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Homebuilt brushless electric motors



  • Winning a friend

    During 2001 i saw at rcline.de a picture of a homebuilt brushless outrunner, made from a CDrom-drive and a few words, how to do this. I was impressed and sent a short mail to the autor. He asked my for my real world adress and sent me one of these as a present. To make a long story short, we are good friends today and try to meet whenever possible. This site is dedicated to Dieter, who is the man behind the tools.

    The first little motor
    CDrom-Conversion CDrom-Conversion CDrom-Conversion with gear CDrom-Conversion with gear




  • The Mini-LRK

    A short time after that the Mini-LRK hit the market. This was the first kit widely available. After assembly, which was not so easy because of a few minor problems with the kit, the motor worked well. The resulting motor has eight magnetic poles and six slots in the stator. The Mini-LRK was the motor for my Daktari and here is an example of missions, that i used Mini LRK for: Video: My-home-2003

    The Mini- LRK
    Mini-LRK, rust never sleeps :-)




  • The Conrad

    At the end of the year 2002 the big german electronics- retailer Conrad sold a small motor for the micro-price of EUR 2,20 (about USD 3,00). This contained a fine nine-slots stator, a bell with a not so bad hard magnetic ring with 12 poles and two ballbearings. This material was base for several motors we built. There is a superb page in german and english on the net for further informations: Powercroco.de. Check it, one of the best pages regarding homebuilt brushless outrunners.

    Conrad- Evolution
    out of the box not enough copper better filled good filled with copper
    original magnetic ring with Neodym-magnets/ but not enough coverage with Neodym-Magneten/ good coverage with milled housing




  • The double-Conrad

    By stacking two Conrad stators one can build motors up to the 300 watts input- class. Check this climb of my soarer E-soft with onboard cam: Climbing The weight was around 1600 gramm including camera. This is another example of the last :-( flight of my yellow Highdecker: Last flight. The BEC failed during flight.

    The doubled Conrads
    8-winds 3x0,5mm parallel wire >
         <img src= 8-winder on E-soft 14-winder on Highdecker Comparison with 1-Euro coin




  • CDROM- conversions

    Old defective or no longer used CDR- drives are a good source for stators. Normally you can find stators with diametres between 19 and 24 millimetre, from time to time including ball-bearings. Fired by two or three small lipo-cells these motors show good results with small foamies. The small Horten-wing Variante 90 flies highly efficient with such a motor. Once i flew six minutes and recharged only 53 mAH after that flight. The little Jet climbs easily vertical up to 70 or 80 metres on three lipo-cells.

    The CDRom- conversions
    CDRom-conversion 24mm stator backside parts stator and bell
    Variante90 with CDR Variante90 with CDR Depron Jet with CDR Depron Jet with CDR
    Variante90 Variante90 Depron Jet Depron Jet




  • The Micros

    These are Dieters newest works for the slowfly-sessions in Winter. They weigh 5,5 and 7,4 gramm and are little jewels regarding precision and design. The slightly bigger one named Kisscatz can turn a GWS 5x3 prop 11900 times a minute at 2,4 ampere on 2 lipo cells. Not bad :-).

    The Micros
    The JEWEL, 5,5 gramm The JEWEL, comparison with 1 Euro coin The JEWEL, rear view
    kisscatz, 7,4 gramm kisscatz front view kisscatz rear view



  • It is march 2007 and Dieter sent me a new micro brushless motor. This one has only 3 windings and four poles and is therefore relatively easy to build. Weight is only 3,6 gramm, but power is enough to turn a STO 2,7 x 2,6 12200 times/minute at a single lipocell and a current of 1 ampere. There's more than enough power for a little BUMP with a weight of totally 23,9 gramms.


    3,6 gramm 3N-4P Bump2


  • 3D-animation of a brushless motor by Jean Yves Martin
    (running under WinXP, problems with other systems reported)


    virtual motor



news scratch BL's slowfly-flying indoors aerial photography experiments electric flight soaring videos links Misc. autogyros waterplanes under construction
pagehistory scratch BL's Slowfly AP Experiments E-flight Soaring Videos Links Misc. Autogyros Waterplanes yet nothing

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