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LX80 RA tracking

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#1301 Stew57

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Posted 03 February 2013 - 03:08 AM

I was thinking more of the pressure generated by the contact angle between the worm and worm gear. I guess they both would have to be changed as a set. If the3 gear train is that big a problem than the fix would be getting toward the expensive side of things.

thanks

#1302 OzAndrewJ

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Posted 03 February 2013 - 05:12 AM

Gday Mark ( gotta stop calling you stew, sorry :confused: )

As you note, to replace the worm with a lower pressure angle unit would require a new worm and wormwheel. Not sure it would cost more than the current design, as its probably just cut by a cnc machine, but its not what they have designed for.
As to the geartrain, i really cant understand why Meade didnt use say the motor/Gbx from the LS units here and a belt drive.
This would have given a very robust motor/gbx/encoder setup that could be easily set up and adjusted, compared to the cheap unadjustable plastic stuff in the LX80s now.

Andrew

#1303 Stew57

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Posted 03 February 2013 - 09:09 AM

The worm gear set did not concern me as much as I could have one hobbed locally. The motor/gearbox would have to fit and looks cost prohibitive. Stew is fine as I was called that by a lot of good friends.

Thanks

#1304 EFT

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Posted 03 February 2013 - 12:46 PM

Gday Mark ( gotta stop calling you stew, sorry :confused: )

As you note, to replace the worm with a lower pressure angle unit would require a new worm and wormwheel. Not sure it would cost more than the current design, as its probably just cut by a cnc machine, but its not what they have designed for.
As to the geartrain, i really cant understand why Meade didnt use say the motor/Gbx from the LS units here and a belt drive.
This would have given a very robust motor/gbx/encoder setup that could be easily set up and adjusted, compared to the cheap unadjustable plastic stuff in the LX80s now.

Andrew


I'm fairly sure that I could have new high precision gears made for this mount, but I don't see spending at least 3/4 of what the mount cost to do so as being at all cost effective in this case. Were the gears the only problem, maybe you could justify it in some cases, but I think that putting in better gears would only accentuate the other problems. However, if someone really wants to pursue that, let me know and we'll see what we can do.

#1305 OzAndrewJ

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Posted 03 February 2013 - 05:29 PM

Gday Ed

I'm fairly sure that I could have new high precision gears made for this mount

But you still have the problem of the plastic gearbox housing and motor.
Based on David Ds original photos of his failed DEC drive, the means to adjust the motor is 2 screws in a plastic housing hidden behind the encoder disk so you cant get at them.
I still reckon a simple gearhead motor like in the LX200s/LSs and a belt drive would be a better fit in this case.
That said, the LX80 gears look like they come from the LX90, so why are the LX80 ones showing such apparent variability in quality?? ( or are the later ones now better??? )

but I think that putting in better gears would only accentuate the other problems


Nah, they are already accentuated. ;)
A good motor gearbox in the unit would at least make it more suitable for polar AP, but you would still be limited to light loads.
Fixing the worm etc to increase the load capacity would still be negated ( in polar ) by the fact that the whole support of the RA axle is still a big cantilevered spring. The closer to the equator the user is, the worse it would get.

Andrew Johansen Melbourne Australia

#1306 EFT

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Posted 03 February 2013 - 11:05 PM

Gday Ed

I'm fairly sure that I could have new high precision gears made for this mount

But you still have the problem of the plastic gearbox housing and motor.
Based on David Ds original photos of his failed DEC drive, the means to adjust the motor is 2 screws in a plastic housing hidden behind the encoder disk so you cant get at them.
I still reckon a simple gearhead motor like in the LX200s/LSs and a belt drive would be a better fit in this case.
That said, the LX80 gears look like they come from the LX90, so why are the LX80 ones showing such apparent variability in quality?? ( or are the later ones now better??? )

but I think that putting in better gears would only accentuate the other problems


Nah, they are already accentuated. ;)
A good motor gearbox in the unit would at least make it more suitable for polar AP, but you would still be limited to light loads.
Fixing the worm etc to increase the load capacity would still be negated ( in polar ) by the fact that the whole support of the RA axle is still a big cantilevered spring. The closer to the equator the user is, the worse it would get.

Andrew Johansen Melbourne Australia

Andrew,

Yeh. I'm really hard pressed to recommend putting any money into this mount, much less to buy it at this point. There are just too many problems. I haven't even been able to see any clear path to improvements that I could make to it. The design is just too far gone and there is no room for improvements in the very limited space available. You fix the main gears and then you run into that horrible motor drive train and are stuck.

