EQ6R Pro vs iOptron CEM70: guiding results before and after tuning

in part 2 we analyze the guiding performance of 2 mounts, EQ6R pro and iOptron CEM70 before tuning and after tuning. WE discuss guide graphs and issues with both mounts. In the summary section we will see what is the better mount. Enjoy.
Mount tuning by Chris (www.cg-5.de)
Music by Lutz Schwartz

[@frosthastrophotography]

Thank you for the video! I'm thinking about upgradering to the 2600 from the 294 and this was very helpful.

[@Mr6sess]

For the price, functionality and the amount of info available when I needed help.... I Iove the eq6-r pro. I have 2 of them and they perform GREAT!

[@montygiavelli8125]

Thanks for the video. I've been using an EQ6-R Pro for three years. After adjusting the belts, the end play of the worm gears and the backlash I have gotten good guiding as long as the atmosphere cooperates. I've had guiding under 0.4" (rare) but with good seeing it is usually between 0.5 and 0.6. With bad seeing it goes up to 0.7 or 0.8. So, the atmospheric conditions really dictate how good my guiding is. Good polar alignment helps a lot. I haven't taken the mount apart but one day I will and remove the old grease and replace with good grease etc etc. thanks, Monty

[@stephanep1330]

Hi, Thank you for the comparison. I also considered buying either an EQ6-R or a CEM70, I finally bought a CEM70 a year ago and very happy with it. To me, the price difference is more linked to the payload capacity, and its own weight (EQ6 is a big truck)... if you are nomad with a heavy refractor, it counts. Concerning guiding and quality, I agree with you: it's about the same except the CEM70 will be able to guide finely with heavier payload, but I feel it's wrong you expect better guiding from CEM70 beacause it's more expensive. If you want better quality, better guiding, you will need to go with 10micron, maybe... and the cost will be very painfull

[@tomsastrophotochannel3243]

Stephane P you get what you pay for. Probably it is too simplified if I say that with more money involved I can expect better guiding. Finally both mounts can guide well enough and usually the limit is the seeing. Cs tom

[@SimjetAU]

All of the mounts need cleaning and better grease. I have a AZ-EQ6 -GT and the guiding was just ok. I pulled the mount apart cleaned all the bearings and regreased with better grease...spent a little time adjusting the backlash for the worm gears and I now regularly see 0.3 to 0.4 on the guiding...very pleased. A little TLC on the mount and the guiding will be fine..certainly at just over half the price of the CEM..the EQ6 is I think a better option

[@tomsastrophotochannel3243]

Absolutely, better grease will increase mount performance!

[@tensorhugh2588]

Thank you for doing this! I'm considering a CEM70 to replace an aging CGEM DX, and your reviews are the best I've seen on this mount yet. I would be curious too in knowing how you tuned the CEM70. Looking forward to more videos :)

[@tomsastrophotochannel3243]

Hi, the tuning was done by my service guy here in Germany, you find him at www.cg-5.de. He did all the tuning; I am just the user of the mounts ;).

[@tensorhugh2588]

@@tomsastrophotochannel3243 Thanks for the link! Your video inspired me to both order a CEM70, and try tuning my CGEM DX!

[@tomsastrophotochannel3243]

@@tensorhugh2588 congratulations! excellent choice, enjoy the mounts ;)

[@anata5127]

@@tensorhugh2588 Why? You can get proper European or American made mount for price of these two sheeit mounts.

[@markbayfield6381]

Its hard to compare as here in the UK the CEM70 with the Tri pier is £3K where the EQ6 with tripod is £1.5k. At half the price and once tuned and running PPEC my EQ6 guides between 0.4-0.7 total rms depending on the seeing. The CEM70 looks great and is lighter but is that worth £1,500…..not in my world.

[@SimonT65]

Interesting video's. I upgraded from a EQ6R Pro to a CEM70EC, the guiding on the CEM70EC is far superior to the SkyWatcher - I average around 0.3/0.5 RMS error with the CEM70EC. I'm hoping that you made videos on tuning your CEM70 i.e. stripping the mount and changing the grease? Also, what grease did you use?

