cotak

In my experience the balance only impacts random deviations, not constant. And we are talking balancing 44-50lb of newt that I see the deviation from balancing issue.

You should do your data capture for GA soon. Your graph is pretty extreme and you'd want to know if it's a mount issue or if it's your configuration. I plunked on my OAG and it improves my PhD results fair bit so it does seems does not work well with EC mounts and short guide lengths, but why I don't really know as of yet. Next for me is to check encoder ring.

Hi Folks A friend from CN looked at your logs (Andrew from down under) and he thinks your mount might have some really out of spec SDE to the tune of 8-10 arc-sec. You need to run a fast capture run (0.5s or faster and subframe mode) in GA and see if you really have such an out of spec copy. If so you need to return it asap. My personal experience has been not so great with iOptron in regards to SDE on my mount. I am in the final stage of checking if my encoder ring fall off. And if not then it might be a return for repair situation for me as well.

You don't really guide this thing. It's more nudging it for drifts. With the SDE it's doing it's little dance around the center point anyhow so it's not exactly going to be where you pointed it.

So we know from the analysis on CN that the EC mounts will decide on its own how to actually react to a guide pulse. This makes the calibration not always the way PhD expects.

If you can return it, I'd suggest just get the non-EC version. The EC is very hard to get guiding well. Generally the analysis of data suggest that the best bet is to go for longest exposure you can use. And lowest guiding rate. When I have and OAG running with a long focal length I find it works quite well. With shorter guide scope now on an 80mm for wide field, I am finding PhD seems to think there are larger deviations. And the guiding is worse, to the tune of 0.9 for 6 second exposures. I just took delivery of a zwo OAG which is thin enough to work with the 80mm and reducer. If it works better like that I'll report back.

Thanks for the info gorann. Looks like the jury's still out.

You don't have to make any adjustments between winter and summer? How large is your temp swing between the seasons? I am curious if the new EQ8 might be something worth my while to look into.

Been busy with work and the mount issues but I tried everything and it's still not working out. Eventually after trying to get as tight the pressure adjustments as possible I cracked a bearing and now need to be replaced. So as preparation for replacing the bearing I took the thing apart. My, why is this thing sold at this price and has this reputation for being very good (pardon my personal opinion)? It is mechanically only very slightly better than the GSO linear rail focuser. After examining the internal structure I am extremely doubtful it can be ever adjusted to resolve my issue. I have an older version of their focuser so maybe the modern one is better but if the mechanics are generally the same I think that would be unlikely.

There's a 2" p-p SDE oscillation that PEMPro reports as 0.3X" RMS. So yes iOptron after many weeks of pestering by me agrees I can return it for repair. However, their guess at a bad bearing for root cause is likely just a random shot in the dark as there's a beta firmware which shows zero oscillations but which cannot be guided and which they seems to have stopped investigating as a possible solution (reason is limited resources, to which I say "go boil you heads). And I know someone's 120EC2 was not fixed after 4 months at their office and was returned with the same problem as I see in my 60EC. As they never answered if the PEMPro 0.3X" RMS will be taken by them at their office as in spec, I have not sent it back as why waste the money in rather expensive shipping from Toronto to Boston. Now, that said in typical seeing nights you wouldn't really noticed as while it's 1-2" p-p it is RMS down to less than that and you stars can be round providing the optics is fine. The experience of the support has left me burn enough that I don't want to continue being a customer for them. It took from July till now to get acceptance for a return for repair. During the course of which repeatedly their responses was "Wait for the software fix" which thus far never came, and in the end I think never will. My conclusion from all the exchange I have had with them is that the techs you talk to don't really know enough to give you good answers, or are prevented from telling the full story. The real brains are in China and you can't get at them directly (likely due to the joint venture structure) so you end up playing a telephone game where you tell the Americans one thing and get answers days later from Nanjing but with all the risk of miscommunication included. The PE Spec for the EC are IMHO worth less than face value. Sure it is supposed to be <= 0.3" RMS but because it is RMS your real PE can be much larger and their techs claims a 1" p-p sine wave should result in 0.3 RMS, well it does in PEMPro except that Ray seems to indicated that isn't the full story as PEMPro might not be correctly sensitive to oscillation frequencies that are not integer multiple of the known fundamental. Trying to get a definitive answer from iOptron has been impossible for all those reasons above. It is a bit of a sad situation because this story confirms all the worse of the American tendencies over on their forum about "premium" mounts. There's a lot of promise in the EC range but thus far it seems there are fundamental cost trade offs made that means they don't quite perform to the level where they truly represent unequaled value. For me that sucks cause having the ability to run 4 second or more guide exposure is great for galaxy seasons which is why I asked if anyone had issues with galaxy season and the recommended 1s guide rate from Avalon.