Ed.

#1307 Starhawk

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Posted 04 February 2013 - 08:56 AM

Andrew, not to put too fine a point on it, but you are specifying the characteristics needed to do what the LX 80's specs claimed. I'm guessing they weren't going to hit their price point with that design.

With that said and the lack of funds for new stuff, this old seem to be a good time for Meade to reexamine the LS mounts for latent capability.

-Rich

#1308 OzAndrewJ

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Posted 04 February 2013 - 04:30 PM

Gday Rich

I'm guessing they weren't going to hit their price point with that design.



Not so sure there.
The cost to make the worm and worm wheel would probably have been no different, as cutting a true worm is a std operation in a CNC gearcutting machine.
The worm carrier itself could have been much simpler ( or just reuse say the LX90 carrier ), vs the completely new massive and complicated to tune unit.
Buying "standard" gearhead motors in bulk wouldnt be much more difficult than having to manually assemble the current plastic gearboxes from a box of bits..
So maybe a few dollars more, but i wouldnt think much.
Not sure how easy it would be to measure/remove the springiness in the RA axle when under heavy load in polar.

a good time for Meade to reexamine the LS mounts



They did, and came up with the LT. :grin:
Whilst i must say, i really like the running gear in the LS,
the lack of clutches and the wonky DEC axle make it a little user unfriendly.
( As does the fact that the firmware isnt supported or patchable )
When i did some bench testing of one, doing DEC guides actually gave
noticable movement in RA due to the close coupling of the DEC bearings and the flexibility of the outer bearing support.

Andrew Johansen Melbourne Australia

#1309 dksolar3294

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Posted 05 February 2013 - 09:53 PM

If you do a drive train, in normal means you cannot see the results. If you load our patches, that allows inspection of a lot of data and hence you can dynamically read the data. Unpatched, you can still use my PEC editor to read the data, but it requires going into download mode to do it.



Andrew: I'm unclear what you mean by 'numbers'. I don't see where the mount itself gives a status report, so I assume it has something to do with your patch &/or PEC editor. How does one obtain it/them & then how is it used? Do you have a web site which explains it?

Don, TX

#1310 OzAndrewJ

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Posted 06 February 2013 - 12:25 AM

Gday Don

I'm unclear what you mean by 'numbers'. I don't see where the mount itself gives a status report, so I assume it has something to do with your patch &/or PEC editor.



Correct.
If you load our patches, you get a "peek" ability, which allows a lot of info to be read without having to go into download mode, and you also get a means to view/edit your drive train numbers via the Hbx.
( as well as a lot of other bug fixes and enhancements )
If you are unpatched, my PEC editor can still read the current drive train data, but it means going into download mode, and hence you lose your alignment/PEC etc.
My PEC editor is at
http://members.optus...om.au/johansea/
use the beta copy at the bottom of page.
It has a full help file with it, but basically, in your case ( and unpatched ),
do a drive train as per the std mechanisms.
Connect my app to your scope and say you want to go into download mode.
It will read and display all your main settings for train/location/sensors/etc on the front screen and in the "Lists" tab, there will be a full breakdown of all the Hbx settings.

As for the Patches, the latest ones are all on the StarPatch site
http://www.stargps.ca/downloads.htm
Load the StarPatch utility and let it grab the latest rom and patch for your handbox type.
Select the patches you want to install and hit go.

Andrew Johansen Melbourne Australia

#1311 dksolar3294

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Posted 08 February 2013 - 03:42 PM

Andrew: That's a pretty extensive collection of work on your & your co-authors part. Between weather & time, I haven't tried a patch yet. However, I was able to try a couple attempts at PEC training. What I noticed is that nearly all my correction movements were West. So, it's becoming apparent the mount is creeping Eastward, which is what I was seeing with autoguide attempts. The conclusion is that my mount is running a touch slow towards lunar rate. The HC menu (Setup/Telescope/TrackRate) has a Custom option. If selected, it ask to enter a new tracking rate. There are ten choices ranging +0, +1, ..., +9. Do you know what these mean? % increase or other. There are no negative numbers offered. I hope to experiment some by trial & error in the next few days to see if I can detect a change.

