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Newbe question: Mini robot kit vs Panda/Domino + parts


#1

I getting close to getting into the FEZ game. For my first project I think I would like to make an obstacle avoiding bot - either a maze or in an open room. (my background is C# development, with virtually zero hardware experience)

I’m considering 2 paths:

  1. MIni robot kit + Sharp distance sensor
  • or -
  1. Get different parts:
    Panda/Domino
    Motor shield
    Component shield
    Tread + chassis
    Dual motor and gear box (Tamiya ?)
    1 or 2 Sharp distance sensors

Option 2 is a bit more expensive, but not a lot, so price wouldn’t be the decider.

Other than putting together myself, are there any benefits to option 2 over 1? How about 1 over 2?

Thinking long term, I could think of having my little bot map the area - using data from GPS/distance or another sensor, logging data to the mini SD card or via WiFi. But that would be a while from now.

Thanks!


#2

I am interested in what people have to say about this. I am also considering a starter robot kit.


#3

For future flexibility I plan to use a domino. I have a working USB gps, and the domino has a sd facility.

I guess I just answered the question.


#4

Beware Long Winded Post Below.

First things first you have to decide what you want to do with the robot.
Seems you have that in order at least.

Now the differnces between making your own kit and buy one.

My first robot was a kit robot. I love it. I stits on my desk and collects dusk. I did everything you can do with it with out replacing the electronics and modifying the hardware. If you are a pure robotics beginner i would suggest a premade kit.

That being said i don’t mean one you buy and slap together. You can look up simple instructions to turn a breadboard into a kit robot. Two servos some double sided tape, batterys and half a tennis ball you you can have a robot. Its very cheap and somewhat expandable.

The robot kit on this site is nice. Its expandable and easy to work with. It is a good buy for the money as a starter robot. I plan on getting one to play with at some point.

You can always go chris’s route and buy a RC platform and stick some electronics on it and watch as it races around the room fast. I would not suggest this for a beginner. Making a robot work at 50cm/s is hard doing it at 30 miles a hour is even more of a challenge and somewhat limits its real uses. it will be fun i did it witha hpi blitz. It for sure will bring a smile to your face.

If you want to jump in and go for the gusto and make the best robot for what you are designing it for. You buy all the parts seperate. The chasis you buy or make. The electronics and the sensors you decide on the motors and all the little pieces. The one thing this really buys you is when you are done you know it inside and out. You know exaclty what it can do and how. You can modify and tweak to a extreme because its your creation. I say this after owning 20+ robots. I stopped counting or the wife would kill me if she really knew. Every robot I build is a piece of me. I spend months tweaking and working on getting the code and hardware to act exactly right. I generally build them with a single purpose in mind.

So if you gonna make a line follower and you want it to be a good one you can buy the best sensors and the best chassis that is low to the ground. Design covers for your line sensors and tweak the algorithm to utter madness. The top speed line robots hit 120+cm/s. The top maze solvers hit maybe 250cm/s.

I guess in the long run. Do you want the robot to be a piece of you or someone else. If you are going to play in robotoics and not get serious use a kit. Don’t look back. Nothing wrong with that. I do hope if you choose that route it sparks some imagination and pulls you in further. Robotics in all forms can be very exciting.

Sorry I know long winded post. If you stayed through the babble just understand what ever your choice try to get the full enjoyment out of it. As i would say to the next FIRST team I coach becareful this is a long deep rabbit hole with many beautiful views along the way to enjoy. What ever that means :o

PS. You can buy many type of kits that are almost limitless. They come with a much higher upfront cost. VEX and a few other make them and they are uber cool what you can do with the hardware they provide. Just ignore the electronics parts unless you wan to get into robotc and what not.


#5

[quote]
You can always go chris’s route and buy a RC platform and stick some electronics on it and watch as it races around the room fast. I would not suggest this for a beginner. Making a robot work at 50cm/s is hard doing it at 30 miles a hour is even more of a challenge and somewhat limits its real uses. it will be fun i did it witha hpi blitz. It for sure will bring a smile to your face. [/quote]

This advice is dead on. I have put tons of time and money into my RC robot trying to get a stable robot platform.

While I am very, very close to that point, it required tens of hours of reverse engineering and research.

Then again, watching it zip around the street is pretty satisfying. :smiley:

As for the speed imposed limits, just remember that it can be geared down to whatever I need it to be. I don’t need to run it at full throttle all the time.


#6

Though limits do exist on how far you can gear it down. Not in capability but in practicality. Yes i am sure its a blast to watch it fly down the road. remember speed is addicting.


#7

Yeah, at a certain point I will run the motor to it’s limits. I can still limit it in code. Seeing my FEZ take off at 25Mph is pretty fun. though.