[@tomsastrophotochannel3243]

Dear Simon, sorry for the delay I had to ask my service guy Chris. He told me to use some graphite and MoS2 grease for all mounts he tunes. In the next month I will make a video with Chris, so stay tuned.

[@gcdiscos]

Thanks for your videos. What grease do you recommend for an eq6? I've used the superlub but I wasn't satisfied.

[@PeterClarke55]

Hi Tom, I am a little confused with your video. Mainly, the guiding was for the EQ6 which had the metal shavings but you put it later that the guiding issue was of the EQ6-R mount? Not sure if it was just a little mistake or have I misunderstood your method?

[@tomsastrophotochannel3243]

Hi Peter, sorry for the misunderstanding. My first eq6 had the metal pieces, my second eq6r pro not. I hope this could clarify. Cheers and cs Tom

[@Hegegutt]

Hi, Great videos, and interesting review. I was wondering, how many hours is each guiding session on the two mounts? Maybe you mentioned it, but i couldnt get it from the video. The reason I'm asking is that 1000 hours for example, would give a more accurate result than lets say 8 hours. I use a belt modded EQ6 Pro (Not R), and in a time frame of ~40 hours, i guide at 0.35 - 0.75 averging at about 0.50 RMS. I am very satisfied with that, and it took ALOT of work to get there - BUT: I have spikes in guiding here and there every now and then, which results in bad stars and having to throw away around 1/4 of the shots. Also I have to have my setup slightly east heavy because of backlash. My point is that im looking to buy the CEM70 to get around the same guiding, but with more consistency (= less work) to get the same guiding results. Would you say the CEM 70 is more consistent in guiding than the EQ6R ?

[@tomsastrophotochannel3243]

Hi, many thanks for your comments. The duration of those 2 analyzed guiding sessions was something between 1-2h when I remember well. I agree with you the more the better.

[@timurpopow291]

Hi, interesting hands on comparison! Was there any particular reason for not going for the CEM70EC instead of the CEM70? I mean, sure, there price difference is like 1500 Euro, but honestly we are talking about 3000 + Euro mounts here. So before you got the CEM70, did you even consider the CEM70EC and if so, why not go for the version with the encoder? It would be really interesting to see some benchmarks of the CEM70EC in comparison with the non-encoder mounts.

[@msacco]

EC versions are awesome for non guiding imaging, when using PHD2 it pretty much corrects the errors and the CEM70 being a pretty good mount as it is, doesn't hugely benefit from that, at least not 1500 euro worth in my point of view.

[@tomsastrophotochannel3243]

Hi Timur, for me the EC has no added value and furthermore I have no experience with it so decided not to go this route. I hope this helps, cheers Tom

[@SimonT65]

@@msacco You still need to use PHD2 with the EC version otherwise your stars become elongated. I have the CEM70EC and use PHD2 set to take exposures at 7 seconds which gives me an RMS error of around 0.3-0.5 depending on seeing. Keep in mind that there's only encoders in the RA axis with the CEM70EC - no encoder in DEC

[@hael8680]

2:37 Which software did you use to get those grafts? Thank you.

[@tomsastrophotochannel3243]

Hi, I used phd2 log viewer, hope this helps. Cs tom

[@WintaSyafrizal-gk9et]

2023 M 8 AGUSTUS = 8 SYA'BAN 9 SEPTEMBER = 9 RAMADHAN 10 OKTOBER = 10 SYAWAL 1444 H

[@anata5127]

CEM70 doesn’t behave right even after tuning. Absolutely unacceptable guiding. I will send it back to iOptron for replacement. It should guide in range of 0.2-0.5.

[@tomsastrophotochannel3243]

HI, what is your current guiding? How does the guide file look like? you could possibly ask in the pgd2 forum. Just as a suggestion, good luck!

[@anata5127]

@@tomsastrophotochannel3243 I don’t guide. Expensive mount. However, I know somebody from club who guide lesser than 0.5 arcsec on CEM70. It could be said that seeing in Texas on average better than in Europe. Nevertheless, CEM70 has to be better than eq6.