Backyard Pier for Losmandy GM811G
I am thinking about putting a pier in my backyard and I am not sure where to start.??This is what I am thinking. ?Would this design work?? What changes should I consider?
Jim W.
EDIT - Max optical train weight would not exceed 40 pounds.
|
Hi Tom,
The rest of our gang is wondering what we are talking about.? Here's a quick recap of our conversation:
Me.? ? ? ? ? ? ? ? ? ? ? ? ? ? Tom Problem?? ? ?I have a 5 sec DEC backlash Does DEC wobble?? ? ? ? ? ? ? ? ? ? ? ? No. Does worm move left to right?? ? No. Is Oldham coupler loose?? ? ? ? ? ? No. Is Dovetail loose?? ? ? ? ? ? ? ? ? ? ? ? ? No. Does DEC rotate if worm is not moving?? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? No.
Me: I give up.??
Tom:. Problem is solved after I changed the worm.??
So somehow when you changed your worm, you tightened something that must have been loose....who knows what.
? Glad your problem is solved!? Go get some pics and have fun,
Michael
On Thu, Mar 4, 2021, 4:31 PM wa1vta01452 < loeblt@...> wrote: Hi Michael, appreciate the phone chat today. I changed the steel worm with another older one I had and the 5 second backlash is gone. No idea why but I'm not complaining.
Tom
-- Brian?
Brian Valente portfolio
|
Hi Tom,
The rest of our gang is wondering what we are talking about.? Here's a quick recap of our conversation:
Me.? ? ? ? ? ? ? ? ? ? ? ? ? ? Tom Problem?? ? ?I have a 5 sec DEC backlash Does DEC wobble?? ? ? ? ? ? ? ? ? ? ? ? No. Does worm move left to right?? ? No. Is Oldham coupler loose?? ? ? ? ? ? No. Is Dovetail loose?? ? ? ? ? ? ? ? ? ? ? ? ? No. Does DEC rotate if worm is not moving?? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? No.
Me: I give up.??
Tom:. Problem is solved after I changed the worm.??
So somehow when you changed your worm, you tightened something that must have been loose....who knows what.
? Glad your problem is solved!? Go get some pics and have fun,
Michael
On Thu, Mar 4, 2021, 4:31 PM wa1vta01452 < loeblt@...> wrote: Hi Michael, appreciate the phone chat today. I changed the steel worm with another older one I had and the 5 second backlash is gone. No idea why but I'm not complaining.
Tom
|
Re: Suggestions for additions to G11 purchase
Hello,
I'm in same boat, just got word the G11G I ordered is ready for pick-up.
Great suggestions here, just wanted to double check on connectivity hardware... I have ordered a GL.iNet GL-AR750S-Ext (Slate), based on the recommendations here in previous topics. Has anyone connected that to a?Raspberry Pi 4 8GB running Astroberry??
Thanks,
Tony
|
Hi Michael, appreciate the phone chat today. I changed the steel worm with another older one I had and the 5 second backlash is gone. No idea why but I'm not complaining.
Tom
|
Re: Servicing My 17 yr Old G11 Mount
Hi Terry,
Nice work on cleaning your mount up.
Look to Mark Crossley's website ? Mark has a whole section about G11 assembly ideas and good tips.
The blue arrow bolts are the Elevation lock down bolts.? Since you need to loosen them to adjust elevation to get polar aligned, you don't really want those tightly locked.? So...what to do...?
I like to put in 3/8 ID Belleville spring washers at various points of the mount.? When these cup shaped spring washers are compressed, they put a variable amount of force on the bolt.? The present flat washers are either fully on or fully off.? You have no adjustment of their force.? The Belleville washers give you this variable pressure.? It especially helps during polar alignment so your vertical acid does not go totally lax during AZ and Elevation adjustments.?
I also put "Tee- handles" on the bolts to give me a way to hand tighten those bolt without needing a wrench (in the dark no less).? So I use either white or colored tee handles like red or yellow to see what I'm doing.? Here are some pictures of where I use these.
Not also that the mount head must rotate in Azimuth too.? So I put the same kind of springs on my AZ bolts.? And under the mount center (see picture if that bolt head) is yet another 3/8-16 bolt...I put springs and flat washers on that to keep the axis center under compression.? You get the idea!
?
Hello Fellow Losmandy Users
I've just started to strip down and service my 17 yr old G11 mount. Tanya, at HGM, kindly confirmed it's age from the Serial Number found on the underside of the Mount base.
