Of course, system time must also be correct.
And do not forget to initialise the scope properly..
I am using very simple method, but it is very accurate (for me):
First I make sure the whole thing is in level (by means of bubble level).
Then, I point the scope to CSP (celestial south pole, near sigma Octans) which is my home position.
Then, I start the scope program. When it is up and running, I can move it freely wherever I want/need, since I have encoders.
I very rarely use Goto (except for difficult things I do not know exactly where they are), most of the time I just use tracking.
If you do not have encoders. I suggest you move the scope to a nearby star, reset coordinates to it (from existing data base, or, I usually prepare the file with objects I want to observe the day before) and then GoTo from there. It will be quicker (because the scope will have to do shorter slew) and more accurate.
Thanks again, Rod. I'll test this out tonight - weather permitting. I don't pretend, for a moment, that I understand why it works. But so long as it does ..
Well, the day has arrived. I have now finished installing the new Bartels board and finished a rebuild of the mount and all the associated electrics. I wanted to reduce cable clutter and this meant building as much as possible onto the mount itself. Here's the result.
Thanks to Road and Bojan for their helpful advice.
Peter
Any Bartelised scopes out there?
There may be plenty of tricks and solutions to be shared....
Hi Bojan, fellow Bartelisers
I Bartelised my homemade GEM ages ago but it is always a work
in progress.
Originally it was on an old 486 machine but has run for about 10
years on an old Compaq P120 (original HD still going strong).
I can vouch for the stalling on high slew speeds.
As mentioned , I tweaked Ramp up and Down settings until
there was a stall, then backed off a little.
I made the whole sytem from the ground up, adding remote
control over fibre from inside my house. ( I do fibre for a living).
My steppers run are 12v and 15v for RA and Dec respectively but run
on 24v with inline resistors for smoother steps.
I can post my Config.dat file if you like, to compare settings.
Also, the Scope-drive forum on Yahoogroups is a goldmine.
Many very smart Bartelisers out there with answers.
Mel himself is always quick to answer also.
Hi Steve,
that's a pretty professional-looking rig and observatory. A couple of things - the mount - looks solid and simple - make it yourself? And the Optic: I'm fascinated by the optic connection to the house and wonder if you could give us a bit more detail on how you did that and how it operates.
I can post my Config.dat file if you like, to compare settings.
Also, the Scope-drive forum on Yahoogroups is a goldmine.
Many very smart Bartelisers out there with answers.
Mel himself is always quick to answer also.
Some key parts of the setup in the pic attached.
regards,
Steve B.
Hi Steve, looks impressive..
I have some plans to Bartelize my EQ6 one day :-) When I have permanent site with dome etc (if it ever happens)
As it is now, it does what I need, so I am not in a hurry.
Yes, Yahoo group was very helpful to me as well. Mel is always there and he also responds to private mail on the subject. He is one of the guys who definitely deserves to be honored as the one of a few who did not take his personal interests as number one when deciding on how to best contribute to the cause of ATM and amateur astronomy in general, IMO..
Hi Steve,
I noticed on your picture you marked serial mouse encoders... Are you using mouse driver or David Ek's box?
I use mouse driver (Gmouse.com), but I have a problem here, it seems the mouse interrupt handling does not work properly and very often the position is not updated while tracking and/or slewing.
Currently, when I want to move the scope, I have to stop tracking, to avoid problems - automatic returning to a position that scope thinks is current and correct and which is not because of missing interrupts (well, that is my theory).
So I plan to mount the David Ek's box (which keeps current scope position in its own controller's memory and sends it to main computer on request), but since I can live with the workaround, and since I am lazy, the box is still on my table, waiting to be mounted and used..
This is the only problem I have with bartels system and it was not resolved on forum (yet). Perhaps because not many people are using mouse driver and this s/w bug is simply ignored?
Yes, it is a work in progress :-)
Hi Steve,
I noticed on your picture you marked serial mouse encoders... Are you using mouse driver or David Ek's box?
I use mouse driver (Gmouse.com), but I have a problem here, it seems the mouse interrupt handling does not work properly and very often the position is not updated while tracking and/or slewing.
Currently, when I want to move the scope, I have to stop tracking, to avoid problems - automatic returning to a position that scope thinks is current and correct and which is not because of missing interrupts.
So I plan to mount the David Ek's box (which keeps current scope position in its own controller's memory and sends it to main computer on request), but since I can live with the workaround, ans since I am lazy, the box is still on my table, waiting..
Yes, it is a work in progress :-)
Bojan,
When Mel first introduced mouse encoders years ago, I added it to the
DEC axis only.
Later I added it to the RA axis too although I turn it on and off
depending on what I'm using the scope for.
I use a mouse driver without accelleration (the floppy you see sticking
out the laptop is the backup mouse driver).
I searched for ages to find a mouse driver that was glitch free.
Basically, once I setup the mouse increments in Config.dat, turn on encoders, I can track and slew with the DEC readout giving me an
update on screen.
If I stay the driven side of my backlash, I'm ok.
