Cheap-ish robot platform

Hi,

Been lurking for a while, time to post something !

I spotted this RC truck on EBay from Seben-Racing and though it looked ideal for conversion to a robot chassis.

It’s also available from Amazon

amazon.com/Remote-Control-Scale-Monster-Yellow/dp/B000ODT7RK

The truck comes with tank style steering which is on/off rather than proportional, still, it was amazing what could be achieved with such a cheap model.

Stock, it will spin on the spot, climb all sorts of objects and gradients.

It has independant suspension and gearing to each wheel and runs from two small-ish motors. It is VERY big and came in an enormous box.

Construction is better than expected for such a cheap model, but the tyres are some kind of foammy PVC moulding. Apart from that, lots of space on board and has springs at each corner. The transmission is by gears down 4 articulated arms to the wheels.

wilhelmy-it.de/seben/pictures/racing_king/king.html

youtube.com/v/GFLU0xfkD3s&hl=en

I thought it would be a good idea to get rid of the on/off controller in place and swap it for a Sabertooth 10x2. Photo’s below.

http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1095-1.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1096-1-1.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1097-1-1.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1098-1.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1099-1.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1100.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1101.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1102.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1108.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1109.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1110.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1113.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1114.jpg
http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1115.jpg

The body shell comes off easily and the lights disconnect via a small connector.
I used the original battery pack (one photo shows a lead-acid I was using for testing) and cut out the rest of the controller and reciever circuitry.

The Sabertooth was installed and connected to the motors and original battery. I added an old 27Mhz proportional set I had lying around to test with before I move on to installing a small laptop on the chassis.

I got smoke

Found that alongside the usual noise supression capacitors on the motor, there were two electrolytic caps hidden from view, for some reason they didn’t like all the nice PWM I was pumping in and complained smokily !! Cut them off and all ok, left the ceramics in place for supression.

All runs fine now and I have good control of speed and direction.

youtube.com/v/Qdr3425YmsA

Much cheaper than the Emaxx option !!

Have to find something else for my Manoi to practice its lifting on :slight_smile:

http://i88.photobucket.com/albums/k199/OracsRevenge/robolifting.jpg

Have you checked the performance with any additional weight that might be represenative of the weight of a laptop and additional bot gear?

Hi,

I just loaded it up with two old style Dell laptops which are 3.4 kg each

These two together took the springs about 1/2 of their travel. The robot seemed a little slower, but no straining noises or anything like that.

So thats about 6.8 kg ( 15lbs) max limit.

The laptop I am hoping to put on it is only 1.5 kg (3.3lbs) which leaves plenty of scope for the rotate kit and controls.

As I said, not a perfect solution, but a cheap and cheerfull way to get me straight into the programming and control side of the robot without worrying about the chassis too much.

I also have a 4WD2 assembled unit in case I fancy going back to a smaller indoor rover.

The below might be another cheap starter platform. Fisher-Price apparently makes their riding toys pretty tough. One lady, who said it was too fast for her child, said it was still too fast when she rode on it.

walmart.com/catalog/product. … id=4308023

Hehe,

I did look at kids vehicles, but was not happy with the power, drivetrain, motors, akerman steering, etc

And they make an awful whine whilst moving :smiley:

Plus … its pink !!!

At least with the car you get motors, battery, reasonable drivetrain, suspension and useable wheels. I got my daughter to sit on top of it today and drove her around a bit. no breakages yet but it was full travel on the suspension.

OK, if it has to be a “guy” platform: :wink:

walmart.com/catalog/product. … id=5079525

That truck looks like a great hackable platform for how cheap it is!

How big is it realative to an emaxx? (I used to have one, but sold it)

I was just going to ask this! :slight_smile: I’ve been wanting a better vehicle to experiment with.

Right now I have one of those Radio Shack R/C Hummers with two pair of MattTracks on it. It go pretty fast and go up normal curbs with little problem. It only has a single motor and normal car type steering. Maybe I should do some customizing on it, but I don’t know how big of a motor controller I would need (just a single, not a dual). I am guessing a 10A controller would do the trick though.

8-Dale

Hi,

Sienna, with the body shell off, the size is 59 x 48 x 31 cm (or 23 x 19 x 12 inches)

Not sure about the Emax though.

I would point out that the Emaxx is a quality machine. This truck is a toy with potential !

LinuxGuy, depends on what you are looking for. Indoors, I use my Lynxmotion rover, but got this for outdoors work with rough terrain and GPS.

