Re: [ap-gto] 1600GTO losing position sense(?)-solved


Dec 25, 2013

 


----------------------------

#42725 Dec 25, 2013

Hi,



I am hoping the issue described below is something I did--loose wire,

bad data entry or some such. I just reassembled my CDK17 to the mount

and reinstalled the CP3 electronics module which had been removed for

safety while working. Wiring was adjusted for thru-mount organization

but not changed. I just powered up to check the system out--everything

appeared to work, although it quickly became obvious the 1600GTO RA axis

was getting lost.......



For example: set up with a level for park 1 as has always worked.....no

problem. Do a goto to polaris, a nearby star in terms of slew--it's off

-- recal to polaris--ok. Go back to park 1 and the mount passes through

park 1 by several degrees in RA but DEC is right on the money. I can do

variations of this simple maneuver with similar results over &

over....each time slightly different. I've also tried a slew from

recalibrated polaris to M42 and the scope ends up about 10 degrees out

of wack......not even close.



My impression is that the RA axis is losing tach pulses or some similar

positional info, but I can't find the problem.



For reference, this happens by keypad and by PC control. The

ever-changing results suggests a positional data issue, but just to be

sure, I have stepped through location, time & date, daylight savings,

upper rs232 port, and all those classic incorrect settings--everything

looks ok. Again, I suspect I've done something inadvertant--just can't

find it.



This is one of those mounts that just hooked up and slewed to the first

target---no fiddling, no issues--any ideas from those more experienced

(or less) than I?



many thanks



John Collins

SW Oregon



----------------------------

#42727 Dec 25, 2013

Hi Joe,



That's a cut & paste problem on my part--yes, I level, power down

waiting 15-ish seconds, power up, select location, then resume from park

1--I think that's right--I've been doing that with great results for

months. If the problem were related to this, I'd expect consistent

results.......wrong, but consistent. I am getting a repeatable type of

error issue but with varying amounts of error.



The procedure I outline is what I've been using--I wonder, though, if

after dismantling everything for several weeks, I need to do the "inform

the mount step".........I'll take a look at the manual again.



thanks for your thoughts



John

---------------

On 12/25/2013 9:42 PM, Joseph Zeglinski wrote:

> John,

>

> After you leveled the mount at Park-1 ... did you then immediately power

> off in that position, then power back on, specifying RESUME from "REFERENCE

> PARK" ?

>

> Unless the AP-1600 is different from the old AP-1200, you can't just

> level, and then slew - the CP3 will not initialize properly.

> Also, you can't Resume from "Last Parked or Park-1", even after leveling and

> powering down. You have to inform the mount, on power-up, that it is to

> assume it is at the "Reference Park", so it can do a proper SYNC to that

> position. Otherwise, it will behave as though no prior re-level had been

> done.

>

> I may be wrong, but I don't think that ASCOM does a SYNC when instructed

> that it is starting from any of the Park positions.

>

> Joe

>

>

>

---------------

>

>



----------------------------

#42728 Dec 26, 2013

Do not sync or recal on Polaris.

Polaris is very close to NCP.NCP has a Dec value of 90 butNCP's RA is all RA's (0-360 or 0-24h)Due to possible orthogonality errors,Polaris is a bad choice to define RA with a recal or sync.Polaris is just too close to NCP.

As always, I could be wrong again.Jimmy



----------------------------

#42729 Dec 26, 2013

Hi Jimmy,



Thanks for your response.. I was not entirely clear in my originalpost, as usual--my understanding is that Polaris is close/but notright on 0/360 --. overall, I agree, but have found that whentweaking or testing, polaris is easy star to find and slew back& forth to/from--that has always worked between polaris andpark 1.......this time it is not working well.. I should be ableto slew back and forth between two defined points, but I'm findingthat after a single slew there is an appreciable error -- forexample, start in park 1 with a resume-from park 1 (after normalstartup), goto polaris, return to park 1.....the mount sails rightby park 1 by 4-8 degrees which creates a counterweights-upsituation.....the exact amount of error varies.. I am alsoconverting syncs to recals as suggested, although I don't know ifthat enters into this particular situation.



