Hi folks
I have a project (one of many) that I want to throw open for suggestions to the forum.

One or two of you may know apart from apparent guru status here, I am an amateur telescope maker, currently working on a 1 metre telescope for which we are actually grinding the mirror ( www.astronomycentre.org.uk for those interested- Hi Martin).

We have a 10 metre dome with two 10 metre long curved doors that need to be operated by electric motors.Opening them manually requires a 13 metre ladder and nerves of steel

While we could mechanically interlock four actuatoro to open the doors (one at the top, one at the bottom on two doors), it isn't a high tech solution, and I would like to synchronise the movement electronically.

We can get big satellite dish actuators for around 100 GBP (0.9 metre stroke, 500KG thrust), which conveniently have small shaft encoders in them.

The doors must be opened (and closed) with no more than 2cm of difference from top to bottom.

In my preferred embodiment, I will have a PWM motor driver next to each motor, receiving power and control remotely.

Now since we have no commercial project here, can we get some suggestions for how to split the drive system up so we use the minimum number of interconnection between all the drives ? with the minimum number fo microcontrollers (one)

The system will need four position limit switches (top and bottom of each door) and some kind of finger/head/arm detector to make damned sure we can't close the doors on someone's appendage.

Each motor pulls up to 3 amps at 36 volts, though we can probably current limit to under two amps.

Steve