spinner bar ratio

[typhoon_driver]

should be fine at that

[Danjr1]

nice, and I'm guessing the car fan works fine at 24v? is 7.4K joules a nice value for a spinner? am i right in thinking hypnodisc was around 4K joules?

issue I'm working at now is how to join a pulley to the bar in a way that it won't snap!

[dragonmaster_1]

Yes they work fine on 24v not burnt one out yet

[dragonmaster_1]

The Mondeo fan motors are made by Bosch. At 12v Nominal speed is 3450rpm no load.
Got mine from the local breakers yard £5 each.

[Danjr1]

sweet. i pass a car dump on the way to work everyday so sourcing won't be a problem.

looking at these types of pulleys, http://www.technobotsonline.com/pulleys ... x16mm.html

how would you join one of these to a spinner?

[typhoon_driver]

7.4kj is a nice figure for a spinner. Boner has around 700joules of energy and does fine.

Remember though, you have to design the rest of the bot to survive the impacts.

Design wise it depends entirely on what you have in mind.

O and i would scrap the cross design and just go for a solid flat bar.

[mattsdragons]

What kind of relay or ESC would you use for a motor like a car fan one?

[dragonmaster_1]

Not sure Probably 2 grub screws through the collar of the pulley. Make 2mall indentations in the motor shaft for the grub screws to locate in to.
I use chain drive on DS so the sprockets are welded on.

[dragonmaster_1]

On DS i use a toggle switch (on off) activated by a servo. Been using that for 6 years never had a problem with it never had to replace it.

[Danjr1]

7.4kj is a nice figure for a spinner. Boner has around 700joules of energy and does fine.

Remember though, you have to design the rest of the bot to survive the impacts.

Design wise it depends entirely on what you have in mind.

O and i would scrap the cross design and just go for a solid flat bar.

the solid flat bar is probably a good call! costs etc