Thursday, August 25, 2011

Wireless Trainer Port

Saw this linked from RCGroups, but couldn't figure out who did it or where it's written up.

Basic Idea:

  • student's Tx is bound to the Rx
  • Rx has trainer cable wired to battery port
  • PPM signals feed into the trainer port from the receiver
  • For simulator, can power from USB

Monday, August 15, 2011

Motor balancing in addition to prop balancing

Old Man Mike posts an interesting note regarding vibrations.  Not only is prop balancing critical, but blade orientation plays an important role as well.  He says:

This chart shows that even with balanced props, there is a sweet spot for mounting that will provide a minimum vibration level. Without testing, it is very unlikely that a low vibration will be achieved and most likely the number will be at least two times greater than the minimum. It could even be much worse. One of the five motor/prop combination had more than 6 times times the minimum vibration for some prop positions and more than 4 times as much even just 45 degrees away from the minimum position!

It typically takes about 10 mins per motor/prop to find the minimum so it adds a bit of time to my quad builds. Since I'm somewhat obsessed with getting low vibration performance with my quads, I think it is worth the effort.

Anti-vibration fasteners

FrozenCPU.com has a lot of grommets, etc, designed to reduce vibrations from hard drives.  Could these be useful for mounting quad controller boards?

Some tiny Futaba Connectors

Coriolan ID's Futaba SH, Pico, and ZH connectors.

Every kind of micro connector imaginable.

rc-connectors.com has just about every small connector ever made, nicely arranged by model.  For example, here's a SMD nan-JST female 3-pin right angle piece.  Just what you need to make a green dot vapor brick AR6400 compatible!

EasyStar Brushless Outrunner

ScrtSqrl has a nifty method using a 30mm medicine bottle to mount a brushless outrunner.