I am the sole owner of this mount and slightly ashamed to admit that I have never carried out any maintenance or tuning adjustments ever, until now.
The mount has been sitting on my concrete pier for this entire time covered in the most part with just a tarp but laterly, since July 2020, with a more
upmarket Telegizmo 325I cover. In these 17 years there was an extended period of non-use which I estimate to be around 8-9 yrs. I restarted using the mount in July 2020 and got
some great help from people here at that time, mostly on what to watch for when re-commissioning the Gemini - 1.
I was some what apprehensive about starting this project but to my great surprise am finding the actual 'breaking down' of the mount into its individual components
to be really pleasantly straight forward and rewarding, mostly due probably to the mount's modularity. The only tools needed so far have been Hex/Allen keys.
So far I've degreased the two roller bearings found in each axis and got these spinning nicely ready for some SuperLube, I am using a citrus based degreaser from 'Muc-Off'. I believe the upper bearings were ceased but now spin freely.
I've removed the old grease from both worms and worm-wheels, without affecting the worm adjustment, in preparation for regreasing both worm and worm-wheel with a small amount of SuperLube.
Have also checked the small screws on the Oldham couplers for tightness - all ok and no loose screws.
Clutch disks and many other parts have been degreased and cleaned. Progress is good and I am enjoying the experience and it's given me the confidence to carry out this work at much
smaller interval than 17yrs in the future. I might post a photo of the mount parts before re-assembly, hopefully tomorrow [Friday].
But to my questions that I am hoping someone will be able to help me with.
Q1: I have attached an image of the mount base [Polar Block' section [?]. I've marked [with Red/Blue Arrows] the two screws located on each side of the mount and am thinking that when polar aligning
the mount that the Red highlighted central screw is the point around which the Alitude adjustment pivots and should not be loosened when PA. The Blue arrow indicates the Altitude locking screws, one each side, which do
need slackening off during PA adjustment and then retightened. Have I interpretted their purpose correctly?
Q2: I am planning on dissassembling the 'Polar Block' on the mount base for access to, cleaning and relube of the long threaded Altitude and Azimuth rods etc and was wondering if it is 'safe' to remove all four of these screws.
I have some mount dissassembly instructions for a G11 but it is based on an earlier mount [badged as Celestron] but this only has the single Red pivot /locking screws.
Thanks in advance for any help with these queries.
Terry [uk]
|
Servicing My 17 yr Old G11 Mount
Hello Fellow Losmandy Users
I've just started to strip down and service my 17 yr old G11 mount. Tanya, at HGM, kindly confirmed it's age from the Serial Number found on the underside of the Mount base.
I am the sole owner of this mount and slightly ashamed to admit that I have never carried out any maintenance or tuning adjustments ever, until now.
The mount has been sitting on my concrete pier for this entire time covered in the most part with just a tarp but laterly, since July 2020, with a more
upmarket Telegizmo 325I cover. In these 17 years there was an extended period of non-use which I estimate to be around 8-9 yrs. I restarted using the mount in July 2020 and got
some great help from people here at that time, mostly on what to watch for when re-commissioning the Gemini - 1.
I was some what apprehensive about starting this project but to my great surprise am finding the actual 'breaking down' of the mount into its individual components
to be really pleasantly straight forward and rewarding, mostly due probably to the mount's modularity. The only tools needed so far have been Hex/Allen keys.
So far I've degreased the two roller bearings found in each axis and got these spinning nicely ready for some SuperLube, I am using a citrus based degreaser from 'Muc-Off'. I believe the upper bearings were ceased but now spin freely.
I've removed the old grease from both worms and worm-wheels, without affecting the worm adjustment, in preparation for regreasing both worm and worm-wheel with a small amount of SuperLube.
Have also checked the small screws on the Oldham couplers for tightness - all ok and no loose screws.
Clutch disks and many other parts have been degreased and cleaned. Progress is good and I am enjoying the experience and it's given me the confidence to carry out this work at much
smaller interval than 17yrs in the future. I might post a photo of the mount parts before re-assembly, hopefully tomorrow [Friday].
But to my questions that I am hoping someone will be able to help me with.
Q1: I have attached an image of the mount base [Polar Block' section [?]. I've marked [with Red/Blue Arrows] the two screws located on each side of the mount and am thinking that when polar aligning
the mount that the Red highlighted central screw is the point around which the Alitude adjustment pivots and should not be loosened when PA. The Blue arrow indicates the Altitude locking screws, one each side, which do
need slackening off during PA adjustment and then retightened. Have I interpretted their purpose correctly?
