VK Logger Ham Radio Forum Archive

Hello,
I have been pondering what to use as a motor to drive a reduction geared system to steer a dish for the SHF bands and had thought that some of the bigger stepper motors or those used in the ghopher vehicles might do the job. The stepper was high on my list of possibilities as I think it can generate quite a bit of torque at each step and would give a great ability to move / steer in small increments without having to get a DC motor up to speed to get some torque.

Has any one out there had any hands on experience with the larger stepper motors? or indeed those DC motors in the Ghophers?

Regards,
Peter, vk5pj

I have a couple of gopher motors. They are rated at 24 volts and 10 amps and have a fair bit of grunt.
My large antenna has one of these driving a 15 to 1 worm and wheel steering box which then drives another 180 to 1 final output. With 12 volts applied, the motor output does around 150 rpm and with 24 volts about three times that. It is a tad slow for the 15 element 6 metre antenna, but would be good for a larger UHF array. It still produces a useful amount of torque with about 3 volts, so that if you choose your gear ratios and voltages you should have a very versatile system, even for a reasonable size dish on 10 GHz.
My mobile setup has one driving an 80 to 1 reduction, directly connected to a 7 element yagi on 144 MHz. That turns fairly quickly, but not unmanageable.

David

Thanks David, its interesting you have used a gopher motor. I need to spend some time learning about stepper motors as it would be interesting to see if they can offer to torque in small lumps and then drive a reduction box. I guess google is my friend.

Regards,
Peter

With decent rotators for 5m dishes, starting at $3000,
we need a supply of gearboxes and motors
AND motor controllers, computer boards, to go ALL the way.

Go to eBay, buy this, this and this. Go to website, get software X and build.
So far I have sources for:
Gearbox 50:1 35mm thru shaft (from China) $70 etc..

See my article in the EME section of there forums.