How could you explain this design?

[ferslash]

one of the guys in our community posted his work:

http://www.x-sim.de/forum/viewtopic.php?f=37&t=672

he says that he is using 4 wiper motors and 2dof??? how come is this??

can you place two identical wiper motors in the same axis so they share the work?
if so... can you connect bouth two motors to the same jrk??

best regards

fer

[prodigy]

You can't connect two motors to one JRK, you need 4 JRK's.
If you read what equipment he has, you will see that he use 2x Velleman 110 board + 2x Sabertooth Dual Motor Driver.
That means 1 Velleman + 1 Sabertooth are for two wipers.

You need to set 4 axis for 4 motors and then configure all the motors, two on the front and two on the back.

Anyway, four wipers are always stronger than two

[motiondave]

You can share the same motion setting between two motors.
It depends, if he has bridged 2 motors off one sabertooth, the become "one" motor and move the same, using the same motion profile.
He is using 2 vellmas and 2 sabertooths, so I guess he is bridging 2.
PM the builder and ask.

[ferslash]

yes i will pm him, i ask him in the forum, but it seams that it has been a while since he is not online

best regards guys

fer

[prodigy]

You can share the same motion setting between two motors.
It depends, if he has bridged 2 motors off one sabertooth, the become "one" motor and move the same, using the same motion profile.

At first I thought that too, but looking at his case and motors position, two on front, two on back, later I've got to conclusion that two motors could share same motion (become "one") only if there will be just one force is used, for example only longitudinal (pitch) or lateral (roll). But if both of those two forces are used together, all 4 motors need to have their own motions. I've draw a small picture to show that example, I've used a formula1 picture, but imagine the tyres as motors

4motors_dof.jpg (94.54 KiB) Viewed 2590 times

But if he positioned his motors like I've draw in this picture below, he could use two motors to become "one" with same motion for Pitch and another two motors with same motions for Roll.

4motors_2dof.jpg (15.41 KiB) Viewed 2590 times

I hope ferlash will understand that better with examples.

[ferslash]

thanks motiondave!! i got it better i will thinking about this case.. looks interesting