This cute little robot project showed up on my twitter feed.
One thing that’s fairly obvious is that the creator is a software type. I’m going to guess that he’s(or she’s) hacked some apps together and wrote up some software. But as they say, hardware is hard. I can help.
Tiny robots have been around since the 1980’s, but I’ve never seen them on the toy market. They always seem to be hacked together in university labs. They look fun to play with though. This is a line follower, about the simplest mobile robot out there.
They can also be very small.
This article has some good tips on how to get started.
I’m going to add the article somewhat. One thing to decide right up front is if this is a hobby or a product. If it’s a hobby project, anything goes as long as you are having fun. If you are planning to go for product, the more disciplined your work right from the start, the more likely that you will get through the inevitable headaches and pitfalls.
First of all, go shopping. Go to the local toy store and see what’s already out there. In this case see how toys for your potential age group are made. Look at materials and assembly methods. Consider things that might have significant impact on the design. Figure out your potential market. In this case, check out what’s coming at the toy fairs. Look for comarketing opportunities.
Second, do your homework. See what others have done before you, for instance the links below. Find out what the state of the art is. I’m going to point out that I knew almost nothing beyond a very little about robots like these when I started this post. Yet I’m able to work toward a working design simply by following my nose and a general knowledge of how to find stuff. All I’m doing is google searches. Believe it or not you can use these techniques to design practically anything.
Find out as much as possible. Especially find people that can help you. This will help get a sound design for your prototypes. One thing you will find
Also start thinking about vendors and open constact with them. DO NOT use stuff purchased from Ebay or other auction suppliers. Go to manufacturers and direct distributers. This will save you a lot of pain when you have to actually make the product. Start asking for RFQ(Request For Quotes) as early as possible. When asking for quotes, think about the quantities that you think that you will need and double them and than double again in the quotes. Ask for Time for lead time for all your parts. Keep an eye out for potential obsolescence. There’s nothing worse than a key part becoming unobtanium in the middle of ramping up for production. Consider manufacturing methods as things scale. The lowest cost will change as the product scales up in quantity.
Third, do your due diligence. Check out any possible regulatory authorities in your market area, which in this case means the world. ROHS is a four letter word, but you need to learn it and remember it. Consult the Consumer product safety people for guidelines, not only where you live, but the US and Europe, Japan and China(Yes I know, but they have regs even if they don’t pay any attention to them) as well.
Consumer Product Safety Commission(US): http://www.cpsc.gov/
Consumer Safety Commission(EU): http://ec.europa.eu/consumers/consumers_safety/index_en.htm
METI Product Safety(Japan):http://www.meti.go.jp/english/policy/economy/consumer/
China doesn’t seem to have a central product safety agency, but does share requirements with Europe and the US.
Not a government agency, but having the seal decreases your product liability and the CPSC will accept testing done by UL and passed as passing their requirements.
If you are selling in Europe this is important.
Last, but certainly not least, ROHS:http://www.rohsguide.com/
This is one of the big reasons to get ahead of the game and use parts from manufacturers
I did some thinking about this before going to sleep last night and had some insights. The first is that you don’t to use lithium batteries. They are a fire hazard and having bunch of them in a room with small children is a non starter. Go with watch cells like the bots in some of the links do. Two, in this case, chip on board is likely to be your friend. You are designing something for production, not a hack, you can take advantage of that. Three. Use motors and not steppers if you can get motors small enough. You don’t need a stepper for something like this. (Did some checking and apparently the choices are vibrator motors for pagers or the small camera steppers. ) Looking at the surplus market, the small steppers are made by Nidec.
TT motor in China.
And Vitech in Taiwan
And some other vendors I haven’t listed here.
Now the fun part(not), starting to chase down spec sheets. Like this one.
For some reason electronic component manufacturers, worldwide, seem to think that spec sheets, especially those for things with mechanical dimensions, like motors and connectors have to be buried deep in their web pages and be poorly scanned PDF files. That is if they are there at all. As for maybe putting CAD models up, somehow the idea that would save a lot of engineering time for poor struggling designers and by making the designers life easier, you might attract business seems to escape motor manufacturers. Trust me on this, if you put easily accessible spec sheets and models on your website I, at least will go out of my way to spec your parts, even if it adds a little to the cost, simply because I want to business with people that take me into consideration.
Seriously, it shouldn’t be easier to find the parts I want on ebay as surplus than is to find the part # and spec sheet on the manufacturer’s website. How hard can it be to set up a search function for motor, stepper, frame size or diameter, working voltage and shaft dia.
Look, in this day and age, the designer’s time is under severe pressure. We are under significant pressure to tighten design cycles and get the product out as fast as possible. Time spent chasing down parts is a luxury that’s rapidly disappearing. Any vendor that realizes that will do well in the end.
Rant over. Ok now some design thoughts, the fun part for me. I had some thoughts. If this is going to be a viable product we have to make sure that there is enough play value to make the cost worthwhile to a parent and the child. The play value has to be longer as the costs go up. Here’s where a little research pays off.
Oh Noes, it looks lit somebody beat us to the punch. Well maybe, maybe not. Now it’s time to think outside the original box and maybe look at what you can DO with a little robot beyond just following a line. One robot isn’t much fun by itself. But suppose you planned for a bunch of robots, each one pretty simple that was a piece to a larger puzzle.
When I start up a new project as an engineering project I start to sketch up the assy. in Solidworks. You can use just about any 3D package for this. I do this to have something tangible for the project as soon as possible. Here’s an early screenshot of the robot.
I’ve got a couple of basic parts, a PC board and my guess at reverse engineering a motor to start. Now all the parts will change as time goes on, but this gives a start and makes the project something sort of real. Note that, for instance none of the parts have cutouts for the wheels or motor and no draft or fillets. And all the parts are mostly neutral gray. I keep the parts gray until I choose what I’m going to use as a material. When I make that decision I will add the appropriate properties to the part
The basic techniques used here can be used for just about anything. Do your homework and see what else is out there. Do your due diligence about regulatory requirements. Start looking for parts. And start sketching out your idea early in the process.
Now why the flat round top? Well I’ve been thinking about some of the things a little robot could do and I was thinking that some of those things could be mad into modules and stacked on top. The flat round top is the beginnings of that.
Any way here’s a quick little guide how to go from a project to a product. It’s not really that hard and Google sensei is your friend. Just plan things out, know your budgets and timelines and you are good to go.
The Let’s Build Series.