I also see similar behavior with larger error on a park 1 - to -M42 slew wherein the mount went right by the target by about 15degrees.....



This being a new day and I haven't been up for 24 hours, I expectI made some dopey mistake......I'll start again fromscratch........I expect my first error was to assume thenonvolatile memory would start right up again after twoweeks........so far I notice that my daylight savings "off"setting mysteriously is "on", although that doesn't account forthe variations from slew to slew--so that's been reset but did notchange the loss of position behavior.



I got shut down last night by flash fog and it's still here--willredo all at next opportunity.



thanks again



John Collins

_______________



On 12/26/2013 9:01 AM, jimmy_an@... wrote:





Do not sync or recal on Polaris.



Polaris is very close to NCP.

NCP has a Dec value of 90 but

NCP's RA is all RA's (0-360 or 0-24h)

Due to possible orthogonality errors,

Polaris is a bad choice to define RA with a recal or sync.

Polaris is just too close to NCP.



As always, I could be wrong again.

Jimmy







----------------------------

#42734 Dec 27, 2013

99% of the time when parks and slews are off it's because of an erroneous time setting. And this can include an improper daylight savings time setting.��Rolando

-----Original Message-----

From: john john@...>

To: ap-gto ap-gto@yahoogroups.com>

Sent: Thu, Dec 26, 2013 12:06 pm

Subject: Re: [ap-gto] RE: 1600GTO losing position sense(?)





Hi Jimmy,

Thanks for your response.�� I was not entirely clear in my originalpost, as usual--my understanding is that Polaris is close/but notright on 0/360 --�� overall, I agree, but have found that whentweaking or testing, polaris is easy star to find and slew back& forth to/from--that has always worked between polaris andpark 1.......this time it is not working well.�� I should be ableto slew back and forth between two defined points, but I'm findingthat after a single slew there is an appreciable error -- forexample, start in park 1 with a resume-from park 1 (after normalstartup), goto polaris, return to park 1.....the mount sails rightby park 1 by 4-8 degrees which creates a counterweights-upsituation.....the exact amount of error varies.�� I am alsoconverting syncs to recals as suggested, although I don't know ifthat enters into this particular situation.

I also see similar behavior with larger error on a park 1 - to -M42 slew wherein the mount went right by the target by about 15degrees.....

This being a new day and I haven't been up for 24 hours, I expectI made some dopey mistake......I'll start again fromscratch........I expect my first error was to assume thenonvolatile memory would start right up again after twoweeks........so far I notice that my daylight savings "off"setting mysteriously is "on", although that doesn't account forthe variations from slew to slew--so that's been reset but did notchange the loss of position behavior.

I got shut down last night by flash fog and it's still here--willredo all at next opportunity.

thanks again

John Collins_______________

On 12/26/2013 9:01 AM, jimmy_an@... wrote:



Do not sync or recal on Polaris.

Polaris is very close to NCP.NCP has a Dec value of 90 butNCP's RA is all RA's (0-360 or 0-24h)Due to possible orthogonality errors,Polaris is a bad choice to define RA with a recal or sync.Polaris is just too close to NCP.

As always, I could be wrong again.Jimmy



----------------------------

#42736 Dec 27, 2013

Hi,



I'll start with the apology....so sorry all, but my compliments--you

were all correct at one point or another, and I included a cut and paste

error in my original post which further confused things. Here is the

story in short (abridged) form:



First clue is that this happened on Christmas--that comes with

visitors--tipsy visitors with curiosity and roving fingers that pick up

and fiddle with everything. And I hadn't slept in 20 hours or so. I

had just serviced the telescope mirrors which were cleaned and a minor

secondary issue was repaired. The mount was fired up, data entries

double checked, the telescope was leveled and set at park 1, and I told

the visitors not to touch anything (while they were left unattended in

the observatory).



Return to the house control position, fire up the computer, and get SkyX

sync'd up with the mount--aok (not so fast). Did a simple test goto to

polaris--close, but not as good as usual--return to park 1....mount went

right through park 1 and ended up with weights up.



So I stopped and manually reset everything and repeated the process,

slewing to M42--ended up way short of target--return to park 1, the

mount stopped short of park 1 with scope-up. At one point, SkyX was

indicating wrong side of the pier.



