Date
1 - 20 of 23
Servicing an AP1200GTO
|
Looking at the regreasing kit I bought from AP it talks about removing mineral spirits with denatured alcohol. But doesn't mineral spirits just evaporate or is there a film left behind that the denatured alcohol removes?
This particular mount has not seen new grease since new 2007 model which makes me nervous , especially since its lived outside in an observatory in southern OR for the first 10 yrs of its life. I took the motor covers off and found that the gears were not overly tight, were not too dirty, and there was a light film of grease on the gears, which made me feel better. I did see a bit of dried grease on the inside of the cover. Not sure what the worm or wheel will look like. The owner included some documents on removing backlash that involve a small hammer or rubber mallet. But I also have a document made by AP for setting backlash that does not have this method. Which is correct or recommended or either will work? Thank you! |
|
|
|
|
|
Hi Abraham
Speaking from my experiences many years ago as an auto mechanic I would recommend avoiding the use of mineral spirits or other solvent altogether. Instead, I would suggest that you just wipe off as much of the old grease as you can with paper towels before reapplying the fresh grease. Pure mineral spirits or other solvent may readily evaporate, but once it becomes contaminated with grease, it will never completely evaporate from the tight spaces between the gear teeth. It takes a surprisingly small amount of solvent to sufficiently thin the grease that it will no longer stay on the gears to do its job. Even though the worm gear on a mount is not subjected to anything close to the dynamic forces that the front wheel bearings on an automobile experience, the fact that we have a stainless-steel worm gear running against an aluminum worm wheel, means that the grease must stay on the gears to keep them lubricated. Mike Mike |
|
|
|
|
|
Bill Long
I sprayed a little simple green on a brush when servicing my mount, wiped off the goo with a shop
towel, and just let that dry before greasing it back up. Seemed to work very well.
I did not use a mallet or hammer to solve backlash issues with any mounts.
From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Abraham <ashadbeh@...>
Sent: Friday, December 30, 2022 3:25 PM To: main@ap-gto.groups.io <main@ap-gto.groups.io> Subject: [ap-gto] Servicing an AP1200GTO Looking at the regreasing kit I bought from AP it talks about removing mineral spirits with denatured alcohol. But doesn't mineral spirits just evaporate or is there a film left behind that the denatured alcohol removes?
This particular mount has not seen new grease since new 2007 model which makes me nervous , especially since its lived outside in an observatory in southern OR for the first 10 yrs of its life. I took the motor covers off and found that the gears were not overly tight, were not too dirty, and there was a light film of grease on the gears, which made me feel better. I did see a bit of dried grease on the inside of the cover. Not sure what the worm or wheel will look like. The owner included some documents on removing backlash that involve a small hammer or rubber mallet. But I also have a document made by AP for setting backlash that does not have this method. Which is correct or recommended or either will work? Thank you! |
|
|
|
|
|
Edward Beshore
Abraham,
To answer your question, yes, the denatured alcohol very effectively gets rid of the film left by the mineral spirits. Give everything half and hour to dry after application and you are ready to grease. Ed |
|
|
|
|
|
I agree with Ed - the mineral spirits followed by alcohol works. I use a toothbrush to clean out the old lube on my 1200GTO and redo it every couple of years. Then you really don't need any solvent, just a toothbrush to clean out the gears. Follow the AP instructions, not too difficult and seating the gearboxes isn't that hard - and you certainly don't need a hammer! Just gently settle them into place and rock slightly to seat optimally. Steve Abraham, --
PLEASE NOTE MY NEW EMAIL ADDRESS!!! Due to Google eliminating cheap domain serving, Virginia and I are changing to regular gmail addresses. The old panishnet address will forward to this address for a short while, but please add the new address, scpanish1@..., to your contact list. |
|
|
|
|
|
Thank you everyone! This is the DEC. Found some bugs in the grease that had accumulated on the sides of the worm over 15 yrs. But this is what the grease looked like. Still seemed ok! I didnt use anything but a toothbrush on the wheel but did use mineral spirits and denatured alcohol on the worm being very carful with it. Basically dipped the toothbrush and then dried it off and used only the residue that was left on the toothbrush to help remove grime. Im hoping the RA looks just as good! The gears were taken out and soaked using the AP method but I didnt soak the plastic gear too much. Just cleaned it off using MS and then DA.
