5 Bears Home Homebrew CNC bench mill MW54 Gas Turbine Wren PropJet Wright Whirlwind Radial Engine Hodgson 9 Radial Engine Autostart ECU Latest News Useful Links Various downloads Ask and Answer, comments too!

5 Bears Downloads, MPEG's, and WAVE files

Wren MW54 MPEGs

astart01.mpg - 3,020K. Full autostart using 5BECU, speed 300 motor, and stock Wren bendix. About 19 Seconds from propane ignition to idle RPM. Interestingly, you can see the blue tinted fuel being intoduced in the clear tube on the right after propane lightoff and re-engagement of the starter.

turbup.mpg - 1,117K. MW54 turbine inlet. Spooling from Idle to Max RPM. Note the healthy gap between the spinner nut and the tachometer probe. The hall effect tachometry works VERY well!

turbupdn.mpg - 376K. Lesser quality video. MW54 turbine inlet. Throttle bursts and changes midrange RPM.

turbshut.mpg - 296K. MW54 turbine inlet. Turbine commanded off, spooldown from idle to 0 RPM.


These MPEG's are of the ECU LCD display, and show how the display looks and responds in a dynamic environment.

Row 1: RPM in thousands, EGT, and Pump Output.

Row 2: RUN annunciation, commanded throttle in percent. SIG (Starter/Ignition/Gas) annunciators are all blank as the turbine is already started.

Programming: Idle RPM 45,000, Max RPM 150,000, Max EGT 700

0to100a.mpg - 894K. Throttle burst from idle to max, Accel time is ~2.7 seconds.

Tburst01.mpg - 1.59M. "Throttle cobbing". Snapping the throttle about in the midrange area, culminating in a burst to 100%.

Trim01.mpg - 861K. Idle Trim mode. The 5BECU, like the RAM electronics, intentionally overshoots idle during start, then trims back to idle. Here, the ECU is trimming down to 45K RPM from 58K RPM. Note the pump output drop from 35 to 32, with RUN quickly announced.

Ramps.mpg - 990K. Cycling through the three "hot" adjustments which can be made while the turbine is running. These are the most important user-defined parameters, and being able to adjust them for best performance on the test stand while running is crucial for easy setup.

Fault demos

NoRC01.mpg - 1.09M. At 100K RPM, I am simply turning off the reciever. Since I have the ECU set to maintain idle with No R/C (a setup option; the other is to kill the turbine), the MW54 is brought to idle.

NoRC02.mpg - 957K. Continuing from the above, the R/C signal is restored, and the ECU goes about its business.

Flameout.mpg - 1.33M. An interesting MPG. When I was trying to make the "No R/C" Mpegs above, my first attempt resulted in a flameout... I had some parameters set a bit too aggressive for throttle reduction. When the No R/C fault is detected, the turbine attempts to idle, but too quickly. Watch the pump drop from 56 to 35. The Wren flames out, and the EGT plummets. Keep an eye on the pump output, upper right. It initially tries to prevent the RPM droop by increasing fuel, but the Flameout predominates as it is driven by EGT. Within 3.5 seconds, the pump is shut off and the turbine secured.

Radial Engine WAVE files

esound04.wav - 89K: 4 seconds at idle

esound10.wav - 210K: Deceleration from full power to idle; 10 seconds in duration.

esound30.wav - 577K: Idle, acceleration to full throttle, then a slow deceleration. Love the sound of the idle!

Convert - an excellent utility

Engineering conversion tool

convert.zip - 171K: This little utility will convert between any 2 imaginable units of measurement.

I cannot overemphasize the excellence of this program, and it's freeware! Download it... You won't be sorry.