#1  
Old 19-08-2016, 10:22 PM
Shano592's Avatar
Shano592 (Shane)
#6363

Shano592 is offline
 
Join Date: Jan 2009
Location: Central Coast NSW
Posts: 1,244
Buck's Tune Up

With the LX200, there is need to do a fair amount of PEC, in order to get clean images.

There are some pieces of software, like PHD2 (I believe), that suggest that after reading the PE over a cycle of the gears (24 minutes in this case), they can correct for it, to some extent. Possibly I have this wrong, and was in fact hoping one thing, while reading another. Something to do with evening out the FWHM, I think. It's all new to me, having decided to push forward to guided imaging.

Anyway, I stumbled across Buck's Tune Up, by Peterson Engineering. I have a couple of their fixes on my scope already, and they do make things smooooth. So, I placed the order, and in 2 days to goods have traversed the US, originating at Rhode Island, and have just boarded a plane in LA. USPS doing well, so far...

I believe the idea is that they are an insert into the Declination gearing, to take up some slack/diminish the significant backlash between the teeth. I'm not 100% sure right now, but when they arrive, I will advise more clearly.


Vision warning - Bold yellow text on black page alert!
http://www.petersonengineering.com/buckstuneup.htm

From the site:

"Installation of this kit will:
1) improve the drive precision in both RA and DEC drives, reducing or eliminating transfer gear backlash.
2) correct other misaligned drive components, improving drive precision and eliminating the chance of incurring drive damage due to this misalignment.
3) If installed before the scope sees much use - allows you to detect conditions where extended use will seriously damage the scope, rendering the drive/drives inaccurate. We're always hearing back from folks who've discovered loose screws or stripped screws, extra pieces of metal floating around in the gear grease, gears that are only cogging (touching tip of tooth to tip of tooth) instead of meshing, drives that are mis-adjusted, etc."

Reply With Quote
  #2  
Old 20-08-2016, 07:13 AM
loc46south (Geoffrey)
loc46south

loc46south is offline
 
Join Date: Jan 2009
Location: Milton - New Zealand
Posts: 176
Hi Shane - once upon a time I used to have a LX200 and I spent many hours and many dollars trying to get it to a state where I could use it for astrophotography - Bucks Gears and his other products do work but sadly the quality and construction of the LX200 series is such that they are not well suited to astrophotography.

Do not be surprised when dive into the internals of your scope you could find all sorts of surprises - mine had aluminum shavings in the grease and stripped bolts only to name a few of the problems I encountered. I virtually rebuilt the mount and in an effort to get it to work properly - I wasn't going to let it beat me - but in the end it did. It was the first telescope I bought and the first telescope I sold -

Details of the struggle here - http://www.pbase.com/loc46south/equipment ---------- sorry site hasn't been updated for a few years - will get around to it one day.

Cheers
Geof Wingham
Reply With Quote
  #3  
Old 20-08-2016, 07:28 AM
AndrewJ
Watch me post!

AndrewJ is offline
 
Join Date: Mar 2006
Location: Melbourne
Posts: 1,905
Gday Shane

Quote:
There are some pieces of software, like PHD2 (I believe), that suggest that after reading the PE over a cycle of the gears (24 minutes in this case), they can correct for it, to some extent.
Its actually better to collect 48 or 72 minutes of data, such that more than one PE cycle can be modelled.
FFT analysis of the data can then ( hopefully ) highlight how "periodic" the errors are, as that will define how well a PPEC model will be in pre emptively removing the errors.

Quote:
I believe the idea is that they are an insert into the Declination gearing
Not an "insert", just replacement gears.
The gears supplied are better quality than the original Meade plastic/brass, but not "that much better" that you would notice in the tracking ( unless your original gears are damaged ).
The big benefit of the tuneup is you get instructions on how to properly set the clearances and meshing in the geartrain.
That said, there are enough "non periodics" in the rest of the Meade geartrain to ensure even the 3 turn PEC model they now use wont work properly.
It can reduce a lot of the major errors, but you still need to guide

Andrew
Reply With Quote
  #4  
Old 20-08-2016, 07:48 AM
Shano592's Avatar
Shano592 (Shane)
#6363

Shano592 is offline
 
Join Date: Jan 2009
Location: Central Coast NSW
Posts: 1,244
Geoffrey, interesting pictorial journey. The G11 certainly came out well in front, didn't it? Unfortunately, the cashflow doesn't allow for a quick replacement of the mount. Not yet, anyway.

Andrew, I was thinking of letting it do more than one round, for the reasons you mentioned.

I'm pretty sure the Tune Up version isn't replacement gears.

"The upgrade is actually a Buck's Gears kit without the gears!"

I hear what you are saying about the non-PEC issues. In saying that though, it is pretty darned good. While guiding is coming into play, just visually, it has been magnificent.

