Blogs

MVVS 26cc in-flight starter motor

Posted by Robert Dielenberg on July 10, 2011 at 6:30pm

Check out our unique in-flight starter motor for the MVVS 26cc on a custom built Senior Telemaster.

The system is lightweight and robust. Works from a cold start. Works again and again... it is great for extreme long duration flights and vibration free (i.e., no image blur) video or stills while the engine is off. Also, for all those people struggling with gyro drift, you can get a good gyro fix when the engine is off as well.

 

Cheers from the MotMen UAV team, Newcastle, Australia.

Tags: 26cc, mvvs, in-flight, motor, starter, system
E-mail me when people leave their comments –
Follow

You need to be a member of diydrones to add comments!

Join diydrones

Comments

  • Paul Mather July 11, 2011 at 7:46am
    I'm certainly no expert on electronic hardware...software is more my thing. But a gyro is a dead-reckoning system. So wouldn't 5 minutes of hellish shaking throw the dead reckoning off whack....and then when the motor's off everything will be good, but it won't remember where flat and level was... I know in my playing with my ArduIMU board (this is the first production board from Jordi with the wrong filters installed) I get over saturation lights all the time just with minimal movement.
  • Robert Dielenberg July 11, 2011 at 7:39am
    Don't forget you have to couple the engine off scenario with good image taking. We've also had a lot of experience with gyros and vibration. Not good. But when the engine is off you get good gyro readings. Has anyone else flown an MVVS? They're pretty good on fuel consumption and very smooth. Engine on/off in flight is very smooth. Running an engine continuously will not give us the image quality we want; on a good glide ratio wing with engine off we'll get excellent images that with high pixel count can be calibrated for different heights using the GPS. You can climb high quickly and glide down a long way. There's clearly a great benefit in that strategy. And we still haven't talked about the other markets that could use an engine starter on a small petrol engine ...
  • Paul Mather July 11, 2011 at 7:15am

    I think their remote start system is really slick. There's clearly a market for that in the R/C world...AP R/C doesn't seem like the right place for it but what do I know?

     

    Still a very cool system.

  • Alexey Burlakov July 11, 2011 at 5:55am

    I tend to agree with MarcS. While ability to take vibration-free photos is good, stopping-and-starting engine doesn't seem to me the optimal power-consumption scheme.

     

    Unless you intend to use termals as source of power, constant-running engine on it's best-efficiency rpm and carefully chosen prop will allow you to fly longer on cruising speed than iterative start-stop climb-glide pattern.

     

    Prop optimized for high-speed cruise will probably cause problems on take-off but this can be solved in several ways.

  • MarcS July 11, 2011 at 5:18am

    OK, the Aerosonde motor is definetely too much... Scaneagle on the oher hand uses a quite similar motor like you do (3W 26cc I think) just outfitted with a smaller carburetor...

    I´m just sceptical if you really win efficiency (fuel consumption per flight hour in the end...) in going up fast and gliding down. Your engine system is definetely heavier (starter + more powerful for climbing).

     

  • Robert Dielenberg July 11, 2011 at 4:42am
    That's correct. We are only using the Telemaster as a test platform to prove the technology. With a high performance wing, folding propeller (cowling around engine for streamlining) we should be able to easily exceed 20+ hours. Aerosonde did a huge amount of work on their engine. That's a much bigger investment than we can afford; we will achieve the same results for much less!
  • MarcS July 11, 2011 at 4:04am

    Did you do calculations if powering up and gliding down is more efficient then having a motor running non-stop on low power? Despite the fact that with survey you want to keep constant altitude the overall energy to keep an aircraft in the air is just the drag over time, which should be the same for both flying methods.

    So a Telemaster is probably not the best reference for drag... Had to fly one as UAV in high winds, even takeoff gets a stunt :-)

    Try to look for proven designs on that task: Aerosonde and Scaneagle: Low drag, highly efficient motors -> Flying times 20h+

  • Alexey Burlakov July 11, 2011 at 12:52am

    Cool. I've been thinking about high-aspect ratio UAV of about 4m myself, that's why I'm so curious about this generator/starter stuff.

     

    Good luck to you guys, I'll keep watching.

     

    PS: How much does current UAV weight? What flying weight is planned for 4m version? 

  • Robert Dielenberg July 11, 2011 at 12:36am
    Yeah. We thought about combining them, but it quickly became unfeasible. The advantage of keeping them separated is less wear and tear, easier to interchange for maintenance. The downside is you carry more mass. However, you can compensate for that by slightly increasing the size of the UAV airframe, from around 2.3 m which it is currently now (I said 2.1m before but I remeasured it) - to say about 3.2 m. Eventually we'll move to a 4.1m wingspan anyway.
  • Alexey Burlakov July 11, 2011 at 12:31am
    So you will have separate generator and starter?
This reply was deleted.