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View Full Version here: : Stepper motor problem & resolution

davidpretorius
23-09-2005, 08:38 AM
Hi,

i have been delayed with motorizing my dob due to the stepper motor controller burning out. No load, but I may have crossed wires, not sure??

Anyway, emailed the supplier, he was cautious about the term "warranty", but advised by all means send it back and he would check.

Anyway the overnight airbag took longer to get to him than the time he took to check the circuit advise of the problem and cost to repair. I bank transferred the money and he did not wait for confirmation from the bank, he rang TNT to come and pick up the airbag.

Received the bag today, and lo and behold, there is a spare chip in there as a backup.

I am very impressed! I know the controllers are only a few bucks from dork smith, but it is the thought that counts.

http://www.ar.com.au/~softmark/ is the supplier and i have no worries with recommending them!
Astroman
23-09-2005, 08:44 AM
What is the Stepper controller you are using, the USB? How are you going to go about controlling both axis for tracking? Or is this just so you can move the scope about in Alt and Az.

Great to hear they fixed it quickly.
davidpretorius
23-09-2005, 09:01 AM
yes, the usb stepper controller. the printer port is taken up by imaging softare with my modded toucam.

i can get 1/2 steps and full steps but no microstepping ( they may look into this down the track ) as i can not program the voltage delivered to the stators.

i am writing a visual basic program in .net called "smart scope" that will do as many things that i can pile into the program.
1. drive the alt/az or ra/dec, depending on setup chosen.
2. track via the program in alt/az or ra depending on setup
3. image track as well based on feedback from the image on the toucam, adjust to suit for tracking and field rotation when in alt/az mode.
Starkler
23-09-2005, 10:56 AM
Ive heard that using fractions of steps and microsteps come at a price of reduced torque. If you have spare torque to waste then its not a worry :)
davidpretorius
23-09-2005, 01:35 PM
yes balancing torque and slew rates is the fun part i see!
MiG
27-09-2005, 12:35 AM
They're 30 or $50 aren't they?
davidpretorius
27-09-2005, 01:58 AM
sorry the chips themselves are a couple of $, the complete board is $50 odd