Hinge (bearing) and Spring

Thrundar

I'm having a heck of a time connecting a hinge (bearing/axle), spring then another hinge, and have it all operate properly. Running free version of SU 7 and SP3RC1.

Also can not modify the UI at all. The (blue) menu has no options. Not in play or running mode when I click a hinge, motor, etc, then click UI...

Physicsguy1

Could you post the model for us?

Thrundar

I'm trying to attach working joints as shown and have the spring hooked up to the top arm and bottom arm. Only can get one joint at a time to work.

Testing multiple joints

phy

You have the spring grouped two times. You can't group a joint more than once.

Thrundar

Ok, then I am totally lost again. For a joint to work it needs to be grouped with the part/s it you want it to have an effect on, right?

Physicsguy1

You can, but i wouldn't use it. Here are some tips: A)you cannot make a group composed of only joints; it must have a non-joint entity. B)Joints cannot be grouped more than once. C)In order for a joint to be movable, you must group it with another object. You cannot change the properties of joints that affect the state, like ignore and static. I will post a fixed version of your model if i can. Hope this helps!

Physicsguy1

here is the file that i fixed. I wrote down what i did to fix it.

PMM-3a.skp

phy

Thanks physicsguy I didn't now what to say.

Thrundar

I finally got back to this and downloaded. It must be that springs do not operate with an arc movement, only straight line of travel. Basically a bouncy linear slider?

Thanks for taking the time to look more into this physicsguy

phy

@thrundar said:

It must be that springs do not operate with an arc movement, only straight line of travel.

Yes that's true

CPhillips

If you want a rotating spring use a servo and set the accel high and damp low depending on how strong and how stiff you want the spring to be.

Thrundar

@unknownuser said:

by CPhillips on Fri May 01, 2009 9:28 pm
If you want a rotating spring use a servo and set the accel high and damp low depending on how strong and how stiff you want the spring to be.

I'm also having difficulties with changing the joint settings. I'd love to be able to adjust the spring. However I need a step by step walk through on how to do that. There is much with SU I don't know and have exhausted the newby tutorials I can find that are written and explained well.

Can you connect a joint to a joint without an object or part as the parent? I'm using SU7 with SUPRC31. I noticed in RC31 that I could switch to version 2...not sure if that would help or hurt things.

Thanks to everyone who is lending ideas here!