Black Magic and Bauer RDT

Home Forums Free Flight FAI Models & Flying Black Magic and Bauer RDT

  • This topic has 11 replies, 6 voices, and was last updated 15 years ago by Anonymous.
Viewing 12 posts - 1 through 12 (of 12 total)
  • Author
  • #40809

    I had one of the original Bauer RDT but did not use it much. I had a difficult method of installing the receiver- difficult to move from model to model. I do most my flying at Lost Hill with a motorcycle and never saw a real need. I become a believe in 2005, Argentina seeing McKeever and Van Nest optimize their practice flying. I return and reworked may models to use the easy external plug on and off. In 2006, the RDT become legal. I learn the hard way. At the 2006 NATs, with RDT installed and transmitter in my pocket, I did the classic ” did not realized I had unlatched and bunted down, recovered at 30 feet”. I watched as the model drifted down the slope to the brick buildings below when it occurred to me that I could RDT the model and save it from a sure crash. After pushing the button and saving the model, I realized that if I had RDT the model right after the bunt, I would likely be less than 20 second flight.

    At Livotto’s latter in the year, I had a similar flight but did think quick enough to DT and get the re-flight. Some of my fellow competitors did not think it was “sporting” to do such a thing”. Interesting, those critical do not have RDT (yet) and I dropped a later round (Instant Karma?). Perhaps I should have set this up as a separate string but let’s move to the more technical aspect of setting the Bauer RDT with a Black Magic timer. here are a few points I noted after setting up the new Bauer RDT on the standard Magic 3 servo timer and jotted the following which may be of help to some.

    Now with RDT being “legal” it is no longer necessary to mount the receiver on the out side of the model to display to the world if you have RDT on or not.

    I made an extension jumper cable with the standard RC servo 3 pin connector on each end to position the RDT reciever on the wing wiggle servo. You can place the receiver were ever. Hobby shops also sell a variety of pre-made jumpers from the RC guys.

    Actually on the timer side of the jumper cable, I removed the pins from the plastic pin case and put heat shrink tubing on each connector. I did this because I used the new timer box Roger sells- I cut the small, thin upper top portion off the box so I can install and remove the timer with the box secured to the fuselage. The standard plastic 3 pin case interferes with this timer removal / installation. You can skip this but then you will need to first remove the box from the fuselage (2 screws) and make all you connector mates with the timer in the box– not easy, that’s why I made this modification.

    Drilled a small hole in the top of the fuselage, slipped a 2 inch piece of small wire insulation on the antenna and secured the receiver with tape. Be sure to get the wiring correct- most important is the red +v is the center pin on the receiver– it is very hard to get the smoke back into these little jewels.

    RDT Receiver: Ken marks one of the outside pins with a black dot– grnd.
    So: Grn, +v, Signal

    Standard Black Magic 2 or 3 servo, from Roger’s instruction sheet;
    2nd row of pins (Furthest from the circuit board) starting from the right (next to the programing jack)
    Servo2 signal
    Servo2 +v
    Servo2 grnd
    Servo3 sig
    Servo3 +v
    Servo3 grnd
    RDT grnd
    RDT +v
    RDT signal

    (I believe some older MB timers may have the RDT grnd and +v swapped– I’ll send this to Roger for his comment)

    I understand from Ken, that as long as the +v goes to the center RDT receiver pin, if the grnd and signal wires get reversed, you will not hurt the receiver- obviously the system will not work.

    Setting the program. In the More screen “Ext Int” (external interrupt) box is checked and External D/T line is set to “10”- look at the More screen and you’ll see what I’m talking about. This means that when you press the RDT transmitter button, the program moves to line 10. Line 10 is set at zero time, “D” box highlighted and the servo position number for the same DT position number you use at your standard DT line. One mistake I and others made is setting the RDT line (line 10) to a longer time (ie 180 set). You press the button and the RDT singals works- sends the program to line 10 were it sits there counting down 180 sec before DT’ing while you’re thinking the RDT is broken. Lesson- keep the RDT line time set at zero and if you need to change the servo position number, you must change in Bo places.

    I mentioned tape was used to secure the RDT receiver to the wing wiggler servo. You must make sure it stays in place. I know a flyer that his only drop at the last finals was when his transmitter shifted and jammed the hook resulting in a stall to the ground. I’m using a small bulkhead that is secured to the fuselage to form a secured area for the RDT unit.

