[Help] Expanding circle (or cylinder)

[Carsten Svendsen]

Hi, I was wondering if anyone has got any ideas for how to recreate the mechanics of this video.

If not, then what other ideas do you have? I need a fair bit of travel, and there would be room to put a motor inside of it

 

Edited March 17, 2019 by Carsten Svendsen

[aminnich]

Are you looking to have the same radial expansion all around?  Does the motion have to be quick? 

[Carsten Svendsen]

3 hours ago, aminnich said:

Are you looking to have the same radial expansion all around?  Does the motion have to be quick? 

The motion can be as slow as a tree growing up (ok, maybe not that slow), and it doesn't have to retain a perfect circle.

The smallest diameter will be approx. 13 studs and then grow to about 16 or something. It's all just a variable really -

[Lucullus]

Maybe you can use a mechanism with a plate that slides along the axis of the wheel, similar to the opening/closing of an umbrella or the collective control of a helicopter.

[allanp]

Could you do something like this?

This would be just the central linkage that expands the outer segments (not shown) by about 2 studs in diameter.

Edited March 17, 2019 by allanp

[XG BC]

im now just guessing what moc you want this to be put in but i think i know it: its gonna be a part of a tunnel drill. The part will grab the walls of the tunnel and then linear actuators or pneumatics will push it backwards and the whole mashine will in turn be pushed forward and the cycle starts all over again.

Am i right?

XG BC

[Carsten Svendsen]

9 hours ago, Lucullus said:

Maybe you can use a mechanism with a plate that slides along the axis of the wheel, similar to the opening/closing of an umbrella or the collective control of a helicopter.

I'm not quite sure what you mean with the first part, but I get the umbrella idea

 

8 hours ago, allanp said:

Could you do something like this?

This would be just the central linkage that expands the outer segments (not shown) by about 2 studs in diameter.

Interesting, with a little modification this could work somewhat

 

12 minutes ago, XG BC said:

im now just guessing what moc you want this to be put in but i think i know it: its gonna be a part of a tunnel drill. The part will grab the walls of the tunnel and then linear actuators or pneumatics will push it backwards and the whole mashine will in turn be pushed forward and the cycle starts all over again.

Am i right?

XG BC

Not quite, actually you're miles off the mark, but hey, sounds like you found yourself a good project ?

[XG BC]

ok im curious to see it when its finished. i sadly havnt got the time to do such a big moc!!!

Good luck with your moc!!!

XG BC

[TinkerBrick]

Is this supposed to be for same kind of lathe? The kind thar locks pipes or ring shap material from the inside.

[Johnny1360]

Maybe use those cam pieces with axles with stops on the end. 

[Carsten Svendsen]

4 hours ago, TinkerBrick said:

Is this supposed to be for same kind of lathe? The kind thar locks pipes or ring shap material from the inside.

No, but that's also a good idea for a moc

 

8 minutes ago, Johnny1360 said:

Maybe use those cam pieces with axles with stops on the end. 

??? I'm not quite sure what you mean

[Johnny1360]

Sorry no pictures but I was thinking you could use part # 6575 Technic Cam, rotating on an axle. Then the axle with stop would ride along the edge of the cam piece and be pushed out or up against the circle, providing the mechanism to expand the circle. Hope I explained this well enough, I know a picture is worth a thousand words, I just can't post pictures, sorry. It is sort of like LEGO does thier smaller engines. They often just use a 1x2 beam with pin hole and axle hole as a cam piece. I like the former though since it is only a half beam width and has multiple axle holes for different range of motions.

Edited March 18, 2019 by Johnny1360