Storing Losmandy G11G DEC horizontally
Hello everyone,
It is my understanding that it is best to keep a SCT stored vertically Collector plate up and secondary mirror set all the way back. If I keep it mounted on the G11. Is it okay to keep the DEC and counter weight parked in the horizontal position ? Does this put stress on the worm gear???
Other than this off the wall question every thing with my G11G is working like a champ. I had a rough start but got it together thanks to everyone here and especially Brian.
THANK YOU
HAPPY SKIES AND KEEP LOOKING UP
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Re: Valid Guide Rates for PEC on Gemini Level 4
UPDATE: The 0.3x and 0.5x from the documentation are incorrect - those are values from the 492 controller, not the Gemini.
Brian
On Mon, Aug 17, 2020 at 2:00 PM Paul Kanevsky < yh@...> wrote: On Mon, Aug 17, 2020 at 04:39 PM, Michael Herman wrote:
So...can someone explain why "autoguide rate" has something to do with PEC??
Hi Michael,
Recording PE data doesn't require knowing the guide rate. Programming PEC data into Gemini - does.
If you are programming PEC manually (using HC or autoguider corrections) then the corrections recorded are relative to the guide rate. If you change the guide rate, the correction rates will also need to be adjusted during PEC playback, and Gemini doesn't do this automatically. So, whatever rate you recorded and programmed PEC is the rate you should use for PEC playback.
When PEC is programmed from the PC, say using PemPro, the corrections are also sent as the number of pulses needed for each of the corrections. This is also based on the guiding speed: if the speed is higher, then fewer pulses are needed, if lower -- more pulses. If the guiding speed is changed after the programming, the number of pulses of corrections will no longer be right and the corrections will be either faster or slower than what was programmed.
Regards,
? ?-Paul
-- Brian?
Brian Valente portfolio
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Re: Valid Guide Rates for PEC on Gemini Level 4
Hi Michael
Rene is the best person to answer this, but here are a few tidbits of my understanding
When you record PEC using a third party tool like PEMPro, the guide rate affects the speed at which corrections are applied (i'm not sure if it's in the capture, the playback, or both). First part is when you gather the data and then upload to the mount, Gemini needs to be at the same guide rate.?
Then when you're guiding, the guide rate needs to be at the same value as well. if you decide you want to guide at a different rate, you need to disable PEC or re-do it at the new rate. ?
for built-in PEC training, i'm not sure how much the above applies
On Mon, Aug 17, 2020 at 1:39 PM Michael Herman < mherman346@...> wrote: I always learn something new on this forum. I presently avoid needing PEC by the few improvements I made to the RA drive. That hot PE down to the 1 arcsec RMS (~2.4 arcsec Peak to Peak) range, typical of my area's seeing.? I do use autoguiding at 0.5x Sidereal rate to correct other errors like polar alignment error/drift.??
Earlier, I did use the Gemini-1 built in PEC training and built in PEC averaging .? It worked fine.??
However, from this thread, I really don't understand why the autoguide rate has anything at all to do with PEC training.? The autoguider is turned off during PEC data acquisition.? The "autoguide" camera is only used to "watch" the tracked star's RA position during sidereal tracking.? You could even be tracking the star with 2 or 3 second exposures.??
The PEC is fitted to the recorded unguided tracking data later, by either the Gemini built in software or the external PC software.??
So...can someone explain why "autoguide rate" has something to do with PEC??
Thanks, Michael
On Mon, Aug 17, 2020, 12:24 PM Brian Valente < bvalente@...> wrote: Update:
i found that reference in the documentation.
i checked with Ray, i think that may be out of date. the valid range is 0.2x - 0.8x
however, I really recommend you stick with 0.5x for two reasons
1. it's the best balance between slower speed (better for PEC) and faster speed (better for guiding)
2. there may be some parts of the code that are hard-coded to 0.5x. i don't know this for sure, i've only heard this in passing, so it may not be true. So the recommendation is 0.5x
also FYI if you change your guidespeed at any time, you will need to redo your PEC to match the guidespeed
Brian
I have always used 0.8x as the guide rate when training PEC on my G11 with Gemini 1 Level 4.? I was just looking at the Gemini instructions in PEMPro V3 and it has this warning:? The Gemini firmware only supports 0.3x and 0.5x guide rates - 0.5x is recommended.? This conflicts with the description of command ID 502, Guide Speed used for training PEC, in the Gemini Level 4 Users Manual.? That seems to indicate the full 0.2x, 0.5x, and 0.8x range is valid.? Which is it?
