Braking help
 

Hey guys - just got a chance to fly my new jet this weekend and it has the new dream works pro link electric braking system. I have the system to brake at 50 percent and on pulsate mode on 9 which is really not much stopping power. The problem is I taxied it around and would notice that it would grab one or the other wheel more than the other. I took the wheel apart and found that the screws protrude the steel plate by a millimeter or two. The directions specified to use these screws so I put it back together and it seemed to stop. I took off and when I landed the jet came to a stop the left wheel had seized itself to the magnet bad. I used a hammer and screw driver to separate the magnet and steal plate. What is causing this problem? It doesn't say to put grease on the magnet, any info would help me out.

Thanks, Allen Leblanc

Do you have the little nylon spacer washer installed? On mine the metal brake disk washer kind of floats and rattles around a little with the three protruding bolts stopping the rotation. When energized the washer snaps flat against the magnet but when de-energized there is plenty of clearance. To get that washer to fuse to the magnet it might have got hot and somehow fused to the potting compound on the magnet. I would take some pics and maybe call Todd at Dreamworks to get his input. For me they have worked quite well, probably 30 flights on my UltraFlash.

Yes I have the nylon washer on both wheels and the recommended screws used. I also notice that it does float freely . I will take pics and send to Todd. Thanks for your help.

i had the same problem, but with another brand. I ended up spraying WD-40/CRC56 on each disk before each flight........ Got tired of that and modified back to air actuated brakes again.

Guys, I found the problem - when I removed the magnet and placed the steel plate on it and then energized it did what it was supposed to...Then when I unplugged it from the wire I still couldn't remove the steel plate from the magnet. When not energized it should drop the steel plate. This is not the case. This caused flat spots on new tires which are no good and magnets that are no good. I read that if a electro magnet is made with inferior materials this would happen. I will call Todd at dream works and see if he will warranty these brakes and tires. Next I will post pics of the electro magnet unplugged and won't let go .

WOW .... That's Crazy :confused: Keep us posted.

Unless an electromagnet core is made from correct materials you need to supply it with AC not DC. What you have is a permanent magnet manufacturing tool.
Try pulsing power through it with reverse polarity.
Andre

Hi, I made along with a friend a small production run of one of the first electronic braking systems available, most of the current systems are a close copy of this. In the pre-production/prototype testing we came across some issues and one which I believe is causing your problem - the permanent magnetisation of the floating steel disc. If you simply pass a DC current through an electromagnet in one direction (and this is the clue) you will magnetise the steel disc and it will then lock onto the electromagnets case (normally iron for best results), once this happens the brake system is not going to work. We designed the software to continually change the current direction over 100 times a second to help prevent this happening - the result is minimal magnetic charging and smoother braking.

I am not sure how others have tackled this problem but simply shooting a voltage through an electromagnet is not going to work.

marcs

I was still feeling that all the electric brakes and gear aren't quite up to snuff yet.

Too bad, because Todd usually has impeccable stuff that works just as impeccably.

Flip the brake disks over so they repel with no current applied.. I bet that your brake controller may have stopped reversing the voltage. The brakes will still work if half of voltage reverser circuit is out but will magnetize the disk. Can you put a voltmeter on the brake leads to see what it is doing?

We have HUNDREDS of our electric brakes already in the market. We have seen less than a handful of defective units but, they do happen. This is actually the first time we have heard of this issue and we are indeed curious to see the cause.
Todd