Let's Make Robots!

needing help on a crane/boom to r/c

hello  everybody im new to this forum

 i build custom radio controll semis for a living .all one of a kind.73 build to date.

my new build is a crawler recovery truck .im at the point where i need to start thinking and building the boom,i want to make a working crane/cherry picker/boom/controll arm what ever you want to call it.

 the arm it self had to extend i say about 24 inch and has to pick up about 4 pounds

im running a 7.2v main battery and a 4.8v receiver battry.i would like to operate the boom from my radio.

could i please get some help here.or maybe buy this item from someone


heres my truck build  http://www.scale4x4rc.org/forums/showthread.php?t=21635

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G'day Semijoe, You can get a kit (it needs to be soldered) that is basically the circuitboard from a servo with a beefed up output to drive more powerful motors. You will need to fit a pot on your mechanism to provide feedback otherwise it will work as a continuous rotation servo. There is also a FET version which can handle more power without getting hot but it cost more.

Otherwise if you don't want to solder the kit you may need to buy a servo that has a powerful motor and get the control circuit from it.

Another option is to use a picaxe IC to intercept the RC signal and drive the motor. A picaxe 08M with a suitable H bridge would work using the pulsin command to read the RC signal.

i working on the boom again

 finally i found some motors that can handle the high torque i was llooking for

 question is the motors have a 2 prung for wiring and the receiver is a three prung.any solutions to this ?

i really would like for it to connected to the receiver ,but if not how do i do it

heres link to the motors i bought  http://www.robotmarketplace.com/products/0-B231.html

please help!


and yes i will put a video of it when it is completed

i bought some motors and gearboxes for the boom

the gearbox and motor was perfect size .i tried it out works perfect.under pressur its a no go.



You know what I think would be perfect for this? Servos modified for continuous rotation. They'd be great for extending the boom and perfect for operating the winder. (Assuming you didn't want to perform either of those operations with a big weight on the end.)

You'll need something beefier to actually tilt the boom. There I'm stuck for ideas. Some of the metal geared servos might do the trick. Look at MFA Como for geared motors.

youve ben a big help thanx
I DEMAND VIDEO!!!! Thanks!

Here are some pnumatics.


I think they use Bimba cylinders in their kits so it might be a good idea to go straigt to Bimba for a look, as well.

--"bimba"-- first hit google 


www.rocketbrandcustom.com baby!!

very nice ,but i dont think i want to go in that direct. awsom though!

well lets start witht the boomits 18inches long.it extends another11 inches out .it has 3 functions.with 3 knobs because its a toy.but i would like to convert to r/c


heres some pictures







 Semijoe, I've seen your work, and I admire your craftsmanship. For the rig you're working on now, I can only think of two solutions: 1) Buy something of the rack (but I have no idea where to look), or 2) get blue prints or technical drawing for a real crane, downscale it, and send it for fabrication. You'll have to switch all the hydraulic pumps and stuff for pneumatics. you can then power the pneumatics from a CO2 cartridge, like the ones in paintball guns. Electronic valves for these sizes and pressures are easily available. An electric pump connected to a miniature air tank would also be possible, but rather large. 

The reason why I think pneumatic is recommendable instead of electric motor movement is that electric motors are bulky, and it would end up looking like you've chopped up a robot across the shoulders and strapped it on to your semi.


But then again, judging from your track record in machining skills, you'll probably prove me wrong.

Keep up the good work. 


/ vzz-clck-"Maneuver"