MagLev C

[el1054]

So, in the rules for construction, they say that our dowel needs a rigid 5cmx5cm flag at the top??? what exactly is this flag they're talking about?

[joeyjoejoe]

We have tested our car extensively today and have discovered something that concerns us.
Our track was set on a standard school lunch table which, it was determined, had an approximate 1/2 inch rise in the middle. When we set our car for the 12+ second mark, it would go to the location of the hump and them stop.
Once we discovered the problem, we shimmed the ends of the track, clamped the center down and then used a level to verify that it was flat throughout. Once we did this, it worked perfectly. Do you think that this type of adjustment would be acceptable at the competition?

[FawnOnyx]

We have tested our car extensively today and have discovered something that concerns us.
Our track was set on a standard school lunch table which, it was determined, had an approximate 1/2 inch rise in the middle. When we set our car for the 12+ second mark, it would go to the location of the hump and them stop.
Once we discovered the problem, we shimmed the ends of the track, clamped the center down and then used a level to verify that it was flat throughout. Once we did this, it worked perfectly. Do you think that this type of adjustment would be acceptable at the competition?

Sounds reasonable to me, but it depends a lot on the event supervisor. Like they might think it's unfair that you get to level your track and everyone else doesn't. But in my opinion, that's mostly the other team's fault since everyone's allowed to bring their own tools.

[darkwinters]

So, in the rules for construction, they say that our dowel needs a rigid 5cmx5cm flag at the top??? what exactly is this flag they're talking about?

At the top of the dowel, you're supposed to have a flag oriented parallel to the track.

The main reason for this is simply to give a good-sized target that's virtually guaranteed to activate the photogates.

[darkwinters]

We're remaking our fan guard- this time by manually making a fan duct (ring and all)- suggestions for a flexible (but slightly rigid) material for the duct?

[wlsguy]

You could try using a 2l pop bottle and cutting off the ends.
If the diameter is a little small for your blade, try using 2 pieces of the bottle and splicing them to get a bigger diameter.
Just be sure to use a glue other than superglue (which melts the pop bottle plastic)

[TheGatesofLogic]

If you're using a stiff wire mesh for the caging then you can loop it to form a duct-like shape and then attach shaped sheets of the mesh to the loop. Unless you are intending to direct the airflow with the duct, they really aren't all that necessary.

[Flavorflav]

We have tested our car extensively today and have discovered something that concerns us.
Our track was set on a standard school lunch table which, it was determined, had an approximate 1/2 inch rise in the middle. When we set our car for the 12+ second mark, it would go to the location of the hump and them stop.
Once we discovered the problem, we shimmed the ends of the track, clamped the center down and then used a level to verify that it was flat throughout. Once we did this, it worked perfectly. Do you think that this type of adjustment would be acceptable at the competition?

Sounds reasonable to me, but it depends a lot on the event supervisor. Like they might think it's unfair that you get to level your track and everyone else doesn't. But in my opinion, that's mostly the other team's fault since everyone's allowed to bring their own tools.

I would add, though, that you cannot count on any particular configuration of the table or bench you will test on. I would suggest doing your leveling and shimming on a board, to which you then screw the track. You should be allowed to shim, but you might not be able to get a clamp on your track in the competition setup.

[SGU220]

Hey guys so I am using kelvin strips on my track and ceramic magnets from Home Depot on my vehicle. However, its seems as if the magnets do not work together properly--when the vehicle gets too close to the track is sticks (yes I did check the polarity). I did use a steel stud for part of my track, which may be contributing to the problem. Is it possible that the two magnets do not per se "work together?"

[joeyjoejoe]

First it would help to know more about your tracks magnet configuration. I am going to assume you have the same polarity on both sides of your track and car. This configuration allows the car to travel down the track in both directions with no modifications.
Look very closely at what parts of the magnets are "sticking". If its the face of the magnets (necessarily a same-polarity contact), then its probably just due to the fact that the magnetic repulsion isn't strong enough-something we have all seen with the strip magnets. I guess it could be related to the steel on your track. I don't know the specifics of your track configuration but would recommend you switch to aluminum if at all possible.
If the magnets are sticking due to an extreme tilt then you need to lower the center of gravity of your car, add weight (again, with strip magnets, I doubt this is the issue) or adjust your side guides to help minimize the tilt.