Re: New G11 / Gemini 2 user with issues..
Beautiful.. And yes, I would love to get
together some time.. First I will continue on with cleaning and regreasing, as
well as learning how to properly use the dang thing!
?
New Question.. In reading everything I
can lay my hands on, I found a PDF this AM that mentioned using a feeler gauge
between the worm block and the worm gear housing and that ¡°this is a
critical measurement¡± but it didn¡¯t say way the gap should be..
?
Is that even the correct method?? I
thought it was more of a ¡®don¡¯t bind the gear from full rotation¡±
and ¡°watch the current draw from the motors¡± type of thing??
?
Granted, I only know enough to be
dangerous, and I am not about to touch the drives unless A) I understand it and
think I can do it or B) get someone else to do it
Or C) until it has to be done because it
ain¡¯t working no more..
?
:-))
?
Derek
From:
Losmandy_users@... [mailto:Losmandy_users@...]
Sent: Tuesday, October 10, 2017
3:49 PM
To: Losmandy_users@...
Subject: Re: [Losmandy_users] New
G11 / Gemini 2 user with issues..
?
?
HI Derek,
I guess that sound could possibly originate in loose "grub"
screws that hold the Oldham coupler metal ends to the worm shaft (on one side)
and the gearbox shaft (on the other side of course).
Those tiny grub screws need a very small US sized allen wrench to
tighten up... remove the DEC worm cover and you will see them (if you have the
original 2-piece worm blocks).
Those screws are known to get loose and then you would get something
like a large hysteresis if the Oldham end can
rotate... (as well as mess up your autoguiding I'd guess).
I live in Sunnyvale, not particularly
far from you, though am down in Southern Cal
this week.??
If it turns out to be something more weird than that, let me know and
we might get together to figure it out.
?
On Tue, Oct 10, 2017 at 3:21 PM, 'Derek C Breit' breit_ideas@...
[Losmandy_users] <Losmandy_users@...> wrote:
?
Wow! Look at all my new friends! :-))
?
I placed a wanted ad on Astromart for a G11 when I blew
out the electronics on my Meade 12¡± LX200 Classic. By the springtime I
will salvage my OTA and have it available for use with the G11, but for now, my
concern is only using it with a custom carbon fiber Stellarvue 130mm Triplet
(Strictly visual / video) that weighs around 27 pounds in ready to use trim..
?
The guy I bought the G11 from was close by, so I could see
it in action in his POD before I paid for it and hauled it home.. A couple
slews.. a couple Gotos.. Sold!
As I assembled it at home, I noticed the Dec Axis does not
spin freely, and it is worse in one direction compared to the other. I assume a
little cleaning and regreasing will free up the needle bearings.. And I have
repositioned the Wavy Washers..
?
In the mean time, I have used it a couple times, and both
times I have driven it into the RA Motor ¨C and my clutches are set pretty
tight.. The last time I did it, it started making a noise.. I haven¡¯t
been overly concerned because I will be cleaning regreasing and adjusting
everything as soon as my grease arrives..
?
Today I put on the RA and Dec Extensions, and was perusing
you tube and found this..
?
?
The sound made at the end of this short video is exactly
what my mount is doing.. Any ideas what causes it and is it easy to fix?? Is it
just an irritating noise that can be ignored, adjusted away, or is it a
¡°Oh Dear God stop using that thing immediately!¡± problem.. ???
?
Derek
Morgan Hill, CA
?
PS.. Before anyone means ¡°The Limits¡±, hold
that thought for the next thread..
?
?
--
|
Re: New G11 / Gemini 2 user with issues..
HI Derek,
I guess that sound could possibly originate in loose "grub" screws that hold the Oldham coupler metal ends to the worm shaft (on one side) and the gearbox shaft (on the other side of course). Those tiny grub screws need a very small US sized allen wrench to tighten up... remove the DEC worm cover and you will see them (if you have the original 2-piece worm blocks). Those screws are known to get loose and then you would get something like a large hysteresis if the Oldham end can rotate... (as well as mess up your autoguiding I'd guess).
