MagLev C

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MagLev C

Postby Jim_R » August 14th, 2012, 6:45 pm

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Re: MagLev C

Postby iwonder » September 2nd, 2012, 3:01 pm

Anyone know of a place to get a cheap track for this event? I tried building one a long time ago and it never worked out very well, but $150 or more is way out of our budget...
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Re: MagLev C

Postby chalker » September 2nd, 2012, 3:32 pm

iwonder wrote:Anyone know of a place to get a cheap track for this event? I tried building one a long time ago and it never worked out very well, but $150 or more is way out of our budget...


We've extensively changed the rules to allow for hand-built tracks. There will be a document posted shortly on the soinc.org event page going over in great detail on how to build one. In addition, we've changed the parameters to allow for 4' tracks, which are significantly cheaper than the 8' tracks most people buy. Pitsco and Kelvin are the only retailers I know of that sell them.

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Re: MagLev C

Postby iwonder » September 2nd, 2012, 3:43 pm

Oh, thanks :) and yes, I was looking at the 8' pitsco track... Expensive stuff.

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Re: MagLev C

Postby twototwenty » September 2nd, 2012, 4:50 pm

Parameters which enable hand-built tracks? That's...interesting.
I hadn't expected the rules to change very much from last year's trial event...I wonder if having an expensive brushless motor system will still pretty much be required to have a chance to place well with this year's rules.

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Re: MagLev C

Postby iwonder » September 2nd, 2012, 4:55 pm

I remember discussion a few weeks back about that where chalker chimed in and made a comment that seemed to imply a 'no semiconductors' clause, I'll try and dig it up.

Edit: here we are...
chalker wrote: It's still a couple weeks before the printed manuals come out, but I'll save everyone the trouble and expense by letting you know the rules will explicitly prohibit brushless motors and integrated circuits of any kind... so stick to the basic brushed motors.

here's the discussion: viewtopic.php?f=119&t=3053&start=150

So to the people that have done this event before, using an ESC, was it ever to your advantage to ramp up the speed instead of just hitting it full on instantly? Seems to me that it would minimize the possibility of jolting everything out of place, last time I tried a maglev it was very unstable/hard to use. Also, how complex are these systems? I assume everything is direct drive from the motor using the standard hobby parts, generally? Or do more competitive teams have some kind of gear reduction?
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Re: MagLev C

Postby Theengineeer » September 7th, 2012, 9:19 pm

chalker wrote:
iwonder wrote:


We've extensively changed the rules to allow for hand-built tracks. There will be a document posted shortly on the soinc.org event page going over in great detail on how to build one. In addition, we've changed the parameters to allow for 4' tracks, which are significantly cheaper than the 8' tracks most people buy. Pitsco and Kelvin are the only retailers I know of that sell them.


Would this mean we can no longer use remote activated systems?
If so, a lot of danger will result. Even with a brushed motor, a propeller spinning quickly can, and will, pose a major threat when the vehicle gets to the end of the track.

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Re: MagLev C

Postby retired1 » September 8th, 2012, 9:36 am

We will all have to wait a couple more days till we get the rules to see what is and is not legal.
Having flown gas powered model airplanes a few years, I think that you are significantly overstating the problem. The electric motor spins at a fairly high RPM but is not terribly strong, so when it hits the pillow at the end of the run, it will either stop turning or be trapped enough to turn it off - if - you have a switch or a quick disconnect in the power line.
If you are concerned with your personal safety, you might want to go to Kelvin.com and buy one of their safety props, assuming that it is of legal size.

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Re: MagLev C

Postby mrsteven » September 8th, 2012, 11:38 am

Im thinking no remotes. Chalkers comment saying no integrated circuits means you have no way to connect a remote controller to the maglev.
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Re: MagLev C

Postby iwonder » September 8th, 2012, 11:46 am

I'm still thinking a switch or bar across the front that would turn the motor off would allow you to stop the car when it hits the pillow, if you're really concerned about safety. I think the point this year is to go back to complete basics, a battery and a motor driving a prop, instead of having complex brushless R/C systems that cost significant amounts of money. Few more days till we know for sure :D
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Re: MagLev C

Postby twototwenty » September 8th, 2012, 12:13 pm

retired1 wrote:We will all have to wait a couple more days till we get the rules to see what is and is not legal.
Having flown gas powered model airplanes a few years, I think that you are significantly overstating the problem. The electric motor spins at a fairly high RPM but is not terribly strong, so when it hits the pillow at the end of the run, it will either stop turning or be trapped enough to turn it off - if - you have a switch or a quick disconnect in the power line.
If you are concerned with your personal safety, you might want to go to Kelvin.com and buy one of their safety props, assuming that it is of legal size.

Actually, safety was something of an issue. My team ordered special propellors that are highly effiecient, but very sharp, and this combined with a powerful motor connected to a powerful lithium polymer battery was no small hazard.

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Re: MagLev C

Postby retired1 » September 8th, 2012, 1:52 pm

Safety should always be a concern. a remote on/off switch, electronic, is not required. A welders glove or a thick oven mitt would protect the hand. Our teams will go with a simple micro switch that is not close to the prop(s) and could be manipulated with a new pencil. KISS principle.

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Re: MagLev C

Postby iwonder » September 8th, 2012, 2:20 pm

While actuating a microswitch with a pencil is a very simple idea, I'd be careful about pushing the maglev into the track before you start it. When you remove the pencil chances are the maglev will bounce around for a little bit while it starts moving, this could effect time scores. it might be simpler to run a string around the back of the device and simply let go of the string. It'd add a little drag as the string pulls out of the vehicle(i.e. if you looped it around a screw on the vehicle) but I think that would be negligible, and it still allows you to keep hands/fingers away from the prop while starting. Personally, I'll probably have a switch mounted up front to stop the device at the end, and will hold the end of the maglev before launch(I'm a little more daring, I guess). Of course, there'll be a power switch at the back, but not a switch you have to continuously hold.
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Re: MagLev C

Postby twototwenty » September 8th, 2012, 3:59 pm

Well, my guess is the rules with regulate how you release your vehicle; in the past, you have had to hold a pencil in front of it and removing it when the ES says go...anyway, the release isn't the tricky part; it's the turning the motor off that is, because some cars flip over at the end of the track, or are bouncing around, especially with powerful motors, and getting to the switch has caused problems in the past.

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Re: MagLev C

Postby JBoyd-NY » September 8th, 2012, 8:37 pm

The maximum length of the track used for testing is 95.0 cm, which is roughly 3 feet 1.5 inches. If you build your own track, it must be 4 feet or longer. There's a really simple way to stop the vehicle to make it easy to turn off the motor, and it works if you have a purchased track that is 8 feet long or if you build your own track and make it 5 feet long. Just change the polarity of the track magnets beyond the 4 foot mark. When the vehicle passes the 4 foot mark (which would be the finish line if the event supervisor uses the maximum length for the test track), the vehicle will encounter the opposite polarity magnets and, instead of being levitated, it will be attracted to the magnets and come to a stop. Once the vehicle is setting on the track and is completely stopped, you can hit the switch to turn off the motor. This method of stopping the vehicle has been used in the New York State B Division competition in previous years with no problems.


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