View Poll Results: Do we need a Controlled Motor/ESC for Racing?
Yes for 21.5 Only
30
15.31%
Yes for 13.5 Only
3
1.53%
Yes for 21.5 and 13.5
76
38.78%
No, leave it open and as it is.
59
30.10%
I have no opinion
5
2.55%
I'm sponsored / own a store, my wallet says NO!
2
1.02%
13.5 Motor Only
6
3.06%
21.5 Motor Only
15
7.65%
Voters: 196. You may not vote on this poll
Controlled Motor and Gearing for Stock Classes
07-15-2015, 08:39 PM
#226
Last year at the EP nationals a talking point was that we couldn't even get a good set of scales. It's nothing more than a pipe dream to think we could get a tool like that for measuring FDR.
Remember ETS draws nearly 400 racers over the series. With that brings the money to invest in such devices.
Australia will never get close to that.
Remember ETS draws nearly 400 racers over the series. With that brings the money to invest in such devices.
Australia will never get close to that.
Scales we don't have an AARCMCC set of because they should be easy enough to source that most clubs would have their own set. Perhaps calibration weights should be sent around though.
07-15-2015, 09:28 PM
#227
Phil.
07-15-2015, 11:38 PM
#230
07-16-2015, 12:58 AM
#231
Phase 1 showed some plausibility.
I swapped one end of a sensor cable for some breadboard pins and hooked it up to a micro-controller to count one of the hall effect sensors. Worked pretty well. Checked it with three motors, only to discover one of them had a dud sensor
Some of you might be able to guess where I'm going with this.
Phil.
I swapped one end of a sensor cable for some breadboard pins and hooked it up to a micro-controller to count one of the hall effect sensors. Worked pretty well. Checked it with three motors, only to discover one of them had a dud sensor
Some of you might be able to guess where I'm going with this.
Phil.
07-24-2015, 05:30 PM
#234
new Hobbywing Juststock ESC and fixed timing motors announced today
the timing of the release could not be better,
http://www.redrc.net/2015/07/hobbwin...or/#more-99690
now to try get hold of some.....
the timing of the release could not be better,
http://www.redrc.net/2015/07/hobbwin...or/#more-99690
now to try get hold of some.....
07-26-2015, 04:23 AM
#235
Ok, for what it's worth, I've prototyped a digital FDR checker and it looks reasonable. If you're interested, read below for details, otherwise, just look at the picture and wonder.
The basic idea is to use an electric motor with gearbox to drive one of the wheels of the chassis. This assembly has a rotation sensor so we can count the number of revolutions.
We attach a lead to the sensor port of the motor mounted in the chassis. In this way, we can also count the rotations of the motor shaft. The FDR is simply the ratio of the motor rotations to the axle rotations. In my two test subjects, the ratio is within ~1% of the calculated one. The accuracy can be improved by increasing the number of samples.
The prototype is rough and ready, as well as fragile. I have limited access to mechanical/physical tooling, but should be pretty easy to package up for someone who knows what they're doing.
The core of the prototype is an Arduino (ATMega328) microcontroller. It's fully programmable and has hardware interrupts that I've used to count the readings from the sensors. Less than 70 lines of C++ code does the rest.
I've got lots of ideas for improvement, but if anyone wants to go this route, I think this shows it's easy enough to do.
The basic idea is to use an electric motor with gearbox to drive one of the wheels of the chassis. This assembly has a rotation sensor so we can count the number of revolutions.
We attach a lead to the sensor port of the motor mounted in the chassis. In this way, we can also count the rotations of the motor shaft. The FDR is simply the ratio of the motor rotations to the axle rotations. In my two test subjects, the ratio is within ~1% of the calculated one. The accuracy can be improved by increasing the number of samples.
The prototype is rough and ready, as well as fragile. I have limited access to mechanical/physical tooling, but should be pretty easy to package up for someone who knows what they're doing.
The core of the prototype is an Arduino (ATMega328) microcontroller. It's fully programmable and has hardware interrupts that I've used to count the readings from the sensors. Less than 70 lines of C++ code does the rest.
I've got lots of ideas for improvement, but if anyone wants to go this route, I think this shows it's easy enough to do.
07-26-2015, 04:00 PM
#236
new Hobbywing Juststock ESC and fixed timing motors announced today
the timing of the release could not be better,
http://www.redrc.net/2015/07/hobbwin...or/#more-99690
now to try get hold of some.....
the timing of the release could not be better,
http://www.redrc.net/2015/07/hobbwin...or/#more-99690
now to try get hold of some.....
It is a replacement for the unsensored EZrun setup that the mini guys use perhaps?
07-26-2015, 04:07 PM
#237
Tech Regular
iTrader: (5)
ESC is a new version of the previous just stock which was sensored. IE different to the sensorless mini combo.
IMO given the application it would be better if the ESC didn't have the ability to update firmware as for the external switch what where they thinking?
IMO given the application it would be better if the ESC didn't have the ability to update firmware as for the external switch what where they thinking?
07-26-2015, 09:41 PM
#240
I hadn't actually seen that one before - they've taken a subtly different route, but the concept is pretty much the same.
It's just a 7mm hex socket connected to the gearbox shaft that drives the wheel on the car. There's no need to remove the wheel from the car, since it just sits over the wheel nut. And yes, it turns clockwise 
You could even blend both concepts to remove the special wheel of the ETS version and the driver motor of mine...
There's a statement that they're commercialising the ETS design via Muchmore, so mine's probably redundant, even if it was fun experimenting.
You could even blend both concepts to remove the special wheel of the ETS version and the driver motor of mine...
There's a statement that they're commercialising the ETS design via Muchmore, so mine's probably redundant, even if it was fun experimenting.