I live in Sunnyvale, not particularly far from you, though am down in Southern Cal this week.?? If it turns out to be something more weird than that, let me know and we might get together to figure it out.
Best, Michael
?
Wow! Look at all my new friends! :-))
?
I placed a wanted ad on Astromart for a G11 when I blew
out the electronics on my Meade 12¡± LX200 Classic. By the springtime I
will salvage my OTA and have it available for use with the G11, but for now, my
concern is only using it with a custom carbon fiber Stellarvue 130mm Triplet (Strictly
visual / video) that weighs around 27 pounds in ready to use trim..
?
The guy I bought the G11 from was close by, so I could see
it in action in his POD before I paid for it and hauled it home.. A couple
slews.. a couple Gotos.. Sold!
As I assembled it at home, I noticed the Dec Axis does not
spin freely, and it is worse in one direction compared to the other. I assume a
little cleaning and regreasing will free up the needle bearings.. And I have
repositioned the Wavy Washers..
?
In the mean time, I have used it a couple times, and both
times I have driven it into the RA Motor ¨C and my clutches are set pretty
tight.. The last time I did it, it started making a noise.. I haven¡¯t
been overly concerned because I will be cleaning regreasing and adjusting everything
as soon as my grease arrives..
?
Today I put on the RA and Dec Extensions, and was perusing
you tube and found this..
?
?
The sound made at the end of this short video is exactly
what my mount is doing.. Any ideas what causes it and is it easy to fix?? Is it
just an irritating noise that can be ignored, adjusted away, or is it a ¡°Oh
Dear God stop using that thing immediately!¡± problem.. ???
?
Derek
Morgan Hill, CA
?
PS.. Before anyone means ¡°The Limits¡±, hold
that thought for the next thread..
?
?
|
New G11 / Gemini 2 user with issues..
Wow! Look at all my new friends! :-))
?
I placed a wanted ad on Astromart for a G11 when I blew
out the electronics on my Meade 12¡± LX200 Classic. By the springtime I
will salvage my OTA and have it available for use with the G11, but for now, my
concern is only using it with a custom carbon fiber Stellarvue 130mm Triplet (Strictly
visual / video) that weighs around 27 pounds in ready to use trim..
?
The guy I bought the G11 from was close by, so I could see
it in action in his POD before I paid for it and hauled it home.. A couple
slews.. a couple Gotos.. Sold!
As I assembled it at home, I noticed the Dec Axis does not
spin freely, and it is worse in one direction compared to the other. I assume a
little cleaning and regreasing will free up the needle bearings.. And I have
repositioned the Wavy Washers..
?
In the mean time, I have used it a couple times, and both
times I have driven it into the RA Motor ¨C and my clutches are set pretty
tight.. The last time I did it, it started making a noise.. I haven¡¯t
been overly concerned because I will be cleaning regreasing and adjusting everything
as soon as my grease arrives..
?
Today I put on the RA and Dec Extensions, and was perusing
you tube and found this..
?
?
The sound made at the end of this short video is exactly
what my mount is doing.. Any ideas what causes it and is it easy to fix?? Is it
just an irritating noise that can be ignored, adjusted away, or is it a ¡°Oh
Dear God stop using that thing immediately!¡± problem.. ???
?
Derek
Morgan Hill, CA
?
PS.. Before anyone means ¡°The Limits¡±, hold
that thought for the next thread..
?
?
|
Hi Michael, folks...Q & A....
yes the the U15/16 PLD ICs are indeed the "16V8BQL" (note "BQL") low power devices.?? I would not use the higher pwr devices for example the "BQ" version uses double the current draw when active and 7 times more in standby.? The "B" device is even worse.? See data sheets.
U15 is the Ra motor encoder IC it is the lower one if viewing the PCB north/south.?? U16 "DEC" is the upper one.
These PLD encoder ICs fail mainly when plugged in the DIN sockets.?? You can miss-orientate this DIN easily even though it has a "key".? This can put +12V onto the encoder lines which damages them.? Losmandy tried varistors and other small things (Transorbs I think)on the PCBs in mitigation but nothing works.?
I'd? like to see failure data rates of older "RJ" PCBs compared to the "DIN" PCBs to see indeed if there is a difference.? Although I can confirm more than one user who has sent me a PCB admitted they misaligned the DIN.