--
Brian?
Brian Valente portfolio
-- Brian?
Brian Valente portfolio
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Re: Valid Guide Rates for PEC on Gemini Level 4
On Mon, Aug 17, 2020 at 04:39 PM, Michael Herman wrote:
So...can someone explain why "autoguide rate" has something to do with PEC??
Hi Michael, Recording PE data doesn't require knowing the guide rate. Programming PEC data into Gemini - does. If you are programming PEC manually (using HC or autoguider corrections) then the corrections recorded are relative to the guide rate. If you change the guide rate, the correction rates will also need to be adjusted during PEC playback, and Gemini doesn't do this automatically. So, whatever rate you recorded and programmed PEC is the rate you should use for PEC playback. When PEC is programmed from the PC, say using PemPro, the corrections are also sent as the number of pulses needed for each of the corrections. This is also based on the guiding speed: if the speed is higher, then fewer pulses are needed, if lower -- more pulses. If the guiding speed is changed after the programming, the number of pulses of corrections will no longer be right and the corrections will be either faster or slower than what was programmed. Regards, ? ?-Paul
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Re: Valid Guide Rates for PEC on Gemini Level 4
I always learn something new on this forum. I presently avoid needing PEC by the few improvements I made to the RA drive. That hot PE down to the 1 arcsec RMS (~2.4 arcsec Peak to Peak) range, typical of my area's seeing.? I do use autoguiding at 0.5x Sidereal rate to correct other errors like polar alignment error/drift.??
Earlier, I did use the Gemini-1 built in PEC training and built in PEC averaging .? It worked fine.??
However, from this thread, I really don't understand why the autoguide rate has anything at all to do with PEC training.? The autoguider is turned off during PEC data acquisition.? The "autoguide" camera is only used to "watch" the tracked star's RA position during sidereal tracking.? You could even be tracking the star with 2 or 3 second exposures.??
The PEC is fitted to the recorded unguided tracking data later, by either the Gemini built in software or the external PC software.??
So...can someone explain why "autoguide rate" has something to do with PEC??
Thanks, Michael
On Mon, Aug 17, 2020, 12:24 PM Brian Valente < bvalente@...> wrote: Update:
i found that reference in the documentation.
i checked with Ray, i think that may be out of date. the valid range is 0.2x - 0.8x
however, I really recommend you stick with 0.5x for two reasons
1. it's the best balance between slower speed (better for PEC) and faster speed (better for guiding)
2. there may be some parts of the code that are hard-coded to 0.5x. i don't know this for sure, i've only heard this in passing, so it may not be true. So the recommendation is 0.5x
also FYI if you change your guidespeed at any time, you will need to redo your PEC to match the guidespeed
Brian
I have always used 0.8x as the guide rate when training PEC on my G11 with Gemini 1 Level 4.? I was just looking at the Gemini instructions in PEMPro V3 and it has this warning:? The Gemini firmware only supports 0.3x and 0.5x guide rates - 0.5x is recommended.? This conflicts with the description of command ID 502, Guide Speed used for training PEC, in the Gemini Level 4 Users Manual.? That seems to indicate the full 0.2x, 0.5x, and 0.8x range is valid.? Which is it?
--
Brian?
Brian Valente portfolio
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Re: Valid Guide Rates for PEC on Gemini Level 4
Update:
i found that reference in the documentation.
i checked with Ray, i think that may be out of date. the valid range is 0.2x - 0.8x
however, I really recommend you stick with 0.5x for two reasons
1. it's the best balance between slower speed (better for PEC) and faster speed (better for guiding)
2. there may be some parts of the code that are hard-coded to 0.5x. i don't know this for sure, i've only heard this in passing, so it may not be true. So the recommendation is 0.5x
also FYI if you change your guidespeed at any time, you will need to redo your PEC to match the guidespeed
Brian
I have always used 0.8x as the guide rate when training PEC on my G11 with Gemini 1 Level 4.? I was just looking at the Gemini instructions in PEMPro V3 and it has this warning:? The Gemini firmware only supports 0.3x and 0.5x guide rates - 0.5x is recommended.? This conflicts with the description of command ID 502, Guide Speed used for training PEC, in the Gemini Level 4 Users Manual.? That seems to indicate the full 0.2x, 0.5x, and 0.8x range is valid.? Which is it?
-- Brian?