Don

#1312 OzAndrewJ

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Posted 08 February 2013 - 04:18 PM

Gday Don

Slow or fast???
I know the latest Audiostar code still has a weird bodge factor in it
when running an LX80 in pure polar mode, or are pulseguiding in RA.
( As you are PEC training, i assume you are polar for all this)
To test this, start the scope indoors and do a dummy one star polar align.
Erase the PEC model and turn PEC ON.
( This will force pure polar mode without the need to pulseguide )
Do not even fit the 909 pluggette.
Use hold mode to bring up the RA/DEC display on the Hbx and note the RA.
Go away and come back in an hour and look at what it says.
Is it still the same????

There are ten choices ranging +0, +1, ..., +9. Do you know what these mean? % increase or other.



They are a percentage factor to apply to base tracking.
( and they are user definable to any number you want )
What they are depends on your firmware version
but they are either 0.1 or 0.01 factors against sidereal.
To test what you have, go to the hbx and select the "Lunar" rate
Now go to "Custom" and hit enter
if it shows -36 the factor is 0.1%, if it shows around -360 it is 0.01%

There are no negative numbers offered.


Yes there are.
Just use the "left" slew key to put the cursor over the sign cell.
Use the up/down or scroll up/down keys to toggle the sign

Andrew Johansen Melbourne Australia

#1313 Starhawk

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Posted 09 February 2013 - 11:33 PM

I have to hand it to the LX 80 on one score- that thing inspires hope like nothing else in the hobby.

-Rich

#1314 OzAndrewJ

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Posted 10 February 2013 - 01:41 AM

Gday Rich

Not really.
I think by now we understand it is perfectly good for AltAz
with light to medium loads and visual in polar
( or maybe OK for piccies with a DSLR only )
Other than the very minor bodge factor used for tracking,
the LX80 itself has nothing to do with this question ( that i can tell ).
Its purely a firmware operation being discussed here,
and that affects all users of Audiostar Hbxs.

Andrew Johansen Melbourne Australia

#1315 rmollise

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Posted 10 February 2013 - 11:14 AM

Based on my experience with the mount, it might be good enough for short exposures with a DSLR. Like the Moon and planets. Anything else? Nope.

#1316 mmalik

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Posted 10 February 2013 - 11:44 AM

...that thing inspires hope like nothing else in the hobby.


Nope; just inspires Andrew :)

#1317 OzAndrewJ

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Posted 10 February 2013 - 02:50 PM

Gday Mr Malik

Nope; just inspires Andrew



Nope :grin:
I try to keep firmware and hardware as seperate problems.
I was really looking forward to this mount for a grabngo dual solar, with the possibility of a bit of polar.
Based on the current "mechanicals" of the unit, i cant see it as being worthwhile for me, as there are smaller simpler mounts that can do the same job if altaz only.
I am still happy to hope that the firmware will get fixed
as that affects all scopes ( incl my ETX-125 ;) )
but till then, we will just keep patching.

Andrew Johansen Melbourne Australia

#1318 Daud

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Posted 10 February 2013 - 07:38 PM

I will finally get to open the boxes with the stored mount. It is too late to return the mount as I purchased it months ago. Initially, I will try it with the Meade SN-6 and a C-8. But I have to confess :rainbow:, I wanted something for quick and lazy visual with the AP130GT instead of the Sirius mount.
What shall I look initially for, the free play in AZ ?
Andrew, why, recognizing the limits of the mount, it would not be good enough for your purpose, grabngo dual solar ?

#1319 OzAndrewJ

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Posted 10 February 2013 - 08:32 PM

Gday Daud

Andrew, why, recognizing the limits of the mount, it would not be good enough for your purpose, grabngo dual solar ?



Firstly, the whole assy is much bigger than i thought it was.
I already have an EQ6Pro that works, but its heavy/bulky, uses an ( odd to me ) handbox, and polar viewing during the day is a pain in the neck. ( I like AltAz )
If the LX80 was mechanically sound, it would be lighter than my EQ6Pro, and i would have the ( familiar to me ) 497 type handbox, so it would have been an OK swap.
That said, i really dont like the gearbox/motor mounting in it.
I could live with the worm design but i really dont like the gearbox.
Thus based on it not really being useful for Polar ( for me ), a huge amount of the base mechanism could be removed, but if you were to do that, why not buy a unit that is already designed that way.

Im still thinking/looking, but till a better option comes along, i will just lug my EQ6Pro.