Some photos of my progress! 
|
|
|
|
|
|
Awesome Abraham. The 1200 is a fantastic mount. Enjoy.
-- Dean Jacobsen Astrobin Image Gallery - https://www.astrobin.com/users/deanjacobsen/ |
|
|
|
|
|
Roland Christen
The "plastic" gear is made from Delrin, which is a very tough material and will outlast the metal gears. The only thing that could damage it is acetone. Alcohol won't harm it at all.
Rolando
-----Original Message-----
From: Abraham <ashadbeh@...> To: main@ap-gto.groups.io Sent: Sat, Dec 31, 2022 12:57 pm Subject: Re: [ap-gto] Servicing an AP1200GTO Thank you everyone! This is the DEC. Found some bugs in the grease that had accumulated on the sides of the worm over 15 yrs. But this is what the grease looked like. Still seemed ok! I didnt use anything but a toothbrush on the wheel but did use mineral spirits and denatured alcohol on the worm being very carful with it. Basically dipped the toothbrush and then dried it off and used only the residue that was left on the toothbrush to help remove grime. Im hoping the RA looks just as good! The gears were taken out and soaked using the AP method but I didnt soak the plastic gear too much. Just cleaned it off using MS and then DA.
Some photos of my progress! -- Roland Christen Astro-Physics |
|
|
|
|
|
Oh wow! I almost reached for the Acetone at the hardware store but then thought AP only said mineral spirits so I went with that. The RA was must worse since it sees more action im sure. It cleaned up perfectly but wow this was the original grease. The original owner would image with this at 3000mm and said he didn't want to fix something that aint broke! Hope thats the case, sheeeesh!!!
|
|
|
|
|
|
And here is the cleaned up mess! if anything I might be using too much grease on the worm. I didnt fill up the wheel teeth to the brim. Just nice and even. Afterward I was so happy and satisfied that I started day dreaming about what I want to put on this beast, multiple telescopes no doubt. My wife just sighs and rolls her eyes !
|
|
|
|
|
|
really nice job Abraham, very clean! On Sun, Jan 1, 2023 at 5:16 PM Abraham <ashadbeh@...> wrote: And here is the cleaned up mess! if anything I might be using too much grease on the worm. I didnt fill up the wheel teeth to the brim. Just nice and even. Afterward I was so happy and satisfied that I started day dreaming about what I want to put on this beast, multiple telescopes no doubt. My wife just sighs and rolls her eyes ! --
Brian Brian Valente astro portfolio https://www.brianvalentephotography.com/astrophotography/ portfolio brianvalentephotography.com |
|
|
|
|
|
Roland Christen
Looks good to me.
Roland
-----Original Message-----
From: Abraham <ashadbeh@...> To: main@ap-gto.groups.io Sent: Sun, Jan 1, 2023 7:16 pm Subject: Re: [ap-gto] Servicing an AP1200GTO And here is the cleaned up mess! if anything I might be using too much grease on the worm. I didnt fill up the wheel teeth to the brim. Just nice and even. Afterward I was so happy and satisfied that I started day dreaming about what I want to put on this beast, multiple telescopes no doubt. My wife just sighs and rolls her eyes !
-- Roland Christen Astro-Physics |
|
|
|
|
|
This definitely looks good to me! Ive never seen an unguided 5 min sub look this good at 805mm. Area of sky is Canis Minor. No guiding needed... apparently. I did hook up the OAG afterward to get the PHD guide graph. Mind you, I have currently no cable management, only rough balance with weight used from a gym machine, no PEC curve loaded since I took the gear cluster apart. Seeing was poor to avg. Still seems like unguided, stars are pinpoints at 5 min.
