48111Re: [SeattleRobotics] FW: Mechanical marvel 240 years ago forerunner of computer!
- Nov 4, 2013Peter>you can't beat a piece of wireThat is why I use GOF serial on proper COM ports for programming.The doll only 'walks' forward seven paces, there is an on switch in the shoulder activated by the dancer, then after a user settable delay (on a pot) the doll walks its paces and stops, I did include some HB Blue LEDS to be light piped to the eyes which blink when switched on and come on when it walks but the girl who made the covering didn't include the pipes.As you will remember the head has to come off in a fight in the nursery so I couldn't put the LEDs in the head.In the past the ENB had used an R/C controlled doll and it often went crazy and looked like an R/C toy.BT connection for theatre props would be my worst nightmare.2.4GHz R/C where the pairing is done by a special jumper cable seems to work ok. I have an effect in Berlin but it is secret until next March when the show opens.The doll has to be carried by a child sized dancer and if I could have found electric motors and gearboxes that were quiet and lightweight and powerfull enough to drive the mechanism I would be really happy!DAvid----- Original Message -----From: Peter BalchSent: Monday, November 04, 2013 11:13 AMSubject: Re: [SeattleRobotics] FW: Mechanical marvel 240 years ago forerunner of computer!
> What I want to know is where did all the backlash go?
If it were me, I'd have the spring that forces the cam-follower against the
cam as close to the wrist as I could get it - so all the linkage rods are in
compression all the time. But you're right: that probably wouldn't be quite
enough. I reckon you can see the backlash in the drawings of the Jaquet-Droz
machine but the Maillardet drawing of a ship is amazingly smooth.
> I have thought about building a Japanese style archer
What the world needs is rich dilettantes with more money than sense who
commision that kind of work. Tim Hunkin's automata are wonderful but clearly
done to a budget.
> No I don't want an umbilical of any kind - wire or wireless - to my
> robots, just some way to put in data as an when and for high level
I was recommending Bluetooth via HC-05 for hobby work but I wouldn't trust
them for anything professional. RN42 are more reliable but even so, you
can't always guarantee a connection will be made instantly. I can imagine
fitting a BT controller for your English National Ballet automaton - a
stagehand operates it via their Android phone during a performance. But,
five minutes before it's due to go on, they find that the BT connection has
failed because the robot has decided to pair with a different phone in
someone's pocket that they were using at rehearsals last week. We have that
sort of problem all the time because we've got half a dozen systems paired
to half a dozen phones and no-one can remember which one they're meant to be
using so they just pick up a random phone and pair it. We have to go round
switching things off to force the pairings we want. (The answer, of course,
it to be more disciplined but we never seem to achieve that.)
If you want a reliable connection, you can't beat a piece of wire.
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