I'm only planning 30-60 second stackables, so hopefully there will be some that can be used.

Going forward!
Reply With Quote
  #5  
Old 20-08-2016, 08:05 AM
AndrewJ
Watch me post!

AndrewJ is offline
 
Join Date: Mar 2006
Location: Melbourne
Posts: 1,905
Gday Shane

Quote:
Andrew, I was thinking of letting it do more than one round, for the reasons you mentioned
Initially, the longer the better. I always suggest people use several hours in one run if they can. If you use Metaguide, PHD2 or PEMPro to record the unguided PEC Off data, there are several apps that allow you to analyse the data, and also overlay it. The overlay mode is really interesting at showing how "non periodic" the data really can be.
Also, after doing the PEC training, you can use my PEC editor to look at how well the PEC training went, by comparing the model in the mount against the external PHD/PEMPro data

Quote:
I'm pretty sure the Tune Up version isn't replacement gears.
Correct, but when you mentioned "insert", i suspected you meant the gears as well.

Quote:
I'm only planning 30-60 second stackables,
You should get that guided without too much trouble, but what you need to see is how rough is your PE data, and more importantly, how rapidly does it change. ie some spots may work well, and others you wont keep up. I have seen data from nearly 100 LX200 mounts and every one is different

Andrew
Reply With Quote
  #6  
Old 20-08-2016, 10:01 PM
wayne anderson (Wayne)
Registered User

wayne anderson is offline
 
Join Date: Jan 2010
Posts: 338
Hi Shane,

Early this year i replaced the plastic gears in my 12inch LX200 with bucks gears which also includes the tune up instructions you will recieve, my scope benifited greatly from this upgrade as the plastic gears were only 80% meshed on the RA and DEC gears and the dec worm gears were not meshing well and the backlash was huge. Now i have 100% mesh on both the RA and DEC gears and the DEC worm gears are now meshing better.

There was a strange knocking sound at first after the bucks gears upgrade and tune up in both the RA and DEC drives which was not present when slewing but started when sidereal tracking started, it settled down after 10 to 20 seconds of tracking, after researching information on the meade lx200gps yahoo group about this noise i found i also needed to upgrade the RA and DEC tension springs with a slightly heavier gauge spring, this is common for some 12 or 14 inch LX200s,* it now works very well.

I am also just starting to use autoguiding while imaging and will be doing PEC training soon for my setup, but i use alt/az setup with a meade de-rotator not a wedge so from my research PEC training for me will require a slightly different setup.

The bucks gears instructions are very easy to follow and you will benifit from knowing you have adjusted it as best as is possible, and also given the scope gears a regrease as well.
Reply With Quote
  #7  
Old 21-08-2016, 05:59 AM
AndrewJ
Watch me post!

AndrewJ is offline
 
Join Date: Mar 2006
Location: Melbourne
Posts: 1,905
Gday Wayne
Quote:
will be doing PEC training soon for my setup, but i use alt/az setup with a meade de-rotator not a wedge so from my research PEC training for me will require a slightly different setup.
Yep, and its called another mount
The AltAz PEC routines in the LX200GPS scopes are completely stuffed.
Polar PEC in the Sth Hemi gets trained inverted, but there is a way to fix that. Alt Az is just plain broken.
I have written a large semi untested patch to fix this, but i only have limited feedback from one user on how well it works.

Andrew
Reply With Quote
  #8  
Old 21-08-2016, 07:30 AM
loc46south (Geoffrey)
loc46south

loc46south is offline
 
Join Date: Jan 2009
Location: Milton - New Zealand
Posts: 176
Hi Shane - I wish you well - it will be a learning experience.

1 - PEC - the PEC in the LX200 is next to useless - I can't remember the correct configuration but the number of PEC cells available per worm rotation are not enough to effectively apply the needed correction.

2 - The mechanical quality of the worm was so poor that the PEC errors were so sharp and sudden that they couldn't be removed, even if the PEC did work correctly.

3 - You are going to find that using it on a wedge is exciting and frustrating experience. The amount of flexure and the build quality of the fork mount makes it almost impossible to guide effectively.

4 - Once on an equatorial wedge you will need to use extra external weights to balance up your OTA - if you don't you run a real risk of burning out the RA Motor. Been there and done that.

5 - You will find that the mount is very wind sensitive - a cow only needed to pass wind a couple of paddocks away and it was enough to start it rocking and rolling.

6 - I even bought an AO-7 and that couldn't tame it.

The list goes on and on - I'm not trying to put you off what you are trying to do - I am just giving you an indication of what to expect - maybe you will succeed where I and others I know failed.

