to break my back that afternoon and now looking at 6-8 weeks before I’m cleared to lift the scope on to it…..: (( Even worse then back order……

Cheers,
Scott

Dick Bakker

Nov 11, 2021

Omg , that is horrible, Murphys law is a certainty to all who practice this hobby of ours, but breaking your back is another dimension.
I hope you recover soon and stay well! Best wishes!

Scott Badger

Topic starter

Nov 11, 2021

Thanks Dick! And yeah, Murphy and I go waaay back…..

My one disappointment with setting up the CEM70 is that even though my current payload is only half of what it can carry, the included counterweight still isn’t enough by 5lbs or so. I ordered what I needed and was going to manage with a jogging weight until it arrived, but it’s pretty frustrating to get a new toy and then find out you also need an additional accessory to make it work….

Cheers,
Scott

Well Written Respectful Concise

Chuck Faranda

Nov 20, 2021

Shogun:
I ran a USB 3.0 cable in through a 3D printed RA cap replacement (though a hole in original cap will allow some cables to fit).

I am waiting for my CEM70, I also plan to run a USB 3 up through the mount. Did you find it easy to remove the rear RA cap? As for the 3D printed cap, is the STL file available anywhere? Thanks in advance for you input.

Dick Bakker

Nov 20, 2021

The rear ra cap is easy to remove. Two screws on the side.
I just received a new ra usb board for my 70G , and had to open the ra cap.

I have usb3 but looks easy to pull another wire through if you have usb2 on the non g mount.

i don't see any performance difference when I use usb2 vs usb3 in my setup with asi533. Not sure it's worth the effort.

BTW my new usb board ioptron sent me functions well, no issues disconnecting mount while imaging.

If I had the choice again, I would opt for the nonG cem70. Just my 2 cents.

Cheers Dick

Shogun

Nov 20, 2021 · Edited: Nov 20, 2021

Chuck Faranda:
Shogun:
I ran a USB 3.0 cable in through a 3D printed RA cap replacement (though a hole in original cap will allow some cables to fit).

I am waiting for my CEM70, I also plan to run a USB 3 up through the mount. Did you find it easy to remove the rear RA cap? As for the 3D printed cap, is the STL file available anywhere? Thanks in advance for you input.

Chuck,

I do have the STL I can send you, but I prefer to share the original CAD files so people can tweak them for their use. I use a site called "TinkerCAD" for basic stuff like this (I use Fusion 360 for more complicated stuff but don't normally share that) and I have it shared their along with a ton of other AP CAD designs. You can just "export" to STL from this site.

If you create a free account on TinkerCAD.com and then click on the "search" icon. Choose the "People" tab and search for "netspec.inc". My stuff is there. Here is the direct link once you have a TinkerCAD account if you don't want to search:
https://www.tinkercad.com/users/9IUnIo2QEBc-netspecinc

Look for the design titled "iOptron - CEM70 iPolar Rear Cap with USB3.0".

A few comments (again you can change to your needs):
1) I added a USB 3.0 panel mount from Amazon (https://www.amazon.com/gp/product/B08CXXS9M1) to the design. This way I can disconnect the cable from my PC at this point.

2) It has one design flaw I have not fixed yet. I want to add some "dimples" on the side of my design where the CEM70 pins hold the original metal one in place. You can either drill some tapered dimples or add to this design.

3) NOTE: It uses the CEM70 power and iPolar circuit boards. Just need a few screws to mount them.

If you have trouble, let me know.

Here are a few pictures of a fast test print compared to original and my current version in use (without my 12v dew heater power hooked up). Sorry, I don't know how to rotate the bottom image using this forum.

Christopher

Helpful Engaging Supportive

Shogun

Nov 20, 2021

Chuck Faranda:
Did you find it easy to remove the rear RA cap?

Two small screws/pins on each side of the iPolar caps (with hex heads as I recall). Few turns (no need to remove them) and the cap pulls out. Very easy. All the wires in there are mounted to two panels that come off with a few philips head screws. VERY EASY.

Concise

Chuck Faranda

Nov 20, 2021

Shogun:
If you have trouble, let me know.

Thank you Christopher!!

Sean van Drogen

Nov 21, 2021

Solved the issue slightly differently by removing a few mm from the standard USB connector on the sides so it could fit through the standard cap hole.