Would someone be willing to send me or post a raw data file from the Data Recorder (new version) so I can see the data format in its rawest form?

A full run in Comma Seperated or something similar would be great.

Thanks in advance
SS

Albie,

The voltage drop is why we run receiver packs in 12th. The speedo won't boost voltage above pack voltage so it falls off under heavy load. It still happens to a degree with 6 cells but is probably a little worse with drag motors.

Now you can test different cells to see what ones pall off the least.

FB

thats the idea im having fred.. i want to test the diff between 48 and 64 pitch gears as some people say 48 robs horsepower.. i personally run 48 pitch and have since day 1 and i cant get the 64 pitch to run for me.. i cant wait for the g force meter so i can do some more testing...

hank i dont run my drag cars outside of national events for any reason in the drag cars i run microswitches and yes i do have a reciever pack in the car .. when it goes bad i will order from you for sure..... i have a tc3 with a cyclone in it that i use to test motors and breakin batts with that is set up with locked diffs. im currently using the tc3 as a test bed just to get aquainted with the onboard computer..
i would like to see a way to graph 2 runs side by side to see the difference between 2 seperate runs to map how changes will effect..

hank any info on the g meter when it will be avail.....albie

No info on the G meter yet.

don't know if this has been asked yet...

Motec (the 1:1 car DAQ and engine control company) has a system where they map out the track layout, then overlay acceleration, braking, g's etc. on the picture. anything like this for this system?

sands

No, there is not anything like this available... but then we are talking about a $200 system compared to a $5000 system.

On the g meter stuff. Have you looked a MEMs devices? They are essentially board mounted accelerometers. I am an engineering manager at an appliance manufactere and we recently added some to a consumer machine for vibration and displacement monitoring. If memory serves, they are less then $5 bulk cost.

www.analog.com is a manufacter of them. Specs range from up to 5g to 10 g, less then .5 mA draw, up to 5 volts and analog output. Resolutions at 2mg and a 2.5 hz bandwidth. Should be more than adaquate for an RC car. They will also do 2 axis measurements for acceleration and yaw.

full link:
http://www.analog.com/Analog_Root/sitePage/mainSectionHome/0,2130,level4%253D%25252D1%2526level1%253D212%2526 level2%253D213%2526level3%253D%25252D1,00.html

Oh yeah, they also have gyros for yaw rate measurement - would be cool for your airplane applications.

thats the idea im having fred.. i want to test the diff between 48 and 64 pitch gears as some people say 48 robs horsepower.. i personally run 48 pitch and have since day 1 and i cant get the 64 pitch to run for me.. i cant wait for the g force meter so i can do some more testing...

hank i dont run my drag cars outside of national events for any reason in the drag cars i run microswitches and yes i do have a reciever pack in the car .. when it goes bad i will order from you for sure..... i have a tc3 with a cyclone in it that i use to test motors and breakin batts with that is set up with locked diffs. im currently using the tc3 as a test bed just to get aquainted with the onboard computer..
i would like to see a way to graph 2 runs side by side to see the difference between 2 seperate runs to map how changes will effect..

hank any info on the g meter when it will be avail.....albie

If I understand this tool correctly - you can get the raw data out, which would let your manually build charts. With drag that would be cool, but with road, the graphs would get out of sync with crashes, traffic, etc. Unless you look at general trends; voltage early in the race and late, temps with different gearing, etc.

I am sure they are using something like that for their development. They have the G-Force (X & Y axis) and a lap timer in development now. No word on when they will be completed.

Hank,
I seem to be unable to get rpm-numbers in?
magnets are placed a diff outrdive.
2 small ones with the black dot outwards.
sensor is about 1.5mm away!.
Amy thoughts?

pizza

Do you have the sensor pluged into the CDR properly? Are you sure you have the CDR set to record RPM? Do you have a the latest version of the software?

I'll triple check and let you know.
thnx

A good way to find the right placement for the RPM sensor is to run the unit in live mode before installation.

Move the RPM sensor by hand to find the point where it registers reliably, then work out how to stick it there!

The magnets should have the black ink side facing the printed face of the sensor.

Hope that helps,

Dave

also make sure you enter all the gear ratio and tire size data i know mine acted up at first till i added all that info... albie

HHEELLPPPPpppppppppppppp..............

Sorry guys, I checked everything but somehow all signal work OK.
Except no RPM at all?????

Any way to measure wheter the sensor is broke or anything?

Regards,
Pizza wo rpm

Contact Bill at billpa@comcast.net and he can take care of it for you.

i spoke with bill 2 days ago he was leaving for a hobby show and wasnt gonna be back till next week.. albie

First, make sure you are using the latest version of the CDR software.. there were a couple RPM bugs in the previous version. Since I am not sure if you have a digital multimeter with a diode tester I will give you the follow ing info. While I am not sure the following test will tell you if the RPM sensor is good, radically different readings will let you know that it is most likely bad. Use a digital voltage meter set to read resistance and check the following.

