Mechanical going Electric

[548swimmer]

I am getting tired of CADding up chassis for robots, so I've decided to build my own over the summer. I've done a bit of research, and decided I want to start off with this chassis: http://www3.towerhobbies.com/cgi-bin...&I=LXGZ87&P=FR

I'm not sure what it will take to make it remote controlled though. I know I need a dual motor gearbox (same supplier) to make the left and right treads run independently. What else do I need to do to make this into a r/c?

[,4lex S.]

There are so many different ways you could build this into an RC platform, it all depends on your resources. If you have enough money for a vex kit with the programming tool (and you want autonomous), I would definitely go with that though.

Searching the rest of the internet for info on how to do stuff like this has often ended well for me, and I would suggest it if you haven't been there already. There are DIY people everywhere.

EDIT: Forgot to mention, if you have an old rc vehicle, and you are willing to let it die, figure out how it works and convert its controls to suit your purpose (nondestructive disassembly is important here, I made that mistake a while ago )

[548swimmer]

Originally Posted by ,4lex S.

There are so many different ways you could build this into an RC platform, it all depends on your resources. If you have enough money for a vex kit with the programming tool (and you want autonomous), I would definitely go with that though.

Searching the rest of the internet for info on how to do stuff like this has often ended well for me, and I would suggest it if you haven't been there already. There are DIY people everywhere.

EDIT: Forgot to mention, if you have an old rc vehicle, and you are willing to let it die, figure out how it works and convert its controls to suit your purpose (nondestructive disassembly is important here, I made that mistake a while ago )

I don't care about autonomous, and I did look for DIY pages. That's where I ran into a problem. I'd love a simple list of what stuff I need, where to get it, what works with what, ect. I know so little about the electrical side of robotics that I don't even know what there is to know. I don't really care about complex programming at the moment, but that could be nice later on if I choose. Can anyone direct me to a website that can teach me he absolute basics?

[Basel A]

I don't know much myself, and I'm sure people here on CD can help you, but at this point it would probably be easiest to enlist a partner on your project (probably from your team, or any electrical person willing to help). Because you don't really know what you're doing, that'd probably be the best choice. Also, that way you could not only make sure it's done right, but also learn what's being done and why. IMO, anyway.

[548swimmer]

Originally Posted by Basel A

I don't know much myself, and I'm sure people here on CD can help you, but at this point it would probably be easiest to enlist a partner on your project (probably from your team, or any electrical person willing to help). Because you don't really know what you're doing, that'd probably be the best choice. Also, that way you could not only make sure it's done right, but also learn what's being done and why. IMO, anyway.

Yeah, that's what I'll end up doing. I found this kit though and I think it'll be a good starting point.

http://www.robotshop.com/New-arrival...basic-kit.html

Any other things I should get to go along with this to start out?

[rahilm]

Originally Posted by 548swimmer

Yeah, that's what I'll end up doing. I found this kit though and I think it'll be a good starting point.

http://www.robotshop.com/New-arrival...basic-kit.html

Any other things I should get to go along with this to start out?

I'm fairly certain that alone isn't going to give you RC capability, it's meant to be autonomous. You're probably going to want to add an XBee Shield, Bluetooth Shield, WiFi Shield, or RF Module, or something of the sort to allow for wireless comms. From there it's writing a program that will send out data from the PC/Control system and then something on the Arduino end to interpret that data and send out signals to the motors.

[JamesCH95]

Edit:
To make that tank unit into something RC you'll need:
2 motors and the 2-motor transmission like you said
Battery pack(s) and charger
2 motor controllers
A radio system, maybe 3 or 4 channels so you could add functionality to the chassis other than driving. Pay attention to the actual control input on the remote and make sure it's how you want to control tank-steer.
Misc wires/cables/switches/velcro

When it's all said and done you'll have put a reasonable bit of $$ into a $15 chassis, you may want to think about getting a larger, more capable chassis.


A buddy of mine, AndyA on CD, and I used to make IFI-powered RC cars.

A victor 883 can handle 24 volts IIRC and can be controlled with a regular hobby RC remote. We coupled a victor 883 with two high-capacity 7.2V RC racing packs wired in series and used those to power a 14.4V companion drill motor. Buying RC stuff second hand from ebay kept costs low. The wiring is very similar to a FIRST robot because you have a PWM signal running to a motor controller that has batteries on one side and a motor on the other, there's just one motor instead of 4, 6, or whatever. It was a very fun hobby and you'll learn a lot, like how a Victor can handle flat-out power for 20-30 minutes without a fan and be fine.

Just a thought.

[Andrew Schreiber]

Originally Posted by rahilm

I'm fairly certain that alone isn't going to give you RC capability, it's meant to be autonomous. You're probably going to want to add an XBee Shield, Bluetooth Shield, WiFi Shield, or RF Module, or something of the sort to allow for wireless comms. From there it's writing a program that will send out data from the PC/Control system and then something on the Arduino end to interpret that data and send out signals to the motors.

