Rainbow Astro RST135 & ASIAIR - Newbie Questions

keramos

So I finally received my RST135 after a looooong wait

I'll be using this mount exclusively with ASIAIR for DSO, therefore I would like to ditch the hand controller.

I reckon I only need the HC for the following:
1) Firmware upgrade - mount and HC (unless both can be done with PC)
2) Set Time/GMT for DST

Steps followed to set time:

Set Time in RST to UTC
GMT +0.00
Checked LST on Mount
Checked LST against Sky Safari

3) May be for Visual in Alt Az mode??

Other than the above will I ever need to use the hand controller prior to using the ASIAIR Pro?

I'm hoping to get back to Solar (both Lunt and Hutech Hinode guider are gathering dust) and wondered if any one had any experience with ASIAIR and Solar imaging using this mount...

w7ay

keramos Other than the above will I ever need to use the hand controller prior to using the ASIAIR Pro?

No, except for what you mentioned, and also the RA/declination offset calibrations, you do not need the hand controller. I never use the Hubo-i when the RST-135 is attached to an ASIAIR. Even when I use the RST-135 for daytime solar work in conjunction with the Hinode guider, with the ASIAIR capturing images and the Hinode autoguiding the mount.

See here if you want to calibrate the RA and declination offsets (the precise home position instead of the uncalibrated home sensor positions), with which you do need the hand controller (to save some time, I had used a two axis inclinometer when I calibrated my offset, instead of his flipping a single axis inclinometer back and forth):

https://www.youtube.com/watch?v=7IC1j8i-1H4

This is important to do if you want the auto meridian flip time to be in sync. You only need to calibrate it once, and after that simply depend on the a level or an inclinometer to establish level to use auto meridian flip (in the worst case, every 1 degree of East-West level error corresponds to 4 minutes of time delay for a flip -- up to five Auto Meridian Flip retries on the ASIAIR).

It is much better to have the hand controller absent since its GPS time would not interfere with ASIAIR's UTC. The GPS of the RST-135 (unlike the RST-150h) is in the hand controller and not in the mount body; and that is also why you also get best GPS acquisition with the button side of the hand controller facing the ground. As fas as DST goes, just let ASIAIR in iOS push the UTC over to the ASIAIR. Neither the ASIAIR nor the RST-135 understands Daylight Saving Time, so they are perfectly "compatible." Syncing location and time has not failed me since ASIAIR v1.3 (when the RST-135 protocol became fully functional in ASIAIR) on iOS as long as you give full Location Services permission to the ASIAIR app.

Chen

johnpd

You may be able to ditch the hand controller but I have had some issues with keeping things such as planets centered or just moving around the Sun or Moon with the ASIAIR. It seems that the little position adjusters on the ASIAIR can be a little finicky. At times they only seem to work when the speed is set to "max" which makes positioning tough. Also you can't do plate solving of the Sun or Moon so I like to use the hand controller to position the scope properly for those two.
I have only used Alt-Az mode so far so I don't need to do a polar alignment. I just do a {HOME} with either the hand controller or the ASIAIR, select my object, and go. If using EQU mode, you probably need to use the hand controller to position the mount to point at the Pole before polar aligning as the standard {HOME} position for EQU mode is West and level. It might be wise to do an initial {HOME} before starting and then moving to the Pole.

A few times the hand controller would not respond when both were set up. I had to restart, but usually it works.

As far as setting times and such, everything is picked up from my iPad although being in Arizona I don't have the DST problem. Apparently DST is still an issue. Why they don't fix that, I don't know.

I have done a little solar with mine at this point. Now that the weather is cooling down a bit, I will do more.

JohnD

keramos

Hi Chen,

Thanks for the reply, so the offset calibration needs to be done only once and then is stored in the mount?

Would there be any situation where one might need to recalibrate the offsets?

w7ay

keramos Thanks for the reply, so the offset calibration needs to be done only once and then is stored in the mount?

The calibration basically measures the location of the internal home sensor index mark precisely, and the result is stored in the mount, and displayed/changed at the Hubo-i. This is the way to ensure that the home position is exactly 6 hours in hour angle from the meridian when the mount is east-west leveled.

I don't think you need to touch it often unless you mistreat your mount.

One of my RST-135 and its tri-pier are left outdoors 24/7/365, under a dry bag when not in use for more than a year. And I have not needed to recalibrate yet in spite of harsh treatment (there is no messy grease in the RST-135). My second RST-135 (serial number 13 from the first production run about 2 years ago) is indoors and not as mistreated.

By the way, for optimal tracking, the mount needs a 16V power supply. Take care of that, also making sure you never loose power since the mount can back drive when there is no power, and it pairs nicely with ASIAIR. I use a uninterruptible DC power supply in case we loose electricity, and a 16V buck/boost converter.

Chen

w7ay

keramos

By the way, if you are willing to use the HUbo-i controller, you can read out the polar alignment error after a 5-star alignment. Lots of work though, compared to a 2-minute ASIAIR polar alignment procedure.

Chen