I found this site a couple months ago and it is full of many k-nex roller coaster creations. There is alot of recreations on this site with many variations of rides.
I went out and bought one of the sets. The "Screamin Serpent" after seeing this site. They are alot of fun.
Just go to model gallery and click on the most viewed and TTD should be there. Its amazing! *** Edited 2/16/2005 11:18:10 PM UTC by Corkscrewy***
Train detection will be done with microswitches. Photocells and lights cam be a backup plan in places that might affect train speed too severely.
Drive wheels are going to be a challenge. Finding toy motors that are small, geared for good slow operation and low noise won't be easy. I might end up mounting the motors below the ground board and run a shaft up a support. This can be done with brass tube and wire. At the top can have either a gear to move the wheels or some kind of a pulley system. I do plan on making a circuits for controlling mulitple speed steppings for more realistic operation. Likely with voltage regulators (LM317) with a pot for fine adjustments. The same could be applied for the lift motor
Brakes are going to be a challenge also. Getting the right amount of pressure to make it slow realistically but be able to stop it effectively. A realistic brake setup may not be possible but an alternate setput may be substituted. Solinoids seem to be the best option. They are fast acting for "clapping" and other fast operations. Seems like this would be best mounted under the ground board as the drive motors. A simular linkage could be connected to the brakes as the drive wheels.
A Control Panel will another thing. I can use all cheap Pushbuttons, switches, and panel lights. I could also use Allen Bradley stuff. Those can be $200+ new, but used are avalible for relativly cheap if shopped around for. I probably would find a few hot items such as illuminated Estop and dispatch buttons. Then I could use cheap stuff for everything else. I've seen some decent aluminum enclosures that arn't expensive.
The actual system that will be controlling it is actually designed for model railroads. The irony in that is that roller coasters use blocking taken directly from real railroads. It turns out that the system is so flexible that it can do most things a PLC can do. Block control, advanced train movements, condition based sequencers, alarm handling, and much more are not only possible, but easy to do. The connection to the computer is serial. Each of the Nodes have RS-232 and RS-485/RS-422 connections. To use multiple nodes RS-485 must be used. RS232 to RS485 cards are avalible since most computers use RS232.
An old computer and a programming launguage is as much of a computer that is needed. QuickBasic is the best option as it is avalible for cheap since it's been dumped. A more modern language such as visual basic, C++, ect. work great too. The actual programming is fairly easy also.
All in all, the control system will cost more than a single CoasterDynamix set. Though I would probably end up with two or three sets if I take the project on.
Rob Ascough said:
One question... why would you build TTD with the Screamin' Serpent sets when the Rippin' Rocket is available? RR seems to be made to recreate TTD!
He didn't use the Rippin' Rocket because when he built this, the Rippin' Rocket had not been released yet. And if he did have the Rippin' Rocket available, it is really loud, and you can not launch a train, only one little car. You would also have to have multiple boosters to make it go over the top of that coaster.
I am from that site, so I am pretty sure that's why. I was building a Kingda Ka recreation, but I ran out of pieces. I wansn't going to use the Rippin' Rocket for those reasons. It would look very unrealistic if you had boosters going up on the tower. *** Edited 2/18/2005 11:47:21 PM UTC by coasterfreak11***
The micro switches I am planning on have roller hinges.
I will have to modify the train design with a contact bar with camfers for the rollers. The chamfers will allow the rollers to roll gradually up and down the contact bar. The downward force onto the contact bar will be small. If it proves to be to much, adjustments can be made. As a last resort, I will probably use Infrared LED's and phototransistors. They seem to be the best optical solution.
I can use the switches for the positions where the train is driven by drive wheels. The points where they will have problems are used in brake runs. I would like to use the same switches it these cases, but I may decide against them later.
The parts for either are cheap. The switches have a mechanical service life of 30 million switches. They also are much easier to setup, require less adjustments to get to work and are more reliable in the long term.
The first thing I will do is setup short test track for testing the switches and making modifications. I will know right then and there what will work and what won't. I have no problem doing mods to the trains for better operation such as replacing berrings, adding weight, ect.
I'm going for realistic operations. Timing is going to be way off because gravity is out of proportion. *** Edited 2/19/2005 3:06:50 PM UTC by Jeff***
But being built of K*Nex doesn't look unrealistic? Wow.. I think I've figured out Intamin's problem - they're using really big K*Nex pieces for their coasters. ;)
When I said it would look unrealistic, I mean even more unrealistic than it already is! :)
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