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Messages - austron

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1
That would probably work best of all! If you have a sufficient large PVC pipe, and the means to safely cut it in half, then definitely do that!

2
It might, it's worth a try, but it would probably be helpful to find something a bit more rigid. The problem with cardboard is that it can crease and kink easily. You can get thin sheets of plastic at hardware or hobby stores for very cheap. A flexible plastic cutting board might work as well.

3
My theory is that the paper half pipe is not rigid enough. The ball is losing too much energy too quickly because it is all going into deforming the paper as it rolls over it. If you made your half pipe out of a slightly more rigid material, such as a sheet of thin plastic, or several sheets of think card stock glued together, I think it would perform much better.

Good luck!

4
General Knex Discussion / Re: Is this worth purchasing?
« on: October 02, 2018, 01:06:03 am »
I personally would say no. That works out to an average of 17 cents per piece, which is quite expensive. My own rule of thumb is never exceed 10 cents per piece when buying K'nex on ebay. K'nexUserGroup sells smaller rods (green-yellow) for 11 cents each. Longer rods are more expensive there, but you can probably find significantly better deals on eBay. You could probably find a cheaper parts-per-piece by buying actual K'nex sets at retail price, even.

That's my two cents, anyway. Best of luck with your part hunting!

5
I personally think it'll be better at the works museum since that machine would have a smaller footprint. That, hopefully, means that there's more movement happening in a smaller area and more tracks to watch at one time. Good luck! :)

That is exactly my thought as well! I am looking forward to creating a much more dense, much more chaotic machine. I want to add as many paths as I reasonably can without sacrificing reliability. I want it to be a giant, almost overwhelmingly dense cluster of action and movement.

6
Project Progress / Rebuilding the World's Largest K'nex Ball Machine
« on: March 08, 2018, 03:00:57 pm »
Hey everyone, I'm still alive!

My 140,000 piece K'nex ball machine at Brickmania is being disassembled to make room for expanded office space. The plus side of this is that my boss has decided to donate our entire K'nex collection to The Works Museum, where my other giant K'nex ball machine is located. Over the next few months, I will be modifying and adding onto The Works' machine with pieces from the Brickmania machine. I am hoping to hit a total of 200,000 pieces!

I've started a video blog to document this process, and as sort of a way to push myself to make my YouTube channel active again.


I'm actually about a month ahead of the video at the moment, and nearly all of the machine has been taken down, with the exception of the giant bridge. We just moved about 1/3 of the pieces over to The Works yesterday afternoon.








7
General Knex Discussion / Re: 3D Printed Tan Clip Improvement
« on: September 09, 2017, 05:45:04 pm »
I have a few more tweaks to make to the design, but once I'm happy with the final version then I will certainly post it here.

8
General Knex Discussion / 3D Printed Tan Clip Improvement
« on: September 09, 2017, 05:28:24 am »
One of the most frustrating things about building with k'nex is when a tan clip snaps off a rod because there was too much torque. This is especially irritating if it was deep inside a complex build.

I've been working on a solution to improve the strength of the tan clips using 3D printing, and I've come up with a design that snaps over a tan clip and rod.

With the addition of this small clip, the rod itself - even a black or tan rod - will snap in two before the improved tan clip ever gives way.

9
Project Ideas and Help / Re: Suspended Projetor Screen
« on: September 06, 2017, 06:47:48 pm »
Hello!

This is actually quite similar to something I made a few years ago, so hopefully I can help!

The first thing I notice is that the rope is slipping off because it is being pulled off to the side as the projector screen rises. I fixed that issue in mine by having the pulleys parallel to the screen, so they turn in the same plane. This will allow the string to wrap further around the pulley as it gets pulled diagonally by the screen. If you need the string to turn perpendicular to the screen, just use a second pulley above the first one. Basically, for each turn the string makes, make sure the pulley is oriented in the same plane.


I would also recommend using a much thinner rope. Thicker rope has a lot more friction and is generally harder to work with. You could get away with some very thin nylon string.

As for motorizing it, you could build a spool, though the amount of string that needs to be wound up would require a fairly large one. Another thing you could try is having several pulleys in a line that are geared in opposite directions, and having the rope sort of snake in-between them. With enough pulleys, it should be able to grip the rope and hold it tight. Attach a weight to the loose end so it doesn't tangle and just let it hang somewhere (maybe use a block-and-tackle on the weight so it doesn't have to hang down so far). If you have trouble getting the pulleys to grip onto the string, put a thick rubber band around the inside of the pulley to give it some more friction on the string.

Here is the one I built if you want to check it out.


Good luck!




10
General Knex Discussion / Re: Compact K'nex rod coupling
« on: September 02, 2017, 06:47:23 pm »
I meant 2 connectors connected by a green rod. A white rod is just about a millimeter too long, otherwise this would be incredibly simple. It can handle a decent amount of torque, but it has a bit of play at high torque. This particular application requires next to no torque, so it should be fine.

Since I made this post I have slightly updated the design.

Yes, I thought so :) Is it something like your automatic transmission gearbox?

Yeah, this is currently my 4th complete redesign of the transmission. It's coming together very nicely this time and I think this might actually be the final build!

11
General Knex Discussion / Re: Compact K'nex rod coupling
« on: September 02, 2017, 07:43:54 am »
This looks increadibly dense! I love it! ^.^

So far it's 70 gears within roughly 3 cubic red rods.

This is my most complicated and dense mechanical creation to date. It has gone through 4 complete redesigns over the past 2 years. I think this is going to be the final version. I'm hopefully close to having it working!

12
General Knex Discussion / Re: Compact K'nex rod coupling
« on: September 02, 2017, 12:12:42 am »
I meant 2 connectors connected by a green rod. A white rod is just about a millimeter too long, otherwise this would be incredibly simple. It can handle a decent amount of torque, but it has a bit of play at high torque. This particular application requires next to no torque, so it should be fine.

Since I made this post I have slightly updated the design.

13
General Knex Discussion / Compact K'nex rod coupling
« on: September 01, 2017, 01:23:51 am »
I've been trying to come up with a way to couple two coaxial K'nex rods in the space between the 2 red connectors in these pictures. (10 blue spacers/one green rod wide).

So far, this is the best I've come up with. Has anyone else come up with other ideas, or do you have any suggestions for improvements on this design?

14
For anyone curious about how it works, the green gear has 84 teeth, as opposed to the typical 82 of a large yellow/black gear. This gives it a perfect 6:1 gear ratio instead of 5.86. The pattern that is generated is a result of the interference between the two ratios. After 42 (I think? someone correct me if my math is wrong) rotations, it will loop back to where it started and repeat the pattern. I built this while idly building with a friend, so there was very little time and effort put into it. I'll have to rebuild it better sometime soon.

15
I have no idea what I'm doing.

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