Sounds good. How did you find galaxy season with short exposures for guiding? I'll be using an OAG and hopefully that's not a big problem to run 1s exposures.

After a frustrating few months with my cem60ec I am now considering changing for a more up market brand. The Linear gets good reviews but it's payload capacity is a bit lighter than similar mounts with worm and wheel drives. It is significantly less costly than the closest competitor for me though and by spec I should be within the 44lb limits but I wonder has anyone ever put that much on one and had good results? My use case will be with a 10" GSO truss newt for the moment. And it's long enough and heavy enough that I'd like to find out what owners of the Avalon thinks.

What is your OTA? It is balanced in all orientations of DEC? The belt and magnetically loaded worms results in a stretchy behavior if your OTA is horizontal balanced but has a vertical imbalance. It could cause similar behavior as what you see although usually it eventually catches up with a large overshoot.

Thanks. This new scope is providing a lot of photons. Going to let me image more targets or do mosaics without too much trouble I am hoping..

http://www.astrobin.com/421758/0/ First (well Nth but the first few tries wasn't interesting due to learning curve with newtonians) attempt at a real image. GSO 250 f4 truss newt CEM60EC (needs the firmware fix for large loads, should be any day now for beta) GSO coma corrector QHY163C at -10C 40x180s

So you confirmed my experience. When I tighten the two screws it reduces the flexure but it made the collimation change with focuser movement. So overall this focuser appears to be expensive (glad I got an awesome deal on it with the scope) but doesn't entirely do the job I require of it. I guess I'll be investigating a feather touch or other alternatives.

After days of struggling with the collimation of my new to me GSO 10" truss newt, I realize that the problem was the moonlite focuser sags. And this is sagging with just a tublug and laser attached. Granted I have the extension attached as the GSO coma corrector needs it. Quite disappointing as this is my first proper focuser and it's got issues. Is this expected? I searched online and it appears that where you want something that absolutely doesn't sag you should go with feathertouch. I also got the original GSO monorail focuser, makes me wonder if, just if, it would prove to be more tolerate of the payload than the moonlite.

This is a really odd ball marketing strategy. The two are essentially the same with one having 5lb more payload which is nothing at all.

Please, he's a rent seeking proprietor not some mythical god who's out to save our RMS. If he can shave 10% off his cost and people would pay more, who would begrudge him that? On the flip side as a business if he can sell his quality mount for somewhat less than it was before (maybe even a significant price drop) he might end up with more business and more revenue as well. We can then discuss about the practicality of doing that while still providing the quality expected.

So there are improvements but the manufacturing costs should have gone down too with the more simplistic structure.

I paid 400 CAD for 4x 8 inch piers for the observatory building, and 1x 24 inch pier which is the base for the metal pier. This includes augering. I just had to supply the tubes, rebars and brackets. Now the concrete on the top of one of the piers was questionable but they did a repair on it and it's ok for now. With a more reliable contractor I think it would be the easiest way to do it without risking your back.

Build a custom Alt-Az adjuster? What is the new pricing anyhow? So mysterious.

You can fill in the inside of a metal pier with sand to help make it as heavy as a concrete pier if you are worried. Local post diggers would come with an auger and mix the cement for you for a few hundred dollars. I worked the math and it wasn't that far from renting and mixing myself so I just contracted that out.

Getting a custom metal pier is usually not that bad. Once you consider the potential cost of injury moving heavy bags of mix and such. The ioptron Alu piers are also quite reasonable. Alternatively a tripier on a concrete floor works ok too.

They also sell a a perm aluminum pier if you don't want to pour so much concrete. For me I had the 24" 4' concrete base done and mounted a skyshed pier on-top. This way in theory the building can be converted to a regular shed by removing the pier and closing the pier hole.