Telescope control completed, now for the testing. UPDATED 10/01/06

[Astroman]

Hi all,

I am in the process of rebuilding an old project, mel bartels scope driver. When I first made this with my dad some 7 years ago we never put it into a box let alone got it working on any mount. I decided while I have the time I would build it again and do with it what was meant to be done 7 years ago. Lets hope it works this time.

Currently I have cut all old plugs off and started re building it, rewiring it and change the appearence of it. I have added test LED's and also extra power plugs incase they are needed in future. Anyway current picture below, man I hate those 25 pin connectors.

[netwolf]

Andrew would you be able to do a brief write up on a how to for this? I am sure many heare would be. The other night i got my first viewing of M42 and i was blown away, in all the time i haave had the scope i have not had much visual scope time. But even in the time i had i was looking at planets mainly. And i find i lose intrest in looking when it moves out of view so fast. Idealy i want a G11 tracking mount or a EQ6 but budgets tight so am willing to experiment with bartels to at least get some minimal tracking. Goto would be a bonous.

Major concern is in fitting motors to the GSO dob, as i am no very good with the mechanical side of things. However the electronics is fine with me. I am intrested to know howyou have sourced motors/gears parts etc for your project. And how you will mount these onto your dob.

Edit:
Out of curoisity does anyone know how to get Jaycar to maybe sell a kit like this? As i understand Mel has made all the information on building this available. Would it be difficult to have Jaycar create a kit for this for people to buy and construct.

Thanks and Regards

[RAJAH235]

Netwolf, It might be better to contact OATLEY Electronics. Prob. more likely to do it?????
:D L.

[netwolf]

Rajah,
I guess the question i would be asked is how many are we likely to sell??
But its worth a try. Thats the electronics, how about the mounting kits and gears worms etc etc. I know Dave and Mick were working on something like this for the dob buggy.

Thanks and Regards

[RAJAH235]

Netwolf, you never know with the ATMers. They might just buy one to save time etc... Be great if the total system was avail from the one place, but usually with this type of 'add on' gear, = electronics from here & mechanics from there.. Hard to say really. It's a very specialised hobby we're in, ain't it?
PTN. In '99, I suggested a circuit for a car 'LED readout' for an ammeter, to monitor the charge/discharge rates using their, (Silicon Chip), LM3914 dot/bar LED driver voltmeter circuit. I don't know how many kits were produced or sold, but they were hard to find just 12 mths or so after release. No market for 'em apparently. Mine works fine.
Now, if Mick & Co. get things up & running, we might just end up with a few more local products.
HAPPY NEW YEAR.
:D L.

[Astroman]

All the PCB parts are available through DSE or Jaycar or any other electrical component supplier. All information regarding this controller can be found at http://www.bbastrodesigns.com. The board he uses for the steppers is not like mine, I dont use the optoisolators. The circuit I am using is similar to this one http://www.geocities.com/CapeCanaveral/9601/pcb.htm but different. The Steppers were sourced from a number of places like old printers, but the best place for them is the old 5 1/4" floppy drives these uses the Nema 23 type steppers, but I understand there are better and smaller steppers out there now NEMA17 400 step/rev. You may be able to find some places that sell them on Mels website.

I am going to be using the cable idea and friction drive for the dob, since I can easily convert my scope back to full bearing use (being home made it was my original intention to add motors.). Cable drive for the base in AZ and friction for the Alt.

[netwolf]

Andrew, thanks what i ment was an ethced PCB plus parts in a bag. Perhaps even a precut box to house it all in. I wish now i had kept my old floppy drive... oh well. But i am sure i can grab a few from the computer markets and meets.
Idealy i want to get Mick's buggy down the track and put this on top, so not to concerned with field derotators etc. But might be good to have a plug in pcb design for this module for those that want it.