Put the black lead (negative) of the meter on the black wire of the RPM sensor and the red lead (positive) of the meter on the red wire... reading should be approx. 33M ohms.

Put the black lead (negative) of the meter on the white wire of the RPM sensor and the red lead (positive) of the meter on the red wire... reading should be apporx. 26M ohms.

Any other combinations of hookups should show open circuits.

would there be any way to synchronize the data graph from this recorder with video from a small camera(something like this http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=19164&item=5700583714&rd=1 ) mounted on the car

The data from the recorder can be played back in real time - with the standard screen of dials and readouts.

So it should be relatively straightforward to synchronise the video with the readouts (all you need to do is find a way of doing a dynamic screen grab from the PC you're viewing the data on). This would have to be done after the run - the recorder doesn't send back live data from the car (yet).

The graphs are just created as a complete graph - they don't draw gradually - so you couldn't watch the graph draw itself during a run.

It would seem to be a simple thing to add an interface to the main unit that would allow you to use an SD card, or something similar to expand the memory, and thus the recording time...

I'm wondering how this would function on a 1/4 scale Sportsman car... RPM, EGT, etc would be very handy...

R

There are a number of 1/4 and 1/5 scale racers that are using it. The only real drawback is it is designed for only one RPM input. What I have found is that after 4 or 5 minutes of data is collected, the data become "unweldy" in that it is hard to graph all of the data even just to pick out the spots you want to look at. To get maximum time just record the items that are important... the fewer items you collect data on the more time it will record.

Depending on what you want to log, you can get about 8 minutes of data from the recorder. I think I was getting about 7 1/2 minutes with 12th (recording servo's, rpm, amps, and voltage). This is more than enough data to see what the car's doing.

With the gas car, I set-up for servo's, rpm, g force and one temp. With those channels selected there's more than enough time. The cool thing is that the system really will measure 40,000 rpm at the flywheel.

I thought I would pass on a few pics of how I am mounting the RC Car Data Recorder g-force and rpm sensors on my T4. I haven’t messed with the data recorder for awhile but figured I’d drag it out because I want to compare on-track performance between my own tuned stock motors against a couple “pro-tuned” motors that I recently received. I’m heading to the Region 5 Off-road Champs and figured this would be a good place to get some data to compare motors. Once I get the data I’ll post the results here.

G-Force Sensor Mounting

First you can see how I mounted the g-force sensor. I used a piece of plastic from bubble packaging. You know the plastic covering that you find on items you buy in your local department store…. It shows the item you are buying and you have to cut the darned thing apart to get it out. Lexan would also well if you have a spare piece lying around.
I just cut out a piece the same length as g-force sensor and formed it around the battery strap. When you clamp down the battery, it holds the sensor snugly in place. The advantage here is that you can shift the position of the sensor to match the CG of the truck. In this case, the CG is approx. over the 3rd cell of the battery pack.
http://photos.hobbytalk.com/data/510/1gforcemount01a-thumb.jpg Larger Pic (http://photos.hobbytalk.com/showphoto.php?photo=2196)
http://photos.hobbytalk.com/data/510/1gforcemount01b-thumb.jpg Larger Pic (http://photos.hobbytalk.com/showphoto.php?photo=2197)

RPM Sensor Mounting

With the RPM sensor, I wanted a place that would make it easy to remove. Ideally, you want to mount it close the motor but I couldn’t come up with a way to easily mount it and make it easily removable. So I decided to mount it on the rear outdrive. I superglued the magnets to the outdrive and then bent a paperclip to so it would screw to the transmission brace and hold the sensor close to the magnets.

This makes it easy to remove but has the disadvantage of not always giving true motor RPMs because of the diff action. Guess it’s a tradeoff that I’ll have to live with.

http://photos.hobbytalk.com/data/510/1rpmmount01a-thumb.jpg Larger Pic (http://photos.hobbytalk.com/showphoto.php?photo=2198)
http://photos.hobbytalk.com/data/510/1rpmmount01b-thumb.jpg Larger Pic (http://photos.hobbytalk.com/showphoto.php?photo=2199)

Hopefully this will give you a few ideas on mounting your g-force and rpm sensor when using the RC Car Data Recorder.

Great pics Hank - it's a good idea marking the G-force directions of the top side... wish I had done that instead of continuously flipping the sensor because I'd forgotten which way was which!

The problem I had was the servo tape I used to stick it down ripped off the label. Luckly I had another so I could see which way was which.