Simple BOT

BeckettM

New Member
Here's a couple of quick pics of a BOT I made.

It was inspired to use for a classroom project on problem solving, in a maze environment.
The commercial product while much faster, was too quick for the children, and the "feelers" on the touch sensors used to bend, and affect the repeatability.
It was also rather hungry on batteries.

The rear is a Tamiya caster, and using the solar motors it is very light on batteries.

Enjoy
Mark
 

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BeckettM

New Member
Thanks

Thanks for that Peter.
The bumper was a key element in the design.

I have attached a close-up, and for anyone keen to copy it, here are few key points :-

* Use fairly high force microswitches (they provide the spring).
* The bumper mounting holes may need to be 'adjusted'.
* The mounting bolts are tapped then locked with a nut (alllows the bumper to float).

For those unsure, the design provides left, right and centre detection (left, right or both switches), as well as allowing some amount of deflection, and non marking of furniture.

The battery holder became a last minute recycled drive holder, which does the job, but needs to be addressed in the coming future.

The chassis was made from 4mm aluminium to allow for drilling and tapping.
If anyone wants the chassis layout as a pdf, let me know.

cheers Mark
 

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BeckettM

New Member
Andrew
Sorry about the delay...Didn't have any chance to access the site for a while.

The board is a High Power 18x Board (CHI035), and uses the LD239D.
The motors were sourced through the Rev-Ed On line shop, and enough parts to make two complete units along with some other bits, to compensate for the 12 pound freight.

Having said that, the parts were delivered to NZ and our rural mailbox in about 4 days.

If you want something that fast, these aren't it, however they have very low power consumption, and repeatable performance was important.

Good luck with your supply

I have seen a reference to some VERY low power steppers on Sputz side of the water.
http://www.goldmine-elec-products.com/products.asp?dept=1106

The next version (if I get some time) would try to use the logic chip from an optical mouse, in order to sense direction and travel, or use stepper motors.

As before, let me know if you want more details. Email me at m(no space)beckett@paradise(fullstop)net(fullstop)nz

(It may be easier than waiting for a return)
Mark
 

Michael 2727

Senior Member
The next version (if I get some time) would try to use the logic chip from an optical mouse, in order to sense direction and travel, or use stepper motors.
Mark the logic chip in an optical mouse are actually a low-res Digital Camera, they
are around 36 to 81 or more pixels and work very fast, maybe a little too fast to be
useful with a picaxe, but who knows, will keep you occupied for 10 mins anyway. :)
 

BeckettM

New Member
Michael
Thanks for that info...I'm sure the 10mins would end up as 10 days....

We had some versions that while normally running at 4Mhz? they had the option to use an external clock in a test mode....and this looked promising (well interesting)

I had also toyed with using one of those Digital compass, but mice are cheap..especially as they were thrown out, with some unused.

Cheers
Mark :cool:
 
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