#8

A premade kit is always best to get started with IMO. That way you can get right into having fun developing stuff for it rather than battling with creating the robot platform in the first place.


#9

Thanks for the responses.

MarkH - looking over the Mini, my biggest concern would be having to solder in the UEXT and SD connectors in the future. Granted the board is cheap, but the thought of - soldering on the pins and shorting something out and thereby bricking it - doesn’t sit well with me.

I’ve done some soldering in the past, but am hardly a pro. Watching the Fez on Fire video where he added the capacitor was a bit disconcerting to me.

I could see myself wanting to play with writing data to a miniSD/SD card in the future - but that would be a little ways off. Too bad there’s not a similar kit available for the Panda/Domino.

bstag - thanks for the long winded post :smiley: That is part of my concern with going with the kit, rather than building my own - it’s not my own creation. My thought in this regard though, is that I don’t have a lot experience/mechanical parts/tools available for any type of metal work. I’ve done wood working, but I don’t think this is applicable. I could go the Foeke (sp?) route and use plexi as I’ve got a Jig saw.


I want to make a decision that will serve me for a while, as I’m sure the wife wouldn’t approve the purchase of another set of parts for the next bot too soon after this one.

Maybe I go with the Mini kit, then in the future, I can re-use the chassis and motors - just having to purchase a Domino & the 2 shields.


#10

I have a few robots made of mainly wood and a couple made from hand cut plexi. In fact one of out best balance bots in DPRG is a wood frame one.


#11

Interesting … what type of wood did you use? Balsa?

Whats DPRG ?

Thanks


#12

He used plywood I think for the balance bot. I have one made out of cotton wood and balsa.

Dallas personal robotics group.


#13

I think I will go with the Domino solution, due primarily to future expandability and costs.

TinyCLR
Domino - 75
Component Shield - 20
Battery holder - 3
DC Motor driver - 17
2 x Distance - 26

SuperDroidBots.com
Tamiya Twin motor - 11
Tamiya Universal Plate - 9
Tamiya Track & wheel - 7

Total: 168
Compared to the 175 + 26 (2 distance sensors) = 201

With the difference in pricing I can get this as well:
1x Distance - 13
Wire - 2
Servo - 19
Total - 34 + 168 = 202

So for a $1 extra, I can mount a servo with a distance sensor, or I can get an accelerometer instead of a couple extra dollars.

Is there something that I am missing here?


#14

I own 3 tamiya twin motor gear boxes. Include replacing the motors and buying some ear plugs. The stock motors draw mucho amps. The gears are noisy as hell.

Saying that I have a robot built on almost the same platform. I bought the bull dozer kit and put the control electronics on top of it. You can also find cheaper prices at http://www.pololu.com for the tamiya stuff…

You can also look at
http://www.solarbotics.com
http://www.pololu.com/
http://www.trossenrobotics.com/
http://www.robotshop.com/
http://www.dfrobot.com/

Awesome research site for beginners http://letsmakerobots.com/
Go read explore before you order.


#15

Thanks for the reply and feedback.

I’ve always liked mechanical stuff and I’m a MS programming nerd. So this (FEZ) seems like a good fit!

I’ll take a look at those links.


#16

in response to the tamiya parts… they are very plastic fantastic. Not terribly good quality.

Spend the money on a better product.


#17

The tamiya parts are cool for fast prototyping with less costs. You will have a twin motor and tracks for just over 10 dollars.

The comments posted are correct. They are noisy and completely plastic. However, for something that costs 100 dollars or more (for a chassis with tracks) comparing to a 20 dollars home made chassis with tamiya kit can’t be compared in my opinion.

It’s cheap, you get what you pay for. :stuck_out_tongue:


#18

Thanks for the warnings about the motor/gearbox. When the motor(s) go up, I’ll consider getting a quality ones at that time.

This is what’s important at the moment for me. For now, I just want to get my feet wet and there seems to be good sized learning curve in front of me - even if it’s Freakin’ Easy :). Once I feel comfortable with the electronics involved - a bit intimidating for me - then I can move on to upgrading my mechanics.

I couldn’t justify adding another $200 to the entry price.


#19

The motors will run along time. The issue will be battery usage for performance. You will replace you batteries 5-6 times more then a lower amp motor. Even though both give the same torque and rpm.


#20

Oh ok … I thought the issue was with reliablity.

I was planning on using rechargeable AAs to drive the motors (and another set for the FEZ when it’s unteathered), so hopefully this won’t be an issue.

That said, maybe I should put a (not theMabuchi FA-130 as that’s the motor being used) Solarbotics on my ever growing list …

I assume that the noise issues people mentioned are related to the gearbox. Is a Pololu or Solarbotics motor/metal gearbox combo a better (albeit twice as expensive) option? Will their shafts work directly with the Tamiya treads?