Brian Valente portfolio
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Re: Valid Guide Rates for PEC on Gemini Level 4
Hi?sbasprez
you should be fine with up to 0.8x, although 0.5x is definitely recommended
Where did you see this error? I am in PEMPro now (and have used it for years) and never ran across that error message, regardless of what guide rate i put in
Brian
I have always used 0.8x as the guide rate when training PEC on my G11 with Gemini 1 Level 4.? I was just looking at the Gemini instructions in PEMPro V3 and it has this warning:? The Gemini firmware only supports 0.3x and 0.5x guide rates - 0.5x is recommended.? This conflicts with the description of command ID 502, Guide Speed used for training PEC, in the Gemini Level 4 Users Manual.? That seems to indicate the full 0.2x, 0.5x, and 0.8x range is valid.? Which is it?
-- Brian?
Brian Valente portfolio
|
Valid Guide Rates for PEC on Gemini Level 4
I have always used 0.8x as the guide rate when training PEC on my G11 with Gemini 1 Level 4.? I was just looking at the Gemini instructions in PEMPro V3 and it has this warning:? The Gemini firmware only supports 0.3x and 0.5x guide rates - 0.5x is recommended.? This conflicts with the description of command ID 502, Guide Speed used for training PEC, in the Gemini Level 4 Users Manual.? That seems to indicate the full 0.2x, 0.5x, and 0.8x range is valid.? Which is it?
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Re: How to pause a 492 digital drive
On Fri, Aug 14, 2020 at 08:41 AM, Les Niles wrote:
While I appreciate the theoretical interest, the luddite in me still asks, what is gained by inhibiting the RA motor output, vs. just shutting off power to the 492?
Throwing the slide switch is going to disturb the mount. But I see no reason a normally on (closed) momentary switch can't be wired into the power switch and be used to cut power when desired.?
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Re: How to pause a 492 digital drive
Another idea to consider:
I thought that the autoguider or motor motion in RA rate of 1X just shuts off the RA motor if it is trying to "slew" in one direction, else 2X sidereal in the other direction.? ? If so perhaps there is a software approach to having RA stand still...
Have fun, Michael
On Fri, Aug 14, 2020, 3:21 PM John Desbiens via <jdlittlewing= [email protected]> wrote: Yea it looks like an RA power interrupt switch on the hand controller is the ticket. Allowing it to track on an alt/az mount moves the object out of the fov faster than if it was off.
Anyway the 492 works pretty nice with encoders, nexus, and sky safari 6. Manual controls induced hesitation, stuttering and backlash. Not to mention the 492 keeps my hands off the mount.
Thanks Everybody,
John
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Re: How to pause a 492 digital drive
Yea it looks like an RA power interrupt switch on the hand controller is the ticket. Allowing it to track on an alt/az mount moves the object out of the fov faster than if it was off.
Anyway the 492 works pretty nice with encoders, nexus, and sky safari 6. Manual controls induced hesitation, stuttering and backlash. Not to mention the 492 keeps my hands off the mount.
Thanks Everybody,
John
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Re: Polemaster Adapter for Titan Mounts
Donald,
Anything you can do to make using the scope and mount easier and more accessible will improve the number of observing sessions you get per year, trust me! Before I got the Wheelie Bar and plopped the LWT from the GM8 on it to carry the GM8 or G11 depending on the scope I basically very rarely observed from the driveway unless I could see that the conditions were going to be spectacular. With the Wheelie Bar I leave the GM8 and FC-100DL (or whatever scope I left in the saddle) setup and covered ready for a quick look at the night sky. I takes me maybe 15 minutes to get it setup and polar aligned well enough to have the GOTOS be close enough to see in a longer eyepiece. Then a Gemini sync command and I'm off to the GOTO races. Don't worry about leaving it setup and ready to go good quality gear should not be significantly affected by heat or cold.?
--
Chip Louie - Chief Daydreamer Imagination Hardware
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Re: How to pause a 492 digital drive
i saw some suggestions for uses previously, but i'm also thinking you could just insert a power switch? :)
On Fri, Aug 14, 2020 at 8:41 AM Les Niles < les@...> wrote: While I appreciate the theoretical interest, the luddite in me still asks, what is gained by inhibiting the RA motor output, vs. just shutting off power to the 492?
[Edited Message Follows] Hi John
here's a quick synopsis of stopping the 492 drive output electronically.
IC U2 (MIC58001) pin 1 (CLR) and 22 (/OE)are connected together and held "low" in normal operation.? This "low state" function allows the IC to provide drive outputs when /OE is "low".? Aka the stepper works.
/OE is provided by IC U3 (MC3847 Line driver) pin 10 (3Y) going "low" when commanded by other circuitry. ??
