Need pancake flipper help!


#1

Does anyone have a good pancake flipper video?


#2

#3

448x has a good waffle flipper.


#4

ok thx!


#5

#6

also i meant the two c-channels that flip a cap onto poly carbonate and then the cap slides back down. Not the 448x kind.


#7

@7517H Nope not that


#8

How so then?


#9

Why so formal? But i meant two c-channels that flip a cap onto poly carbonate and then the cap slides back down.


#10

This is exactly that, but the cap slides down the standoffs instead of polcarbonate.


#11

Oh woops, I was looking at the wrong robot ; )


#12

Can we officially differentiate between a pancake flipper and a waffle iron? A waffle iron is a wrist by general consensus. Either this design or the L bracket design is a pancake flipper. Can we decide which here?


#13

Yes, yes we can.
https://images-na.ssl-images-amazon.com/images/I/711-2lH3hvL.SL1500.jpg
Case in point: Note how the Waffle Iron first squeezes or grips the waffle before making a rotation perpendicular to its hinges.

https://media.istockphoto.com/vectors/pancake-flipping-on-the-pan-vector-id940313188?k=6&m=940313188&s=612x612&w=0&h=8ZgeXk18dYNr32N3szkrpvPofdKP0KpHEVlNaj5eL0U=
Next case: The pancake is flipped mostly unaided and in midair, pivoting around its center in a similar manner to the waffle, though its axis of rotation is perpendicular to that of the waffle’s, if we were measuring from one frame of reference.

Waffle iron intake = deliberate wrist-flip (i.e. using brackets or a claw and a motor)
Pancake intake = momentum flip (i.e. using a fork and motor)


#14

Sounds great. But what about the difference between the flipper above and the L bracket flipper?

Or can we just say that a horizontal flip is a waffle, and a vertical flip is a pancake?


#15

You can easily reverse that by changing your reference (viewing) angle by 90 degrees :slight_smile:


#16

The reference angle, I think, is the plane the robot moves in- the horizontal one.
And the angle is the front of the robot. But I can see how this can get confusing. I do like the intentionally gripping vs. “throwing” concept.


#17

They’re both flips/rotations around a horizontal axis. A rotation around a vertical axis wouldn’t help you much for this purpose; it would need another accompanying rotation about a horizontal axis to do anything, and once you’re doing that you don’t need the vertical axis rotation anyway. Rotation around a vertical axis is wonderful for driving around the field, though.


#18

I see where the confusion is. My fault. It’s a reflection about the X and Y axes, rather than the Z axis.


#19

Uh, that’s worse. Reflections are distinctly different than rotations. You can see this quickly when you try copying something on one side of the robot to give it planar symmetry, forget to reflect it, and find there is no way to rotate it to get the reflection you wanted. If you like math and functions, this is can be seen in the difference between odd (rotation) and even (reflection) functions. And as for axes, those are completely arbitrary. Commonly you’ll see y as the vertical, and other times you’ll see z as the vertical. In physics you’ll find them all over the place, commonly none of them being vertical.

If you want to refer to this properly, you were closer before when you went to rotations. But you should specify rotations about one horizontal axis (the direction the lift faces) versus rotations about another horizontal axis (perpendicular to the direction the lift faces).


#20

Okay, so let’s use rotations. I’ve always heard of Z being the vertical axis, but I can see it as being depth as well. Maybe it would be less confusing to stray away from mathematic terms.