Then I got sucked into the trouble shooting, which generated the posts.



After interrogating my visitors, I realized that after watching me do

the manual setup, one of the visitors was fiddling with the handbox (two

times) while I was returning to the control desk -- so when I

initialized SkyX, I captured an incorrect position.........and the

adventure unfolded from there.



I was visitor free last night and was able to straighten this out--so

the mount is fine and somehow I did not have a pier crash--I am stunned

with how my allegedly mature visitors completely miss the point of my

asking they not mess with stuff. They are yet another reminder of where

the bizarre "don't do this/that" signs in public places come from.



I appreciate the efforts of those who responded and I will add handcuffs

and hog ties to my bag o' tools...and possibly replace my friends. I'll

also add "no visitors" and "do not dispose of used diapers in the

telescope" signs.



John Collins

SW Oregon



----------------------------

#42737 Dec 27, 2013

You can just unplug the keypad. Don't worry, it can be done with power on, and the keypad will remember where it was when you plug it in again -��with power on. That way the only thing they can do easily is to remove the safety stop on the counterweight shaft, and then loosen one of the 18 pounders, which will slip off and crash thru the concrete, narrowly missing two sets of toes.��Rolando

-----Original Message-----

From: john john@...>

To: ap-gto ap-gto@yahoogroups.com>

Sent: Fri, Dec 27, 2013 3:04 pm

Subject: [ap-gto] 1600GTO losing position sense(?)-solved

Hi,

I'll start with the apology....so sorry all, but my compliments--you were all correct at one point or another, and I included a cut and paste error in my original post which further confused things. Here is the story in short (abridged) form:

First clue is that this happened on Christmas--that comes with visitors--tipsy visitors with curiosity and roving fingers that pick up and fiddle with everything. And I hadn't slept in 20 hours or so. I had just serviced the telescope mirrors which were cleaned and a minor secondary issue was repaired. The mount was fired up, data entries double checked, the telescope was leveled and set at park 1, and I told the visitors not to touch anything (while they were left unattended in the observatory).

Return to the house control position, fire up the computer, and get SkyX sync'd up with the mount--aok (not so fast). Did a simple test goto to polaris--close, but not as good as usual--return to park 1....mount went right through park 1 and ended up with weights up.

So I stopped and manually reset everything and repeated the process, slewing to M42--ended up way short of target--return to park 1, the mount stopped short of park 1 with scope-up. At one point, SkyX was indicating wrong side of the pier.

Then I got sucked into the trouble shooting, which generated the posts.

After interrogating my visitors, I realized that after watching me do the manual setup, one of the visitors was fiddling with the handbox (two times) while I was returning to the control desk -- so when I initialized SkyX, I captured an incorrect position.........and the adventure unfolded from there.

I was visitor free last night and was able to straighten this out--so the mount is fine and somehow I did not have a pier crash--I am stunned with how my allegedly mature visitors completely miss the point of my asking they not mess with stuff. They are yet another reminder of where the bizarre "don't do this/that" signs in public places come from.

I appreciate the efforts of those who responded and I will add handcuffs and hog ties to my bag o' tools...and possibly replace my friends. I'll also add "no visitors" and "do not dispose of used diapers in the telescope" signs.

John CollinsSW Oregon



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#42740 Dec 27, 2013

If I was lucky--I have a rubber floorso it would bounce, hit someone in the head, then land onsomeone's foot--multi-law suits..........they could also lob emptydrinks and snacks into the trash can.....I mean telescope......

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On 12/27/2013 1:27 PM, chris1011@... wrote:



You can just unplug the keypad. Don'tworry, it can be done with power on, and the keypad willremember where it was when you plug it in again -��with poweron. That way the only thing they can do easily is to removethe safety stop on the counterweight shaft, and then loosenone of the 18 pounders, which will slip off and crash thruthe concrete, narrowly missing two sets of toes.��Rolando-----Original Message-----

From: john john@...>

To: ap-gto ap-gto@yahoogroups.com>

Sent: Fri, Dec 27, 2013 3:04 pm

Subject: [ap-gto] 1600GTO losing position sense(?)-solved



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