Giant RC servo?

[mt2man]

Anyone know where I could find a large servo that could be controlled remotely?

An rc car servo would be too small for what I'm after, I've read about converting wiper motors using the potentiometer from a rc servo using relays etc but this would mean it would basically be either lock to lock and not progressive enough for steering.

Plan is to make a mini quad bike remote controlled for the next gathering basically mini quad with a child's ride on jeep body ontop pulling a small trailer with a bucket seat in it, getting pulled along like a chariot haha

Big 1:5 scale cars might be upto the task but I'd need quite a torquey motor!

Just a silly idea ATM but really want something fun for next gathering around the campsite!

[MonzaPhil]

EPAS from a Corsa or suchlike?

Sent from my mates kitchen using proboards

[mt2man]

Thats an idea actually! Suppose the input force of steering is alot less than the output so that could be a possibilty, could be expensive though

[markbognor]

Maybe use a stepper motor from something "industrial", and a home made stepper motor controller that plugs into the RC reciever and translates the pulse input from the rc transmitter and outputs the relevant pattern to move the stepper motor to position.

I'd be investigating using a PICAXE chip - www.picaxe.com / www.rev-ed.co.uk

www.picaxe.com/docs/picaxe_manual3.pdf Page 15 on for stepper motor interfacing.

www.joliebrisemodels.co.uk/picaxe/ These two go into some detail about using the Pulsin command in the picaxe programming to deal with output from the RC receiver.

www.instructables.com/id/Robot-1-Little-Jimmy-based-on-PICAXE-18M2/#step0

[cianha]

I'd be looking at large scale (1:5, 1:4 ) radio controlled yacht servos.

[toreno]

could u not just put a slow motor chain drive onto a steering rack then controll it forward and reverse with two contact switches turned on by the actual rc servo from a rc car pushing them?

if that makes any sence at all

[pete1871]

You might be pleasantly surprised on how strong some rc servos are....used to race rc cars and we used to fit 10kg movement servos for steering...they were damn strong, I bet you can get stronger ones to....

[pete1871]

www.kingslynnmodelshop.co.uk/p1385/Spektrum_A6030_High_Torque_Digital_Aircraft_Servo_20Kg-on_order/product_info.html?utm_source=google&utm_medium=shopping&utm_campaign=xigen_shopping_feed&gclid=CPz8sYSxw8ACFabMtAodsnYASQ

See if that works?

[pete1871]

www.kingslynnmodelshop.co.uk/p4429/Savox_SA-1283SG_30Kg_Hi_Torque_Digital_Servo/product_info.html

Or this one?

[mt2man]

Hmm 20kg force should be plenty to be fair!

[MiataMark]

Why RC? If the bike is going to be connected to the trailer can't you just run wires (like chariot reins)?

[mt2man]

Because i wish to use this project as part of my HNC project so attaching ropes to the handle bars isnt really upto the standards of HNC, so i am wanting to research into electronics, engineering and fabrication

[Xenocide]

I'd look into a stepper motor and maybe a chain multiplier sort of arrangment as generally a pulse is a degree or two. I've got one I was fiddling about with with an arduino and I can't stop it from turning with my hands. It's about 60x60mm at a guess

[mt2man]

I was thinking about replacing the handle bars with a cog and having a motor mounting to the frame and having it chain driven, the problem i am having is stopping the motor from rotating too far and burning out the motor or breaking steering linkages etc. Which is why i was going down the servo route to use the poteniomenter etc, but it seems the wiper motor idea will still struggle with how car it will rotate.

I have taken apart a servo, and removed the motor, extended those wires to a relay, attached it to a larger motor and it works somewhat. Its very fast and keeps turning untill the poteniometer in the servo reaches its full rotation and then stops, it goes both directions but will be too quick and too many turns for what I'm after, unless i can attach it to a drill or something with controllable speed and a gearbox of somesorts.

[composimmonite]

Rather than adapting plain motor what about adapting an electric ram. The type with a motor that turns a screw thread. As used for electric gates and boat trim adjustment. They operate slowly.

[Xenocide]

Yeah you could try a linear actuator. If you're going for a steering drag arm sort of arrangement you could mount the actuator in line with that and drive it directly.

[mt2man]

I had also thought about actuators! But couldn't really find any powerful enough in rc format, but might be able to adaptt something!

[MiataMark]

Sept 3, 2014 8:17:10 GMT mt2man said:

Because i wish to use this project as part of my HNC project so attaching ropes to the handle bars isnt really upto the standards of HNC, so i am wanting to research into electronics, engineering and fabrication

I wasn't thinking of ropes but more just removing the RC element, but if that is part of your project then fair enough.

Although ropes might be more exciting...

[lewist123]

Just use a jumbo RC servo as linked above. A 30kg servo should easily be up to the task of turning the steering. You can then use standard RC gear, or feed the servo the required pulses using some other controller.

[mt2man]

What's people opinions on these?

pages.ebay.com/link/?nav=item.view&alt=web&id=261573919088

I'm not entirely sure it will be quite upto the task, but for £20 it might be worth a shot!

Only concern really is the plastic arms you attach to the servo, I can't see them being strong enough really