Regards

[Astroman]

The only way you could get the PCB and parts is to order diectly from Mels business. I hand drew my PCB and dont have the technology to make my own board, although my dad has sucessfully made printed circuit boards using a laser printer and some etchant from DSE. He mentions the method here ---> http://www.qsl.net/vk5cu/

[Astroman]

Okay the rebuild is complete and I tested it out lastnight, worked great until I went to try it out again lastnight and nothing happened, I rechecked the plugs on the controller and everything looked okay. It was getting late so I decided to call it a night. This morning I went out and tried it again this time I noticed that the parallel plug on the laptop side had come off OOPS! I replugged it back in and to my amazement, it all worked perfectly. I connected the motors up and they worked first time also,boy I am glad its working.

I am in the process of adding the Alt gearing to the scope, I reinstalled all bearings and am making up the motor adapter to go through a 60:1 worm set. this connects via a chain to the Alt wheel. should give me atleast 120:1 reduction if not a little more. plus using chain it is stiff enough not to move too far but flexible enough to allow me to move the scope by hand if needed.

All I need now is for this heat to go away so I can continue to build it, not nice working in a 51C temp shed.

A little movie I made of the lights on the controller.. about 6mb big.... http://www.theastroweb.com/astronomy/telescopes/stepper2.wmv

[Astroman]

OKay another update,

I have added the ALT gearing now, and will finish it tomorrow. It is being held by G-clamps right now, but a bracket is being made. The Stepper motor has not been tied down yet, it probably doesnt need it, seems to work fine, but it does jump due the torque of the Steppers which are 4.6v 1.1A stepper running at 12v, so there is more than enough power there. My 4yo son was very impressed with the scope moving on its own without me touching it. All he wanted to do was press the buttons on the controller to make it go up and down. Slew rates in the ALT axis are somewhere near 12 - 15 degrees a second at a high speed possibly higher, but I stepped this down to around 6 degrees/sec because the torque of the scope at the higher speeds almost made the scope tip over. settle down time of the scope is less than a second from looking at the tube, have not looked through the eyepiece yet.

Anyway pics below of the progress.

[Astroman]

OKay, I admit it,th is is going to be a little more than just an update to the controller. Now I have added the Azimuth gearing and the Alt gearing to the scope, also connected the power rig and controller to the scopeaswell, only thing to do now is repair the wires I accidently cut during transport outside to take the images below and get another sproket from work since I only had one, where I actually need two.

Anyway I tried it out before stuffing it up and the Azimuth works well, not 100% but almost there, the Alt axis works 100% but I took the sproket off to do the Azimuth.

Anyway pictures below.

[Astroman]

Okay another update:

I have made up a temporary gear and attached it to the scope, I also mounted the laptop on the base and now in the process of putting some wheels on it so I can move it around. so far so good. I had it move from 0 degALT, 0 deg Az to 90 deg alt, 180 deg az with only a couple of little hiccups,not bad for a home made spur gear. Can't wait to get a proper one. I will hopefully get it out tonight and see how we go under the sky. The laptop dosnt hold charge anymore so have to run off 240v (more cables) and it loses the time and date so like a standard Autostar I have to enter the information on start up. What a PITA.

[Astroman]

OKay here is a video of the scope in action, it's not a good video and the audio isn't quite synced to the movie, but you can hear the drives going aswell as my son and myself in the background.

http://www.theastroweb.com/astronomy/telescopes/telescope.wmv it's 2mb big.

[h0ughy]

awesome, thanks for showing us all!

[Astroman]

OKay here is a couple of pics and a movie (at 2x speed) of the telescope in action. Movie shows it slewing to its home position at 0 Alt 0 Az.

http://www.theastroweb.com/astronomy/telescopes/leftscope.jpg

http://www.theastroweb.com/astronomy/telescopes/rightscope.jpg

and the movie

http://www.theastroweb.com/astronomy/telescopes/scopemove.wmv @2x

[stringscope]

Andrew,

Very impressive. Many thanks for putting the pics and movie up.

Cheers,