Data Loggers  
View related threads: (in this forum | in all forums)

Tower Hobbies
Enter up to 4 keywords or Tower stock numbers
Logged in as Guest



Users viewing this topic: none
  Printable Version
       



All Forums >> RC Airplanes >> Pylon Universe - RC Pylon Racing >> QM-40 Racing >> Data Loggers Page: [1] 2   next >   >>  

Login
Message << Older Topic   Newer Topic >>
Data Loggers - 8/18/2004 2:26:29 PM   
AD2004


 

Posts: 2
Joined: 8/18/2004
From: , AUSTRALIA
Status: offline 		Has anyone used the Eagletree data logger in their racer?
I am considering purchasing one but would appreciate any info particularly from pylon racers to help with my decision.
www.eagletreesystems.com
       Post #: 1

RE: Data Loggers - 8/18/2004 4:29:02 PM   
Ed Smith


 

Posts: 2820
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		I have never used a data logger. I have seen a few people try them out. The device provided information but how to use it seemed to be the issue. The few people that I know did not follow up and really put the information to good use. It seemed more like idle curiosity. You may be able to us it for your application but racing is pretty basic stuff. We can tell if we are fast enough for free.

I could see a monitoring device where in flight adjustments could be made. But just an information collector I am not so sure. There are not too many racers that bother with them.

Ed S

(in reply to AD2004)
       Post #: 2

RE: Data Loggers - 8/18/2004 4:39:11 PM   
DHG


 

Posts: 896
Joined: 4/24/2002
From: Denver, CO, USA
Status: offline 		My racing partner and I split the cost of one earlier this year. We are both going faster now. If nothing else, it's great for choosing among different propellers. Some make the engine sound terrific, but don't improve the airspeed. Others go well in the straights, but bog down in the turns. All this is useful information.

I like it better than the radar gun because you don't have to stand under the flight path, and the readings are not affected by wind.

Duane

(in reply to Ed Smith)
       Post #: 3

RE: Data Loggers - 8/18/2004 5:05:27 PM   
flycatch


 

Posts: 347
Joined: 7/24/2002
From: Barstow, CA, USA
Status: offline 		I have to agree to the last poster "dhg". Being in the UAV field it has proved to be a valuable tool. You must be aware of the aiborne measurements it can gather. Using this information will fine tune your airframe for all environmental conditions.

(in reply to DHG)
       Post #: 4

RE: Data Loggers - 8/18/2004 7:08:21 PM   
John Z Williams Jr


 

Posts: 121
Joined: 9/17/2003
From: Boulder, CO, USA
Status: offline 		Yes, Duane and I have been using the eagletree system to test planes, props and engines, clearly an advantage to finding out what props work well, which props slow down too much in the turns and which props work well in the straights and in the turns, I could not see a 5mph to a 7mph difference in speed, but the data recorder can!!! It clearly helped up to develope props, we run the black prop and see if we can beat that with wood, what was interesting is like Duane said, some that ran 24,500 or 25k on the ground sounded awesome in the air, we thought we had the mother load... Wrong, it sounded great, but was not faster, but slower by 8-10mph than the prop peaking at 23,200 or so... We thought by sound and looking at it the higher rpm prop was smoking, but in reality it was slower!!! WE had one prop that would unload and go like stink across the field, but when put down on the course it bogged down to much and ended up being 10-12mph slower than the black apc prop... let it go across the field and it was 4mph faster than the black prop, this was usefull info!!! They can also measure by a dual axis g force meter acceleration out of the turns and off the line to # 1.
Rpm in the air is helpull too... You can make sure you are reaching that majic 27k number in the air and when you reach it!!! Is it right after the turn, or is it half way down the straights or is it right at the end of the straight right before you pull again???
These are great quesions that can be answered by the data recorder... The clock will give you total lap times, but to study what the props and plane and engine are really doing in the turns and in the straights, the recorder can not be beat!!!
If nothing else it let me know the apc black prop is hard to beat and out of 15 props, I made one that was slightly better!!!
That let me know which one to run!!! Then we ran Duane's plane and it was on fire, it let me know how the extra weight on my plane affected speed in the straights and turns!!! He had 8mph on me!!! Boo Hoo, if first you do not succede, try try again... I would have never know this because our lap times were almost identical!!! This shows you can take a plane that is 8mph slower and still turn the same lap times as another pilot with a faster plane, now if I could get my plane going that extra 8mph, I would be set eh???!!!
Of course Duane was running his monster BSE Jett Motor...

(in reply to flycatch)
       Post #: 5

RE: Data Loggers - 8/18/2004 7:17:37 PM   
Ed Smith


 

Posts: 2820
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline
quote:

I have never used a data logger. I have seen a few people try them out. The device provided information but how to use it seemed to be the issue. The few people that I know did not follow up and really put the information to good use.



I will take back some of what I said. Obviously there are at least two exceptions. Interesting to note they kept it secret!!!!