Q2: I am planning on dissassembling the 'Polar Block' on the mount base for access to, cleaning and relube of the long threaded Altitude and Azimuth rods etc and was wondering if it is 'safe' to remove all four of these screws.
I have some mount dissassembly instructions for a G11 but it is based on an earlier mount [badged as Celestron] but this only has the single Red pivot /locking screws.
Thanks in advance for any help with these queries.
Terry [uk]
|
Re: Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
*IF*
you could Barlow that guide scope, or use a guide camera with smaller pixels, OR
BOTH) and still guide at a 1/4 pixel.. ?
?
But
¡°1.0 ¨C 1.6¡± ¡° with a focal reduced 80mm scope and a
DSLR would qualify as pretty much perfect tracking already, wouldn¡¯t it??
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of McFarlane, Gilbert via groups.io
Sent: Wednesday, March 03, 2021
9:58 PM
To: [email protected]
Subject: [Losmandy_users_io] Is
this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6
arc seconds
?
Stuck at home, I decided to learn more about phd2, and try to tweak my
mount.? ?All my efforts did not seem to have much of an effect.?
?I generally achieve RMS of about? .25px ,? and about 1.0"
to 1.6 ".? ?This doesn't sound great to me, I was hoping for
about half of that - but my images seem to be ok.? ?(Guide camera is
QHY 5L-II with 3.75 um, with 130mm QHY mini guide scope.? ?Camera for
imaging is a K5 Pentax dslr.? Imaging scope is an 80mm f6 APO with a Televue 0.8x flattener.)? ?
The most irritating part has been trying to reduce the Dec backlash measured by
PHd2 - which has stayed at 6 - 9 seconds despite numerous lubes, adjustments,
and even Belleview washers.? ? Motor is attached very tight.? I
have tried changing the balance, tight axis, loose axis.? Everything I
know to try other than replacing the motors or the little plastic motor
connectors - but they seem tight.? ?I tried switching the motors, but
no change in Dec backlash.? ?Any thoughts?
The mount has the separate worm blocks and brass worms.? ?Using the
492 controller and the ST4 camera controlled interface and USB 3.0.
Thanks, Gil
Ventura, CA
?
|
|
This email has been checked for viruses by
AVG antivirus software.
|
|
My 2020 year and some recent pictures
I know, there are some great astrophotographers among us, but I would like to present my photos too.
I dont't have a dedicated astro camera. I use Canon for DS photography and ASI or Celestron non cooled camera for planetary imaging.?
Recently I have tried to use my SCT 8" for astroimaging but I will not continue this project in the future. I would like to focus on lunar/planetary nad wide field astrophotography with my short refractor.
Below are two trial images of Bode and Cigar Galaxy I took with my SCT. I am very unhappy with the results. Field is not corrected enough and the stars are very bad.
I also attach a collage of my 2020 photos and some new pictures as well.
Your comments are welcome
Seb
|
New tripod for my Losmandy GM8 mount - this is how I did it :)
I never liked my field tripod too much. GM8 with those thin legs? standing next to my old Celestron CG5 mount with its robust tripod look weird. Because Losmandy HD tripod is to expensive, I decided to buy a preowned tripod. I wanted a Celestron or Sky Watcher tripod with 2" legs. Finally I bought the SW tripod for about 40$. There was only one problem with it. It was ... white.
Firts of all, I stripped the tripod and painted it in black. Then I ordered a Losmandy MA adapter and a custom made adapter from serwisastro.pl . I am very happy with the result , so I present it to you.
Below are some pictures:
Regards
Seb
|
Re: Weird tapping noise from RA gearbox or motor. Please, watch a movie.
Than you guys for your help. I'm going to? solve this issue this weekend. I believe your tips will help.
Seb
|
Re: Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
Err... Gilbert (where did I imagine it was Robert?)...
On Thu, Mar 4, 2021, 8:23 AM Michael Herman via <mherman346= [email protected]> wrote: Hi Robert,
My GM8 had a loose DEC saddle dovetail.? I discovered the 2 top mounting bolts were slightly too long...the dovetail was slightly loose.??
My solution was to file off the 1/4-20 bolt ends so the plate was finally snug.??
Please check your dovetail plate for any wiggle.
After that, mount your scope.? Grab the front and back of the scope and try to wiggle it in DEC.? It should ideally not wiggle at all. If it dies wiggle, figure out where:. Is the worm shifting left to right?? Is the worm lightly snug into the ring gear?