Mostly this is at night or in darker conditions.? Tom/Paul?Rene/Me (and others) have been warning of this for a long time.?? Its just the DINs were chosen for availability, price, reasons I am not privilege to.? But make no mistake plugging the Ra/DEC? motor leads incorrectly with pwr on can and will damage these ICs.
David....I always thought the motor encoders were US Digital...I just looked at an old one...its actual fact HEDS 9000 series "Broadcom".? I'll check this later today I've obviously had this wrong for some time.? I have replaced one motor encoder inside a motor.? But this was a Maxon motor...soooo nice...and smooth worth fixing.
The U11/12 PIC 17C4X Ra/DEC processors rarely fail.? In fact I've never seen one.? I once repaired a PCB that had almost all major ICs dead but not these....I mean how does that happen?
So folks..."Never try to plug/un-plug your motor DIN connectors with power on in the dark"!
Brendan
?
|
Re: Super greasy worm gears on my GM8
Hi, Thanks a lot Chip. That's pretty much the answer I was hoping for  I haven't used it that much really so I hope it will keep on going as it previously has. Otherwise I guess I'll have to upgrade some of the parts since it is really quite old now.
|
Re: Super greasy worm gears on my GM8
Hi Fredrik,
If your GM8 is working well as it sits I suggest just leaving it alone and wiping the very excessive amount of lubricant in the photos using a clean, lint-free tech wipe and call it a day. Cleaning and lubing with fresh lube, not matter how good, will not help anything unless there is a problem like poor tracking or spikes in the tracking file.
Chip?
|
Super greasy worm gears on my GM8
Hello. This is my first post here and I'm very happy to have found this group.
I own a GM8 that's apparently from the 90's. I've used it with autoguiding to take 5 minute exposures without problems and that's good enough for me. The tracking seem to be working well.
I'm gonna clean and relubricate the clutches (with Super lube as suggested by y'all) but I don't know what to do with the worm bearings. They look super greasy and dirty but I am very cautious since I don't want to do anything unnecessary as it is currently doing what it should. Here are the images of the RA and DEC worm bearings: RA:
DEC:
Should I worry about this or just let it be?
Thanks,
Fredrik
?
|
You should use the ATF16V8BQL, rather than the ATF16V8B, as that is the only one that drops into low power mode when it has no signal transitions on the inputs.
Dave
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: 10 October 2017 16:56
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: Motor stalled.......
OK. I've ordered 10 of these chips, and I found a 20-pin DIP to SOIC socket on eBay to allow me to program these.
Next steps... await the experiment... of giving it a try.... and talking to John...!
Best,
Michael
On Tue, Oct 10, 2017 at 8:42 AM, Michael Herman <mherman346@...> wrote:
OK.
I see the chip listed here in the Mouser catalog as:
Atmel made these in the 20-pin SOIC (small outline IC) package -- no one else made the product in that package.
They are $0.95 each from Mouser, + lowest shipping charge $5.
The datasheet is here:
The problems will be getting a DIP to 20-pin SOIC socket to program these, and to see if my existing programmer with its DIP socket will work..
It is ironic that Atmel is near me in San Jose... they got bought by Microchip recently...
Best,
Michael
On Tue, Oct 10, 2017 at 8:09 AM, mknwfhccabsgfi2b7fvsii57vq43ikvdv4r3sfuo@... [Losmandy_users] <Losmandy_users@...> wrote:
Micheal, I will call you this evening.
John
--
Michael Herman
mobile: 408 421-1239 <tel:(408)%20421-1239>
email: mherman346@...
--
Michael Herman
mobile: 408 421-1239
email: mherman346@...