Andrew Johansen Melbourne Australia

#1320 SeptemberEquinox

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Posted 11 February 2013 - 02:12 AM

I'm thinking about buying a goto mount.. After reading this, it is clear to me that do more researches on Celestron VX instead of Meade LX80. Celestron's customer service is superb. I haven't had an experience with Meade customer service, but it doesn't sound too promising. I like the fact that LX80 has abilities to go AltAz and EQ.

I wish, I'm patient enough to read all of the replies on this thread. But the problem is still going on after 66 pages long.

#1321 Starhawk

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Posted 11 February 2013 - 09:41 AM

Ok, that is a funny post.

Smile, Andrew. I hope you realize many of us have developed sincere respect for your efforts, and smile every time we see a new post beginning with G'Day.

-Rich

...that thing inspires hope like nothing else in the hobby.


Nope; just inspires Andrew :)



#1322 dksolar3294

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Posted 19 February 2013 - 03:28 AM

Andrew, Thanks for the guidance. I see now how the custom track rate works. My Lunar rate is -365. When I see my tracking drift Eastward, it is running slow. On my first night to try correcting the drift, I found +100 would hold an actual star steady. The following day, I setup in my garage & let the mount run for an hour in the default sidereal rate. The RA/Dec readout stayed near steady with no indication of drift. A few nights later, I again aimed at an actual star and the watched the readout & the star position. Both the RA/Dec & star held steady. Wondering why no drift and thinking the mount was working properly, I elected to try autoguiding again this time using the serial HC link. I used PHD in the ASCOM output mode. During the calibration step, an E command was sent and the mount moved correctly Eastward. When the W command was given, the mount kept on moving Eastward with no hint of attempting to change. On the N command, the mount pretty much stopped. This the same as I was getting with the 909 AG plug. I used both a Win7-64bit and a WinXp-32but PCs with same result. Following those attempts, I again aimed at a star & noted the mount had resumed its Eastward drift confirmed by the readout showing increased RA position numbers. When I then attempted to counter the E drift with the custom rate variable, I basically saw no change in track speed. I ran the custom rate up to +1000 with no effect. Cycling the power on/off had no effect.

My conclusion from this is that the tracking is squirrelly and the AG inop. The APM 07509 has been on back order now going on 3 months, which pretty much confirms my conclusion. Until new firmware is available, I'm gong to abandon further AG attempts. I've got a Meade 10" SN (30#s) sitting in corner & I'm going to mount it on the LX80 and see how it handles that much weight visually.
Don

#1323 OzAndrewJ

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Posted 19 February 2013 - 04:34 AM

Gday Don

When the W command was given, the mount kept on moving Eastward with no hint of attempting to change. On the N command, the mount pretty much stopped. This the same as I was getting with the 909 AG plug.



I have just managed to get my hands on a new 909 unit and i have to say i cannot understand what it is doing. It is very "erratic" in how it works.
The std rs232 pulseguiding should work tho, as all my bench tests indicate that
it works correctly as long as you have PEC turned ON.

My conclusion from this is that the tracking is squirrelly and the AG inop.



I think funny stuff may happen tracking wise, as there are 2 modes it works in. In my latest patch, i have rewritten how the polar tracking etc works to try and force it to reset its rates correctly, but i dont have a real LX80 to test it on. It works OK on my LX90 boards, but i still think there is something odd in the LX80 motor cards.
I just cant prove it.

Andrew Johansen Melbourne Australia

#1324 OzAndrewJ

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Posted 20 February 2013 - 10:44 PM

Gday All

I have just managed to get my hands on a new 909 unit and i have to say i cannot understand what it is doing. It is very "erratic" in how it works.



After an inauspicious start, i now have it working on the bench :jump:

I must say, the QC on the device was not very good.
A lot of solder slag/flux was left on the board and it would appear that this was creating a high impedance short between the 12V supply and the clock. Not good. :mad:
As such, one of my handboxes worked part time ( but most didnt work at all ),
probably based on what value of pullup resistors they had on the clock lines.
After cleaning all the flux etc off, it started behaving again.

As expected, once working, it does work with all flavours of Autostar,
ie 497, 497EP and Audiostar, but i still think there will be low level
timing problems that may/may not affect use with a guiding app.
I cant test that yet.

Andrew Johansen Melbourne Australia

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#1325 jonbosley

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Posted 21 February 2013 - 03:54 PM

Request moderator to lock this tread so a part 2 can start or something. A 67 page behemoth is a bit much even for cloudy nights and rainy days.

Jon






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