113 replies to this topic

[Tyrant]

Actually, today I had dropped some parts off over at my friends house, who is doing most of the wiring, and he said that he was able to get it to work. The only problem right now is the power supply overheating, and we think we fried it. So we are going to look for a better power supply, something with some thermocouplers so it won't overheat again. Right now I am pounding out the details such as the magnet lengths, the spacing, and the timing of the switches. I should be able to start printing out ties on tuesday, and hopefully have it all assembled and working by the time my Christmas break is over with and I have to head back to Rolla (Jan 8th).

-Tyrant

[Tyrant]

Well, last night I was over at my friends house, and we worked on it from 9pm till 7am, napped for 2 hours, ate, went to Gateway, came back and kept working on it till about 3pm. And we made a hell of a lot of progress. The system works manually now, where we tap the switch and the current changes. Now all that is left to do is to wire the switches and mount them so the car can activate it on its own.

I put together a video of the work we did last night. It is about 20mb, 5:41 minutes long. It's worth it though. (slight language warning, it was 4:45am, I was caffinated, I was in a bitchy mood) :-p

Enjoy.

http://media.putfile.com/LSMVideo

-Tyrant

[Ace o Spades]

Hahaha...Doesn't go too fast...but its a hell of a lot better than my friend's attept way back in 5th grade...

[Tyrant]

It's still not the final attempt, in the videos we are controlling the current flow by hand, pressing the switches. We aren't perfect so we can't time it exactly esspically since the speed ramps up. Thus we are going to be mounting 10 switches so that the car itself will activate the switches, so its timing itself, thus picking up more speed. I personally can't wait to see it all hooked up in its final glory.

-Tyrant

[sfmm_freak]

Pretty rad if you ask me. Much credit to you for taking on this task. I feel so left out, i havent been reading any of these topic[the ones specifically about models] because i wanted to independently build Redux without temptation of starting somethign new, or using other peoples ideas. This Topic grabbed my attention.

I was working on LSM launch systems for a several months, i has assistance from my Enginnering Professor, and the head Engineering Advisor at the community college i go to for night enrichment classes. I didnt get the desired results because of limitations[mostly availability of matierals and weight of the train].

Recently, i've been working on an automated triggered magnetic braking system For Echelon Redux. I havent required help from the said people, but who knows.

[CP-ephY]

I understand how all of this works except for one thing. How exactly, does the magnetic switch reverse the current flow in a circuit with a battery as the source. I thought DC = one way only...

Edit: I couldn't see the diagram that you posted very well. So I only understood half of how you said the switches work to switch the polarities

[Tyrant]

Well, for the second version we used relays, which reverse the flow of the current. The current comes in one way, but the relay simply just sends the flow going one way, or the other way, it is sorta like a "gate", if a switch is turned off, the gate is closed, if switch A is turned on, the gate is opened to the left and the current flows. if switch B is turned on, the gate opens to the right, and current flows.

To update you guys on the progress, we were able to get it to work on its own, but it went rather slowly since it isn't tweaked perfectly. Right now there hasn't been any progress in the past couple of weeks because I am back in college, and the FIRST Robotics season is starting up. However we hope to get back into the project soon after that and get it tweaked to perfection.

-Tyrant

[CP-ephY]

How does the relay know how often to open each "gate"? Did you just find one that has an appropriate frequency to smoothly launch the car? Can you post a simple circuit including the relay and the electromagnet b/c that would help me a lot. I tried to draw the circuit and I always see a path for a short circuit to occur...

Edit: I drew a diagram. This is how I see the circuit. The rectangle is the relay and the circles are the electromagnet. So, first it sends the current down going into the electromagnet from the left and going back into the negative end of the battery. Then it switches and the current goes to the right. It is intended to go downwards as shown by the blue line and go through the right side of the electromagnet, thus changing the polarity. However, the current will probably not choose this path and instead go upwards and complete a short circuit.

[Tyrant]

This is actually the circut we used. The only change is that the reed switches were replaced by microswitches. Ron is the guy that worked with me on it (you can see him in that video). So safe to say this circut is a little more complicated than what you drew up CP-ephy.

http://www.ronstoppa...lsmFinalSch.jpg

I also included a picture of the wired DPDT Relays as well as what the LSM looks like at this point. Notice the insane amount of wires coming out of everywhere. :eek:

-Tyrant

[CP-ephY]

wow that's awesome. I looked at the circuit with the first 36-V battery, and I understand that perfectly. But, what does the other circuit that connects to the reed switches supposed to do? And how does the DPDT relay know when to move the switch? Or is it that when the reed switch closes and completes the circuit in the presence of the magnetic field from the electromagnet, the DPDT relay shifts and closes another circuit. Sorry for all the questions, I just like to have a good understanding of how things work.

[coastergeekrtc]

The reed switches complete the trigger circuit. They are triggered by the magnet on the train. The relay is wired to apply pushing and pulling forces on the train...simple but not easy to build.

[NitroRyder33]

"You know what I havent had in a while?

...Big League Chew"


haha second pic, niice.

-Ryan

[CP-ephY]

So the reed switch triggers the relay to switch current flow?

[coastergeekrtc]

Yes, causing the magnets to change the direction of force.

[Tyrant]

We didn;t use red switches thoug, we used microswithces cause the maginetic feidl of the electomangets F'ed with our redswtiches cause they were oto senseitve.

sory bout the spelling, im not too articlulate sirgh tnow.

littl esitpsy.

-Tyrant

[coastergeekrtc]

Ah, same as my CD launch...

[CP-ephY]

Tyrant could you give me the specs on the relay and switches you used. I was thinking of making this launch also just for fun..I know enough about electricity and magnetism to build it. I just didn't know about these cool devices you used..

[coastergeekrtc]

Shouldn't you wait untill he finishes and actually gets it to work?

[CP-ephY]

I know from the circuit diagram he made that it should work if everything is put together properly

[Tyrant]

It does work, the problem we are having now is perfecting everything so it works at its full potential. This involves precisely changing the location of the switches and stuff. Right now the magnetism isn't perfected so its using all of its potential energy into pushing the train. That just takes a lot of trial and error. But right now the circut works.

The specs:

- 120v 15amp car battery charger used for the current flow (need a lot of amperage)
- Thick guage wire (insane amount of amperage heats up wires quickly)
- 24 guage copper magnet wire
- 1/2" x 1/4" x 3" iron cores
- 20 VDC DPDT Relays. This can be subsituted with these: http://www.radioshac...rentPage=family
- Microswitches (can be subsituted with any SPST switch)

-Tyrant