[Non-text portions of this message have been removed]
|
how can we Gemini owners prevent such damage in the first place? The most common cause of these problems is (as I understand it) mis-connecting the motor DIN plugs. I know they are polarized but I¡¯m told it¡¯s still possible to mis-plug them. Dave From: Losmandy_users@... [mailto:Losmandy_users@...] Sent: 10 October 2017 15:00 To: Losmandy_users@... Subject: RE: [Losmandy_users] Re: Motor stalled....... I have fortunately not found Gemini units with this damage - yet. I cannot yet do that repair, as I have not yet developed the programming kit to make these replacements, but I will look into that. Better: Can anyone say what is causing these chips to fail? Is there a simple preventative measure owners can take to avoid such damage? Best, Michael On Oct 10, 2017 4:33 AM, "'David C. Partridge' david.partridge@... [Losmandy_users]" <Losmandy_users@...> wrote: The decoder ICs U15 and U16 are no longer obtainable from Losmandy or Aveox. However they are just AFT16V8BQL-15SU PLDs which need to be programmed. I have the jedec file to program them if you have a suitable programmer and SOIC adapter. The two ICs are the SOIC-20 parts at the upper right edge of the G-1 PCB. You'll need hot air soldering kit or "Chip-Quik" to remove them. If you aren't comfortable doing that then either Michael Hermann or I can repair for you (I'd suggest Michael if you are in USA as I live in the UK). You can test the shaft encoder with the motor removed from the mount and without the Gemini controller. Use a 5V supply, ground to pin 1, +5V to pin 4 of the HEDS-9100. You can then turn the motor pinion by hand and observe the signals on pins 3 and 5 HED-9100. If you only get a signal on one or neither, then replace the encoder. Clear skies Dave Partridge [Non-text portions of this message have been removed]
|
OK.? I've ordered 10 of these chips, and I found a 20-pin DIP to SOIC socket on eBay to allow me to program these. Next steps... await the experiment... of giving it a try.... and talking to John...!
Best, Michael
On Tue, Oct 10, 2017 at 8:42 AM, Michael Herman <mherman346@...> wrote: OK.?? I see the chip listed here in the Mouser catalog as:
Atmel made these in the 20-pin SOIC (small outline IC) package -- no one else made the product in that package.?? They are $0.95 each from Mouser, + lowest shipping charge $5.??
The datasheet is here:?
The problems will be getting a DIP to 20-pin SOIC socket to program these, and to see if my existing programmer with its DIP socket will work..?? It is ironic that Atmel is near me in San Jose... they got bought by Microchip recently...?
Best, Michael
|
OK.?? I see the chip listed here in the Mouser catalog as:
Atmel made these in the 20-pin SOIC (small outline IC) package -- no one else made the product in that package.?? They are $0.95 each from Mouser, + lowest shipping charge $5.??
The datasheet is here:?
The problems will be getting a DIP to 20-pin SOIC socket to program these, and to see if my existing programmer with its DIP socket will work..?? It is ironic that Atmel is near me in San Jose... they got bought by Microchip recently...?
Best, Michael
?
Micheal, I will call you this evening.
John
|
Micheal, I will call you this evening.
John
|
Hi John,
You can reach me, Michael Herman, at? or by phone (I'm in California) at 408 421-1239
I suggest you call me to discuss this problem.??
Best,?
Michael
?
Thanks David for the advice. I now see the IC's on the board now. I wonder if it would be worth swapping them to see if the problem changes to the RA instead of the DEC. In the mean time, How can I contact Micheal in the US? Also, how do I check for signals on the encoder? Not sure If I have the proper equipment.
Thank you very much!
|
Thanks David for the advice. I now see the IC's on the board now. I wonder if it would be worth swapping them to see if the problem changes to the RA instead of the DEC. In the mean time, How can I contact Micheal in the US? Also, how do I check for signals on the encoder? Not sure If I have the proper equipment.
Thank you very much!
|
I have fortunately not found Gemini units with this damage - yet.? I cannot yet do that repair, as I have not yet developed the programming kit to make these replacements, but I will look into that.? ?
Better: how can we Gemini owners prevent such damage in the first place?
Can anyone say what is causing these chips to fail???
Is there a simple preventative measure owners can take to avoid such damage?
Best, Michael?
?
The decoder ICs U15 and U16 are no longer obtainable from Losmandy or Aveox. However they are just AFT16V8BQL-15SU PLDs which need to be programmed.
I have the jedec file to program them if you have a suitable programmer and SOIC adapter.
