[hankster]

It's been talked about for awhile. Some have even taken kart systems and used them on their RC cars. Soon you will no longer have to resort to those extremes.

Eagle Tree Systems is in the final stages of releasing a data acquisition system for RC cars. I got a test unit to help them debug it and while I haven't actually got it installed and running. I can give you a few preview pictures.

The test unit (which doesn't even have a case yet) included the following:
Y cables for the steering and throttle servo (for position recording)
RPM sensor
Current sensor
Voltage sensor
Temperature sensor

Weight (no case) including all of the above sensors is 1.5 oz.
Size (no case) 2.75" x 1.25" (about the size of a normal ESC)

Not sure what other options will be available, but it looks like there is room for 8 more channels of data!

I plan on installing it today and giving it a test run as soon as the rain stops... never fails, just when you need decent weather, you get rain!!!

We plan on offering this system for sale and will have a dedicated forum for questions, tips, etc.

Below are a few pics to wet your appitite. I'll post more info as I get further in my testing.

 

[pepe]

Will it be out by Christmas? I need something else to put on my list,

 

[hankster]

I guess it depends on how the testing goes.

 

[tw78911sc]

G loads

I'd rather see info like side G loads and slip angle info in helping me get my chassis dialed in. It would be great to see the difference between sets of springs/tires/bodies/wings etc and then tie it to the RPMs

How much does it weigh? Do you download to a laptop?
Tom

 

[hankster]

First, the unit I have a first production prototype, it doesn't even have a case yet. The software is still beta, so what I now have is subject to change.

Not yet sure of the full options that will be available but looking at the raw data I see places for X & Y G-Force. The data is downloaded to a computer. The present software allows playback in a "real time" display. While that may not be optimal display for closely inspecting the info, the software they have for airplanes does allow for graphing. You can also import the raw data to Excel.

Weight (specs in the 1st message) is 1.5 oz as shown.

Since it is raining here I haven't had a chance to run the car outside. I did run it in my livingroom but the 8 x 6 foot of space available didn't really tell me much except that it worked.

I am attaching a graph I did in Excel for some of the data on this test run. The RPM & Amp Draw use the left scale, the Pack Voltage, Receiver Voltage and Motor Temp. uses the right scale. This was captured at 8 samples per second so you can see I have about 25 seconds of data here.

 

[hankster]

Another note on the data that can be collected. It will record any "glitches" you get in either your steering servo or your ESC... good for finding out if a receiver voltage drop is causing control problems.

 

[DynoMoHum]

can you give us a ball park figure on what the street price is likely to be on something like this?

I'm drooling already.... This is a gadget guy RC racers dream... and that's exactly what I am...

 

[hankster]

The current street price for the aircraft system is $150.00. I suspect the car system will be priced very close to this. Since I don't know for sure we can guess that it will be close to the aircraft system since the functions are pretty much the same. They normally include a couple sensors, my guess is these could be the 2 servo Y cables and the RPM sensor.

Also... another goodie, they are working on making it a lap counter also. An external IR beam will trigger an onboard IR sensor to record when your car passes the beam. I suspect it could be used with multiple beams to get split times on different parts of the track.

The nice thing is, is that the system is modulor. You can buy the main unit now and buy other sensors as you need them... they just plug in and you configure the system to collect whatever data you want. Want RPM, Volts and Amps now... great, just get those sensors. Want G-Force or Lap Counting later... no problem, just get those sensors and plug them in... reconfigure the unit to collect that data and you are set to go.

 

[DynoMoHum]

Sounds like a fair price to me... (well less would be better... but anyway)...

IR beam trigerd lap/segment time... COOL.

For me Amp, volt, and RPM would be great. It might be really cool to have Volts at battery and Volts at motor... however this may not be all that usefull, since the voltage at the motor is plused and that may make it somewhat hard to interpet in any meaningfull way.

Put me on the list of buyers...

 

[hankster]

To take motor voltage, you could just connect the voltage sensor wire to the motor instead of the battery... I haven't tried it so I have no idea how well it works... will have to try that.

Considering the present day motor dynos (single purpose units) are priced at 500 bucks or so, $150 seems like a bargin to me...

 

[McLin]

It certainly seems as though this is a “serious effort” and not just a toy. Where the motor information would be nice to have, I think I would be more interested in chassis information. I’m not sure just how they would go about that but things like shock and front-end movement would be good to know. ANYTHING that would show what is really going on when the rubber meats the road!

 

[patcollins]

This is pretty interesting, I really dont see a need for it for RC cars atleast for me. My interest is in it because I do data acq for a living on military aircraft, but my stuff typically is in the 100 lb range but that is for 100's even 1000's of parameters. Hank if the company needs any technical suggestions for data acq as it could relate to RC cars direct them my way.

 

[hankster]

This is designed off of a already manufacturered and marketed unit that is built for RC cars. Considering the "guts" are pretty much the same and only the layout was changed to make it smaller, the only real R&D is for the software. For what I would consider a "low end unit" (under $200.00) it does a lot.

I'd like to see 4x the memory, higher sample rates and more sensors. But then would there be a market for something that cost twice as much?

Right now I have my car wired for RPM, voltage, current, motor temperature, steering and ESC. As it is, the wiring is a rats nest. I suppose it could be made a little neater but having many more sensors then this can end up being a real pain to wire and maintain.

Pat, I'll contact them and see if they require any assistance.

 

[pepe]

I agree with Mclin, the more we know about what is REALLY HAPPENING on the track the better off we are,this may just completly change the way we think about set ups.Not only that but think what it will do for manufactors when it comes to new designs.

 

[Fred B]

The major addition of the new system is amps. They have an area on the board for acceleration so I'm assuming that it's just not in there yet.

Once you have amps and RPM, it's off to the dyno. You can also see the changes in gearing which is a must in 12th. I'll be running it a little more this weekend.

 

[DynoMoHum]

Ok, once they get the load sensors G force and all that stuff, then transmit it to a remote seat that I sit in and it gives me real time feedback so I can feel the car break loose in the corner and correct for it...

 

[hankster]

For those that are testing the system, could you please contact me via email. I'd like to have a private area where we can discuss the system and what is being found. Also, we can discuss how best to address some of the improvements that are needed.

 

[hankster]

Here is a picture of the case that the unit will be enclosed in. I understand the production label is slightly different then the one shown in this picture.

 

[patcollins]

What are the servo connections for?

 

[hankster]

It records the position of the steering servo and throttle esc/servos.