How much wood CAN a MicroBot carry, if a MicroBot would carry wood - Which It Will?
Probably should have checked this out FIRST. Turns out the CRAB has a weight limit - which is about 62 grams or about 2 1/4 ounces. The BotPot now weighs - a bit under 7 ounces (220 grams). That SHOULD have been Design Criteria #2 (the first being Hide The Bot space).
The obvious solution would be to turn the walls of the Pot thinner. And IF I'd turned this prototype out of light dry wood - say poplar, claro walnut or magnolia for example - part of the weight problem would be taken care of from the get go - and the piece wouldn't deform much due to moisture loss shrinkage. Naturally, never choosing the easy way, I started with "green" wood - and California Pepper Tree wood.
Now wood turners have been turning paper thin pieces from wet wood. But they turn basically cones, NOT "hollow forms". Trying to turn a hollow form with thin walls - in green wood - is an exercise in futility (or insantiy). Green wood doesn't have the strength and rigidity of dry wood - so it flexes more and more as the walls get thinner.
Solution:
Get the rough shape and hollow things down to about 1/4 inch wall thickness - and then let the piece dry some.Problem:
Green wood deforms as it dries - so what had been centered and symetric - doesn't stay that way since the grain ain't symetric. THAT means each time the Piece In Progress is chucked up on the lathe - it has a new center! And THAT means you can't turn symetric thin walls. And THAT means there's a good chance of turning right through the side of the piece. With probably 10 hours into this piece - so far - there's no way I'm going to risk losing this piece at this point.Solution:
Holes! Lots and lots of holes. In the turning world that's called "piercing". Just keep drilling holes until the piece's weight is at or below 62 grams.Problem:
The piece now weighs 220 grams. To get to 62 grams I'd need to remove 158 grams - which comes to removing 72 percent of what's there now. Three quarters of what I have - has to disappear, leaving just a quartrer of what you see in the photos above. Not sure that can be done - without destroying the look of this piece - which I like.Solution:
Use a lower gear for the CRAB bot and hope more torque equates to more load capacity. Would mean the BotPot would crawl away rather than scurring away - but hey - it'd move! (Life is full of compromises).So, I'll appeal to the HexBug folks and see if they can be of any help (are you listening Innovative and Imaginative HexBug people?).
Alas, after two days of waiting for a response from HexBug - which was never to arrive - time to try again.