ASK Cubby – You Ask The Questions, I Dodge The Answers
“Motors and rotors
Morning Cubby, 4.39am Local time (sweden). Any idea or a good tip to strength the sintered magnets in a BL motor for say MT use?..i mean to hold it together?..i used a 1717 that where reinforced ( from factory ) with thin glassfibre..but i knew i used it to and beyound the limit on rpm when i juiced that motor with 8s..it handled 3 packs then the magnets exploded ( temp where no issiues )..changed that to a Leopard brushless 1730rpm..still 8s..and after 15 packs still works like a charm..but this one do not have any reinforcments.. any tip?..or should i like we all do..bash hard and ev wait for that moment..6s aint an option..😁.
Awsm reports like always
Cubby- Yo hey there Tommy, thanks for the email.
So, you had a brushless motor, put a bunch of voltage to it, it spun a ton of RPM, then the rotor exploded. Congrats, you are a real basher!
To answer your question, no, there isn’t anything you can do about shattering a rotor because of excessive RPM. First off, there simply isn’t much room to put a wrap on a rotor as the tolerances inside a typical brushless motor is quite tight. And two, even if you were to wrap it with a Kevlar tape, chances are you would have a hard time keeping the tape on at those types of RPM.
About the motor you blew up, that might not have been purely RPM related. It sounds like there may have been a fault in the rotor, or perhaps you hit something hard (you are a basher after all) and slightly damaged it previously. Big landings, tagging curbs, etc, put huge g-forces on a truck, as well as your motor. To boil it down, if you really bash hard, you are going to blow/break/destroy motors, it is just part of the dealio.
Right now a brand new Traxxas TRX-4 Defender is being shipped to my house. Have you driven one? What would you change first?
Cubby- Well hola there Wendell, thanks for the email.
Yes, I have driven the Traxxas TRX-4. Actually, I’ve driven one a lot, as in most every weekend since several weeks before they were released. I’ve gone on numerous trail drives, as well as some ridiculous bashing that we put every one of our test vehicles through.
The very first mod that I would recommend is simply a new servo. The stocker actually does a decent job for general bashing, but for hardcore use or for real crawling, a gnarlier servo should be considered a must have. A 200+ oz Hitec will not only dramatically enhance the TRX-4’s crawling capability, but will also be more durable than the stock unit. Oh and btw, you’ll need to install a Castle BEC BEFORE you put a serious torque servo in your rig.
After that, I would go with a different body. I would do that for two reasons. The first reason is to customize it to what I like. Yes, the stock Defender body is very well done, but I don’t want to show up and have my TRX-4 look just like everybody else’s. Secondly, the stock body puts a lot of weight up high. This allows the truck drive in a scale realistic manner, but when on the trail with my buddies, I would like to be able to make the most difficult obstacles as easily as possible. Therefore I would look for a new body that I liked the style of, as well as one that would help lower my truck’s center of gravity.
The next thing I would change would be the tires. Once again the stock tires are actually pretty decent, but also once again I would be looking for more straight up trail performance. The tires that I use the most right now are the Pro-Line Hyrax. While the Hyrax tires don’t look as scale realistic as some of the others on the market, they freak’n work! They give amazing amounts of traction in the rocks and do an incredible overall job on the trails that I typically drive on.
But that’s just me. It’s your money, buy what you think will improve the truck and what strikes your fancy. Oh, just don’t forget to send me pics afterwards.
So there it is, another ASK Cubby is done for the week. Do you have a question? Want to know something? Just like to complain? Maybe you have a chip you need to get off your shoulder? My email is always open- thecubreportrc at gmail dot com.
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