R/C Model Prototype Test Methods?

[pr0ject_2501]

My group is designing an LSA for our Senior Project. We have decided to build an R/C model to verify its flying qualities due to the lack of available wind tunnel. We are planning to scale the model based on off-the-shelf model engine power and matching inertia; we are still researching sizing. What I would like to know are methods of testing the model.

Specifically what types of instruments can be used to qualify its flying qualities or anything you think may be important. Any suggestions are welcome. It can be as low tech as eyeballing angle of attack and approximating speed with a stopwatch, but I do not want our measurements to be limited to those methods.

I have come across using sound recordings and doppler shift to determine speed, but unsure of the instrumentation used.

Also, I could use any suggestions for reducing model weight. Is there anything bad with having a hollow foam structure.

[eflightray]

For model telemetry, have a look at the Eagle Tree site (http://www.eagletreesystems.com/overview.htm)

As for the model, unless you have someone who can fly a radio controlled model, and fly quite well, stick with a well recommended trainer model.
The 'Sticky' threads at the top of the Beginner Training Area (Electric) forum (http://www.rcgroups.com/beginner-training-area-electric-8/) give a lot of information on types of models and what is required.
If you are using an I.C. engine instead of electric power the information there still holds good.

There are various materials that can and have been used for model aircraft, the various forums here on RCGroups cover all of them. Most are fairly easy to repair, as crashes are almost inevitable.

If your group intends designing a model, it's probably best to base the design on a existing model as it increases the chance that it will fly first time.

Also doing a search on the web for 'model aircraft plans' should give you plenty of ideas, just remember, unless you have an experienced RC pilot in the group, stick with simple trainer type models.

Good luck with your project.

[pr0ject_2501]

We have someone experienced flying and no one else will fly it with or without supervision until after we get all the data we can/need. The pilot is not in our group so we still need to build it as beginners.

Thanks for the help.

[LTR417]

Start small scale then move to larger models. larger models (in the quarter scale range) fly more realistically, which will help when diagnosing more subtle flight characteristics. Small scale mach-ups should be used to get the sizing of control surfaces right.
as far as foam construction goes you should check the scratchbuilt foamies section. as long as you use stressed skin techniques or if its completely hollow, use several layers of fiberglass

[TheThomas]

Use the Eagletree Systems. Pretty hard to beat for the price, you can buy all sorts of stuff for it including 2 axis accelerometers (maybe 3?). You can download all the data on the ground later or even get a live feed. GPS, airspeed, you name it.

As for designing a model, try to make the inertial properties similar. If you make a quarter scale model, you're probably not going to be flying it at 400+ mph to match reynold's # so you might be using boundary layer trips to simulate full scale RE's. Your best bet for manufacturing might be using a built up balsa structure since it'll be hard for a beginner to get vacuum bagging wings to be light on short time and money.