screwjack actuator

Need technical help on some problem? Let us know and we will see what we can do
Frank Skilbeck
Posts: 39
Joined: November 1st, 2017, 9:20 am
Contact:

screwjack actuator

Postby Frank Skilbeck » May 21st, 2020, 12:43 pm

Looking to activate a canopy opening and a commercial linear actuator is going to be a bit too long to fit in easily. One option would be to convert a servo to drive a threaded bar with end stop microswitches, similar to an electric retract. Anybody done this?

Barrie King
Posts: 158
Joined: December 4th, 2008, 9:35 pm
Location: Retford, Notts
Contact:

Re: screwjack actuator

Postby Barrie King » May 22nd, 2020, 6:21 pm

Yes I did it for a mate to operate wing swing on a small Tornado. You first need to remove the internal stops on the gearbox to allow it to rotate fully, then take the wires off the feedback pot.
I will have to check what I did next.

Alan King
Posts: 88
Joined: May 8th, 2011, 3:38 pm
Contact:

Re: screwjack actuator

Postby Alan King » June 17th, 2020, 11:27 am

did a similar thing with a servo too but instead of microswitches used a linear potentiometer to stop it.

process I used was to make up a screw to fit into servo output, I used a cheap metal gear servo, literally used a woodscrew and threaded end of it to screw into servo where belcrank arm retainer screw would normally go , locked it in place on the output arm.

I then removed the potentiometer and fitted the linear potentiometer , this was controlled by the screw travel.

nut to fit screw was made from phosphor bronze drilled and then self tapped with a screw of same pitch.

you could also possibly use a rc yacht winch servo which you can adapt to pull canopy up and down on a cable arrangement.

Frank Skilbeck
Posts: 39
Joined: November 1st, 2017, 9:20 am
Contact:

Re: screwjack actuator

Postby Frank Skilbeck » June 18th, 2020, 12:27 pm

Alan thanks, we'd come to the same conclusion and have just received a hitec winch servo, this is 3.5 turns so with the standard pulley has around 10" of movement. We'll be able to put in a bit of slack and set it up so that by increasing the "throw" we can slide the canopy back off it's rails for removal. Well that's the theory.

Steve Perry
Posts: 227
Joined: July 12th, 2015, 7:47 pm
Contact:

Re: screwjack actuator

Postby Steve Perry » June 18th, 2020, 8:53 pm

Have a look at one of those low cost Hobyking retract units that use screw jacks, pull out the jack and electronics from one and you have a plug in solution :)
Rapid RC stock Hobbyking stuff and may have one that you can eyeball at a show if there are any this year, try an email to Rapid asking them if there is one that has the travel that you require :)


Return to “Technical Help required”

Who is online

Users browsing this forum: No registered users and 3 guests