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Old 05-06-2011, 09:02 AM
JensR JensR is offline
Green Horn
 
Join Date: May 2011
Location: Bath, UK
Posts: 176
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Default Re: CAT Grader in 1:14 with M-Series controls

Wow, thanks very much folks

> Quite the Frankenstein!

#hahahaha#
Yes, I have sourced bits and pieces from "everywhere". Lots of modified parts from R/C cars (Tamiya, HPI, Traxxas) or circuit-board accessories (spacers and these threaded "stands") and lots of parts from Conrad and some from robotic companies as well as DIY stores.

Glad you liked the ripper/scarifier, The Machinist. I changed the design slightly for the front.

It is a bit more sturdy, but wouldn't easily fit on the rear.
The monstrosity that is the lever is rather terrible, in either case:

I was thinking of using a low profile servo and sinking it into the 30mm square tube so that only the servo arm sticks out. But these are rated at only half the torque of the full size servo and I am not sure whether I should give it a try.

As to the controls: They work great - but I am still learning them. It's not easy to control so many functions. Also I had to set up my transmitters properly so that the controls aren't too twitchy. If you let the servos run at full speed, even a slight twist of the stick will completely change the position.
I also added a mixer so that leaning the front wheels still leaves them pointing forwards.

BTW, I don't think I'm skilled with electronics - all of this is simple electrics only: Cut the wires to the transmitters' potentiometers, crimp on servo plugs (tedious, but easy), extend cables to joysticks' potentiometers which also get a crimped servo plug and you are done.

I've already done a few videos. But they are all pretty bad and flickr's compression does not help.

Test in corridor, with improvised controls:
http://www.flickr.com/photos/22070130@N07/5190391463

55 seconds of grading:
http://www.flickr.com/photos/22070130@N07/5524641557

This one is sped-up, showing what I did to the beach
http://www.flickr.com/photos/22070130@N07/5525285576/

Cheers
Jens
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