[TC14] The Zipper (8 pods)

[Rudivdk]

For this contest I'm building a ride inspired by The Zipper:

Here is my current progress:

I started with the rotating arm to get a feel for size and weight. Currently there is a lot of sagging on the chains, I tried to build in a tensioner with springs, but I do not know if it will be strong enough in the end. Also the driving wheels for the chains rely purely on friction, this might be to weak as well. I have an alternative in mind, but first I will create all pods to see what happens with all weight attached.

More to come...

Edited July 10, 2018 by Rudivdk

[Superkoala]

@Rudivdk and @mocbuild101

Same Topic name, same inspiration but different project to come. I will grab some popcorn and look forward see what will happen

[mocbuild101]

Really?!! And posted within minutes of each other! This is going to cause some confusion...

I think I'll change my topic's name just slightly 

Nice progress with yours anyway 

Edited July 10, 2018 by mocbuild101
...and ended our comments the same too...!

[The_Icestorm]

I love the use of the rims. Some hubs would make it really look good!

Interesting to see that people are converging on recreating certain rides, like you/mocbuild and myself/shadow_elenter.

[pagicence]

This is excellent. First spin them one way, then the other. Just to make them sick enough.

[Rudivdk]

WIP update. Its becoming a monstrously big build...

Redesigned the arm to be stronger, using 4x the rack&housing parts. Integrated the tensioners on both ends to keep the chain links from sagging and produce enough friction to the wheels driving the chains:

Hooked up an XL motor to one of the wheels at the end of the arm from the center turntable pivot (ouside the arm) and it runs :

 

Speed of rotation looks good for now. I still have to connect the motor to the other driving wheel as well, so I'm confident it will work with the added weight of the remaining 7 pods. Then add the posts to mount the turntables and add drive to the rotation of the main arm. I have to make a frame on each side, because the arm will be to heavy to be attached from one end only...

[Seasider]

How have you transferred the drive though 90deg for your wheels? I need to do something similar to drive my belt on my ride

[Rudivdk]

I used two sets of double bevel gears at 90 degrees and an axle through the arm to connect the center motor to the outside wheels. Just make sure to brace them properly and they can hold quite some torque.

[Rudivdk]

Had a productive building session today, I've built the complete tower structure to hold the rotating arm:

It's getting bigger and bigger, I completely depleted my stock of yellow 15 and 13 beams on the tower frame! But it looks great if I may say so myself...

I've used @tkel86's geometry tool for calculating all the triangles to create the tower structure, very useful tool.

[Seasider]

I think this competition is going to spawn a load of very large models. I did an initial play at sizing for mine and discovered my initial thoughts mean it’s gigantic.

 

your model looks great so far. Colour scheme works well

[Erik Leppen]

This is starting to look very interesting. The bright colors are really suitable, and the tower looks quite rigid despite being very light on parts. I'm not sure the way you mounted the XL motor is mathematically sound, but if it fits, it fits, and it certanily looks interesting and uses only a few parts. Do you have a link to the geometry tool you used?

The motion of the red triangular things folding around the chain at the ends looks really cool too!

Also, why is the arm extendible? Or, what is the reason for using the red gear-rack housings?

[Rudivdk]

7 minutes ago, Erik Leppen said:

This is starting to look very interesting. The bright colors are really suitable, and the tower looks quite rigid despite being very light on parts. I'm not sure the way you mounted the XL motor is mathematically sound, but if it fits, it fits, and it certanily looks interesting and uses only a few parts. Do you have a link to the geometry tool you used?

The motion of the red triangular things folding around the chain at the ends looks really cool too!

Also, why is the arm extendible? Or, what is the reason for using the red gear-rack housings?

Thanx Erik!

The motor is actually fitted 'in system' completely. The tool I used was mentioned in this topic (in which you actually commented about the tool yourself...):

I'm quite happy with the red frames folding myself, took some time to figure it all out but its actually fully copied from the original machine. They are more pronounced in my model because of the size of technic beams compared to the scale and the bright color.

I have made the endparts of the arm extendible with springs to have an automatic tensioner on the chain. With the chain on it, the springs are about half compressed, to stretch out the chain and provide minimum slack and sagging as possible while also preventing too much strain on the parts (mostly the 12l axle through the rims and the electric motor itself). I found that it was not possible to make it like this with a solid built arm (either too much sagging or to much stress/bending of axles). The red gearrack housings give the most stability for a sliding piece because of their length, create a rigid backbone to the arm themselves, are lightweight compared to their structural integrity and they happened to be the correct color for my intended colorscheme.

[Johnny1360]

Ha my favorite ride as a wee lad, also known as the pocket emptier, feller could make a fair bit of money standing around under it. Also a dangerous ride as far as mishaps go, even outlawed in many places, more than a few people lost their lives sadly. 

[Rudivdk]

3 hours ago, Johnny1360 said:

...the pocket emptier...

That is also a nice name.

3 hours ago, Johnny1360 said:

 Also a dangerous ride as far as mishaps go, even outlawed in many places, more than a few people lost their lives sadly. 

I've read about that part, the manufacturer actually slowed down the rotation rpm by almost half after some of the accidents. I'm still in doubt whether to gear it down to 'safe' speed or go all crazy...

What do you guys think: safe rotation speed or 'ludicrous' speed?

[pagicence]

Go all crazy! I want to see figures flying off.

EDIT: You got me thinking, if you want different speeds you can use a simple 2 speed gearbox, safe speed and fast speed modes, or you can use those lego batteries with speed control nob, that way you will have progressive acceleration and deceleration which is helpful for people getting on and off the ride.

Edited July 14, 2018 by pagicence

[Rudivdk]

Testrun:

Lots of work still to be done:

- most important: brace all gearing to prevent the cracking...

- hook up a second set of XL motors on the other side to increase torque and make the motion smoother (and perhaps a bit faster)

- redesign the pods to balance them out and make them spin everywhere while the wheel is turning.

- create raising/lowering boarding ramp beneath the pods for easy entry.

- decoration

[mocbuild101]

8 hours ago, Rudivdk said:

make the motion smoother

Looking at the video, it seems like it's because there's only one pod attached - once all the pods are on, it should run much smoother.

[Rudivdk]

7 minutes ago, mocbuild101 said:

Looking at the video, it seems like it's because there's only one pod attached - once all the pods are on, it should run much smoother.

Probably yes, but it will also increase the weight of the chains drastically. Anyway, who doesn't like some extra power...