    My new MK models have their RDT. It has 2 buttons on the Transmitter. #1 to DT and #2 to extend the DT time 30 second. This #2 button is worth the price of admission. Oh what it’s like to launch in firm Lost Hills evening air and watch your model glide. A push of the #2 button extends this thrill. At the last Ike’s, I was late to the award ceremony because the #2 button kept getting pushed resulting in a 13 minute flight, never above 75 meters.

    M&K timer does not have the DT time set from tow hook manipulation, I have made this request to the factory. On one fly-off flight this year I did not have time to re-set my DT and used the #2 button to extend the flight to make the Max. Was I in violation of the FAI rules???

    This should get this string hopping.

    Thermals and #2 button pushing, JIM


    For reference; from latest FAI rules:

    3.1.2 F1A models may use radio control only for irreversible actions to restrict the flight (dethermalisation). Any malfunction or unintended operation of these functions is entirely at the risk of the competitor.

    Seems my only defense is that there was no “action” if “action” is defined as something that changes the aerodynamic configuration of the model.
    Think I’ll be sure to set my timer for FO flights for now on. Maybe start law correspondence school.

    Thermals, JIM



    Wiring for a timer older than 2004 is more complicated than you
    say. That the last pin in the row is signal and the one next to
    it common ground. You should get power off one of the positive
    servo leads.

    There is information on the Magic Timer web site

    Roger Morrell



    I have a Bauer RDT and managed to melt it after picking up the WRONG BMT wiring diagram ! I think its a great system but have suggested two things: 1) have the extend glide function as you describe and 2) have a large sign that says ‘Switch it Off” as I keep on leaving it switched one and have wasted one battery already.

    Ken says the extend glide function requires integration with the Magic-Man and hence is not a trivial exercise. I use the Multiclass timer with a 3min glide extension button and find, like you, its perfect for just watching the puppies fly. However, I’m certain the use in contests has been discussed before and is illegal as the radio link can only control dethermilisation and glide extension isn’t that.

    Roger Morrell


    My first observation is that you fly the wrong class, are not a former World Champ and probably come from the wrong country,…. but the most effective argument for getting anything revolutionary into the rules e.g. the original Radio DT for F1C – is safety.

    The second is that at the recent recent Free Flight Forum in the UK where I presented a paper on Electronic Timers and the like there was some dicussion about Frederick Aberlenc’s timer. This timer has the capability to alter the trim of the airplane from a wrist mounted transmitter and has more than 2 buttons. In the meeting Ian Kaynes commented that the FAI “management” knew of this device, were aware that it was outside the rules and were waiting for someone to protest.

    The manufacture of the Multi-class timer, also known as the Danish timer has moved from Denmark to Switzerland but the evolution of the device has not really continued.

    Many of the original users of the Danish timer are now using Frederick’s timer. Clearly a bunch of eminently respectable gentlemen who would not use the 3rd or 4 th button let alone the second. However in the Free Flight Forum discussion there was a comment that a certain other gentleman who flys a different class and is well known for ethical elasticity has not yet discovered Frederick’s device or it may be to big to fit in his airplane…



    Well ladies and gentlemen it looks as if we have started down the slippery slope. It didn’t take long did it. What started out to be a solution to a safety issue (crashing F1Cs,as I recall), has become an apparent acceptated contest strategy by at least few or our fellow sportsmen. Does this bother you? It should. You know there are a lot of RC duration events on the books including FAI if that’s what you want. Look I have no problem with RDT when it is used for the purpose intended but using it for any other purpose must be concidered an affront to the very spirit we call Free Flight not to mention the FAI Sporting Code.
    Respectfuy yours,
    Paul Crowley

    Lee Hines

    For the record, I am in full agreement with Paul on this subject,
    as some of you know.
    And do not own an RDT, btw.

    Roger Morrell

    There is no doubt that Radio D/T is a big advantage. It has safety implications and has major green and finanical implications. radio d/t lets us test at local sites without driving long distances. It willl even let us hold contests at those sites. One can say that the radio unit is expensive but it is cheap when you look ath the cost of an airplane. I regard the biggest cost of of a winning airplane my time that I have spent in trimming that airplane, not the money paid to Vivchar, Stamov, verbitsky, Andruikov, Nelson, etc ..

    The ability to extend the d/t after the max is attained is a model and even flying site save feature. Because it stops the model landing in a bad place, that could include power wires or a major highway. The case that Jim did of extending his d/t before the flight was over was technically incorrect but only marginally outside the spirit of the rules and I would expect a very rare likelyhood.

