MagLev C

[Daemonzan]

I have had a great time using ceramic magnets, as I am currently supporting a 1.4kg car with space to spare. I just ordered the highest grade ones i could find and it only cost me about $30. It has worked out fantastic for me so far

[joeyjoejoe]

This goes out to all of you who have NEO magnets on your track.

I was wondering if any of you noticed that your car would hover less and less as time went on? We did and it wasn't difficult to discover why.
First of all, we didn't used NEO magnets in Regionals or States. They were too expensive at the time. Afterwards, we found a site that had a sale on them and I bought enough to make a short 2ft track. Initially, we had to add a LOT of weight so that the car would actually sit between the side walls. Once I got the car weighted enough, I noticed that it sank an eighth of an inch down after an hour or so of sitting on the new track (I marked the side rail with a sharpy). An hour or so later, it was down another 16th of an inch so we decided to conduct an experiment.
We took two ceramic magnets and placed each of them between two rare-earth magnets. One ceramic magnet was placed so it was opposite in polarity to the NEO mags so it stuck like glue but the other was placed so its poles were the same as the NEO magnets that it was sandwiched between. Even though you'd think it would be impossible to do this, the second ceramic magnet was still held in place since the ceramic magnet couldn't oppose the NEO magnets with enough force to overcome the attraction of the two NEO magnets to each other. After an hour or so we performed a test on both ceramic magnets. These magnets have a small hole in the middle of them. I placed a known good ceramic magnet on a wooden dowell and held it down on a table with double sided tape. Then I placed each magnet on the dowell to measure the distance that their repelling forces would elavate them above the known good magnet. The ceramic magnet that was held in place while repelling the two NEO magnets had almost no magnetic properties anymore. Following what I thought was logic, I expected the other magnet to actually have been made stronger but this was not the case. It was just as strong as before the experiment. We had two identical cars for our regional and state competition. I left one car on the new NEO track overnight and performed a comparison the next day on the original ceramic track. The car that sat on the NEO magnets all night plopped completely down on the ceramic magnet track!
This capability of NEO magnets to demagnetize ceramic magnets begs the question: How are those of you who are using Neodymium magnets performing your tests? Are you quickly getting test runs in then replacing your ceramic magnets on your car? It would seem that if you weren't doing this, the parameters of your tests would change so drastically so as to render the data useless.

[Jdogg]

Well, we don't have money the to spend on a neo track. Even with a sale these tracks cost close to 1000 dollars, thus we don't have these issues on the large scale you described. But we have had our car sink into our track over time with regular pitsco tracks.

[lmatkovic3]

We quickly test and then take the car off the ramp. There isn't a noticeable change for a day of testing, though I'm sure we end up switching them every once in a while.

[chalker]

This capability of NEO magnets to demagnetize ceramic magnets begs the question: How are those of you who are using Neodymium magnets performing your tests? Are you quickly getting test runs in then replacing your ceramic magnets on your car? It would seem that if you weren't doing this, the parameters of your tests would change so drastically so as to render the data useless.

Hence one of th main reasons we forbid rare earth magnets on vehicles - they will permanently damage 'normal' tracks.

[joeyjoejoe]

Hey Chalker!
How much trouble would it be to have the person responsible for the solar system background and kitten mouse pointer changes executed??

I can hardly read anything now.

[chalker]

Hey Chalker!
How much trouble would it be to have the person responsible for the solar system background and kitten mouse pointer changes executed??

I can hardly read anything now.

Tell me about it......

[Stingray355]

We recently had our vehicle weighed at a competition and the weight was much different than we expected, about 200 grams more than what it actually weighs in our case. They used an expensive electronic scale and we often run into situations where the official weight for a device is off by 1% or less this was far beyond a 1% difference. Later in the day we think we figured it out. I believe there was a large piece of steel in the base of the scale that was being attracted by the magnets on our device and adding around 200 grams of phantom weight. Since our device weighs a bit more than 1600 grams this created around a 12-13% error. Many of the devices weighed much less and if they had similar magnetic strength they may have had a much larger error on their official weights.
We use a large foam block to weigh our device and to keep the magnets well away from our scales. We have heard stories of scales being damaged by powerful magnets and wanted to protect our equipment from such a fate.
Since it was too late to change the situation at our competition we just have to accept it for what it is. We often hear that SO can be unfair but it is equelly unfair for everyone. Sometimes that is true but sometimes it is not.
I hope everyone will communciate this info to all of the folks that will be running the remaining events this season so that it is not an issue for other teams. Good luck to everyone.

[AtRi]

Hello

My partner and I are looking into ways to make our MagLev safer. We have been coming up with ways to make our train shut off without us touching it for our design for the national competition next month. So far we have come up with two ideas. One, we are going to put a push button on the front of our train that will trigger and turn off our maglev when it hits a block of some sort that has been placed on the track. Second, we are looking to have a circuit (not integrated) that automatically breaks after a set time (say 8 seconds or so). My questions are has anyone else developed a safety system? How did you do it? I don't think it should be an issue sharing these ideas as they are strictly for safety purposes, and do not actually affect performance in the event. Also, at the national competition, does anyone know if the proctors will be able to identify our circuit and not integrated? We don't want to get disqualified for having a circuit being used for safety mistaken as an integrated circuit. Thanks!

[alecfxl]

Hello

My partner and I are looking into ways to make our MagLev safer. We have been coming up with ways to make our train shut off without us touching it for our design for the national competition next month. So far we have come up with two ideas. One, we are going to put a push button on the front of our train that will trigger and turn off our maglev when it hits a block of some sort that has been placed on the track. Second, we are looking to have a circuit (not integrated) that automatically breaks after a set time (say 8 seconds or so). My questions are has anyone else developed a safety system? How did you do it? I don't think it should be an issue sharing these ideas as they are strictly for safety purposes, and do not actually affect performance in the event. Also, at the national competition, does anyone know if the proctors will be able to identify our circuit and not integrated? We don't want to get disqualified for having a circuit being used for safety mistaken as an integrated circuit. Thanks!

An easy way is sheet metal or reversed track.