Author Topic: PEC problem ? (Read 29891 times)

drknoppi · « **on:** Wednesday, 30.10.13 - 18:44:29 - CET »

Hello guys,
i found a new problem on my mount . First Polar axis is good, North direction is good, after start the LFEP the object drift to the right side of he fov f.e. sun with a speed of 16 arcsec/sec. But somtimes the object stands without movement to the right ? I think that the PEC table seems to be wrong ?
In dec i found no deviation to noth or south.
My questions : Any ideas ?, can i read out the pec table, can i delete the pec table ?
Best regards
Rainer

Armando · « **Reply #1 on:** Wednesday, 30.10.13 - 19:11:36 - CET »

Hi Rainer,

You can delete the Pec table by simply making a new Pec training (with TouchUp mode disabled) by the handbox.
Anyway I think the issue is not related to PEC.
Are you using parking commands?
Could you also check LFEP tracking startup mode by the handbox (without ASCOM connection)?

CS
Armando

P.s. Are you using FocusMax? A previous release disabled tracking at startup...

Armando · « **Reply #2 on:** Wednesday, 30.10.13 - 19:16:02 - CET »

You can also disable PEC with no need to delete the PEC table...
But I'm pretty sure the issue is not related to PEC.

drknoppi · « **Reply #3 on:** Wednesday, 30.10.13 - 19:28:59 - CET »

Hello Armando, ist seems that the LFEP make no tracking at al f.e.sideral solar a.s.o. because the normal speed without any tracking is exactly 15 arcsec / sec. So i think the startupconditions were wrong ?
Tracking rate is solar . Tomorrow i try to check startupconditions .
Thanks for your fast answer .
Best regarda Rainer

Armando · « **Reply #4 on:** Wednesday, 30.10.13 - 20:05:07 - CET »

Hi Rainer,

Quote from: drknoppi on Wednesday, 30.10.13 - 19:28:59 - CET

... without any tracking is exactly 15 arcsec / sec.

Sorry, I assumed 16 arcsec/sec was a typo...

Something is wrong.

Let us know... Maybe motor parameters are corrupted.

CS
Armando

drknoppi · « **Reply #5 on:** Wednesday, 30.10.13 - 21:21:38 - CET »

Hello Armando, i mean that the normal rotationsspeed of the earth is 360 degree / 86400 sec , that is
about 14,7 arcsec per sec, nearly 15 arcsec per second . My measurement on sun showed a movement of the sun disk ( 32 arcmin) at the diameter from about 120 sec - nearly 16 arcsec per
Sec ! I hope Now you can understand me. I think my english is Not the best 😜
Best regards
Rainer

Armando · « **Reply #6 on:** Wednesday, 30.10.13 - 22:46:47 - CET »

Hi Rainer,

Quote from: drknoppi on Wednesday, 30.10.13 - 21:21:38 - CET

Hello Armando, i mean that the normal rotationsspeed of the earth is 360 degree / 86400 sec , that is
about 14,7 arcsec per sec, nearly 15 arcsec per second . My measurement on sun showed a movement of the sun disk ( 32 arcmin) at the diameter from about 120 sec - nearly 16 arcsec per
Sec ! I hope Now you can understand me. I think my english is Not the best 😜

I initially excluded the PEC state as a possible cause of the issue because I assumed that you wrote 16arcsec/sec because of a typo...
In a few words I read 15arcsec/sec and I assumed your mount was not moving at all.

Then, according to your 2nd answer, I realized you had made no typo and you had exactly meant 16 arcsec/sec by your 1st message...

This was the reason why I wrote: "Sorry, I assumed 16 arcsec/sec was a typo...".

But now I'm a little confused too.

Initially I assumed your mount was not tracking at all.
Then I realized it was moving at 16arcsec/s.

Now I think your mount moves at about 31arcsec/s (or maybe 1arcsec/s in the wrong direction).

In any case something is wrong.

Give a look at motor parameters, including RA motor direction.

CS
Armando

drknoppi · « **Reply #7 on:** Thursday, 31.10.13 - 16:06:53 - CET »

Hello Armando,
you were right - the problem was that at a basic power from 462 mA the stepper in RA not moved anything in normal speed, but
2x , 8x , 16 x were o.K.
Why ? : The weight of the Telescop- Canon 40 Da , Counter weight of 24 kg were to much to move .
I changed the value basic to 802 mA and restart the mount . And i see normal movement of RA !!!! ; ))))

o.k.
Thank you for your help
Best regards
Rainer

Armando · « **Reply #8 on:** Thursday, 31.10.13 - 18:49:09 - CET »

Hi Rainer,

Quote from: drknoppi on Thursday, 31.10.13 - 16:06:53 - CET

I changed the value basic to 802 mA and restart the mount . And i see normal movement of RA !!!! ; ))))

Great!

Keep in mind the current value you set in LFEP is 2x phase current; so now, for both RA phases, current is not greater than 400mA...
In a few words never set a value greater than 2x stepper_nominal_phase_ current.

Quote

Thank you for your help

Glad to have been of help.

