U-Force 75 power on/off ??!?!

[Lou_]

Hi

I have just reveive my Schulze U-Force 75 (but not the hacker motor for the moment)
I'm surprise when I see that is NOT an power ON/OFF system for make "online" the car ...
Only the solution to put the accu to turn it "ON" ?

How to put an "on/off system" ??

[re-inferno]

You could solder a switch into the black servowire thus letting the controller "boot" as soon as power ist applied, but it won't get any signals from the receiver.

However, a switch is just an additional component that may fail, especially in offroad conditions, plus the UF should shut down the motor as soon as it recieves no/incorrect signals - try to turn your transmitter off when driving and see what happens (or do it with the wheel aloof the ground)
But don't do it that often as clipped PPM signal can damage your servos as long as the reciever doesn't have internal corrections.

[TheSteve]

I think no on/off switch is a wise engineering choice. With the amount of power the batteries in RC cars use they should always be disconnected when not in use. A further reason is if you're using Lithium Polymer. One over discharge and the battery could easily be dead. With an on/off switch you may not be disconnecting the battery pack. Even if the switch was in the off position its still going to be taking a small amount of current, enough to ruin LiPo batteries if left too long.

As re-inferno said it is also an additional point of failure.

[WhaDL]

Actually, a switch is absolutely mandatory for racing. Any competitive racer will solder his batteries in, rather than use a plug. So what happens if someone in the race before yours is using the same frequency as you are ? You don't have time to wait until that race ends, then solder in your batteries and still make your race.

Any brushless system that doesn't come with a switch just isn't ready for racing.

[DualBL]

well...
if you are not running your car, you are supposed to disconnect the batteries. Hacker says so, and so does Schulze.
alot of the controllers that were smoking a year ago, were because people just left them plugged in.
as for the frequency thing... you just unplug the controller from the reciever, and problem solved.
-Nick

[re-inferno]

WhaDL

Well... what about taking out the reciever's crystal? ;)
Or you could even disconect the controllers servo lead - which would be a lot more complicated if they're secured.

Honestly, I'm glad, that the BL-Controllers don't have a switch. There's one thing I've learnt from 1/8 offroad racing: Anything that could fail will do so, so keep your gear as simple as possible.

Besides, If the airplane guys don't use direct soldering on their packs (where they have to keep up with 150+A and more than 20cells) why should the "competitive racer"?

Funny thing is, any decent power orienateted BL sys (Twist 47-55, Basic 5300, Hacker 8s, 6s) could overcome any Brushed combo even on inferior batteries (e.g, 2400 p&m vs. 3300 p&m) in terms of power and (depending, even) runtime and secondly, any of these BLs will exceed the capabilities of any 1/10 scale on a decent track if you really want to, so why mess with direct soldering connections?

[WhaDL]

I don't think taking out the crystal would be a really good idea. I'd just put in a switch to turn off the power to the receiver. I've actually done that with a Lehner, and it behaved quite well with no signal from the receiver.

As for not soldering, I think you'll always see competitive racers doing it. They ALL do it now. And even when they start running BL, they'll continue to do it to get the most out of their system - heck, they do it now with 8-turn mods.

Besides, even if you plug them in, it's a whole lot more convenient to just reach in under the body and flip a switch, rather than trying to connect a plug in the short time that you have at both the start and end of a race.

And the switch isn't intended to eliminate the need to disconnect the batteries when you put the car away - it's just to ensure the car will not respond to another radio when the battery is connected and your radio must be off.

I'll hang my hat on this one - any BL system that does not come with a switch will never catch on at the 'big' races. There's several reasons Novak is the only BL approved so far for ROAR racing. And one of them is the fact that it has a switch.

[re-inferno]

Besides, If the airplane guys don't use direct soldering on their packs (where they have to keep up with 150+A and more than 20cells) why should the "competitive racer"?

...which again questions the direct soldering itself.

It may be useful in brushed motor racing but with BL it's a different story.
If some competitive racers won't adapt themselves, nor think of the sense DS (practically doesn't) make, well not my problem.

All I can say is that we never ran switches in the 1/8th because they would fail anytime, even dust-covered etc.