The DEC backlash from the guiding assistant ran for 5 min was 230ms. Less than 1 arc min off the pole. SOOOOOOO apparently you can ignore the recommended service interval an AP1200 since 2007 and in the year 2023 it will perform perfectly. At least at 805mm it will. Not sure about 2800mm from my C11HD. Next is PEC curve and learning how to use the HC better. Im freaking thrilled. 
|
|
|
|
|
|
Abraham, your enthusiasm is infectious. We look forward to your results with some cable management and PEC correction. Keep having fun! Karen AP
From: main@ap-gto.groups.io <main@ap-gto.groups.io>
On Behalf Of Abraham
Sent: Tuesday, January 31, 2023 5:09 PM To: main@ap-gto.groups.io Subject: Re: [ap-gto] Servicing an AP1200GTO
[Edited Message Follows] This definitely looks good to me! Ive never seen an unguided 5 min sub look this good at 805mm. Area of sky is Canis Minor. No guiding needed... apparently. I did hook up the OAG afterward to get the PHD guide graph. Mind you,
I have currently no cable management, only rough balance with weight used from a gym machine, no PEC curve loaded since I took the gear cluster apart. Seeing was poor to avg. Still seems like unguided, stars are pinpoints at 5 min. -- Karen Christen Astro-Physics |
|
|
|
|
|
Thanks Karen, the fun continues. Roland said creating a PEC curve would be fun and it was! Although it was a bad night to do it and I was shooting through tiny willow branches, this is what I came up with. I hardly knew what I was doing just clicking buttons on PEMPRO trying desperately to follow directions. This little curve uncorrected with PEC off was 2.62 total. But I need to do it again on a better night and get the scope out of the sticks, and probably polar align it better. 
|
|
|
|
|
|
Roland Christen
That's pretty good and not out of the ordinary for the 1200 mount. Many years of use have honed the gears close to perfection. I've seen others with similar results.
Rolando
-----Original Message-----
From: Abraham <ashadbeh@...> To: main@ap-gto.groups.io Sent: Wed, Feb 1, 2023 3:14 am Subject: Re: [ap-gto] Servicing an AP1200GTO Thanks Karen, the fun continues. Roland said creating a PEC curve would be fun and it was! Although it was a bad night to do it and I was shooting through tiny willow branches, this is what I came up with. I hardly knew what I was doing just clicking buttons on PEMPRO trying desperately to follow directions. This little curve uncorrected with PEC off was 2.62 total. But I need to do it again on a better night and get the scope out of the sticks, and probably polar align it better.
-- Roland Christen Astro-Physics |
|
|
|
|
|
Dan_Paris
Your pictures will be very helpful for someone changing the grease for the first time. I did the same when I received my second-hand AP900, and found that it was much easier to service than my previous mount (AZ-EQ6).
Regarding the PEC curve, you're right that it worth recording it again during a night with better seeing. My first curve gave 1.4" peak to peak if I remember well, and the current one is 0.7" peak to peak. Quite an improvement. Clear skies, Dan |
|
|
|
|
|
WHoa! and the AP900 is spec at 5" peak to peak so you have one thats far better!!! Yeah I was shooting through high clouds and tiny branches. I did do a second one a few days later but found that I was not doing it exactly according to the PEMPRO manual LOL I keep reading through it , apparently I needed to center a good mag 7-8 star and check a few other boxes. Im really looking forward to it again.
|
|
|
|
|
|
You mean like this???
I hardly knew what I was doing playing with pempro, I had to use the directions and invert the curve and send it to the mount. After correcting the curve and uploading it to the mount, I ran it again with PEC on....... it gathered data again and I analyzed and saw the flat curve and .35 RMS........ but pempro also asked if I wanted to upload that to my mount. I said no.....cause the curve I uploaded is the one the generated the flat line, I cant do that again right? Im not sure if im making sense. Lol 
|
|
|
|
|
|
>>> pempro also asked if I wanted to upload that to my mount. I said no.....cause the curve I uploaded is the one the generated the flat line, I cant do that again right? You should not upload the second "confirmation curve". 0.35rms unguided is an excellent result On Thu, Feb 16, 2023 at 10:26 AM Abraham <ashadbeh@...> wrote: You mean like this??? --
Brian Brian Valente astro portfolio https://www.brianvalentephotography.com/astrophotography/ portfolio brianvalentephotography.com |
|
|
|