RC Truck and Construction

RC Truck and Construction (https://www.rctruckandconstruction.com/index.php)

- Construction Equipment (https://www.rctruckandconstruction.com/forumdisplay.php?f=6)

- - ADT build (https://www.rctruckandconstruction.com/showthread.php?t=12921)

Hi everyone, I've been tossing around the idea of building a articulating dump truck for some time. So this winter I thought i would give it a try. Now this will not be close to some of the amazing builds that are on this site. This will be more a cut, weld, kinda build. Ive got ton of inspiration from andyathome rock truck build. It won't be modeled after any particular truck but I do have a small toy one from my earlier years that I've been using for reference. Here's a picture of it. .

https://s1.postimg.org/3n0s2k3hxb/Sc...106-214617.png

So i started with some half inch square tubing i had kicking around from a boat trailer build.

https://s1.postimg.org/58u36d94yn/20171028_212539.jpg

I'm gonna run 6 25rpm geared motors.
http://www.robotshop.com/ca/en/12v-2...BoCD1sQAvD_BwE

Rims and tires I'm gonna use the same as andyathome used the wild willies. I got some closed foam inserts for it so the tires won't squat too much with the weight of it. So I got some tubing that the motors would fit inside as I don't have a lathe to turn the inside to size. Drilled some holes threaded it for some bolts to hold the motors in there.

https://s1.postimg.org/280hbnrr0f/20171028_212524.jpg

Cut some metal to attach the motors to the frame so it will pivot in the middle to have some suspension like movements.

https://s1.postimg.org/2xj9o0f067/20171028_212516.jpg

Got the bracket cut out and tacked to the tubes for the motors and bolted to the frame. The front I hard mounted it to the front frame.

https://s1.postimg.org/9g709o2s9b/20171030_204121.jpg

https://s1.postimg.org/16tuxftkrz/20171029_204213.jpg

https://s1.postimg.org/7phlj3i00f/20171031_163007.jpg

https://s1.postimg.org/1bfr1oj19r/20171101_192740.jpg

https://s1.postimg.org/9b9mp34awf/20171029_204117.jpg

For steering I'm gonna go with a 6rpm motor.
http://www.robotshop.com/ca/en/12v-6...gearmotor.html

I got some different wheels comming with more offset to bring the tires in towards the frame more hopefully they will work. Not sure what I'm gonna use for lifting the box either some actuators or a screw lift. I'm up at work now and hope to get some done when I get home. It'll be a slower process but I have lots of time. The body i will try my hand at styrene.

Already some great progress. Looks to be real deal!

Nice progress so far keep it up!

Thanks guys. I've thought out the swivel and hope to get that completed and everything welded up. Also want to finish off the pan for the front. I've made a deal with a buddy and bought his princess auto ( Canadian harbour freight) lathe and mill so might help with more delicate areas.

Great start! :popcorn: I'll be watching this one, subscribed.

I found some actuators that look like rams and emailed for more info. Hers the link to see if anyone else inquired about them.
http://www.servocomponents.co.uk/Ele...ear%20Actuator

Quote:

Originally Posted by Efroeh (Post 159385)

I found some actuators that look like rams and emailed for more info. Hers the link to see if anyone else inquired about them.
http://www.servocomponents.co.uk/Ele...ear%20Actuator

Those are neat, me likes it a LOT! Please do let us all know how well they work out for you. Those would be PERFECT for a few projects I have awaiting to be started on.

Quote:

Originally Posted by skeeter (Post 159389)

Those are neat, me likes it a LOT! Please do let us all know how well they work out for you. Those would be PERFECT for a few projects I have awaiting to be started on.

I will for sure. I think there not gonna be cheap by no means but will have to see compared to hydraulic they might be as good and with out the headaches.

Most likely not cheap at all. I've used the Firgelli/Acutronik actuators on stuff & they run about $70 U.S.D. per unit.

Ok so I got some prices back for those actuators and there not cheap. Prices are 270 to 290 for 100mm ram and 150 each. Plus a controller and programmer about 150 each. Which is a little bit much since hydraulics could be done for that price.

OUCH! For that price, I'll stick with the square type from acutronix.

Quote:

Originally Posted by skeeter (Post 159438)

OUCH! For that price, I'll stick with the square type from acutronix.

My thoughts also.

Very nice build!

I'm looking forward to the updates with a lot of anticipation!

For some while I've been pondering with an ADT build myself, but it likely won't happen for real for a few years more.