So, what you ideally want to do is change this
state on IC 2 pins 1 and 22 to a "high" but no damage U3!?? This would be best done thru a steering transistor/FET/diode/or electronic sw.?
Actually ?no, a logic OR gate would be easier! Added Drive SW (On HC) OFF = low as input yo one leg of iOR gate. Other OF Zgate leg input input ?low from U3. This OR OP = low Out. This U3 is /OE
Now ?activate added SW to HC to give a high out ?The OR ?will flip state to opposite to /OE now a high meaning it’s drive is off ?
?This would that allow normal /OE? normal functional operation but allow us to to change this to a "high" by activating an added button (in the HC) that switches this and a sml OR gate IC. Should even be simpler ways with guides and resistors?
Ideally you need to change the HC RJ 6 pin to an 8 pin (RJ45).? The PCB indeed has 8 pads and holes already its just they only fitted the 6Pin version (left the outer pins unconnected)...but you can change this.? This would allow you to add another switch into the HC and run its wires as needed thru the 8P8C RJ45 plug socket to the circuit that switches/OE.?
However you would need to ensure you wire this and the old pins to the correct existing positions....not change them to the wrong pin place.?
It can be done I haven't gone too deep into it and of course....if you do pursue it I cannot be held responsible for anything that goes bad.? It would be up to you top decide.? Sure it can be done.? There are fine details to design the switching "state" without damaging? U3 but his can be done.? U2 state just follows that pin 10 U3 commands it to.? A "high" /OE stops all output of U2, aka it stops Ra and DEC drive.?
Brendan
-- Brian?
Brian Valente portfolio
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Re: How to pause a 492 digital drive
While I appreciate the theoretical interest, the luddite in me still asks, what is gained by inhibiting the RA motor output, vs. just shutting off power to the 492?
toggle quoted message
Show quoted text
[Edited Message Follows] Hi John
here's a quick synopsis of stopping the 492 drive output electronically.
IC U2 (MIC58001) pin 1 (CLR) and 22 (/OE)are connected together and held "low" in normal operation.? This "low state" function allows the IC to provide drive outputs when /OE is "low".? Aka the stepper works.
/OE is provided by IC U3 (MC3847 Line driver) pin 10 (3Y) going "low" when commanded by other circuitry. ??
So, what you ideally want to do is change this
state on IC 2 pins 1 and 22 to a "high" but no damage U3!?? This would be best done thru a steering transistor/FET/diode/or electronic sw.?
Actually ?no, a logic OR gate would be easier! Added Drive SW (On HC) OFF = low as input yo one leg of iOR gate. Other OF Zgate leg input input ?low from U3. This OR OP = low Out. This U3 is /OE
Now ?activate added SW to HC to give a high out ?The OR ?will flip state to opposite to /OE now a high meaning it’s drive is off ?
?This would that allow normal /OE? normal functional operation but allow us to to change this to a "high" by activating an added button (in the HC) that switches this and a sml OR gate IC. Should even be simpler ways with guides and resistors?
Ideally you need to change the HC RJ 6 pin to an 8 pin (RJ45).? The PCB indeed has 8 pads and holes already its just they only fitted the 6Pin version (left the outer pins unconnected)...but you can change this.? This would allow you to add another switch into the HC and run its wires as needed thru the 8P8C RJ45 plug socket to the circuit that switches/OE.?
However you would need to ensure you wire this and the old pins to the correct existing positions....not change them to the wrong pin place.?
It can be done I haven't gone too deep into it and of course....if you do pursue it I cannot be held responsible for anything that goes bad.? It would be up to you top decide.? Sure it can be done.? There are fine details to design the switching "state" without damaging? U3 but his can be done.? U2 state just follows that pin 10 U3 commands it to.? A "high" /OE stops all output of U2, aka it stops Ra and DEC drive.?
Brendan
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Re: How to pause a 492 digital drive
Hi John
here's a quick synopsis of stopping the 492 drive output electronically.
IC U2 (MIC58001) pin 1 (CLR) and 22 (/OE)are connected together and held "low" in normal operation.? This "low state" function allows the IC to provide drive outputs when /OE is "low".? Aka the stepper works.
/OE is provided by IC U3 (MC3847 Line driver) pin 10 (3Y) going "low" when commanded by other circuitry. ??
So, what you ideally want to do is change this
state on IC 2 pins 1 and 22 to a "high" but no damage U3!?? This would be best done thru a steering transistor/FET/diode/or electronic sw.?
