Date   

Re: Runway Dec Motor

moofrost@...
 

Took it apart, went to home depot and bought a soldering iron, followed the color pin out from the RA. Back to working perfect!

 Thanks all. 


Strange declination motor behavior.

Rory Duncan
 


Greetings from central Florida! I finally got big blue up and running again after doing a complete rewire and rerouting of all cables. I have a servo 2 with the most recent firmware installed on it. When using servo config all seems well. As soon as I connect using the sitech.exe, and turn on tracking, the declination motor starts bouncing. When I say bouncing, I mean about once a second it "bounces" back and forth by a precise amount. Maybe 20 pixels or so on my guide camera. It toggles between these two positions over and over. If I go into the config in sitech.exe, and turn on "freeze declination motor while guiding", it stops this behavior, but guiding software can't move Dec any more. If I tell the scope to stop tracking, yet remain connected, it's fine. I have my polar axis REALLY close, but being able to guide Dec is still important. Years ago when I had this setup working before, it did not have this behavior, and I haven't changed the servo values since.

Any ideas would be great!


Some stats on the mount
32 inches between the forks.
Total weight about 800 lbs
Sitech running on 24v
Pittman servos through 720 tooth worms gears
Currently has 4 "small" ota. 10 inch schmidt newtonian f4 1000mm, 8 inch vixen vc200l 1800mm fl corrected classic cassegrain, 80ed refractor 500mm, and 200mm guide scope with qhy5 guide camera. 


Rory Duncan


Re: Runway Dec Motor

moofrost@...
 

Ty Don. I'm told they are male Din cables. I'll try to go that route, but if not then it may be time to buy 2 motor kits from you. I never did like these connectors, way too easy to come undone. First I'm trying contact cleaner. I'll revert once I have a solution in case it benefits anyone else in our group.


Re: Our Ice Storm and Power Outage

Mike Colyar
 

I’m usually in Southern Baja every winter for six months. I carry my 5105 in my pack when I go dirt bike riding in the mountains. T-shirt weather, my dirt bike and ham operation. It doesn’t get much better.

Such here in the cold is just punishment. Grump.

Mike


On Feb 21, 2021, at 12:22 PM, Russell R via groups.io <rem.64@...> wrote:

That's "temporary" snowflakes to you Mike.

Texas coast
Russell R.


Re: Our Ice Storm and Power Outage

Russell R
 

That's "temporary" snowflakes to you Mike.

Texas coast
Russell R.


Re: Our Ice Storm and Power Outage

Mike Colyar
 

You snowflakes. I haven’t see 50 degrees since thanksgiving! I live in the far N.W. corner of Washington State.

My theory of why so much cutting edge design work comes out of the N.W. is that we don’t see the sky for months at a time so there is plenty of time to work indoors and think up more wonderful stuff.

Mike

On Feb 21, 2021, at 8:16 AM, CandCShaw <candcshaw@...> wrote:

Hi Don!  I sort of feel guilty enjoying the 60s here in east-central FL!!!!   Very few evenings are good for observing and fewer ok for imaging however. But watching the Wx for a lot of the country, I really feel fortunate!!!!

Chuck


On Feb 21, 2021, at 3:20 AM, Don W <westergren@...> wrote:

Texas isn't the only cold place in the USA.  Dan is in Oregon.  The midwest and east are also very cold, but they are prepared for it.  I am sitting in sunny southern California in 70 degree sunny daytime weather.
Don W


Re: Our Ice Storm and Power Outage

CandCShaw
 

Hi Don!  I sort of feel guilty enjoying the 60s here in east-central FL!!!!   Very few evenings are good for observing and fewer ok for imaging however. But watching the Wx for a lot of the country, I really feel fortunate!!!!

Chuck


On Feb 21, 2021, at 3:20 AM, Don W <westergren@...> wrote:

Texas isn't the only cold place in the USA.  Dan is in Oregon.  The midwest and east are also very cold, but they are prepared for it.  I am sitting in sunny southern California in 70 degree sunny daytime weather.
Don W


Re: Our Ice Storm and Power Outage

Don W
 

Texas isn't the only cold place in the USA.  Dan is in Oregon.  The midwest and east are also very cold, but they are prepared for it.  I am sitting in sunny southern California in 70 degree sunny daytime weather.
Don W


Re: Runway Dec Motor

Don W
 

Hi,
The runaway servo is most likely the loss of signal from the encoder.  The cables you show  in picture 1 (the two coaxial power cables and the modular encoder cables go to SiTech.  The other cables are not SiTech.  So they are not cables you can buy.  You have to fix them yourself.  Most likely one of the two encoder signal wires are not making contact or are broken.
Don W


Re: Runway Dec Motor

moofrost@...
 

Update. It's the cables. But i can't tell in the store which cable is which. 


 I swapped the Dec cable with the Ra cable and voila Dec was working fine again. Anyone know what the name of the connectors are? Or if they sell these cables premade?


Re: Our Ice Storm and Power Outage

moofrost@...
 

