Archives

All posts for the month August, 2013

Ramifications…

Posted by Jai Cornes on August 17, 2013
Posted in: Robots. Tagged: . Leave a Comment

Oh! So the whole point of that little lecture on DC motor control was to point out this:

tiwi2

This sexy AutoDesk Inventor 3D simulation has motors bolted via the static face to the chassis, with a minimum of distance between the support and the wheel. Because that’s optimal, and because that’s normal for brushed motors. The motors have only just arrived, the simulation only has 4 parts *and it is already wrong* because it makes assumptions.

Which is not a big deal. But it’s a warning. “It worked in CAD” is an insidious trap for young players – the question is, when it fails to work in real life, do you change the part to match the drawing, or the drawing to match the part?

Oldskool.

Posted by Jai Cornes on August 15, 2013
Posted in: Uncategorized. 2 comments

A non robots post! My friend Nathan, who is possibly more addicted to coffee than I am, and certainly more of a connoisseur, recently had a terrible experience – the handle on his coffee machine broke!

It is, I gather, a La Pavoni style lever machine, and this is the bit that broke:

2013-08-11 19.50.12_mid

 

Tragedy.

Continue Reading

Tiny tiny tiny

Posted by admin on August 14, 2013
Posted in: Robots. Tagged: , . Leave a Comment

I think I now have all the parts for the tiny project I’ve had in mind.

It starts with the omniwheels:

omni

 

These are smaller than I expected, but that’s fine, everything else is going to be small too. Omniwheels are slightly less useful than Mecanum wheels , because you can’t create the kind of sideways movement you can with Mecanum wheels, but that leads to some drive theory a little outside the standard “4 wheels and a gripper” paradigm.

Continue Reading