Actually ?no, a logic OR gate would be easier! Added Drive SW (On HC) OFF = low as input yo one leg of iOR gate. Other OF Zgate leg input input ?low from U3. This OR OP = low Out. This U3 is /OE
Now ?activate added SW to HC to give a high out ?The OR ?will flip state to opposite to /OE now a high meaning it’s drive is off ?
?This would that allow normal /OE? normal functional operation but allow us to to change this to a "high" by activating an added button (in the HC) that switches this and a sml OR gate IC. Should even be simpler ways with guides and resistors?
Ideally you need to change the HC RJ 6 pin to an 8 pin (RJ45).? The PCB indeed has 8 pads and holes already its just they only fitted the 6Pin version (left the outer pins unconnected)...but you can change this.? This would allow you to add another switch into the HC and run its wires as needed thru the 8P8C RJ45 plug socket to the circuit that switches/OE.?
However you would need to ensure you wire this and the old pins to the correct existing positions....not change them to the wrong pin place.?
It can be done I haven't gone too deep into it and of course....if you do pursue it I cannot be held responsible for anything that goes bad.? It would be up to you top decide.? Sure it can be done.? There are fine details to design the switching "state" without damaging? U3 but his can be done.? U2 state just follows that pin 10 U3 commands it to.? A "high" /OE stops all output of U2, aka it stops Ra and DEC drive.?
Brendan
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Re: How to pause a 492 digital drive
Another is to time the movement across a pair of crosshairs to calculate the separation of a binary pair.
?
Lately I turn off tracking, watch some TV and go back out without worry of the scope hitting the mount.
?
BG
?
Sent from for Windows 10
?
toggle quoted message
Show quoted text
From: k warren
Sent: Thursday, August 13, 2020 4:48 PM
To: [email protected]
Subject: Re: [Losmandy_users_io] How to pause a 492 digital drive
?
One reason, old school, is to time a star moving across an eyepiece to calculate field of view, if I remember correctly.
Ken
On 8/13/2020 9:25 AM, David C. Partridge wrote:
Why do you want to stop RA traking surely the object will rapidly drift out of view?
?
D.
?
?
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Re: How to pause a 492 digital drive
One reason, old school, is to time a star moving across an
eyepiece to calculate field of view, if I remember correctly.
Ken
On 8/13/2020 9:25 AM, David C.
Partridge wrote:
toggle quoted message
Show quoted text
Why do you
want to stop RA traking surely the object will rapidly drift
out of view?
?
D.
?
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I just measured those bolts. Both the bottom hold down bolts for the worm blocks to the mounting plate, and the side OPW bolts for the worm blocks to the OPW, are 10-32 thread.
Greg will source the bolts he needs locally...in Australia.
All the best, Michael
Sonny,?
There is nothing authentically American about using imperial fasteners.?
As to why Losmandy uses imperial fasteners I think they were more widely in use by American machinists at the time the mounts were designed and machinists like everyone else tend to use what they know.
Why Losmandy continues to use imperial fasteners I am fairly sure has to do with economics and ease of continued support.?
Neither of these has much to do with being authenticity American unless you are talking about being pragmatic.?
--
Chip Louie - Chief Daydreamer Imagination Hardware
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Re: Polemaster Adapter for Titan Mounts
Thank you all again for the superb replies.? I am probably going to go with the G11G and Polemaster w/ sharpcap.? I do like the idea of the tripod on the dolly. If I do that, then it will be a huge temptation to roll the rig back into my garage, which, I really do not feel comfortable with (as far as temps go).? If I go with a Teleview NP101is or an NP127is, that is (to me) a very much considerable amount of $$$ sitting out in a hot garage or cold garage (seasonal).
But then again, the guys that have sheds, PODs, and piers don't worry about such things (and I probably should not either). In Mississippi, only in August does it get what I call very hot usually up into the upper 95-98. I have a temp gauge in my garage that I have on occasions noticed it about 105° -108°.
I also like the ADM mount for the camera, I have to keep that in mind as well !!!
Donald
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Sonny,?
There is nothing authentically American about using imperial fasteners.?
As to why Losmandy uses imperial fasteners I think they were more widely in use by American machinists at the time the mounts were designed and machinists like everyone else tend to use what they know.
Why Losmandy continues to use imperial fasteners I am fairly sure has to do with economics and ease of continued support.?
Neither of these has much to do with being authenticity American unless you are talking about being pragmatic.?
--
Chip Louie - Chief Daydreamer Imagination Hardware
|
Paul Kanevsky
Michael Herman
Chip Louie