ASIAIR GUIDE RATE

pogo

Hi I am using a ASIAIR with an Astrophysics Mach 1 Mount. I run into a problem when guiding. If I start the calibration process the steps that are sent to the mount are at much higher speed than guide rate, more like slew speed. It then immediately loses the guide star. On the telescope interface, I have no option to set the guide speed. On the hand controller I can also set guide rate but it does not help. Only if I change it a few times on the hand controller, the guide program for some reason will then use the correct guide speed. Does anybody have any idea how to control this?

I use an USB cable from the ASIAIR to the mount and guiding runs via that cable. Can I also use the st4 connection to make the guiding correction from the 120mini to the mount’s guiding interface?

Thanks,

Peter

hdastro

Hi Peter,

Not sure if this will help but try changing the SLEW speed in Asiair Preview screen. I tried this week and my EQ6R-Pro is working just fine now. I had it at 1X for SLEW, and guiding was not very good. Changed it to 8X, and now guiding is good.

ZWO has stated that the SLEW and GUIDING speed seem to be tied together in the Asiair, at least for the Synscan. Not suer for yours however, but I think it is worth a go.

Hope that helps.

Cheers

pogo

Thanks,

I played with that but it still was messy unfortunately. I set it to guide speed there and it would still run way to fast during calibration. I found that if I change the guide and/or slew speed on my hand controller a few times, then it seems to work fine. Thanks for your help!

pogo

I also have another question. I have the ASIAIR send the 120mm’s guide corrections to the mount directly via the mount’s usb connection. If I were to use the 120mm’s st4 connection instead would the guide commands than be sent via the st4 cable automatically or do I need to change a setting for that? I cannot find that anywhere.

w7ay

Hi Pogo,

To use ST-4 for guiding, you need to set the mount to "On Camera ST4" in ASIAIR in the Mount Menu..

That, unfortunately, will not allow you to do any GOTO (from Telescope Setup window or after a plate solve) or perform slewing (from Home window).

So, while ST-4 will make Guiding work (the mount uses its own guide speed in ST4), nothing else will work since ASIAIR assumes that is it not connected to a controllable mount.

What you experienced is similar to the guide/slew speed problem that I have with the RainbowAstro RST-135 in the firmware (2.64) that accompanied the current ASIAIR v1.2.1. The bug did not exist in Firmware version 2.61, and also did not exist with ASIAIR 1.2.1 Betas.

I solved the problem by first launching ASIAIR from an Android device that ran ASIAIR 1.2 and telling ASIAIR when prompted not to update the firmware.

While connected to Android and after capturing an image (this completes a connection), I can then run ASIAIR app on an iPad.

The iOS version of ASIAIR does not give you the option to keep using the 2.61 firmware, but by doing the above, since ASIAIR hardware is already active, the ASIAIR app on iOS will not force a firmware download.

(Yes, with some caveats, you can connect to ASIAIR from multiple tablets and smart phones.)

After iOS ASIAIR app is completely connected, I can then quit from Android and continue to run ASIAIR from iOS for the rest of the night. ASIAIR has a much more fluid GUI under iOS.

This is a nuisance, especially since after a few nights of doing this, ASIAIR on Android will, just like iOS, force you to update the firmware, and you then need to spend a minute or two to uninstall the Android ASIAIR app, and reinstall the Android app from the older v1.2 APK file again, and then click on all the "Got it" bubbles that pop up in ASIAIR.

However, as a last resort, reverting back to Firmware 2.61 might also work for you if you have (1) a SD card backup which contained the v2.61 firmware, and (2) an Android device and more importantly, (3) still have the old ASIAIR v1.2 installer (APK file) that had the Firmware 2.61 payload.

(You do not need a real Android device to perform the above, BlueStacks on MacOS or Windows will work instead of a real Android device.)

Who knows what surprises v1.3 will bring, however. But lets hope that they do some proper regression testing concerning slew/guide speeds in future releases.

Chen

pogo

Hello Chen,

Thank you for your very informative answer! I suppose I can experiment a bit with what you suggest. However, while it is a nuisance, I can get it to work with changing slew and guiding speeds with my hand controller a few times. Once it works it guides fine the rest of the night.

I am going to try the st4 guiding that you suggest though. Once I got the target centered and guiding started, I do not really need all the GoTo and platesolving anymore anyway.

Interesting mount that you have by the way, how do you like it?

Cheers,

Peter

w7ay

Hi Peter,

>> Interesting mount that you have by the way, how do you like it?

The RainbowAstro RST-135 has a few flaws. One is the wimpy altitude bolt (I constructed my own leg leveler for the North leg of the tripod to achieve polar alignment), and the fact that not being a worm gear, gravity and the weight of a heavy OTA can back drive the strain wave gear if you happen to remove (or lose) power to the mount (I solved that by adding a battery backup for the mount power).

Other than that, it has be a dream mount for me, replacing a Takahashi EM-11.

The torque from the strain wave gears ("harmonic drive motor") really lives up to what you read about them. If not for the back drive issue, I can easily believe that it can move a 30 lb. load without a counterweight (I have been staying below 15 lbs). There is so much torque and so little backlash that you do not need to balance either the RA or the DEC. The tripod would topple before the gears give up :-).

You must guide this mount for imaging. The strain wave gear in it limits the periodic error to be no better than about 40 arc second peak to peak. Like the Avalon M-zero, the error period is long (432 seconds for the RST-135), and easily guided away by using a very short sampling time (0.5 second), I can get better than 0.5" RMS total tracking error (limited by seeing and wind) with the limited PHD2 in ASIAIR. MinMo in PHD2 would definitely help this mount (and the Avalon M-zero), if ZWO ever decides to add it.

Best of all, the mount had been working up to ASIAIR v1.2 (Firmware 2.61). Sadly, not ever since.

By the way Peter, if you have not already planned to do so, you can permanently attach an ST-4 cable, even before you switch from your mount to "On-Camera-ST4." This way, you won't accidentally move the OTA after centering your object and switching the mount menu to ST-4.

Clear skies,

Chen

pogo

Thanks again Chen, good tip that last one. I will try that out.