That is correct, my personal suggestion if you are stuck on using the arduino would be to use http://www.sparkfun.com/commerce/pro...oducts_id=9367 and connect via wifi. There will be a LOT of programming to do here.

As a warning, do NOT buy just the module thinking you can solder it yourself. They are .1" spaced solder pads and are a real pain to solder to.

If you don't want to program I would see if you could borrow one of the old IFI systems from your team or buy a Vex kit. Personally, I would buy a Vex kit. (Of course, I am LOOKING for an excuse to buy one so I can try to convince KU to put together a team)

[artdutra04]

Originally Posted by Andrew Schreiber

As a warning, do NOT buy just the module thinking you can solder it yourself. They are .1" spaced solder pads and are a real pain to solder to.

.1" spacing is a walk in the park to solder. It's surface mounted (SMT) parts that are royal plain.

All it takes to solder small things is good eyesight (or a magnifying glass, which is helpful for SMT parts) and a steady hand. The latter takes some practice at clearing your mind to reduce shaking, but once you've done it enough you can chug a cup of coffee still be able to solder parts.

A good way to practice soldering is grab some old electronics; 1990s or earlier vintage is recommended as many of these still used through-hole (.1" spacing) parts. Do NOT disassemble CRT monitors or CRT television sets, as they contain very high voltage components that retain deadly charges for years. I'd recommend VCRs, as they also contain a few motors to play with. But just desolder and resolder parts on the circuit boards. To desolder parts you'll need a solder wick or solder sucker (or just heat the solder up and slam the board on the table and momentum will cause the solder to fly out ).

[Andrew Schreiber]

Originally Posted by artdutra04

.1" spacing is a walk in the park to solder. It's surface mounted (SMT) parts that are royal plain.

All it takes to solder small things is good eyesight (or a magnifying glass, which is helpful for SMT parts) and a steady hand. The latter takes some practice at clearing your mind to reduce shaking, but once you've done it enough you can chug a cup of coffee still be able to solder parts.

I can do the .1" spaced no problem the issue is that they are pads and I have never done those. I'm sure someone who were better at that sort of stuff would be able to.

[548swimmer]

Change of plans. I'm going to build my own robot completely from scratch. I was planning on using the following items:
http://www.robotmarketplace.com/products/IL-TKT1.html
http://www.robotmarketplace.com/products/IL-GMS100.html

I will also be creating a chassis myself to mount these. Beyond this, I don't know what I need. Having it R/C would be really cool, and I'm open to programming necessary. As far as only autonomous, I'm not sure that'd be a good to take on that much at once. I am open to exploring it later on though. Any guidance on specific parts or general advice would be greatly appreciated.

[JamesCH95]

Your team is old enough that you might have one, or both, of the edu-bot RCs lying around. These are good bases for smaller robot projects.

IMHO you should go with a drive train and chassis that's a little more substantial, heck for a few bucks more you can get noticeably more powerful motors: http://www.robotmarketplace.com/products/0-72001.html

As for what you'll need:

A speed controller or relay for every motor
A robot controller or R/C receiver
An R/C transmitter
A battery pack
Fuses, switches, wires, ect

[548swimmer]

Originally Posted by JamesCH95

Your team is old enough that you might have one, or both, of the edu-bot RCs lying around. These are good bases for smaller robot projects.

IMHO you should go with a drive train and chassis that's a little more substantial, heck for a few bucks more you can get noticeably more powerful motors: http://www.robotmarketplace.com/products/0-72001.html

As for what you'll need:

A speed controller or relay for every motor
A robot controller or R/C receiver
An R/C transmitter
A battery pack
Fuses, switches, wires, ect

I know that we have some of the IFI systems, is that what you're referencing?

[JamesCH95]

Originally Posted by 548swimmer

I know that we have some of the IFI systems, is that what you're referencing?

Two years, 2003 and 2004 IIRC, included a "mini" IFI RC in the KOP. One used an IFI operator interface and was called the "EduBot controller" another connected to regular R/C (Radio controller) outputs and I can't remember what it was called

Both of these are relatively small and run on 7.2V power, typical for R/C applications. Unfortunately both of these controllers have been discontinued, but you can still find some support info online if you have a PN.

[548swimmer]

Originally Posted by JamesCH95

Two years, 2003 and 2004 IIRC, included a "mini" IFI RC in the KOP. One used an IFI operator interface and was called the "EduBot controller" another connected to regular R/C (Radio controller) outputs and I can't remember what it was called

Both of these are relatively small and run on 7.2V power, typical for R/C applications. Unfortunately both of these controllers have been discontinued, but you can still find some support info online if you have a PN.

How easy would it be to just use an IFI system and scale everything up?
I could get victors from our massive supply, I'd already have the R/C interface. Then all I'd need would be motors and wheels right?