CAT Grader in 1:14 with M-Series controls

[FreddyGearDrive]

Wow! Now this is slick! I'm totally blown away with the radio configuration! But then again, The whole machine is SWEET!
Nice job!
FGD

[JensR]

Thanks again

I was at the beach, testing the new driven front axle - works very well.
But then the steering servo stopped working. It came back to life for a few seconds later. Not sure what happened.
I finished the day steering with just the articulation.

Back home I managed to squeeze in a standard-size servo.

I made a video, too.
http://www.youtube.com/watch?v=pjL3S6gX6h0

Not as good as some of the stuff I see around here, but hopefully still fun to watch.

Best wishes
Jens

[Lil Giants]

That's fun to watch! You're becoming quite the pro at operating it.

Can you dial in EPA for your throttle ch? Just a thought, maybe cut the forward max to 50% so it doesn't lurch while you're blading... maybe less.

That last 15secs, that was a great viewing angle, do you have some one helping you film? Be great to see more footage from that view.

[JensR]

Thanks

You are right about the lurching.
I did have Dual/Rate programmed. (That's the red button in my earlier video of the controls.)
However, for whatever reason, I cannot get the ESC to behave. This means if I get proper D/R in forward, I hardly get any speed in reverse.
Not sure what is happening here. So I disabled it for the moment.

For realism, the steering speed is also too high. I cannot change this on my current radio, though. Might put it in one of those Turnigy servo-delays.

The viewing angle as the end is done by me - I'm sitting on the ground and driving the grader with my left and aiming (more or less) the camera with my right.

Cheers
Jens

[hauler_10-4]

WOW

[rc_farmer]

Glad to see you grading some sand, its very impressive.

[rc_farmer]

Originally Posted by JensR

Thanks

You are right about the lurching.
I did have Dual/Rate programmed. (That's the red button in my earlier video of the controls.)
However, for whatever reason, I cannot get the ESC to behave. This means if I get proper D/R in forward, I hardly get any speed in reverse.
Not sure what is happening here. So I disabled it for the moment.

For realism, the steering speed is also to high. I cannot change this on my current radio, though. Might put it in one of those Turnigy servo-delays.

The viewing angle as the end is done by me - I'm sitting on the ground and driving the grader with my left and and aiming (more or less) the camera with my right.

Cheers
Jens

Help me to understand why you chose to use D/R for fwd/rev or am i misunderstanding whats happening.

[JensR]

Thanks guys

D/R on the forward/reverse gives you a much finer-grained control on the stick.

With D/R the full stick movement means only half (or so) of the speed, so it makes finely-controlled driving easier.
This obviously requires motors that are strong enough with the lower voltages. But if you have that, it's almost like a second gear. Well. Almost.

I hope it's just a setting problem and I can get it back to work and maybe even get it to work better than before.

Hope this makes sense?

Cheers
Jens

[JensR]

Wow, cannot believe it's been another year!

In the meantime I have done a lot of things and still need to do some more.
Given it's my first project of this size, I don't mind, but I really want to get it done - but not rush it too much, either.

I have painted the machine and as it's my design, I decided to go with my "corporate" colours
I made a larger mouldboard and did a better, more dirt-resistant mouldboard side-shift, including a rubber skirting to prevent dirt to fall onto the .
The front blade was increased in size, the ripper servo-saver stiffened up.
The floating mechanism for the circle lift was improved - less drain on the servos, better clamping force.
Circle sideshift was converted from servo to M6 threaded spindle.
Articulation is controlled by a sail servo now, allowing comfortable steering modes.
Improving the saddle rotation is my biggest worry currently. The sail servo does not cooperate with my "hydraulic module" (makes servo speed proportional to stick position, as opposed to servo position proportional to stick position). I know the real machines do not have an active drive on it. Rather they use the main cylinders to force the saddle to rotate. I might have to do that, or will have to look into other alternatives.
I also put a lot of weight into the machine, now at 9.6kg and therefore still slightly lighter than a 16M would be in 1:14.5, but it has helped with traction a lot, especially as the machine is 6x6 (which the 16M doesn't offer ).
The circle drive was improved by having a proper worm&wheel and not mis-using a worm on a regular gear.
I also managed to improve the geometry/kinematics of the whole thing so that I can lift the mouldboard a bit higher.
And lastly, I installed some lights

Here's the collection of images going to through the building stages

http://flickr.com/gp/22070130@N07/13BERN


and here are a few selected ones showing the "recent" stage:





from
http://www.flickr.com/photos/2207013...57626598857828





Cheers
Jens

[dabears]

Looks Awesome!!! Very cool!

[doodlebug]

I like the color scheme! nice progress.

Cheer's, Neil.

[Hemi1966]

Jens, I really like the color. It's nice to see something else than yellow

[Stefan]

Looking great, Jens. Very cool! At some distance you hardly notice it´s not 100% scale. Especially when the lights are on.

Stefan

[Dieselchopper]

Very cool good job.

[JensR]

Thanks everybody! Much appreciated

Did a bit more detail work, painted the new blade and rotation mechanism, installed a better ESC and just these last two weeks built and installed a new better floating mechanism.

Managed to shoot a bit of video, again, not very high quality:
https://www.youtube.com/watch?v=_nXoehdzEL0

Updated pics at the usual location:
http://flickr.com/gp/22070130@N07/13BERN

[Espeefan]

Great updates! Glad to see this machine is still alive and kicking, with some improvements to make it better. I do like the fresh paint and working lights. From the right angle it looks nice and realistic.

[rc_farmer]

Very well done.....

[JensR]

Thanks folks!

Has it really been over a year again?!
Looking at the photos, it seems hardly anything has changed!

http://flickr.com/gp/22070130@N07/13BERN

But behind the scenes, I did a lot of time-consuming improvements on the floating mechanism, serviceability and reliability of the mouldboard sideshift and have converted the saddle-drive with a saddle-clamp, similar to what the 1:1 graders have. The torque generated from the forces on the mouldboard to the variety of gear motors I had used before was just too high. I still think a motorised saddle would be neat, but it would require quite a bit of re-engineering, fitting a larger gear motor and most importantly a sturdy worm drive...

Recent (and ongoing) improvements include converting the front motors to brushless motors with considerably more power. That's done now, but I need to hide the dual ESCs and extra wires inside the frame.

For the next year or so I have a few improvements planned for the main drive as well, plus a whole list of electronic features. All of these will be tested on a wooden mock-up - if they work, I'll transfer them to the real machine.

This will allow me to use the grader while I work on those gadgets. I've been out driving a few times over the last weeks and have done a few youtube videos, which you can see on my youtube channel

https://www.youtube.com/user/YensR/videos

Hope you enjoy these!

Best wishes
Jens