All the best, Michael
On Thu, Mar 4, 2021, 2:55 AM McFarlane, Gilbert via <gilboastro= [email protected]> wrote: Stuck at home, I decided to learn more about phd2, and try to tweak my mount.? ?All my efforts did not seem to have much of an effect.? ?I generally achieve RMS of about? .25px ,? and about 1.0" to 1.6 ".? ?This doesn't sound great to me, I was hoping for about half of that - but my images seem to be ok.? ?(Guide camera is QHY 5L-II with 3.75 um, with 130mm QHY mini guide scope.? ?Camera for imaging is a K5 Pentax dslr.? Imaging scope is an 80mm f6 APO with a Televue 0.8x flattener.)? ?
The most irritating part has been trying to reduce the Dec backlash measured by PHd2 - which has stayed at 6 - 9 seconds despite numerous lubes, adjustments, and even Belleview washers.? ? Motor is attached very tight.? I have tried changing the balance, tight axis, loose axis.? Everything I know to try other than replacing the motors or the little plastic motor connectors - but they seem tight.? ?I tried switching the motors, but no change in Dec backlash.? ?Any thoughts?
The mount has the separate worm blocks and brass worms.? ?Using the 492 controller and the ST4 camera controlled interface and USB 3.0.
Thanks, Gil
Ventura, CA
|
Re: Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
Hi Robert,
My GM8 had a loose DEC saddle dovetail.? I discovered the 2 top mounting bolts were slightly too long...the dovetail was slightly loose.??
My solution was to file off the 1/4-20 bolt ends so the plate was finally snug.??
Please check your dovetail plate for any wiggle.
After that, mount your scope.? Grab the front and back of the scope and try to wiggle it in DEC.? It should ideally not wiggle at all. If it dies wiggle, figure out where:. Is the worm shifting left to right?? Is the worm lightly snug into the ring gear?
All the best, Michael
On Thu, Mar 4, 2021, 2:55 AM McFarlane, Gilbert via <gilboastro= [email protected]> wrote: Stuck at home, I decided to learn more about phd2, and try to tweak my mount.? ?All my efforts did not seem to have much of an effect.? ?I generally achieve RMS of about? .25px ,? and about 1.0" to 1.6 ".? ?This doesn't sound great to me, I was hoping for about half of that - but my images seem to be ok.? ?(Guide camera is QHY 5L-II with 3.75 um, with 130mm QHY mini guide scope.? ?Camera for imaging is a K5 Pentax dslr.? Imaging scope is an 80mm f6 APO with a Televue 0.8x flattener.)? ?
The most irritating part has been trying to reduce the Dec backlash measured by PHd2 - which has stayed at 6 - 9 seconds despite numerous lubes, adjustments, and even Belleview washers.? ? Motor is attached very tight.? I have tried changing the balance, tight axis, loose axis.? Everything I know to try other than replacing the motors or the little plastic motor connectors - but they seem tight.? ?I tried switching the motors, but no change in Dec backlash.? ?Any thoughts?
The mount has the separate worm blocks and brass worms.? ?Using the 492 controller and the ST4 camera controlled interface and USB 3.0.
Thanks, Gil
Ventura, CA
|
Re: Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
I should add I use a 50 mm guide scope (focal length 207 mm) and I usually get PHD2 DEC backlash estimates of between 0.8 and 2 seconds. Mine is also a 492 system guided by ST4.
|
Michael, What is the principal differences?between?PemPro and PECPre? The last is free, the first is not cheap. Does the upgrading Tucked? Motors any impact on the GoTo or tracking precisi¨®n, or is only aesthetic) Thanks
Luis Barneo
El jue, 4 mar 2021 a las 2:23, Michael Herman (< mherman346@...>) escribi¨®: I have that mount and successfully upgraded it.
I used the original long OPW (no longer in production), replaced the old steel worm on RA with a new brass one, added an R4 Belleville spring washer to both axes, replaced the RA worm bearings with R4ZZ ABEC-7, and lastly a McLennan 25:1 metal gearbox on RA. Also using a Gemini-1 and new high torque motors.
I use high friction clutch disks to prevent clutch slippage during imaging.? I have a 12 inch Meade SCT on it these days.??
?PE was down to under 1 arcsec RMS (about 2.8 arcsec peak to peak). Reports attached.? Contact me privately if you have further questions,
Michael?