    There is no question that some people are pushing the rules and what should happen is someone lodge a protest at a World Cup meeting instead of whining. If people did not like how Jim used the radio d/t at the Maxmen – we have a process for this – open your wallet, not your mounth and lodge a protest. I believe that Jim did is within the rules, but there are other things that are not. From a personal point of view I would do that, except that it looks like sour grapes as I make on-board electronics for free flight.

    I would like a protest so the rules are clarified. Ian kaynes indicated that he was expecting someone to do that.

    There is no question that if we want to keep flying free flight electronic timers are here to stay. The classic d/t fuse is no longer OK because of fire risk. The sources of the clockwork mechanisms are drying up. We can make electronic timers for simple FF cheaper than with clockwork. Electric Ff is becoming popular and with applogies to Hank Nystron, one has to be crazy to put a clocktimer on an electric model.


    The magic man


    One thing worse than a slippery slope is freezing to death on flat land.

    The obvious solution is to set the DT time for 10 minutes and use the RDT to DT the model. The rule allows a RDT- DT before the flight time is over. Ken Bauer does this, I just have not gotten the confidence to do this– the tranmitter battery goes dead or is in the warm-up pants I just changed out of and left at the car. The purest claim that early DT is also not very Sporting– one should not deny oneself the pleasure of marching through a muddy carrot field.

    Regarding CHE suggesting for the Bauer Transmitter for an off-lock, an alternate solution is to have a beeper sounding when the transmitter is on– this is how M&K does it– pesky sound in your pocket eventually gets your attention– might be a problem with those that are audiably challenged but at least one of them thinks this is evil and will deny himself of such unwarrented pleasure! Would rather march thru the foremented muddy carrot field.

    The other silly thing I hve done is panicking when I mistakenly push the LED instead of the the DT button– like I said, I learn fast.

    For the record– M&K had a “trimable” R(C)DT system, They no longer use this unit and specifically decided not to produce such units for sale for the reason Roger explained– just waiting for protest. In thier development and use, they found some but not overwhelming advantage to be able to dail in the optimal trim in a test flight before a fly-off. Guess there are some flat spots on the slippery slope.


    “Regarding CHE suggesting for the Bauer Transmitter for an off-lock, an alternate solution is to have a beeper sounding when the transmitter is on”

    Yes, I’ve suggested this to Ken but to be fair he’s really busy to change things at the moment to help idiots like me (my comment) out of a problem; I fully understand. He suggested the BIG sticker which is easy for me to do.

    The Multiclass RDT has the LED light flashing all the time to tell you its on but, yep, I’ve left that overnight as well. Maybe I have an alergy to ‘OFF’.

    I think we are all agreed that RC trimming is a bad thing for other than non-contest flights. I would love a system as it takes me months to get a model trimmed in the UK (maybe a few hours at Lost Hills) and this would really help me speed things up on the odd good flying day I have. Our sport is based on sportmanship and honesty but if someone wants to cheat by using RC trimming then they always will. I know my morals wouldn’t let me do that.

    Bill Shailor

    I recall awhile back referring to this as “remote controlled D/T”. I was taken to task for including “controlled” in the definition. The reason I was given seemed confusing at the time, and my thinking was that if the term R/C D/T was used, it would have a negative effect on how folks percieved this new technology. It would be too closely linked to R/C flying.
    But since the dethermalizing is being controlled by a remote location, away from the model, the term is apt and descriptive. I still don’t get it, I guess. Clearly, it provides a tactical advantage and the initial selling pitch, safety, has limited application. But it is allowed and that’s the way it goes.
    I am glad to see the unit that allows trim change in flight seems to be losing favor. We can talk about morals all we want, from high platitudes, but even if one modeler uses it in competition, our sport is damaged. It is no longer Free Flight. Rather than wait for its use and the resulting protest, why not simply ban such technology at the outset?


    Bill, do you call your garage door opener RCGDO? Think about it, the semantics are important.

    Now that I’ve stirred this up, I do want to clarify– my use of extending an official flight DT time was not done in conscious intent to break or test the rules. The thought came while on the drive home.

    I do agree with CHE on as a whole we are an honorable group and largely self policing. If a bad apple does cheat, he will eventually be found out. There are many easier , simpler and cheaper ways to cheat. We even create rules even on the appearance of cheating!


Viewing 12 posts - 1 through 12 (of 12 total)
  • You must be logged in to reply to this topic.