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my DDM85 is chirping

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#1 prefetch

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Posted 04 November 2014 - 03:00 AM

so i've upgraded my equipment - added a FLI centerline filter wheel, and a FLI 16803 camera.  lots more weight!

 

what i immediately noticed after i balanced my new setup and then ran a regular auto tune is that as a slewed my mount it would chirp.

 

that's right, it would make chirping noises as it slewed.  exactly like a bird or cricket would chirp.

 

has anyone else seen something like this??

 

i'm going to work more on balancing to see if that will fix it.  i've just never heard anything like this from my mount, and it's weirding me out!

 

here's a video of it: http://youtu.be/2R0nvleHSqA


Edited by prefetch, 04 November 2014 - 04:15 AM.


#2 nakbrooks

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Posted 04 November 2014 - 08:37 AM

I've had that on my DDM85XL carrying a heavy payload. Almost certainly it is a balance issue. After I carefully rebalanced (with the OTA In different attitudes) and manually retuned the problem went away. Also, difficult to tell from the video but you seem to be slewing quite fast, slowing it a bit might also help if the payload is heavy.

Edited by nakbrooks, 04 November 2014 - 08:40 AM.

Nigel Brooks
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#3 Waldemar

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Posted 04 November 2014 - 09:40 AM

That happened to me with my DDM60Pro when I had an unballance in the 3rd axis (radial equilibrium about the tube axis). The weight of the focus motor on one side of the telescope was the problem.

Once I balanced that out, it was gone. I you mounted your filterwheel on the side, that may be the problem.

 

BR,

Waldemar


Waldemar
--------------
Mount: DDM85 Standard 12V ; Telescopes: TEC140 + 140FF + Quad TCC ; Celestron RASA; TMB 92SS + 27TVPH Cameras: ZWO ASI 174MM cool; SBIG STF8300M; ATIK4120EX; TRIUS SX-36
Filters: Astronomik and Baader NB + RGB; Lunt double stack 75 mm unobstructed signature series + BF 3400; Dutch weather and light polluted skies.  

#4 prefetch

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Posted 04 November 2014 - 02:48 PM

whew.  okay, this makes me feel a lot better that it's happened to you guys.  i thought my motor was messed up.  i'd had shuddering before, and whining before, but never chirping!

 

alright, i'll work really hard on achieving a near perfect balance and hope the chirping goes away.  thanks so much for the replies.  



#5 prefetch

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Posted 07 November 2014 - 03:42 PM

so i spent several hours trying to balance my C14 last night.  i mostly worked on the radial balance step, and started with the declination.  i followed the principles in this video:   which i found very helpful.  

 

so the results are that it still chirps occasionally, but i can now achieve a 400 second exposure w/ round stars.  before, i could only do about 180 seconds.  this is all without MLPT.  

 

but i can't achieve a 600 second exposure with round stars, which frustrating to me.  i have an Ha filter i'd love to use, but i believe the minimum useful exposure is about 600 seconds, and i just can't get it to work w/o getting some star distortion.

 

any advice?



#6 Denis Vien.

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Posted 10 November 2014 - 11:46 AM

Hello everyone, I introduce myself, my name is Denis Vienat, I live in Switzerland, in the Jura Bure, I'm new to the forum, thank you to welcome me.
My setup: Scope Dome 3 meters, Mount ASA DDM85 S Telescope: Meade 12 "ACF, CCD Orion Star Shoot, Starlight Xpress Filter Wheel LTD
That makes two weeks my new ride arrived, but I have concerns for balancing on Autoslew, I do not understand the proceeding.
Thank you for reading me and waiting for your valuable advice
thank you very much
Denis



#7 Jay

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Posted 11 November 2014 - 08:58 AM

Hi Denis and welcome  :)

 

Using Autoslew and the "balancing tool" is quite simple and you shouldn't worry about it. In addition, the automated tuning procedure will also work very well in most of the cases and no "manual" tuning is required. It might be easier to explain the proceedings after you've had a change to play with the new mount and Autoslew for a while. Meanwhile you might want to read the Autoslew / Sequence manuals ...several times ;) 

I also think that Meade 12 AFC will probably be a lot easier to balance than a Newton telescope.  

 

Best regards

Jay 



#8 Jay

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Posted 11 November 2014 - 12:18 PM

Sorry Denis, it seems like you already have the new mount ?

So are you having problems with balancing the system or tuning the motors ? 

 

As you might have read from previous posts balancing the system properly is the precondition for the well functioning mount. And ASA mounts are very sensitive for the right balancing. Using the "balancing" tool in Autoslew is a very effective way fine tune the balance and to check that the balancing is good enough. 

 

 

Jay


Edited by Jay, 11 November 2014 - 12:33 PM.


#9 Jay

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Posted 11 November 2014 - 02:30 PM

prefetch,

Was just looking the balancing video which seem to spend a lot of time explaining a very simple procedure. Anyway, I wouldn't move and flip around my telescope so roughly and fast with the ASA mount. Even when the power is turned OFF, be gentle when moving the scope around...  



#10 prefetch

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Posted 11 November 2014 - 03:07 PM

jay,

 

i agree, the video is incredibly long for a relatively simple set of instructions, but i like the explanation of the radial aspect of balancing in DE, which i haven't seen explained elsewhere, and that was valuable to me.  and yes, he seems to whip his scope around quite a bit more than i would.  ;-)

 

i'm curious how long people are able to take unguided images.

 

i think i'll make a new post since this thread is getting long and wandering off the original topic of 'chirping'. 







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