VEX-Lego Hybrid: Mini PackBot

[Steve0100]

Howdy All-
Inspired in part by the Mythbuster's VEX PackBot, I've made a mini- version. It's been a testing and proof of concept platform for a number of VEX hacks and experiments.

It's a fusion of Lego and Vex, with some Erector set parts as well (absolutely essential for any VEX hacker).

I'll call it VLEP 1.0 for the hell of it. (VEX Lego Erector PackBot)

http://static.flickr.com/49/169833388_be4e4a5238.jpg

http://static.flickr.com/55/169833390_c97a7d498e.jpg

http://static.flickr.com/46/169833393_82d2b19cbe_m.jpg

http://static.flickr.com/68/169833395_01d9f83a8c_m.jpg


You can view a few other more- detailed photos on Flickr, user name steve0100
http://www.flickr.com/photos/58208036@N00/

VLEP VEX Hacks:
1) Motor output to Lego Motors, re-use of motor casing for electronics
2) Mechanical linkage of VEX and LEGO parts
3) Many Erector Set connecting parts
4) No motor clutches- I really don't think they work that well anyway
5) Where is the hidden RC receiver?

This has been a very educational project, with many other hacking tangents. For example, I've experimented with several different new ways of mounting the motors (More later, including pictures. It involves drilling through the void space of the motor to create more mounting points/ Bolt pass-throughs(Note: this void space is taken up by a potentiometer in the servo, so NO drilling through your servos). Take apart a VEX Motor to see what I am talking about, and If you'd like to interface a Lego or any other small DC motor, all you need is a basic soldering iron, a de-soldering pump ($8 RadioShack, pick up a VEX motor or two on clearance while you are there :) )

My next step is to add sensors and programming, and to take care of the slippery Vex tread.

Don't be afraid to take apart/ Mangle/ open/ your Vex Parts. Just be sure to share it when you do, and happy hacking!
Steve

[Bill_Hancoc]

Very cool....now that makes me want to get a VEX set...again very cool. now imagine a vex frc combo bot

[Rohith Surampudi]

that is extremely cool, how did you wire the legos into the VEX controls?

ps. nice pictures, very clear and crisp

[Steve0100]

that is extremely cool, how did you wire the legos into the VEX controls?

ps. nice pictures, very clear and crisp

Hi Rohith
Thanks! I credit a beautiful, bright cloudy day here in Oregon for the pictures. Perfect light.

As for the Lego motor interface,
here's a picture that will help explain:

http://static.flickr.com/69/169833399_1e6fb36a4e.jpg

You basically just take apart a VEX motor module and desolder the DC motor from the circuitboard, which contains the electronics to decipher the Pulse width Modulation signal from the controller and to drive the motor.

To get to the motor, you need to remove all the gears. The last gear at the bottom of the stack, the large white flat one, will come off with a gentle pry with a small screwdriver. This will reveal the second motor screw. remove the screws, and pry apart the bottom part of the module.

After desoldering the motor, you then re-solder a lego wire connector in place of the motor terminals (snipping off the excess wire- not shown in the photo)

This would make a great beginner solder project. Just be sure that you wear eye protection whenever you solder, especially when using the vacuum solder pump. Also- I use lead-free solder, which works well, just keep in mind that you will not get the same shiny finish that you get with lead solder that tells you that you have a good solder connection.

Keep an eye out for these motors at RadioShacks- now that they are on clearance, many stores have frequent Clearance blow-outs. Just last week I snagged a few more Vex accessories at an additional 25% off. $7.50 motors gave me the courage to take one completely apart- which turned out to be very easy and informative.

Steve