Edubot a good idea, but need work.

The edubot kits are a great idea, but I am disappointed in the mechanical aspects of the kits. Observing students working with them for the first time, they have a lot of trouble building square chasis, mounting motors and wheels so they don't bind, bulid a caster that works, etc. Square axels in a square hole don't turn too well. Mechanically/vision challenged individuals have trouble
with tiny collars and set screws.

The electrical components mated to a Lego or even K'nex chasis would be cheaper-better-faster. Since there is FIRST Lego League, I am surprised this was no done.

As a matter of fact - I think I will suggest to our team as a project figuring out how they could incorporate the Edubot motors on a Lego or K'nex.

[Neal Probert]

I agree, this kit needs lots of improvement. We're probably the guinea pigs for it. I was hoping that this kit would allow us to model and prototype the full size bot.

I didn't think there was enough variety in the metal parts for building up structure. You have to cut pieces to fit, leaving you with a mess of parts useless to do something entirely different.

I would rather have round holes as well. Also I would dispense with the hex wrenches and go with philips, torq or even flat screwdrivers.

The collars with the set screws are not very good and don't seem to hold well. A premade caster wheel would help. Btw, can we dispense with the big honking joysticks and use a gaming pad instead?

Come to think of it, I think the old Erector set was better and easier to work with loads of pieces in varying size and length. I don't know if the newer Meccano sets are any good.

[dlavery]

I actually think the EduRobotics kit is pretty good, and very useful for a lot of pre-competition season activities. But you have to have realistic expectations of what you can do with the kit, and the purposes for which it was intended. Equally important, to have a good experience with it you will need to understand how it was intended to be used, and how how the parts were designed to be used.

Square axles in a square hole don't work too well

That is why all the kits include bearing plates. All those little bars with 5 holes that line up perfectly with the square holes on the long structural beams. The ones that provide nice, centered, round holes to support the axles and prevent binding. The ones that are very carefully described in the EduRobotics Mechanical Handbook. In other words, RTFM!!!**

You have to cut pieces to fit, leaving you with a mess of parts useless to do something entirely different.

This gets right to the issue of understanding the philosophy that was used to create the kit. Tony Norman provided the key to this when he previewed the kit at the 2002 kick-off. As he described the structural components that would be provided with the kits, he said (paraphrased) "when the teams build their real robots, they have to work from raw stock materials - beams, sheet goods, and rods. The kit is designed to help introduce those ideas. It will include beams, sheet goods, and bar stock. From those raw materials, you can use the same basic techniques for fabrication that you will need to understand when building the competition robots (e.g. cutting, bending, forming, joining, drilling, etc.)." The kits were not intended to be infinitely reusable replacements for Erector sets. You are expected to machine your raw materials into unique shapes that are used to demonstrate a particular design concept or idea. Just like the real robot competition, you have a finite supply of materials initially available. If you use up all your raw materials, you can go and buy more (see the EduRobotics mechanical parts web page).

It is particularly important to understand that the EduRobotics kits are not intended to be a shake-the-box, be-all/end-all solution for prototyping robots. You should not expect that everything you will need for your prototype design will be supplied in the kit. You won't get all the parts you need for your FIRST competition robot in the FIRST kit of parts, and you probably won't get all the parts you want for your prototype in this kit either.

Instead, you should look at the kit as a starting point, from which you can (and should) extend and expand upon. If you don't have the exact structural member you need in the assorted metal shapes, then fabricate your own from wood and add it to the system. Don't have the an optical sensor you want in the kit? Get one from Radio Shack for $0.99 and figure out how to interface it to the robot controller! Go back and take a look again at the intro video - note that during the workshop at the kick-off last year, the participants didn't limit themselves to just the kit parts. The basic structures are built from kit components (the beams, sheet goods, and rods), but there are also a lot of "custom additions" made out of styrofoam, paper, cardboard, and tape. And all those mini-teams were able to put together a working system in only four hours.

Alan - you have exactly the right thought in mind when you said you wanted to challenge your students with interfacing the EduRobot motors with Lego and K'nex parts. Learning how to expand on the kits should be a part of the prototyping process! If we view the kits as a too-limited set of resources, then maybe we need to look at the situation from a different viewpoint. We should look at them as sets of raw materials that provide quick solutions to a lot of the basic infrastrucure needs (control system, motors, wheels, etc.), upon which we are encouraged to hang custom solutions. So get creative!

Btw, can we dispense with the big honking joysticks and use a gaming pad instead?

Just wait a while...

-dave

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** RTFM (Read The Frick'n Manual)

[Neal Probert]

You make a lot of valid points regarding the kit. Something to get the hands dirty and feet wet on putting this stuff together.

However, it is time consuming and detracts a little from learning the basic principles. A team will have to make the time to get together and work with this in the pre-season.

It's also a bit expensive for classroom usage, which is the direction we want to take next year in getting the students warmed up for the season.

However, it makes for a great way to get into pre-season competition.

