Magnetic force measuring.

Questions and Ideas to track building, how are you doing it? need help? new features? share your ideas.
SlotCarRental_com
Posts: 41
Joined: Sat 10. Aug 2013 08:39

Re: Magnetic force measuring.

Post by SlotCarRental_com »

When I previously mentioned using a wheel or ball bearing magnet, I was imagining a hinged guide arm just like those.
If the ball can be mounted freely enough like a ball point pen tip, it should be able to roll in the cars running direction, and sideways, for lane changes.


I was also wondering, what would happen if instead of that one guide magnet on the arm, there was 2 magnets, with less width, but more forward/back length.
Less width so there is less side to side slop, and two magnets for redundancy and to make up for smaller magnets.


I have a lot of ideas I've been sketching...
One major idea is to re-orient the steering knuckles, but its hard to describe so I will try to make a decent sketch of it, hopefully in 3d rather then pencil.


If my Form 2 machine ever gets here I could 3d Print my own chassis... but more delays, hopefully before middle of the month.
WesR
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Joined: Fri 21. Dec 2012 17:37

Re: Magnetic force measuring.

Post by WesR »

DSCF9699 (500x374).jpg
DSCF9699 (500x374).jpg (170.38 KiB) Viewed 12898 times
As per suggestions, a metal (aluminium) arm with two 3mm diam. x 2mm magnets. Both mods are probably a slight improvement. Something for the next generation Magracers!
Re. the arm with wheel/ball whatever, this would ride up over the high spots in the wire but if the wire is low, you would still loose magnetic guidance so the wire would still need to be pretty accurately laid so I am not sure if there would be any benefit.
SlotCarRental_com
Posts: 41
Joined: Sat 10. Aug 2013 08:39

Re: Magnetic force measuring.

Post by SlotCarRental_com »

I was thinking about the multiple magnet thing again last night.
It should help the car stay in the proper line, in areas where the wire routes cross each other.
At least I hope it does not hinder it any...

How did it effect lane changes? did they need to be longer?

Another thing that might help keep the guide arm at a set height, is a larger diameter hinge axle, instead of the skinny screw, like maybe a spacer or something to thicken it up..
( ( O ) )
I thought about having the far end rest on a lip on the chassis itself, but that would hinder height adjustability.
SlotCarRental_com
Posts: 41
Joined: Sat 10. Aug 2013 08:39

Re: Magnetic force measuring.

Post by SlotCarRental_com »

This is a rough sketch of what I had in mind for an alternative steering mechanism.
For, narrower bodies, centering the mag coil, and to allow "solid" front wheels, for bearings and or rims.

Image
kiklo
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Re: Magnetic force measuring.

Post by kiklo »

My 3D printet 2x3mm magnet version and steel pin. Hard to print 1,5 mm guide pin. Very little flex.

Not really tested yet, but quick test = seems better.
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Racing Regards

Kim K.
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HeliumFrog
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Re: Magnetic force measuring.

Post by HeliumFrog »

Great work all. Here's a few more ideas!

If you have a look at the force exerted by the magnet sideways when the car turns, probably the best place for the roller would be behind the magnet. The closer the roller is to the pivot point the less side force would be needed to drag it sideways across the track. There might be a sweet spot where the side force required to drag it is just less than the steering force exerted by the steering solenoid but still provides support to provide a gap. A nylon plain roller might be better or even ptfe or oilon as they have low coef of friction.

I think if Wes comes up with a smaller diameter wire solution glued directly this would be ideal. Perhaps there might be a way to mount the wire on the underside of card board scored to the correct depth and then mount this onto the base board. You could use standard card sections of track.

As some of you know I tried shim steel for the guide "Wire" and this worked quite well and could be glued directly to the board and covered with paper mache. I did find lane changing quite hard as the car tends to stray left and right when running along a 5mm wide shim track and can miss the lane change. I think this idea does have some merit though as it would be possible to get some standard curves and lane change plates laser cut in a press out sheet very cheaply. Perhaps there is a way to taper the width down just before a lane change or some other configuration.

Would it be possible to have a very thin metal sheet that covered an entire pit area so the cars could pull in anywhere off the racing line?

Here is the video of what I achieved using shim

Last edited by Keld on Wed 13. Apr 2016 09:33, edited 1 time in total.
Reason: youtube inside post
WesR
Posts: 371
Joined: Fri 21. Dec 2012 17:37

Re: Magnetic force measuring.

Post by WesR »

I tried my twin magnet guide again today on my new .5mm wire track but it didn't seem as good as the single magnet for some reason.
I have also been experimenting with flat wire but I think it's perhaps time for a new topic on this.
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