Anyways, I was playing with the idea of using gas springs for the bed lift (very cheap) and then a powerful gear motor to pull it back down again with a wire rope. I was thinking something like 2x15kg gas springs 150mm stroke:
- https://www.aliexpress.com/item/free...296134474.html

and this gear motor:
- https://www.ebay.com/itm/231911256302

And then some wire rope around 1mm thickness:
- https://www.ebay.com/itm/222599707119

There is very little extra room to go on for the cylinder with the very long stroke they have to have to get a proper angle on the bed when tipping. I don't think an inline electric motor (like in the electric actuators) will enable you to get a cylinder that mounts in the normal positions or will provide the normal tipping angle for the bed.

Best regards,
Stein :-)

Quote:

Originally Posted by SteinHDan (Post 159648)

That's a good idea for lifting the box. I'm gonna try the actuators from actuonix first as I have a few sitting around.

Also I think I'm gonna change my mind with steering and go to a large scale servo. The gear motor would be good but can't get it to auto center and be harder to control I think.

Auto centering for steering is nice, my haul truck uses hydraulics and it is difficult to drive, centering would be nice. I think the German ones have a pot wired into the motor for centering the adt, guess I’m saying it can be done but may be too much electronic thought for me :). Keep the progress pics coming. :)

You can get any gear motor to be an RC servo by using a controller board like this one:
- https://www.ebay.com/itm/172264924286
(there are more types)

With this setup, you don't even need to have the pot on the motor output shaft, so for example, you could have a screw drive to lift the bed, but then mount the pot on the bed pivot point. The controller would run the motor to get the right angle on the bed, regardless of the mechanism used to get it there. Also, you could use a linear pot. Or even a multi-turn pot, e.g. with 10 turns to give the full range. Lots of options.

You can get them pre-mounted on gear motors so that it's actually like a normal servo (except that they require 12v / 24v additional power input).
- https://www.ebay.com/itm/131683084318
- https://www.ebay.com/itm/131683049823
- https://www.ebay.com/itm/141859318550

Lots of gear ratios and motor types to choose from.

I think the benefit of these servos, is that they are quite cheep and also that the gear output ratio match much better what you want for the steering servo than a normal RC servo does. They are mostly much too quick and not so strong.

You could also build this from scratch very cheaply using an arduino uno, a monster motor shield, the gear motor of your choice and a 10k pot. I think you could build the full controller then for less than $15.

There is a guy that has build a servo with this approach and described it here:
- http://www.instructables.com/id/DIY-Servo-Motor/

I wasn't actually thinking of having a auto-centering steering in my build. But when you mention it, it's a bit of a nuisance to continuously heard the truck to just go straight. So maybe I'll go that route myself.

I was also thinking a lot on the steering and how it plays with having one gear motor on each wheel. If your gear motors on the wheels have a high reduction, they will not turn when you steer. Rather they will just stay put and make it very difficult for the steering motor to do the steering. This is no problem on the original of course, since it has a differential between the left and right wheels and would allow the wheels to turn in the opposite directions when steering.

So I was thinking to combine a steering gear motor with the approach I used for the Bruder loader conversion:
- http://rctruckandconstruction.com/sh...ad.php?t=12500
It has tank-style driving for the left and right wheels. So when you steer left, the right motors are run faster and the left motors are run slower on the front and the reverse on the back.
I'm thinking about combining these two for the ADT, so that the tank-style steering will help the steering gear motor turn the wheels, especially when standing still or going slowly. I'l thinking on ramping the tank-style steering on the wheels so that when going fast forward or backward, there is no tank-style steering but only normal full throttle on both the left and the right.

Best regards,
Stein :-)

Quote:

Originally Posted by SteinHDan (Post 159683)

Wow awsome explanation of that. I wondered about the drive motors not steering well with the gear ratio I have. But I'll see how it goes. I like the idea of the tank style steering. I'll look into the controller for the gear motor for steering. I'm not very confident when it comes to electrical stuff so I'll see what I can do. Also wonder if that controller would work with 11v. Id like to use a 3 cell battery.

Yes sir, Stein is a sharp cookie. He knows how to explain things in a manner that you get an idea what he's trying to say. He's got a knack for explaining complex things in simple terms, ESPECIALLY when it comes to the confusing, complicated computers!

yes thanks for that information. and easy to read, now I have no reason for not doing that!! another side project to add ;) will be referring back to this information when time comes, thank you again, love this forum and the people on it!! efroeh, keep posting info on this if you go this way, will keep watching,,,,,