Btw, the kit does not use gears, but relies on sprockets and chains. I find that interesting. No pneumatics either.

[team222badbrad]

when the teams build their real robots, they have to work from raw stock materials - beams, sheet goods, and rods. The kit is designed to help introduce those ideas. It will include beams, sheet goods, and bar stock. From those raw materials, you can use the same basic techniques for fabrication that you will need to understand when building the competition robots

Dave I know why you like the kit though.....You helped design it.....

Tin snips are not exactly used for cutting raw materials for robots.
They tell you to use these to cut the metal beams and they dont work to well....... It took us about an hour to make 6 cuts.... we tried tin snips they wouldnt cut through, we tried band saw it bent them in the vise, and finally we found out that the good old hacksaw works the best!

The servo gears are cheap we allready broke 2 sets.....upgrade to metal

not a very good selection of metal pieces, you really only have enough to build a good frame

You only have 1 pair of 4 wheels that are the same size.

The bearings are difficult to line up on the rectange holes.

We cannot find an allen wrench to fit the locking collars for the shafts, the one we have that came with the kit is too small.

Bad Brad

[Johca_Gaorl]

Originally posted by team222badbrad
The servo gears are cheap we allready broke 2 sets.....upgrade to metal

You only have 1 pair of 4 wheels that are the same size.

I noticed both of these things, and agree that they needed to upgrade to metal. More than one set of 4 wheels would be nice too.

[Cory]

Originally posted by Neal Probert

I would rather have round holes as well. Also I would dispense with the hex wrenches and go with philips, torq or even flat screwdrivers.

Replace hex wrenches with Phillips? Are you crazy? flathead screws and screwdrivers have to be one of the worst inventions in the history of the earth. It is not an easy task to tighten a flathead bolt/screw, because it is constantly slipping out of the slot, and as soon as you put any significant amounts of torgue into it, you tent to mangle the slot, making next to impossible to remove it. I think hex wrenches are great, and would use them over a screwdriver any day.

[Adam Y.]

Tin snips are not exactly used for cutting raw materials for robots.

Errr use a hacksaw. It's like cutting butter with a knife.

The servo gears are cheap we allready broke 2 sets.....upgrade to metal

How did you go that??

You only have 1 pair of 4 wheels that are the same size

How hard is it to get aircraft tires the same size from a hobby shop? I have to say though its quite annoying working with such tiny pieces.

[dlavery]

Originally posted by team222badbrad
Dave I know why you like the kit though.....You helped design it.....

WRONG! I had nothing to do with the design of the EduRobotics kit hardware. The first time that I saw it was along with everyone else at the 2002 kick-off, when Tony Norman was showing it around, and the rookie workshop was held. And I didn't get one into my grubby little hands any earlier than anyone else did - I waited until they were avialable and bought one through the Innovation First web site.

But what I have done is really try to understand what can be done with the kit and how it can be expanded, rather than focusing on what it can't do. Where I have had ideas for improving the kits, I have been very quick to send my suggestions to Tony and the folks at IFI. But I have no expectation that they will give my suggestions any more weight than those from any other source - nor should they. As a result I have been quite happy with the functions that the kit has provided that have allowed us to conduct rapid experiments with autonomy, adding sensors, new interface designs, etc. One of the results has been the set of autonomy exercises we wrote (which, hopefully, other teams will also find useful).

I may be alone on this, but I like the relatively small size of the parts. It has meant that I can put togeher a robot while sitting with the kit parts spread in front of me on the table in my den, while watching reruns of "Magnum, P.I." at 2:00 in the morning, and I don't have to worry about slinging stuff all over my garage shop. And when I am done, it all packs up into the little white box that fits confortably under one arm, leaving the other arm free to hoist a 52-ounce Super Big Gulp of Diet Coke. What more could you want!

-dave

[ahecht]

My biggest complaint is the mounting screws on the motors. You need a box wrench to tighten them, and it is really easy to strip those holes. What was wrong with the #8 screws they used on everything else in the kit?

Also, the chain is pretty lousy. The chain that came with my Lego Technics kit was thicker and stronger.

Still, the miniFIRST teams here at WPI have been able to cook up some pretty cool stuff.

[team222badbrad]

WRONG! I had nothing to do with the design

Dave I saw your name somewhere that said you helped do something, can't remember where though.......

Quote taken directly from FIRST EDUrobotics-A Primer for Success

Use the tin snips to cut, from both sides, to the notch in the corner.

We broke the one gear by just driving it around.......

[DanL]

My biggest complaint about the kit is the lack of chain. After making the drive train they described in the Module, I had about 5 links of chain left over. I might be able to put it to 25, 30 links if I move the wheels really close to the motor shaft, but still, thats not enough to even hook up a third wheel. How expensive is it to make a plastic chain? The InnovationFIRST site says 6 bucks for a foot, but I'm sure you could make it cheaper. On the other hand, how easy is it to find a chain that fits? I definately think they should have included more chain or found a way to produce it cheaper.