If I go backwards and introduce some backlash take-up, I get positioning
errors.
So to keep it simple it is only mostly used as a 'push to' goto function.
I set on a known star in stars.dat.
Do an equatorial co-ordinates reset.
Then push the scope until I am at my desired GOTO location.
(I can drive there with the handpad, but it all depends what side
of the backlash I am on).
Hi Steve,
that's a pretty professional-looking rig and observatory. A couple of things - the mount - looks solid and simple - make it yourself? And the Optic: I'm fascinated by the optic connection to the house and wonder if you could give us a bit more detail on how you did that and how it operates.
Peter
Hi Peter,
Mount is very old, my father made it when I was an apprentice.
I added the RA stepper drive, the DEC stepper drive and most other
functions.
It has a mixture of manual setting circles and digital (mouse encoders).
I made my own PCBs for the Scope-drive circuit including the handpad.
The handpad can plug in at several places including local (within the dome), or via optocouplers over the fibre( inside the house or shed).
I use VNC to control K3ccdtools over an ethernet link to the house but
mostly from locally within the dome.
I have never tried LX200 over serial or ASCOM methods.
The Adelaide weather, especially during winter, is so changeable that
I can never go inside and afford to forget the dome for even 10mins
Bojan: I agree with your comments re: Mel.....a truly inspiring gentleman.
This thread has been quiet for a while so I thought I would add a few pictures of my Bartelised scope. I finished it recently and have been testing it out - most recently at the ASV starbeque at Heathcote.
It is a 12 inch F5. I have used epoxy moulded gears for the reduction system. It tracks well and I am told is relatively quiet (for a stepper system!). I need to work on the goto side of the mount. I can usually get objects within a wide field eyepiece if the slew is not too long.
Obviously this is not a highly engineered mount so I am happy with these results. I am going to look into the error correction options in Mel's software to see if I can improve the gotos. I use the DOS version of Guide as a planetarium program for this system.
My only real problem at the moment is that I keep blowing the fuse going to the circuit board. I am going to replace the power cable and if that does not help a friend suggested I try the current limiting circuit.
I hope this is of interest. Any comments or suggestions welcome.
As for blowing the fuse, you must find the reason for this.
Current limiting approach will help (so the fuse will stay in one piece), but if you have an intermittent short somewhere, you will still have system malfunctioning due to intermittent power..
Thanks for the comment and your advice while I was building this. The fuse is no longer a problem. I replaced some dodgy wiring and all is well there now. I do have the current limiting circuit to allow faster slews. Gotos are reasonably good for a wood and epoxy mount. I can get all objects in the field of view of a low power eyepiece. Tracking is always more than adequate for visual observing. The only issue I have is that gotos sometimes become less accurate after 3 to 4 hours. If I re-initialise on 2 stars then everything is fine again.
I am currently in the Northern Territory observing with my new travelscope while on holidays. Skies are great although we have had clouds the last couple of days. I miss the tracking and ease of locating objects with my Bartelised scope.
I think I have blown one or more transistors on my circuit board. Last night I left my scope unattended while in tracking mode. While I was away the laptop shut down while the board was on. Unfortunately I can no longer slew in altitude and the motor just makes a faint buzz sound in tracking mode. I replaced the hex inverters but still have the same problem. I tried another computer and had the same problem so it is not the parallel port.
I am thinking I should replace one or more of the darlington transistors on the altitude side. I am using TIP102s but I have 4 TIP122s which I believe can be used instead. Should I just replace all 4 on the altitude side or is there a simple way to identify which of the transistors is damaged? I have a cheapo multimeter but I am pretty ignorant when it comes to electronics - can do basic soldering though.
Hi Rod,
There is no need to replace all of them...
The easiest way to test the transistor is with Ohm-meter.. and transistor outside the circuit (but it should work with transistor soldered in place as well). However, the multimeter should have high enough test voltage, to deal with Darlingtons. Try using Mohm range if diode test doesn't work.
You should have low resistance from Base to Emitter, and from Base to Collector (Tab).
However, in opposite direction you should have high resistance.
From Collector to Emitter you should have high resistance, while in the opposite direction, you should have low (because of build-in protection diode).
Try to experiment with the TIP122 you have, not mounted.
If scope.exe loses control of the switching, the full current that the supply can give could go through the board and to the motor(s) and the weakest link get's a workout.
Have you tested that the motor is OK? Try swapping it with the other working motor. You say that the motor buzzes, then I guess that some of the trannies/coils are OK, otherwise if it was completely dead, then all the trannies/colis have been nuked.
If you need another board or motor, just shout. I have a spare.
Thanks for your advice and generous offers. I am embarrassed to say that after looking more closely, the problem was a blown fuse on the overvoltage circuit. I have the overvoltage circuit installed to allow faster slews. I had forgotten they also had their own fuses.
I also found a loose wire on one of the cigarette lighter adapters that supplies power to the board. I suspect that may not have helped matters. Motors are fine and the circuit board also appears OK.
