Moving a piston with math #1

[JoeLaFrite007]

Great tut !!!

You are mentioning an easier solution with IK...I'm fighting with this concept since a couple of days without results : do you have a video tutorial to explain how to rig this with IK ?

Again, thanks very much for this "math animation" tutorial that is very well done !!!

[presbarkeep]

very nice video... very nice video indeed.

[crazyarranz]

@streincorp thanks for the reply. i still can't figure out how to get it to B to Rod? so i need to work on the expression to get them to attach?were do you even start to learn how to write expressions?

[streincorp]

@crazyarranz u mean expressions on 3ds? …self taught. But also the 3ds's help > user reference is more useful (I still use the old 3ds 7)

[Discipol]

@streincorp you madam, are awesome.

[crazyarranz]

first off great video really helps. so i think i did everything the way you did but im haveing trouble like SundewAU is haveing point B is not attached to rod? My math is realy bad so not sure what you ment in his reply?

[streincorp]

@crazyarranz physically B is attached to the rod but virtually is linked to the chassis, then its movement is ruled by the expression.

Now I'm working on a way to allow B to move up or down the x axis

[SundewAU]

Is there a way to maybe link Point B to a fourth point, lets say Point A2, that is fixed to the top of the rod? I've tried a couple of thinks but so far unsuccessful...

[SundewAU]

Wow, thanks for that tutorial! I finally got a working piston engine!

Only one problem now, I'm trying to build a VR engine in which the cylinder-axis's are moved away from the middle of the crank to avoid the pistons intersecting at BDC. But if I move Point B and the Piston itself up or down (with the engine lying on its side), the distance between Point A and B obviously grows larger than the rod's length and Point B starts to lag behind the crank's rotation and the rod's movement.

[streincorp]

@SundewAU referring to the scheme at 4:05

if u want to move point B up u need to edit the equation:

put (r*cosφ + z)^2 instead (r*cosφ)^2 under the SQRT, where z is the new position of B (normally is z=0).

Put directly the value of z in inches not the variable to avoid errors.

IMPORTANT: first edit the equation then move B to fix the system.

[SundewAU]

@streincorp I've tried that, but it completely messes up the animation. The rod and subsequently the piston are all over the place. In most cases with common stroke- and rod lengths the amplitude of the equation becomes too big and gets chopped off at 0 so the piston actually moves into the crankshaft.

[streincorp]

I'm sorry, put "-z" if u want to move the piston up

[V4FF4NCUL0]

Then they say that Maths is useless, lol.

[emilioenigma]

wow!! incredible tutorial!! thanks so much!! grazie mille!!!

[MasterBolitz]

Thanks a lot for the post, it's just what I need!!

[XXena93]

defenetly the best video i have seen in Youtube, even though I got lost in the first 15 secs.

[streincorp]

is your problem with math or 3d studio? :)

or isn't my vid so clear?

[XXena93]

its hard, lol

my dream is to become a car engineer and i dont get the 3d stuff yet :p

[ECUABORI1]

MY HEAD HURTS.OW!

[scientificboysclub]

thanks for your tutorial ...!

[scientificboysclub]

I never thought that 3d max allows math equations ..

WOW .. it's awesome !

[scientificboysclub]

you are mechanical engineer student right ?

even that math is looking advanced LOL...

[scientificboysclub]

Man ?? how did you learn that advanced stuff in max ?

[streincorp]

like a child with a game: no one tell him how to play.

To learn 3ds stuff, follow curiosity and fun!

math rules over mechanics XD

[scientificboysclub]

well I know this ..

same words were said by some someone ....

I am doing the same .. ha ha ha ..