CS
Armando

P.s. keep up the good work on the Sun ;-)

drknoppi · « **Reply #9 on:** Thursday, 31.10.13 - 20:06:46 - CET »

Hello Armando,
glad to hear from You ! - you wrote :

1. "Keep in mind the current value you set in LFEP is 2x phase current; so now, for both RA phases, current is not greater than 400mA...
In a few words never set a value greater than 2x stepper_nominal_phase_ current. " - That means that in my case the current value is not to high ??
What mean : "2x stepper_nominal_phase_ current." Where i can get this Information ?
2. I tested a new Combination of Software ( AstroPhotographyTool 2.33 and your LFEP-Ascom-Driver ) Works really good - see Screenshot .
3. Thanks for your help again

Rainer

Armando · « **Reply #10 on:** Thursday, 31.10.13 - 20:26:41 - CET »

Hi Rainer,

Quote from: drknoppi on Thursday, 31.10.13 - 20:06:46 - CET

Quote
1. "Keep in mind the current value you set in LFEP is 2x phase current; so now, for both RA phases, current is not greater than 400mA...
In a few words never set a value greater than 2x stepper_nominal_phase_ current. " -
That means that in my case the current value is not to high ??
What mean : "2x stepper_nominal_phase_ current." Where i can get this Information ?

Let's say, just for example, that your motor datasheet indicates 500mA as the nominal current for each phase; if so, you will have to set a current in LFEP never greater than 1000mA.
If you don't know the motor you're using, then you should identify it and search for the appropriate datasheet...
Maybe your motor is the one originally included in your mount; in this case you should be able to find details about it online or ask on this forum.
Anyway I'm tempted to think that you're not overloading your motor by using 802mA in LFEP: typically higher current values are used...
Feel free to ask here if in doubt.

CS
Armando

drknoppi · « **Reply #11 on:** Thursday, 31.10.13 - 20:58:45 - CET »

Hello Armando,
now i understand, i will look in my datasheets to get the value - thanks.( nanotec - motors)
At the end a last picture , that is a combination of sun white - light - image with Meada 8 " AFC in focus with
Canon 40 Da with Astronomic OWB filtre and Sun Image from 12:14 Uhr from SDO 304 nm .
Thank you !!

drknoppi · « **Reply #12 on:** Thursday, 31.10.13 - 22:25:59 - CET »

Hello Armando,
my Datasheet says 950 m A / Phase - that means maximal 1900 mA for RA or Dec ?
So my recent current at 802 mA for both Phases is o.K.
See Datasheet from nanotecs
Good night
Rainer

the_lizardking · « **Reply #13 on:** Thursday, 31.10.13 - 22:53:30 - CET »

Hi Rainer,

you are a lucky guy,... I went upt to 1800mA and more and still see only eggs,... :-P
Rate for your motor seems to be ok now,...

cs

drknoppi · « **Reply #14 on:** Thursday, 31.10.13 - 23:13:02 - CET »

Hello Mike, nice to hear from you 😃,
Search the Problem is only possible with a good analysis
And some measurements. So i found that the RA -Axis showed
No any rotation, but the paddle speeds were o.k.
So I look to the RA axis and found the Problem .
The recent current was to low, now its better 😄.
What about your Setup ?
Best regards
Rainer

Armando · « **Reply #15 on:** Thursday, 31.10.13 - 23:55:30 - CET »

i Rainer,

Quote from: drknoppi on Thursday, 31.10.13 - 22:25:59 - CET

my Datasheet says 950 m A / Phase - that means maximal 1900 mA for RA or Dec ?

1900mA is the max current you can use if you're using bipolar 1 winding connection. In case of bipolar serial connection you can set no more than 1340mA...

Quote

So my recent current at 802 mA for both Phases is o.K.

Yes, as already expected

CS
Armando

drknoppi · « **Reply #16 on:** Friday, 01.11.13 - 01:13:32 - CET »

Hello Armando,
i think i use the serieal mode A and Á', B and B', my values
Recent in fast mode are each 1702 mA in RA and 1702 mA in Dec without any problems.
Why max. 1340 mA , which mathematic term is here behind ?
Good night
Rainer

Armando · « **Reply #17 on:** Friday, 01.11.13 - 01:22:33 - CET »

Hi Rainer,

Quote from: drknoppi on Friday, 01.11.13 - 01:13:32 - CET

Why max. 1340 mA , which mathematic term is here behind ?

according to the datasheet if you're using brown, orange, red and yellow wires (serial connection - 2 windings in series for each phase) the max allowed current for each phase is 670mA and you have to avoid values greater than 2*670mA=1340mA in LFEP...

CS
Armando

drknoppi · « **Reply #18 on:** Friday, 01.11.13 - 03:04:15 - CET »

Good morning Armando

,
O.k. - today i reduce my values to 1340 mA each RA and Dec to avoid phase truble
In the near Future !

in one hour its time for me to stand up,

Best regards and an successful day
Rainer

drknoppi · « **Reply #19 on:** Friday, 01.11.13 - 11:18:44 - CET »

Hello Armando,
i am back

and i will send you a new
screenshot from active APT/LFEP- Screen in combination
with the newest Animation from SDO ( Helioviewer ) with the same
area as the sunspots in wavelength 304.
Rainer