Backyard Aquaponics
A place to discuss aquaponics

At the risk of having a conversation with myself - how about something like this for the motor http://www.jaycar.com.au/productView.as ... &SUBCATID=

or

http://www.jaycar.com.au/productView.as ... &SUBCATID=

I'm not flash on interpreting the torque ratings - but it sounds like this sort of thing would free lift a small aluminium door. It is reversible.

If you don't mind overkill and 24v, check scrapped medical appliances.
The rams (electric) on wheelchair/ patient lifters are rated at about 400kg, even though the frames only usually have a swl of 180kgs.
Electric wheelchairs have 2x motors @ 24v with huge torque.

Man that is overkill . I want to run this thing of a 7AH 12V battery. With one up and down cycle a day - should last for ages before needing a charge.

My garage crane (read patient lifter) only has 2x 12v 7ah batteries. Stick the ram somewhere solid and you wouldn't need a door, just lift the side of the shed up

wiper will have plenty torque. gimme a bit, i'll post a wiring diagram.

PARTS LIST:

12v BATTERY
Photo switch with DPDT output (if it doesn't have this then just get an aditional 12V DPDT relay to wire in)
two microswitches for limits

ive shown the two micro switches physically linked as they will be 180d out of phase (ie when one is open one will be closed)

this will open and stop when photo switch turns on and close and stop when limit switch opens.

will also remain closed or open if someone tries to force it as the limit switch will re-supply power if the door is forced.

enjoy.

(I've drawn the up down switches mechanically wrong but you get the concept.)

use this: http://www.jaycar.com.au/productView.as ... &SUBCATID=

OR this: http://www.jaycar.com.au/productResults ... RM=KEYWORD (looks like it might be DPDT

fit this to either if they are not DPDT: http://www.jaycar.com.au/productView.as ... &SUBCATID=

but might be better getting the realy and a din rail base for easy screw connections from an elec. wholesaler.

Proper connects from DPDT relay are:

bridge one NO and one NC from each "side"
one NO to one limit switch
one NC to one limit switch

common of one side to +ve supply
common of other side to -ve supply

enjoy again

I want an invite for the 1st test run...want to watch it turn in on itself as the the motor runs the wrong way

I'd expect Veeber to perform a test run by putting the door mid way and holding both limit switches down then letting one go momentarily.....................my luck he'd break a finger or some shit.

I was going to build one of these babies ages ago, but kept dreaming of headless chooks...........they're not the smartest of animals

you seem to have overlooked the suggestion of car window motors which hold it all: motor, drive system, limit switches, up/down switches,
and are approximately the right size for your application
and they work at the right speed
these motors are very powerful (ever tried to stop your car window?)
they can be scrounged
all you need is a timer and/or twilight switch and a relay

car 12 volts relays are the cheapest an can be scrounged too
one car wreck will give you all the equipment for two or even four doors

you might need two twilight switches: one for opening at first light, the second one for closing after last light
that would only close the door some time after your hens have naturally retired to their sleeping quarters

frank

frank you mustn't have been following the thread.

the motor assemblies have ONE limit switch and the motor/gear asssembly, thats all.

Hence the need for external switches.

if you can draw up a way for the motor to operate via levers and the ONE included microswitch then feel free to post a diagram & schematic.

Frank is talking about window motors not windscreen wiper motors Steve.

Steve - thanks for all that stuff - I'll try and digest it later

As for the motor - the reason I showed the Jaycar ones is that I figured they might be easier and possibly cheaper to source than windscreen ones. But maybe you skimmed past that post .

Frank - I'll have more of a think about the widow motor thing. Will do some research. Reason we may have read past it was all the stuff about using the car as the pen

Yep - you've missed one of my posts Steve - I actually linked to that twighlight switch

Frank - now I think about it, I'm not so sure that many of the window motors have limit switches on them. I'll check my car - but I'm pretty sure that if I keep my finer on the button, then the motor keeps running. Some have the automatic down where you press once and it goes down - switching off at the bottom, but don't tend to have the same feature for up. My Ford doesn't have it for down or up.