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motor noise and motor LEDs
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With low values of (esp.) P, the system tracks, but responds very slowly on inputs via hand controler. I've raised the values, and now it's fine. No additionals needed with respect to this issue.
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Don W
Hi Frank,
What do you mean "the system is too slow"? You can set the speed of servos in ServoConfig using degrees per second. According to your previous message you set 2.5 dps for RA. You can set that to anything higher but the actual speed probably won't change. Set it lower and it WILL change slower. The thing that limits max speed is your servo output max speed and the gear ratio (and the voltage you are using). Don W |
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I've tried using these settings, but the system is too slow. Actually, settings are higher, but not as high as pre-set. System works fine; problems solved. Txs for help provided.
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I've followed the opposite approach compared to what's written in the manual.
Step 1: I and D to zero; P up 'till vibration/instability/instability started. Back to 60% of that value. Step 2: I up 'till slight overflow started, looking at the error during slew. Step 3: D up 'till overflow back to apporx zero. Value differs greatly from pre-set. Now the motors run silently and with minor errer. So far satisfying; I will try this evening under the (hopefully) clear sky in Northern France.  |
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Hi Dan,
Txs for support. The drive motors: Faulhaber 3257 G 024 R, with Faulhaber HEDL 5540A encoder. The gear reductions for azimuth: gear head Faulhaber 23.040000:1 --> Harmonic Drive 50:1 --> friction drive 120:770. Total reduction: 7392.0:1. The gear reductions for altitude: gear head Faulhaber: 3.714285 --> Harmonic Drive: 50:1 --> friction drive: 35:1,370. Total reduction: 7269.39:1. # encoder ticks per revolution in azi: 14,784,000 (the printscreen shows a different figure; that's wrong). # encoder ticks per revolution in alt: 14,538,773.  |
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Dan Gray
Hi Frank, That's normal LED behavior if you're in the drag and track mode, or slew and track mode. That's how you can tell if it's in that particular mode. Can you describe your motors to me along with a gear reduction, etc? Can you make a screenshot of your servoConfig parameters? Or just email me your *.car file? I want to take a look at your pid parameters to see If we can decrease the noise. Dan On Mon, Sep 19, 2022 at 11:52 PM Frank <fclbhol@...> wrote: Txs, Don, for the answers you povided. With respect to the 50 Hz: I didn't know that; now it's clear. I will do some tests in order to find the right material (some hard rubber I had coincidentally available didn't make any difference, as expected). |
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Txs, Don, for the answers you povided. With respect to the 50 Hz: I didn't know that; now it's clear. I will do some tests in order to find the right material (some hard rubber I had coincidentally available didn't make any difference, as expected).
With respect to the LEDs: why then does 'not powered' happen during normal operation? Yesterday evening, I had the set-up running in the living room (it was clouded outside, of course), and at a certain moment, I noticed the LEDs behvaing like 5 seconds lit, 1 second off, 5 seconds lit, 1 second of, and on and on. I do not know whether I do need to act (change something?) if a LED is sometimes off or behaves as described. Vitually impossible to be a power supply problems: the set-up runs on a 20 Ah 12V LiFePO4 battey, charged the same day, with a 10A 12VDC --> 24VDC converter. I'm aware of blinky; that's clear to me. TXS a lot and KR, Frank |
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Don W
Hi Frank,
On the subject of noise, if you have flat areas that might resonate, putting some kind of damping material on flat surfaces will deaden the sound. Thick insulation like 3/8 inch thick neoprene foam might help. Search for sound deadening for cars. Don W |
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Don W
Hi Frank,
SiTech controls the movement and speed or position of the servos by applying ± voltage to the servos at something over 50 KHz, that creates noise and you have a huge aluminum "speaker". I doubt you can fix that. The LED's as far as I know, mean: Lit it is powered Off it is not powered. Don W |
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Dear all,
I've installed all motors (Faulhaber) and Sitech II on my aluminium 30", and have all running. Two things that are special: Noise. As my telescope is made of aluminium, motor noise is quit seriously amplified by the frame. There is a large difference between holding motors in my hand and installing them on the telescope. But supplying power with a constant DC supply (so not regulatede - bypassing the Sitech) reduces the noise a lot. I;ve tried to manipulate the PID-settings, but that does not make any difference. Is it normal that a motor controlled by a PID is more noisy than a motor fed by a constant DC power source? Motor LEDs. Blinky mode is clear to me. But what does it mean when a LED shows continously vs. a LED does not show? LED showing and LEDs not showing happens regularly, and I've no idea what's actually going on. KR, Frank |
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