On Wed, Mar 3, 2021, 4:35 PM wa1vta01452 < loeblt@...> wrote: I have some very specific questions for someone familiar with the early G11/CG11 mounts? DEC axis assembly.? Anyone out there before I continue with the details?
Thanks
Tom
|
Re: Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
I¡¯ve been using PHD2 for the last 3 or 4 months. The best guiding I¡¯ve had is 0.8¡± RMS (about 0.7¡± RA and 0.5¡± DEC) but I¡¯ve also seen it go as high as 1.5¡±. It is very dependent on seeing, and how windy it is, or whether any cables are dragging or snagging. It also depends on where you aim the telescope. I usually see slightly worse figures for RA than for DEC (maybe 30% or so higher). The worst guiding for me is objects at around zero DEC (such as Orion). The guiding gets better for me as you get higher up in DEC, most likely because periodic error is less there. Even though I am imaging at a scale of about 1.4¡± per pixel, the guiding i have been getting seems good enough. I think I am in a place where the seeing is not great and there is also light pollution.
|
Is this typical guiding performance for an older g8? RMS around.25 px , 1.0 to 1.6 arc seconds
Stuck at home, I decided to learn more about phd2, and try to tweak my mount.? ?All my efforts did not seem to have much of an effect.? ?I generally achieve RMS of about? .25px ,? and about 1.0" to 1.6 ".? ?This doesn't sound great to me, I was hoping for about half of that - but my images seem to be ok.? ?(Guide camera is QHY 5L-II with 3.75 um, with 130mm QHY mini guide scope.? ?Camera for imaging is a K5 Pentax dslr.? Imaging scope is an 80mm f6 APO with a Televue 0.8x flattener.)? ?
The most irritating part has been trying to reduce the Dec backlash measured by PHd2 - which has stayed at 6 - 9 seconds despite numerous lubes, adjustments, and even Belleview washers.? ? Motor is attached very tight.? I have tried changing the balance, tight axis, loose axis.? Everything I know to try other than replacing the motors or the little plastic motor connectors - but they seem tight.? ?I tried switching the motors, but no change in Dec backlash.? ?Any thoughts?
The mount has the separate worm blocks and brass worms.? ?Using the 492 controller and the ST4 camera controlled interface and USB 3.0.
Thanks, Gil
Ventura, CA
|
Re: Used GM-8 Guiding Help
When neutrally balanced it's high up, like an inch from the top, then my east bias I would move it down maybe 1/4" (when weight was on east). I'll definitely try out moving down at least an inch next time. I still would like to try increasing overall load as well, I wonder if the light breezes are affecting my mount big time since it's so light. As for the hemisphere, I actually have that part correct haha
Thanks again!
|
Re: Used GM-8 Guiding Help
Is
your 7lb weight at the end of the CW Shaft, in the middle, or up close to the
scope??
?
Either
way, for that setup, I would move it an inch if only for testing purposes..
?
Derek
?
toggle quoted message
Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Nick
Sent: Wednesday, March 03, 2021
7:43 PM
To: [email protected]
Subject: Re: [Losmandy_users_io]
Used GM-8 Guiding Help
?
Now that's a sight hah! I think I'm going to move forward with cleaning
the mount again now that I'm much more familiar with all the parts. I do think
a larger east (or west, I've seen Rainer vouch it worked better for him even
though it's against the norm)bias will help. My current "bias" is the
mount slowly rotating if I let go with clutch all the way loose, and this is a
very light rig (73mm refractor, 7lb counterweight). I would also like to try
and add some load on the scope side, I can start to understand how a mount
would perform better under higher loads.
Thanks for hanging with me everyone, didn't really expect to have this going 90
posts later hah, it's definitely a humbling journey, but I enjoy it
?
|
|
This email has been checked for viruses by
AVG antivirus software.
|
|
Re: Used GM-8 Guiding Help
Now that's a sight hah! I think I'm going to move forward with cleaning the mount again now that I'm much more familiar with all the parts. I do think a larger east (or west, I've seen Rainer vouch it worked better for him even though it's against the norm)bias will help. My current "bias" is the mount slowly rotating if I let go with clutch all the way loose, and this is a very light rig (73mm refractor, 7lb counterweight). I would also like to try and add some load on the scope side, I can start to understand how a mount would perform better under higher loads.
Thanks for hanging with me everyone, didn't really expect to have this going 90 posts later hah, it's definitely a humbling journey, but I enjoy it
|
Michael Herman
Luis Barneo
McFarlane, Gilbert