SEN 1483

Table of Contents - SEN 1483

  1. M&K Flappers for sale
  2. AMA/EAA Contest for young eagles in the USA
  3. Fried servos on FB
  4. SEN 1482 etc

M&K Flappers for Sale

M&K Flappers for Sale

(NOTE: I (Rene) am submitting this message by request of my friend Roland Koglot)

For sale is 1 original M&K Flapper (Long or Extra Long, customer choice). Model is in very good and complete factory condition. Asking price 3000 Euros OBO. Model can be delivered to Max Men in Lost Hills or other contests by request.

Interested parties please contact Roland Koglot at This email address is being protected from spambots. You need JavaScript enabled to view it. or Rene Limberger This email address is being protected from spambots. You need JavaScript enabled to view it.

For younger flyers in the USA - See the AMA/EAA Young Eagles Contest

Go to the AMA or EAA web sites or see AMA on FB

Academy of Model Aeronautics gles/contest.html
Complete the following information to win a headset courtesy of Lightspeed. You must be a Young Eagle between ages 8-19, and a subscriber to this newsletter. Only one entry per month. You may only win once every 12 months. No purchase required.

Burnt servo discussion from FB

We noted on FB a comment from well know F1A sportsman Per Findahl who claims another record at the other end of the scale – the most number of fried servo in F1A models. This lead to the following discussion which may be of interest. We would like to know if other people can beat Per's record. We would also be curious as to what peipople are using as the flap servo on their latest models. This appears to tbe the servo that takes the greatest load on a flapper f1A model. Per uses the Hitek HB 65.

Per Findahl
Back from the ice again ! Nice weather, and I thought to test the new flapper again. Towing was nice, no turbulence. But suddenly the flap-servo burnt..... No problem with the model, but a wasted flying day. I think this was servo 33 burnt in a freeflight model for me, nr 5 from HS 65. Can anyone beat me in the servo burning contest ? I think I'm the best servo customer in the world ! Why can't they make good servos!

Bram Van de Kerkhof

Maybe you should make a freeflight special servo. Allard already made a digital interface. Think Rene could help here.

Alexandre Cruz

Ever tried the JR DS285MG? It is really precise and strong at 12-13g I recall

Javier Abad

Pele,all servos burned were driving the flaps?I have used HS55 & HS65 no problems so far,at 6v.

Roger Morrell

Javier maybe Pele launches harder than you? Or maybe the mechanical design of your airplane is better? The servo designer probably wonders why the freeflight guys abuse his servos. The servo sales guy doesn't care :-). I have noticed that... the HS 65 can get into a funny state where it draws over an amp. This is more likely if you are driving out side the normal operating range. This could happen if you are right at one end of the range of movement. You may just need a bigger servo. Their digital equivalent may have more power even if it is harder on the battery. Typically digital servos are more sensitive to getting good data from the timer.

Javier Abad

Roger, I keep my wings at constant camber = BE models ;-)

Per Findahl

It doesn't matter where I put the servos. I even burnt about 10 rudde r servos=no force at all ! It must be some virus ! Oskar is the same, he burnt 10 times more servos in his RC helicopters and planes then our whole club together ! Perhaps we just fly too much !

Per Findahl

But now there is a new HS 65 in the new flap-fuselage again. Hope it will last some more flights......

Allard van Wallene

I never burnt a servo. Very strange......

Roger Morrell

Maybe it is to do with the voltage, most servos will take 6 volts But not all more than that. That is probably why you do not burn out the servos Allard because of your power supply system. Hitek will not take an unregulated 2 cell Lipo. Dymond's competition servos will take 9 volts, that why the D47 is great when a reliable small servo is needed - F1B or F1A rudder. When moving from NiMH to LiPo, it is not just the voltage , the LiPO will deliver a lot more current, so in the past with a NiMH the internal resistance of the battery protected the servo against too much current. This is not the case with a LiPo.

Rene Limberger

Per, this is with M&K timer? they deliver boosted 6V to the flap servo, right?

Per Findahl

Yes, the 6 volts is part of the problem, for sure. I wanted M&K to go for 5 volts to all servos, but in the end they decided 6 volts. It is a bit high, and of course the servos suffer.....

Roger Morrell

Have you checked if it is really 6 volts, not more?


Per Findahl

No, I didn't check, I just trusted the factory !

Roger Morrell

The servos do not last forever but the ones you are using are not too bad and even with the amount you fly it seems like a high failure rate. While I can't comment on how M&K's electronics works and if you exclude obvious abuse such as co...nnecting the servos the wrong way around I would check 3 things. (1) Wear, including frayed wires and connectors, R/C connectors can last less than 100 connect/disconnect cycles. (2) Mechanically binding surfaces or using brute servo force to move a surface instead of good mechanical design. (3) Too high a servo voltage or out of spec pulses from the timer. I would think the latter is not likely as M&K would have checked that and the Hitek servos are more sensitive than some other makes and won't work if the pulses are too far out. It is possible that the passive components in the step up circuit have drifted causing a too high a voltage. All of this is probably obvious to a flyer at your level but judging by your comments you do seem to have a higher than average failure rate.

SEN 1482 and other SEN stuff

This issue was bounced by Timer-Warner/RR/Adelphia etc, we did work with our provider to try and find out what was upsetting TW/RR and have made some different adjustments. We did resend it  but in case you did not get it ,    it can be found online for subscribers who use this ISP.

The SEN e-mail address should not be used to contact the SEN editorial staff on non-SEN matters as under some circumstances a reply is not possible.

Roger Morrell