Ed S

(in reply to John Z Williams Jr)
       Post #: 6

RE: Data Loggers - 8/18/2004 7:29:16 PM   
John Z Williams Jr


 

Posts: 121
Joined: 9/17/2003
From: Boulder, CO, USA
Status: offline 		Yea, that makes me wonder how benificial to my racing cause it is to spread all my secrets and knowlege to the entire pylon community??? I have already been yelled at for talking too much... Ed thats right "the data recorder is useless, there is nothing you can find out from it than you can find out from using the trusty stop watch!!! Big waste of money!!! Do not try this at home...
Save you're money for a new engine instead...

(in reply to Ed Smith)
       Post #: 7

RE: Data Loggers - 8/18/2004 8:58:17 PM   
DHG


 

Posts: 896
Joined: 4/24/2002
From: Denver, CO, USA
Status: offline 		Judging from the instant popularity of Ed's backwards fuel tank idea, I'd say the safest place to keep your speed secrets is right here on the Web. After all, if a guy's willing to spread the info around, how good can it be?

(in reply to John Z Williams Jr)
       Post #: 8

RE: Data Loggers - 8/19/2004 3:16:37 AM   
Ed Smith


 

Posts: 2820
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline 		Ok, Ok it is war is it?


So with all the money spent on the Data Logger how come it took yuo guys so long on the NMPRA site to figure out head shims??????????


Data logger, sounds like something they use to chop down trees!

Ed S

(in reply to DHG)
       Post #: 9

RE: Data Loggers - 8/19/2004 1:51:58 PM   
HighPlains


 

Posts: 2639
Joined: 3/2/2003
From: Over da rainbow, KS, USA
Status: online 		"Data logger, sounds like something they use to chop down trees! "


Yeah, let the "chips" fly!

(in reply to Ed Smith)
       Post #: 10

RE: Data Loggers - 8/19/2004 4:05:54 PM   
John Z Williams Jr


 

Posts: 121
Joined: 9/17/2003
From: Boulder, CO, USA
Status: offline 		Ok, I have to reply to this one, aaaaa it did not take me any time to figure out my shims, what I wanted to do was switch from my delponte method of measuring timing and try Darrols low timing of 189 and 10, but he would not give me a simple straight answer and asked me to post it on the nmpra web site, and bye the way I got many emails from fai guys and speed guys telling me they do take into account between 2000 and 3000 in qm motors and fai motors and the speed guys informed me they not only take into account the 3000 for rod slop the also must put in another 2000 for rod stretch in a motor that turns 40k, they assume the piston will go up 5000 higher than you would measure from bdc minus stroke!!! So its not that I did not know how to measure a motor both ways, as I have tried all the timings many times for over 5 years now, its just I wanted his way of measurement, not the actual numbers, but he wanted me to post that on the nmpra so everyone could see the question and he could answer it.... NOt My Choice!!!
So with all that said, I did switch from my normal way of measuring to the bdc minus stroke method and the motor is going pretty good now, so I will leave it... On my qm motors, I have been running them right were Dave sends em out, they are new and run very well, thank you....
and thats all I have to say about that.....

(in reply to Ed Smith)
       Post #: 11

RE: Data Loggers - 8/19/2004 4:53:55 PM   
PylonWorld



Posts: 1346
Joined: 12/29/2001
From: Monroe, NC, USA
Status: offline 		How did you guys position the pitot tube?

I had been considering getting the Eagle Tree System unit, but I couldn't figure out how to place the pitot tube out of the prop stream without causing drag or changing the flight characteristics. I've even considered building wings with the pitot tube built into the wing.

Are you using the Eagle Tree Systems Flight Data Recorder V2 or the original V1??? Since the original doesn't mention the G-Force module, I'm guessing that you have the V2 version.

For those interested, the manuals for the FDR V2 and accessories can be found at http://www.eagletreesystems.com/Plane/plane.html

_____________________________

Don Stegall
RCPRO Chairman of the Board

(in reply to John Z Williams Jr)
       Post #: 12

RE: Data Loggers - 8/19/2004 5:16:25 PM   
John Z Williams Jr


 

Posts: 121
Joined: 9/17/2003
From: Boulder, CO, USA
Status: offline 		We are using the v-2 version, has 16 datum points... I drilled a small hole 3/32 in or close to leading edge of wing about 15" out from fuse and ran the tubing inside of hollow composite wing and had it drop out inside fuse... Duane made a foam wing core and made a trench to lay the tubing in, all of our planes now have the set-up built right in the wing so we can plug in the recorder at any time in any plane!!! It only weighs about 3/4oz and is the same size as a small receiver...

(in reply to PylonWorld)
       Post #: 13

RE: Data Loggers - 8/19/2004 6:30:09 PM   
Ed Smith


 

Posts: 2820
Joined: 12/29/2001
From: Brantford, ON, CANADA
Status: offline
quote:

... On my qm motors, I have been running them right were Dave sends em out, they are new and run very well, thank you....



So after all the allowances for "Rod slop" all the allowances for "Rod stretch" the beating with the mallet AND the data logger, they run best as supplied by somebody who really knows what he is doing.

For even better performance try the backwards tank!

Ed S

(in reply to John Z Williams Jr)
       Post #: 14

RE: Data Loggers - 8/19/2004 7:28:33 PM