wrestling with autoslew and ddm85...

[prefetch]

so mars is near opposition and i decided to put my pt.grey grasshopper3 on my mount to get some pictures.  i took off my atik, and placed the grasshopper on, with a powermate 2x.  the weight difference and length are about an inch or so and 4-5 ounces.

 

i started up autoslew, and did a balance check.  i made a minor adjustment to the weights.

 

while doing a 3 star polar align, i realized the 2x powermate was making it really hard to find stars, so i took it off.  obviously that threw the balance off a bit, but i figured it would be okay.  i went ahead and completed it and adjusted the mount.

 

then i figured i'd better do another one.  then strange things started happening.  the DE slew started to stick.  like it would just freeze up.

 

strange.

 

i don't remember everything i did, but i did some restarts, reboots, and then i noticed the DE drifting while it was sidereal mode!  this is not supposed to happen.  it would just drift by .02" every second or so.  just a steady drift.

 

and then slewing would get stuck in RA, freeze up and stop.

 

again, more reboots.

 

one time after i shutdown autoslew, i physically moved the mount back to the homefind position, but it wouldn't move!  it's the like magnets were fighting against me.  i shut off the power to it, and it then moved freely.  so weird.

 

then i uninstalled my pt. grey camera, and did a restore on windows 8 to the previous configuration to really clean out the drivers.  i also reinstalled autoslew to make sure it's drivers were in place.

 

sigh.

 

anyway, still wrestling with it.  not sure what's going on.  it's balanced well, and there aren't any error messages.  scratching my head.

 

is the DDM85 and autoslew just a temperamental beast?  or am i just unlucky?  or do you think something is wrong with my hardware?

 

 

[prefetch]

so i switched back to my atik camera, and everything is working normally now.

 

ugh.  so i think this mount is just crazy sensitive to weight/balance and tuning.  if that's not dialed it, all sorts of drama happens.

[lukepower]

Hi Prefetch,

 

the balance indeed is very important. AFAIK, you are supposed to make your pointing model with the exact setup you are going to use afterwards for imaging, so no camera/corrector/whatever change permitted. It's not only about the balancing, it's about the model: As soon as you change something in the geometry of the telescope sitting on the mount (like, moving it on the connecting plate) the pointing would be changed. Same could happen if you change the imaging train (in a perfect world it wouldn't...). And the balance, well, ASA told me more than once I need to balance spot-on, especially with a heavy setup...

ANyway, if it is not working I would suggest to contact ASA's support and schedule a remote session. They are quick in finding the common causes

[prefetch]

thanks for the insights lukas.

 

so, i think i found the problem.  the ptgrey driver doesn't get along with the ASA driver.  

 

the problem was fixed when i did a restore back to before i installed the ptgrey driver, and when i had everything working perfectly, i tried to install the ptgrey driver again.  it installed, the camera ran, everything was okay, but then when i tried to slew the mount, it got stuck in DE and started acting crazy.

 

in my experience, drivers with ptgrey cameras are a nightmare - and this problem shouldn't be a surprise i guess.

 

blech.

[lukepower]

Ah well, drivers... Good to hear you nailed the problem. I also was strugglin with an updated driver for a Logitech Webcam I used to check the scope position from remote. It constantly causes a BSOD (blue screen of death) after about an hour of use, and only a reboot helps... Funny enough, as long as I don't start the webcam software all is fine. But hey, who cares

[prefetch]

i updated the ptgrey driver for the USB card, and reinstalled the ptgrey camera driver and it started working for a bit - i got about 4000 images of mars, but the seeing wasn't red hot.  anyway, it's the first time i've imaged mars, so i'm excited to see how it worked out.

 

but then the problems came back - when i tried to slew, it would get about halfway there and then it would slow down and appear to stop or go into a crawl where the completion of the slew would likely take hours.  no errors, no freeze ups - it was weird.

 

i'm going to send in detailed logs to ASA and see if they can tell me what's going on and confirm a driver conflict.

[prefetch]

SOLVED!

 

so after many hours of trial and error i finally determined what the problem was.  my gamepad controller is a bit screwy and not calibrated correctly.  when it was "at rest" it would actually be sending a signal to the mount - about .01" every second.  when i did a reboot or installed a new driver for a camera, or whatever - sometimes it would settle down and stop sending signals, but then after another reboot it would decide to send signals again.  a very subtle screwy thing in that controller.

 

i was almost ready to give up - i hadn't heard anything back from ASA on the logs i sent them, and i stripped my system of all non-standard windows drivers and still, no permanent success.  just occasional functionality, followed by bad behavior.  

 

so on a whim, i just clicked the gamepad off on autoslew and tried to slew the mount, and it worked!  no freeze ups or delays or weird things.  after more testing, i concluded that this was indeed the problem.  

 

anyway, i'm just posting this to share my trials and tribulations, and also in case anyone else runs into a similar problem!!

[Roger]

Excellent.

 

The knowledge base on these mounts is building up in here thanks to great team spirit.