Hello! As part of the project in my final year of high school, I have to model and then simulate the system I am in charge of. (photo of the kinematic diagram on solidworks attached).
Rotating the cylinder of the blue coin is supposed to roll the "egg" on the frame (the black piece). Due to the shape of the wheel, the horizontal and vertical guides are supposed to translate each according to the axis on which they are dependent via sliding links as the movement progresses.
This will allow me to do a study of the movement on mecha3D, but I can't create a cam between the wheel and the ground on solidworks. When validating, the error message "One or more features of the cam have a radius smaller than that of the counter cam. This can lead to slip errors when sliding components" appears and prevents the reconstruction of the connections on mecha3D.
I searched for several hours if I didn't make a mistake somewhere, if the constraints were good etc... But nothing to do, I don't understand why it doesn't work.
That's why I need your help because I really need it to work.
Thanks in advance!
PS: I am on Solidworks 2012 but I have the possibility to switch to the 2015 version.
I tried to do the tangency, and if I did it correctly it doesn't work. It's good by right-clicking on the surface of the wheel once you've selected the cam constraint, right? Because I tried by doing it like this and the tangency doesn't even appear, whereas with a circle it is.
I didn't say it clearly but the wheel is a bit special, it is shaped like an ovoid. So that you understand, I want the wheel to turn to lift the system (a modified and motorized wheelchair) to allow the crossing of obstacles.
@gt22
I don't know the right tool at all, and what do you mean by the surface of the course? I don't have too much time to look :/
For the constraints it's possible but I only have a few coincidences/slide/coaxial, nothing special except the cam.
In the attached files, the part "ellipsoidal wheel kinematic diagram (test)" is just a modification of the wheel to try if it worked like that. (By the way, I forgot to rename it, it's supposed to be an ovoid wheel and not an ellipsoidal). The second wheel file is more of the right shape, but it is a bit old file, the correct dimensions are 425mmm instead of 250 between the top and the axis of rotation (the cylinder), 165 instead of 180 for the width and 160 instead of 80 between the bottom and the axis of rotation.
If it is ever unclear, do not hesitate to ask for clarification or to ask me to send the modified parts.
For the "suitable" tool I'll let gt22 explain to you. ;)
For the tangency, you select the Tangent constraint (and no longer Came) in Standard Constraints>Constraints and your entities to constrain its the edge of your ovoid, in yellow on the pj and the delimited plane in pink.
Dbz, indeed I hadn't done it like that, but if it works it's nikel! I'll try tomorrow, I'll keep you posted!
You didn't get any error message telling you that the radius of the cam is less than that of the counter cam or something like that? Which version of solidworks did you use to make it work?
Gt22, thanks for the definition I'll go to bed less stupid haha^^
To move the piece I usually let press left click and drag, I don't know if it changes anything.
On the other hand, besides the error message that appeared when creating the constraint, my real problem is that it was not possible to create a simulation of the movement with mecha3D. The cam was created with an error, the automatic reconstruction (is it a good idea to do it like that by the way?) did not work properly.
Sorry for taking a long time to try; I finally did it but it still doesn't work... I have attached a photo for you to see.
I don't know if it's readable so I'll transcribe it here. When trying to put the tangency between the ground and my wheel, I get the message "the selected entity is not valid for the current constraint type" that appears when I try to select the wheel. Dbz, what version of solidworks are you on?
PS: on the picture I use a plan created on the ground, and not the surface of the ground directly because I tried directly and it didn't work. In desperation I wanted to try like this.
PPS: sometimes the cam function is created normally ('end I think') but in mecha 3D it appears with an error, saying that the calculation of the ideal coordinate system had failed. And when I try to calculate the simulation anyway, solidworks crashes suddenly and closes when I click on the calculator.
(Assembly toolbar) or Tools, Component, Move.