Adjustable scissor lift?

Hi folks,
I would like to figure out how to make an adjustable scissor lift. By “adjustable”, I mean I’d like to be able to rotate just one piece of the scissor lift and the entire scissor lift expands or collapses.
I’ve been playing with this off and on over the past 6 months… I can’t seem to get there. Here is what I have so far:

  • I make each scissor section a component (a “section” has an inner & outer arm on both sides of the scissor. Right now the arms are groups, not components)
  • I have 5 scissor sections that are all stacked in the collapsed position
  • I can rotate one of the outer arms and all outer arms rotate. But of course the problem is then:
    1) the inner arms have not also rotated
    2) the scissor sections have not displaced (in other words, they are not connected)

At one point I thought I had the outer and inner arms considered as the same component so that a rotation of the outer arm (say in the CW direction) caused the inner arm to rotate in the CCW direction. I can’t seem to recreate that (maybe the outer and inner arms are not really mirrors of each other… I’ve forgotten… seems like mirrored components aught to work.

Recently I had the brilliant idea to try recursive components: the top scissor section would be part of the next lower component which would then all be part of the next lower section… and so on. Sketchup does not like having a component be a part of the same component.

I can get the motion that I want by using Fredo6 “Animator”. But when I exit Animator the model returns to the starting position. It would be cool if Animator would have an option to leave the model as-is when exiting, or at some point along the timeline. That would be a cool way to get any position I want.

Has anyone figured this out?

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Off topic: is this commercial?

Regarding the Animator question, @Fredo6 would be your guy.

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Thanks Kaidenh,
No, not commercial. Is it really off-topic? Seems like this is a Sketchup general use question related to components, groups.
Hadn’t thought about going right to Fredo… thanks, good idea!

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Just use positioners to save the position of objects along the timeline. This is the 4th icon on the toolbar. Positioners are actually independent of Animator. You can move objects around and save their position. and later recall their position.

image

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I love it!!! Thanks so much Fredo… wonderful!!!

I think it should be possible to create a Dynamic Component to model this.

I haven’t time to create one, but you could try it with component options something like the following

Overall target height OR arm angle from horizontal
No. of arms
Arm length
Arm width
Arm depth
Pivot offset (distance between arm ends and pivot hole)

You can then calculate the position of each arm and move the arm geometry into position.

In reality, what moves the scissor action? A screw thread shortening the distance between the bottoms of the inner and outer arms?

Is this approximately the geometry you are describing?

Or are the two top arms only half length with the load being carried at the central pivot point? Like this?

Thanks John,

Your fist picture is the configuration that I was working with.
Unfortunately, dynamic components require a Pro license.
But, the good news… or, I should say fantastic news is that really the Fredo6 Animator plugin is the best solution IMHO, and does not require a Pro license. In fact it’s free, but I was so delighted that I $donated. Animator allows you to create primitive movements like “scissor arm rotate 5 degrees” and “raise scissor section by 2 inches”, etc. Then you copy/paste multiple primitives in series and/or parallel to get the complex model moving as a unit. Animator uses these primitives on a timeline so that you can have multiple objects animating at different speeds and times along the timeline… similar to movie creation with tools like Camtasia or MacOS Movie.
But, for my purposes, I already had an Animator set of primitives to raise the scissor lift. Today, Fredo showed me how to pick a point on the timeline (corresponding to my desired scissor height) and then save that position for use outside of Animator (Animator is really an application with GUI that takes over the Sketchup execution).
So, creating the motion primitives within Animator are not trivial, but Fredo has a very good Youtube tutorial with an example of a moving forklift. For my first entre into Animator, my Scissor lift took me about 6 hours to create, with many visits back to Fredo’s tutorial. But, now that I have this scissor lift animated I can configure it to any height for future uses.

That sounds pretty good - glad you have a solution that works for you.

I meant my question was off topic, not yours.

Oh, that makes more sense… sorry for my misinterpretation… thanks for the clarification.

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Hello
This probably wont help you, but just as a comment…
I have used MS Physics as a free Sketchup extension for a while, and quickly knocked together a working scissor lift. you cannot set it at a certain position with just at a click, but can use any keyboard keys to move it up and down. Highly recommend MSP.


image

(hoping this helps someone somewhere)

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Thanks Jacob. I will definitely check out MS physics.