Gnarly! Where are you guys at Dan? I am in Pflugerville, TX and it was pretty much this you have here. Brutally cold and everything was icy.


Runway Dec Motor

moofrost@...
 
Edited

Howdy all. 

 I have been using the Sitech Sidereal controller for a couple of years now with VERY few issues. I love it on my Losmandy G11. 

 Today when I got everything running I have a runaway Dec motor. Just wondering if from this video you guys can see anything being off...

 Also, I installed the "new" sitech and it wont run on windows 10, any ideas?

 Here is the video of the runaway dec.

 https://youtu.be/0qHh5FYiw8U

 Disregard the 3.7, I upgraded to 3.9 its a physical issue, not a software issue for sure.

 Goes to blinky

 I was using it last night without issues, covered the mount and just uncovered it now, nothing was moved or changed. 

 I will say, the conectors are getting long in the tooth.

 It is the old style (round) connectors and I believe in the store all that is available are the new style plugs. 


Re: Does this mount use Sitech controller software?

Don W
 

Hi Dan A
Absolute encoders do a remarkable job virtually eliminating periodic error.  That is with direct drive mounts and with servo worm/gear mounts.  The key is that the absolute encoders are on the mount axis for RA and Dec or Alt/Az or Alt/Alt mounts.  A recent example of this is the AstroPhysics Mach2 mount.  All these mounts require alignment to Earth - Polar Alignment or perfect Latitude/Longitude.  Non-equatorial mounts also require very accurate encoders on the rotators used to compensate for rotating sky.  Dan uses an Alt-Alt mount able to track satellites from horizon to horizon - something a GEM can't do easily.

The only thing direct drives do that worm drives can't is high speed slewing.  They both can rely on axis absolute encoders - no PE, but require alignment to operate properly.

One note is that direct drive require excellent (perfect) balance.  When power is off, direct drive doesn't hold the axis, unless there is a powered brake - the mount will fall to the balance point.

Don W


Re: Does this mount use Sitech controller software?

dan adi
 

It looked identical to the NMT-500, so I thought I should ask. 
I think they still use the sitech controller from what I saw in a few youtube videos.
I looked around at these direct drive mounts, but the price is pretty high :) 
The Astelco is around 40K EUR. 
In sitech.exe I know there is the modeling option. After the model is made, does it affect (improve) only pointing? or does it also correct the tracking, thus enabling long unguided exposures? 
For example, I looked at direct drive mounts from ASA, and the software corrects errors in real time, like 100 times per second, thus enabling crazy long unguided exposures. 
Very interesting technology but pretty expensive for amateurs. A more reasonable approach is done by 10 micron, absolute encoders, but not direct drive.
Do you think there is a big difference between absolute encoders coupled with classic gears/worms vs absolute encoders and direct drive?
I am thinking that direct drive mounts can go along time with no servicing required ... 


Re: Does this mount use Sitech controller software?

Dan Gray
 

It used an early version of the ForceOne.  We re-used the existing encoders, but we had to add an interpolator to the sine/cosine signal from the encoders.
I can't remember the model number, but it is an Astelco.
Dan


On Sat, Feb 20, 2021 at 5:45 AM dan adi via groups.io <cioc.adriandan=yahoo.com@groups.io> wrote:
Hello, I found this mount on mr. Dan Gray site https://www.youtube.com/watch?v=UfvRGd9OuWE
Is this the Astelco NTM 500 mount?
Does it use a Sitech controller? 


Re: Does this mount use Sitech controller software?

Don W
 

That video is a view of a prototype mount demonstrating the SiTech Brushless control system.  Conventional SiTech controllers all control brush type servo motors, which must use gears to move the mount axis using either worm/gear or friction drives.  These mounts are limited in speed to a handful of degrees/second motion.

The video you reference  uses direct- drive brush type motors - no gears.  Using direct drive and absolute encoders (65 million tics/rev) the mount can move at phenomenal speeds like 90 degrees/sec and be extremely accurate.  These are expensive mounts and controllers.  However they use the same software we use on our SiTech mounts - SiTechexe.exe.

I don't know the name of this mount.  Dan Gray has made several brushless direct drive mounts over the years.  His first years ago was an Alt-Az mount that would swing around and up and down like it was doing batting practice.  It looked dangerous.

Don W


Does this mount use Sitech controller software?

dan adi
 

Hello, I found this mount on mr. Dan Gray site https://www.youtube.com/watch?v=UfvRGd9OuWE
Is this the Astelco NTM 500 mount?
Does it use a Sitech controller? 


Re: Mesu 200 Mk2 Tracking stops close to equator

Roland
 

Thanks. 

On 19 Feb 2021, at 22:54, Yann-Eric Boyeau <yann_eric_boyeau@...> wrote:


Hi Roland,

Max PE stated as 4’’ peak to peak on this page :


YE

Le 19 févr. 2021 à 22:58, Roland <mrcas62@...> a écrit :

 I’ve had a look at the Mesu site but, as far as I can see, there isn’t a lot of information.  Do they have a spec for PE?