The two ICs are the SOIC-20 parts at the upper right edge of the G-1 PCB. You'll need hot air soldering kit or "Chip-Quik" to remove them.
If you aren't comfortable doing that then either Michael Hermann or I can repair for you (I'd suggest Michael if you are in USA as I live in the UK).
You can test the shaft encoder with the motor removed from the mount and without the Gemini controller.
Use a 5V supply, ground to pin 1, +5V to pin 4 of the HEDS-9100. You can then turn the motor pinion by hand and observe the signals on pins 3 and 5 HED-9100. If you only get a signal on one or neither, then replace the encoder.
Clear skies
Dave Partridge
|
The decoder ICs U15 and U16 are no longer obtainable from Losmandy or Aveox. However they are just AFT16V8BQL-15SU PLDs which need to be programmed.
I have the jedec file to program them if you have a suitable programmer and SOIC adapter.
The two ICs are the SOIC-20 parts at the upper right edge of the G-1 PCB. You'll need hot air soldering kit or "Chip-Quik" to remove them.
If you aren't comfortable doing that then either Michael Hermann or I can repair for you (I'd suggest Michael if you are in USA as I live in the UK).
You can test the shaft encoder with the motor removed from the mount and without the Gemini controller.
Use a 5V supply, ground to pin 1, +5V to pin 4 of the HEDS-9100. You can then turn the motor pinion by hand and observe the signals on pins 3 and 5 HED-9100. If you only get a signal on one or neither, then replace the encoder.
Clear skies
Dave Partridge
|
Not sure what you mean?? Do you need a number off the board? Did not get this from Losmandy.
John
|
The PCB ident is under the ICs.
Did you get this from Losmandy?
Brendan
|
Thanks for all the advice guys! Did some checking today and it seems to be either the DEC encoder U15/16 or the optical encoder on the motor. The encoder is $51.00 US plus shipping. I'll start with U15/16 which I can't locate on the pcb for some reason. How can I purchase one of these in the USA?
Thanks
John
|
Not tried to read those yet, it is the soldered on quadrature decoder chips that I can make. The PIC17C42 ICs I have yet to attempt.
Dave
From: Losmandy_users@... [mailto:Losmandy_users@...]
Sent: 09 October 2017 06:48
To: Losmandy_users@...
Subject: Re: [Losmandy_users] Re: Motor stalled.......
If it is the U15 or U16 chip, then David Partridge in the UK has these or can make them.
I have not yet tackled that. These chips are in sockets on the main board and can easily be
pulled out (say with an automotive sharp hook tool) and replaced by the owner.
If it is the motor's encoder element, then, again, I have no experience with that trouble.
In either case, I am surprised the prior owner did not experience the problem and that John, who
just acquired the system, is stuck with this problem from his first experience.
Best of luck,
Michael
On Sun, Oct 8, 2017 at 9:26 PM, brenatlilydale@... [Losmandy_users] <Losmandy_users@...> wrote:
John
Seen this before in DEC and RA, repaired a DEC one not long ago (hope its not same one doubt it).. Unfortunately it's a bad DEC encoder IC. Yes there is a remote possibility its a DEC motor itself or DEC H bridge but I'm pretty sure its as I said.
Upon switch on both motor pinions lock...aka they are applied drive voltages on both sides of their H bridges. Their pinions will have major resistance to movement and be difficult to turn (if you can and do it will log a boot fault in the HC). When you see the HC msg "system boot at xxxx....xx" the Ra pinion starts driving at sidereal rate., the DEC will stay locked resistant to movement and will only move if commanded.
On the system I repaired that had the same symptoms and bad DEC encoder IC (above), the DEC pinion was weak and rotated slowly on pwr on and drove crazy if one of the HC DEC buttons was pressed.
Both Ra/DEC motor encoder ICs U15/16 are firmware installed. Repairer: Rene? (Germany); David Partridge (UK); Michael Herman (USA); Me (Australia); Losmandy (USA)...anyone I miss?
Brendan
--
Michael Herman
mobile: 408 421-1239
email: mherman346@...
[Non-text portions of this message have been removed]
|
Michael Herman
David C. Partridge