8.09.2020 ASCOM[AWR] can't Goto the inside of a dome!

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Tuesday 8th. It took me a a good couple of hours in all. First I had to remove both telescopes [again] using the block and tackle. Then dismantle the cradle/Tollok bush and wormwheel to remove the shorter Dec shaft. Then replace that with the longer one. 

 

Then refit the telescopes, wormwheel and counterweights. Of course it rained at critical moments when I had the observation slit open for better light. Then there was the wind gusting like a turbine around the inside of the dome. 

 

Removing and refitting four 5kg counterweights, while standing on a stepladder, is not a trivial matter. Each weight must be supported in one hand while sliding them safely off the end of the shaft. Then I have to swing around by 90° to place them in a stack on the base ring. 

 

I use a long plank to support the long end of the Dec housing. Plus a tensioned rope to stop the Dec housing from lifting. This is tied to the base of the pyramidal pier near the floor. I made the mistake once of removing the weights when there was only the 7" on the other end. It swung around so viciously that it nearly batted me out of the slit. No injury, but never again!

 

I still need to check the free balance of the mounting plus telescopes without any friction. This is not something to be ignored. The wormwheels add friction even without their three plastic plugs pressing against the shaft. When tightened these form a simple slipping clutch. I drilled and threaded two more holes over the original one to get more friction for the drives. Otherwise they just went round and round without the telescopes moving.

 

You can't slew the telescope[s] manually. That would mean the ASCOM[AWR] drive system loses its orientation on the sky. Orientation? What orientation? All telescope movements must be driven. No matter how incredibly slow the slews. No matter how incredibly poorly the Gotos find celestial objects. [Like never! Not once. Not ever!]
 

This on an observatory housed mounting which is never moved about. It is regularly checked for alignment by drift in SharpCap. I routinely check online that the AWR screen is showing the correct LST at the start of a new session. It used to forget LST and had to be set manually in the IH2 menus. The telescopes always start from the Home/Parking position, horizontal pointing east. Fail safe? Nah.

 

I have the observatory site entered to the nearest second of arc. I check the OTA is horizontal with a precision digital clinometer. The clinomter is used to double check the Polar altitude angle. I have to check, every single time, that the Dir[ection] of Dec drive is Neg[ative.] It changed arbitrarily to positive for ages. Leading to dangerous, nose down. <cough> goto slews to find the sun high above in the sky.

ASCOM[AWR] can't even find the Sun or the Moon no matter how often I sync in C-Du-C/Skycharts. A straight, Dec. only, Goto slew from East/horizontal to the very nearby Sun in the early morning is completely beyond its ability. No matter how small the required movement. I usually watch the Sun's shadow of the main tube[s] on the observatory wall. If the shadow[s] end up round I'm supposed to ring the Guinness Book of Records. I have them on speed dial.

To call it a Goto drive system is patently false advertising.  After several years of endless exasperation I have finally come to accept it. So I just use the drives to track after manually finding and centring an object using the control paddle. I turn up the gain in SharpCap. Until I can find the nearby Sun from the off axis glow on the monitor screen. Usually by manual slewing in the general direction of the Sun.

 

Imagine trying to find an object too dim to easily see on the monitor? Mars isn't remotely dim recently. In fact Mars was sitting right next to the Moon. So I focused carefully and then synced on the centre of the Moon. Then I sent it on a short, Goto slew.  It still couldn't find Mars with the SharpCap gain turned right up! 🙄

 

ASCOM[AWR] <cough> Goto is only useful to send the telescope[s] Home after an imaging session. This saves having to hold the uncomfortable, raised buttons down on the Simple control paddle for several minutes. As already said, you can't just slew by hand. The drive system is confused enough already without teasing it with such complications! 

 

It can't even get east and west correct. So how can I expect it to do anything more? And no, this is not remotely free software. I paid £50 twice for consecutive ASCOM [AWR] DRIVERS. Neither could find the inside of a dome! 

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Meanwhile, after balancing the dual telescope system I tried capturing surface granulation in white light using the 7". The '174 camera was plugged into the 2" Lacerta solar prism. I tried all three GPCs and without. The surface detail was just visible in SharpCap but too faint to register in AS!3. ImPPG could make "cells" but they were horribly noisy and the image full of artefacts. Something to try in the early morning before the seeing goes horribly bad? 

 

I added a 32mm eyepiece to the H-alpha telescope in place of the usual camera. There was nothing visible on the disk or the limb. I tried tuning the etalon but it only produced a darker "doughnut." Which expanded and contracted with tuning. 

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