We'll the big event is over. and I'm Excited!!! I won 2 battles!!! Finally I won something!!!

OK enough of that.

Problems encounted.

-1- Radio issues......36Mhz FM sucks but hey we all know this.

-2- Weapon a little weaker in structual streangth that I thought it was.

-3- Weapon not big enough ie does not enflict enough damage.

-4-On inspection this morning I seam to have bent a drive shaft on one of the scooter motor drives.

Possible Solutions

-1- Maybe a floating failsafe to designed around a picaxe to go between the receiver and IBC. Maybe a Spektrum radio

-2- Redesign the weapon to incorperate some changes. Bigger Bar and Belt driven system with Motor mounted inside the Bot.

-4- New scooter motors.

Some interesting figures for anyone interested.

I used a current clamp to measure the current of the Magna Fan motor in stall condition this morning. NOTE the motor used has a bent shaft on it hence these may not be true readings. as shafdt so bent from mounting saw on it and then fighting that the motor does not spin.

Anyways.

12 Volts Motor drew 15 Amps or around 180 Watt
24 Volts Motor drew 26 Amps or around 620 Watt

So I think it is safe to assume that the motor produces more than 550 Watts of useful power at 24 Volts.

You said:

"So I think it is safe to assume that the motor produces more than 550 Watts of useful power at 24 Volts."

In stall condition the motor does not create any work other than creating heat.
It only creates (it's maximum) torque (no rpm) and torque alone is not work.
At stall, 100% of the power stays inside the motor and becomes heat.

I don’t know if I formulate myself correctly but you get the point.

Thank's for that.

So I really need to have the motor working hard almost stalled when I make the measurement then???

Hmm i wonder if welch will lend us orbit to test the stall current on a range of fan motors!
Another fairly effective weapon if the new belt driven bar design gets too hard/expensive is simply a direct driven saw blade of one of those fan motors, to date kang hasn't broken its motor, and retread had inflicted the most damage to jolt in one single match EVER (i think) simply using a thin fan motor and a small circular saw blade!
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YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

Mat and myself have broken 2 of those thin fan motors off a magna by direct driving saws. you end up bending the shaft and the copper plate inside doesn't turn anymore.

This week's project.................

Floating failsafe board to go between receiver and IBC. My order of picaxe chips should arrive monday or tuesday and I hope buy the end of the week I'll have something going.

Also in the works is an automated weapons control system ie sense the presence of another bot and fire weapon. May not be that useful in a fight but will be damn cool.

I've got a floating failsafe working on the bench.

It requires a minimum of 5 good pulses to start but a maximum of 3 bad pulses to stop.

3 bad pulses equates to around 1.5 seconds I hope that isn't to long. but each time the receiver doesn't send out a pulse the picaxe waits for 0.6 seconds.

refer code below

'Floating Failsafe 1 channel
'by Neweyn Millen
'version 1
'30/1/2006

'Using Picaxe 08M

'EXPERIMENTAL VERSION!!! USE AT YOUR OWN RISK

'i/o 4 signal in
'i/o 1 signal out
'i/o 2 LED

main:
b3 = 0
servo 1,150
prog1:
pulsin 4,1,b0
'debug b0
if b0 > 100 and b0 < 200 then floatup
prog2:
if b0 < 100 or b0 > 200 then floatdn
prog3:
if b0 > 100 and b0 < 200 and b3 >= 5 then gosig
prog4:
if b3 < 5 then failsafe
prog5:
goto prog1



failsafe:
low 2
servo 1, 150
goto prog5

gosig:
high 2
servo 1,b0
goto prog4

floatdn:
if b3 > 1 then floatdn2
goto prog3

floatdn2:
b3 = b3 - 1
goto prog3

floatup:
if b3 < 8 then floatup2
goto prog2

floatup2:
b3 = b3 + 1
goto prog2

Comments welcome

Nice Work Neweyn..

If you have an oscilloscope available, can you check the propogation delay from input to output ? I'd be curious to see if the picaxe is slowing the servo signals down significantly..

Have you drive-tested it yet to see how much difference it makes in succeptibility to interference ? a big change-over toggle switch would make it easy to bypass the picaxe and see how much difference it is making
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no cro unfortunetly,
I plugged it into the bot and got nothing so I'm just error checking everything now. I was using a different receiver for testing. I had a servo plugged in and it didn't seam to have any delay.

Some interesting observations

-IBC assumes midpoint of 130 not 150 (IE not wheel movement)

OR

- the servo out command has a small flaw in it. meaning it measure's 20 us out. I had to add a peice of code that converted 150 received from radio to 130 to send to IBC or the bot wouldn't stop when you let go of the sticks.

-There appears to be no delay.

-The failsafe works heaps better on the desk than in the bot but it does work.
It occationally gets a bit twitchy

I just had a look at the IBC/OSMC code, and 150 is definitely the center point, so there must be a bit of slip in the picaxe code somewhere..

Have to do some 'scoping to find out where exactly though.
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I just confirmed some more details.

using just the debug command and pulsin command the pulsin command does read at around 150 not 130. so the error could be in the servo command or of course someware else in the software.

current software only minor changes from previous design.
although it works fairly well now

I have also added some sheilding with alfoild to the micro board and that helped heaps.

'Floating Failsafe 1 channel
'by Neweyn Millen
'version 1
'31/1/2006

'Using Picaxe 08M

'EXPERIMENTAL VERSION!!! USE AT YOUR OWN RISK

'i/o 4 signal in
'i/o 1 signal out
'i/o 2 LED GREEN / PEIZO
'i/o 0 LED RED
'130 is failsafe position

main:
b3 = 0
wait 4
servo 1,130
prog1:
pulsin 4,1,b0
'debug b0
if b0 > 75 and b0 < 225 then floatup
prog2:
if b0 < 75 or b0 > 225 then floatdn
prog3:
if b0 > 75 and b0 < 225 and b3 >= 4 then gosig
prog4:
if b3 < 4 then failsafe
prog5:
goto prog1



failsafe:
high 0
low 2
servo 1, 130
goto prog5

gosig:
low 0
high 2
b0 = b0 - 20
servo 1,b0
b13 = b0

goto prog4

floatdn:
sound 2,(70,7)
if b3 > 1 then floatdn2
goto prog3

floatdn2:
b3 = b3 - 1
goto prog3

floatup:
if b3 < 8 then floatup2
goto prog2

floatup2:
b3 = b3 + 1
goto prog2

Circuit diagram, I think it's right???
http://robowars.org/forum/album_pic.php?pic_id=1146

pinout numbers on the picaxe would be helpful, and what is the 200hz thingy ?
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