I would imagine that if you got the 10A controller, you would be set up for most robotics experimentation that didn’t involve Robotwars type power and control ( I have a pair of 4QD controllers for my more aggressive robots :slight_smile: )

Dug a big hole in the garden today, so got my son to try out the vehicle amongst the big clods.

youtube.com/v/U5EEBoXVQ-Y

Building up a laptop this week and trying to shockproof it, remove everything it doesn’t need and get it booting from USB memory stick. Will remove the LCD panel as I am sending the VGA port output directly to a transmitter.

Watching that first video, i have to say I’m pretty impressed by the terrain that it transverses. It’s very stable over obstacles. I’m surprised.

I think you have something good to hack there.

Using Dell C610 laptop internals for the on-board procesing, starting to follow the online tutorials for getting Windows XP to install to a 4GB USB memory stick. Not all that straight-forward but certainly possible.

Been going through the C# express tutorials, starting to get used to it. Long time since I did any programming.

Hopefully I will be using Roborealm with an SSC-32 and the Sabretooth 2x10 to initially get this robot tracking things around the garden

Decided to order the SSC-32 and SEQ-01 from Roboshop.ca as the shipping to the UK was about $15 (Shipping from Lynxmotion would have been around $90 !!!)

You are comparing shipping companies, not necessarily robot stores. We are currently working on adding USPS to the website. I do not know how long it will take, but he is working on it. By all means use Robotshop, just understand we are working on the issue.

Ok, thanks, can’t come soon enough, I just had a payrise :wink:

Hi Orac,

As far as installing XP goes it can be done fairly easy, certainly in that space. I cut down XP to under 1Gig for my project, and it can be done down a lot less if you are willing to take the time :slight_smile:

But I do agree getting it to boot from a drive can cause problems.

All the best.

Richard

Hi,

Been playing around with Roborealm and wanted to test camera, laptop, etc before putting it all together properly.

youtube.com/v/FVGC1WKUVmk

The laptop bay is an Ikea kitchen bucket, chopped in half.

I built a MAX232 level shifter to connect the Sabertooth to the Laptop.

I was a bit worried about it all taking off and crashing out of control so I scratched my head for a simple fail-safe.

hobbytron.com/MiniTypeFlyerRCAirplane.html

I decided to make it from a cheap (sub $20) Radio control plane that had already suffered a close encounter of the turf kind. I just disected the whole thing and then swapped the prop motor for a relay that passes power to the rest of the robot when it recieves a signal from the original hand-held transmitter. The reciever board is about the size of a postage stamp and seems to drive the relay ok.

The robot follows the ball pretty well, but I am having a tough time in getting it to concentrate on the ball and ignore changes in lighting conditions.

I am sure that I can fine tune it all, but a little worried that it might lower the FPS to a point where it is sluggish in following the ball.

Lots of testing over the next week. When I am happy, I will start stripping the laptop down and designing a proper enclosure for the electronics and a tilt unit for the camera.

Pete

Hi,

A short progress report.

The systems have been tested out seperately, I have been cramming it all into the robot for the last few days, hoping to get it ready for a Robot show in Birmingham UK this weekend.

Parts so far

Toyabi Skullcrusher RC monster truck
SSC-32 for webcam pan and tilt
Logitech Pro 9000 webcam
Sabertooth 2x10a speed controller
Dell C610 laptop system board + proc + memory + wireless
12v - 19v converter to run laptop from 12v SLA battery
12v 7Ah SLA battery
RS232 - TTL converter (homemade) for Sabertooth
USB - RS232 coverter for SSC-32
Remote control unit and keyfob - this is a failsafe so I can cut power to the Sabertooth speed controller
Belkin USB hub
Old Satelite decoder - emptied this and used it as a box to house it all in.

Software

Windows Xp
Roborealm
UltraVNC - this is a free bit of software that allows me to remote control the laptop m/b on the robot from another laptop close by using a wireless card. It means I don’t have to have a mouse and K/B connected to the robot to tweak things like brightness, etc in Roborealm.

I can also monitor the robots webcam, and if I figure it out, Roborealms new keyboard input controls will mean that I may be able to use the cursor keys on the controlling PC to turn it back into really over-complicated RC car !!! :slight_smile:

Just some wire-tidying to do before I put the lid on and continue testing with the webcam on-top.

Pete

http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1140.jpg

http://i88.photobucket.com/albums/k199/OracsRevenge/DSCN1141.jpg

Hi,

I had a sucessful test of this Robot at a show last weekend.

All worked perfectly.

I have created an Instructable for the project which includes videos, etc of the Robot in action

instructables.com/id/RC-truck-robot-conversion/

The next step is to use the SSC-32 to do more than tilt the camera and to feed back sensor data into Roborealm.

I may also use it for rotating a Maxsonar for tying in distance measurement with RR object location.