Cheers
Geof
Attached Thumbnails
Click for full-size image (17.jpg)
94.4 KB23 views
Reply With Quote
  #9  
Old 21-08-2016, 07:45 AM
Shano592's Avatar
Shano592 (Shane)
#6363

Shano592 is offline
 
Join Date: Jan 2009
Location: Central Coast NSW
Posts: 1,244
Quote:
Originally Posted by AndrewJ View Post
what you need to see is how rough is your PE data, and more importantly, how rapidly does it change. ie some spots may work well, and others you wont keep up. I have seen data from nearly 100 LX200 mounts and every one is different
Hi Andrew,

Yes, in my online travels, I have seen a few PEC charts for the LX200. Exactly what you have said is true. None the same, and all that I have seen with some serious peaks and troughs. Well, if I take enough images, then I *should* have something to work with! 30 second subs - a couple hundred should suffice for starters...

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

Hi Geof,

1. TBA - AndrewJ, is there a mod for that?
2. TBA
3. It already is. I have had the wedge for several years, but have never really tried to use it. It is a steep learning curve already, without imaging.
4. The OTA has always had external weights, and is balanced before the arms are locked. That is always something I have done.
5. Wind has always been an issue at f/10, but I take your meaning.
6. Taken under advisement.

I'm not deterred. Any improvement adds value, to my mind.

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

UPDATE: Tune Up package has already hit Sydney, as of Saturday. Let us see how long AusPost takes, once Customs releases it.
Reply With Quote
  #10  
Old 21-08-2016, 10:43 AM
AndrewJ
Watch me post!

AndrewJ is offline
 
Join Date: Mar 2006
Location: Melbourne
Posts: 1,905
Gday Shane

Quote:
all that I have seen with some serious peaks and troughs.
Yep, but again, its not the total pk-pk that is important here, it is how smoothly does it change, and is it repeatable.
You need to individually measure up each mount before you can answer that. Some worms are smooth and others ( like Geof can be ragged )

Quote:
the number of PEC cells available per worm rotation are not enough...
1. TBA - AndrewJ, is there a mod for that?
Nope, but there are actually 200 bins per rev of the worm.
That means the PEC model makes a correction every 2.4 seconds, which is more than good enough for any reasonable underlying PE.

Andrew
Reply With Quote
  #11  
Old 21-08-2016, 10:56 AM
Merlin66's Avatar
Merlin66 (Ken)
Registered User

Merlin66 is offline
 
Join Date: Oct 2005
Location: Junortoun Vic
Posts: 8,904
Nothing's impossible...
I used an ol' Lx200 12" wedge mounted on a cut down HD tripod for spectroscopy....
The Dec bearings were replaced with needle rollers (as per MAPUG site)
the wedge was stripped and re-built to tighten things up and the HD tripod cut down in height by (I think) 400mm (again instructions on the MAPUG site)
When well balanced in RA/Dec it performed well for me.
Limitations with the fork clearance to accommodate the spectroscope became the driver to change to an EQ mount and later to a lighter OTA.
I now use the C11 on a NEQ6pro mount.
Attached Thumbnails
Click for full-size image (100_0874.jpg)
99.7 KB26 views
Click for full-size image (100_0877.jpg)
103.3 KB29 views
Click for full-size image (100_0878.jpg)
104.1 KB25 views
Reply With Quote
  #12  
Old 24-08-2016, 10:35 AM
Shano592's Avatar
Shano592 (Shane)
#6363

Shano592 is offline
 
Join Date: Jan 2009
Location: Central Coast NSW
Posts: 1,244
Pity the MAPUG site data is gone. It would have been an interesting read.

Well, the tune-up kit arrived today (yesterday, but I didn't check the mail box).

This is what USD$42.99 gets me (image).

From left to right:

4 cable ties
5 Allen keys of various sizes
1 drill bit, around 3mm
1 bag of Pete's Red Grease
and at the bottom, what look to be 2 bronze sleeves with matching O-rings.

There is also a pretty extensive (17-pages) instruction novel.

Let's see how this goes.

Updates to follow. I'll have to try to get FWHM 'Before' figures this weekend, then 'After' numbers next weekend.
Attached Thumbnails
Click for full-size image (IMG_20160824_112833.jpg)
175.9 KB25 views
Reply With Quote
  #13  
Old 24-08-2016, 03:17 PM
Merlin66's Avatar
Merlin66 (Ken)
Registered User

Merlin66 is offline
 
Join Date: Oct 2005
Location: Junortoun Vic
Posts: 8,904
The MAPUG archives are still available on www.astronomysite.com
Reply With Quote
Reply

Bookmarks

Tags
buck harley, fwhm, lx200, tune up

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time is now 09:20 PM.

Powered by vBulletin Version 3.8.7 | Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Advertisement
Testar
Advertisement
Bintel
Advertisement