Roland.



On 19 Feb 2021, at 10:48, Jaspal Chadha via groups.io <jaspalchadha@...> wrote:

Hahaha Paul! 

I wouldn’t recommend  everyone to start tightening nuts and bolts. 

It’s a isolated case for sure, My RA was noisy when slewing around the sky and I think this was causing some slippage. 

It was always this noisy from day and slippage....but it  was intermittent ... the mount didn’t come on a wooden create but man handled carefully.  So maybe something happened between transport...

Under Lucas’s supervision via Skype he picked up on the noise and I adjusted the motor tension. 

I’ve run the mount for two nights now and no issues at all... but again it’s early stages. 

If you look at the RA motor there is a protective case, unscrew the two hex nuts, if you pull that down it will give you access another bolt which holds the motor in place - mine was loose - I pulled the motor downwards a few mm and locked the everything up. 

The RA now sounds like the DEC .... Smooth and quite and no rattling sound. 

Please do not start opening the RA - there is a lot more to it from what I have explained above. For now I have saved a lot of time sending the mount back to Lucas. 

Overall I am happy with the service Lucas has provided. 

Jas 





Kind Regards 

On 19 Feb 2021, at 09:05, paul K <paulskirk53@...> wrote:

you left us hanging there Jaspal, we're dying to get the spanners out...  :)

Paul


Re: Mesu 200 Mk2 Tracking stops close to equator

Yann-Eric Boyeau
 

Hi Roland,

Max PE stated as 4’’ peak to peak on this page :


YE

Le 19 févr. 2021 à 22:58, Roland <mrcas62@...> a écrit :

 I’ve had a look at the Mesu site but, as far as I can see, there isn’t a lot of information.  Do they have a spec for PE?

Roland.



On 19 Feb 2021, at 10:48, Jaspal Chadha via groups.io <jaspalchadha@...> wrote:

Hahaha Paul! 

I wouldn’t recommend  everyone to start tightening nuts and bolts. 

It’s a isolated case for sure, My RA was noisy when slewing around the sky and I think this was causing some slippage. 

It was always this noisy from day and slippage....but it  was intermittent ... the mount didn’t come on a wooden create but man handled carefully.  So maybe something happened between transport...

Under Lucas’s supervision via Skype he picked up on the noise and I adjusted the motor tension. 

I’ve run the mount for two nights now and no issues at all... but again it’s early stages. 

If you look at the RA motor there is a protective case, unscrew the two hex nuts, if you pull that down it will give you access another bolt which holds the motor in place - mine was loose - I pulled the motor downwards a few mm and locked the everything up. 

The RA now sounds like the DEC .... Smooth and quite and no rattling sound. 

Please do not start opening the RA - there is a lot more to it from what I have explained above. For now I have saved a lot of time sending the mount back to Lucas. 

Overall I am happy with the service Lucas has provided. 

Jas 





Kind Regards 

On 19 Feb 2021, at 09:05, paul K <paulskirk53@...> wrote:

you left us hanging there Jaspal, we're dying to get the spanners out...  :)

Paul


Re: Private: Re: Re: [Sitechservo] Mesu 200 Mk2 Tracking stops close to equator

Jaspal Chadha
 

That’s great to hear Jose fingers crossed for you

Kind Regards

On 19 Feb 2021, at 21:41, Jose Ignacio Sanchez Rodriguez <jsanchez.es@gmail.com> wrote:

Thanks for asking Jaspal. Lucas made me perform a few tests on the mount to asses if the clutches were performing well. Which they seemed to be.

After that he tried to listen the sound of the axes while slewing and determined that the RA axis did not sound as it should.

So we tried to move down the RA motor, the same that you did in your mount. But we did not achieve a noticeable change in the sound. As the mount head was in its tripod and it was difficult to reach the RA motor and, more importantly, for Lucas to get a clear look at it via Skype, we decided to meet again on Monday with the mount head detached and laying on a table (RA motor up) to try to adjust it better.

So it looks promising.

On Sunday I will run the Guide Assistant with the rig on the CEM 60, so I can advance on the testing. After the adjustment on Monday y will do the same with the Mesu as soon as I get clear skies. This will probably be on Thursday or Friday.

Lucas was very helpful and it was very reassuring for me to have this face to face interaction.

I’ll keep you posted.

Have a nice weekend,

Jose

Enviado desde mi iPhone

El 19 feb 2021, a las 22:01, Jaspal Chadha via groups.io <jaspalchadha=icloud.com@groups.io> escribió:

Jose how did you get on today ?

Kind Regards

On 18 Feb 2021, at 22:55, Jaspal Chadha <jaspalchadha@icloud.com> wrote:
Hi all

I want to say that my problem in the RA drift is now solved ( fingers crossed )

Pointing anywhere in the sky and guiding under 1 arc MIN 0.34 RMS at times.

I guess the issue was within the RA and by tighten it has stopped the drift. There was also no need to change the ticks after that.

Chin up all.

Kind Regards






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