Repost: Kraft Custom 12 All transistor Transmitter Conversion

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MJF
Posts: 81
Joined: 12 Jun 2018, 15:22
Location: Ontario Canada

Repost: Kraft Custom 12 All transistor Transmitter Conversion

Post by MJF »

Reposted from Nov 2017 on behalf of Mike "mjf"
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This set uses the PIC Reeds emulation encoder.
All wiring is now complete and tested. The Encoder board and FRSKY DHT 2.4 module are secured with two layers of double sided tape intended for securing automotive trim. Two layers are used just incase I press too hard on the plug in connectors which may cause any sharp solder points on the back of the board to pierce one layer which could cause a short letting all of the smoke out of the colorful components on the board rendering them useless. You can never get the smoke back into them. The round knob is connected to a 10 K pot to enable slowing the servos to emulate the speed of the old Bonners. The toggle is part of the FRSKY DHT 2.4 module kit which has telemetry capability. My Rx does not so the toggle is set for one way comms.
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Here is the finished transmitter looking original with the exception of the dinky 2.4 antenna instead of the 4 foot center loaded one.

The weather finally cleared this weekend with temps at 6 degrees C and 15Km winds. It was time to make the 80Km trek to our Huronia Radio Control Club flying field to test fly my Kraft Reeds conversion.
The converted Kraft reeds radio is installed in a well used second hand Sig Kadet LT40 which is very easy to fly especially on proportional.
Control functions are: Motor, Elevator, Aileron & Rudder with trims on all controls thanks to Phil G's emulator board- trim functions which of course the original did not have.

Flight #1 had a OS 46FX for power which was no problem on proportional but on reeds was lunar rocket like on take off especially with a slow person on all those toggles.
Flight #2 I had changed the engine to a well used OS 40FP which has plenty of power for this model - most flying at less than 3/4 throttle.
Flight #3 Getting more familiar with the toggles now & got in some light aerobatics (loops & rolls)

Flying with a reeds type radio is a very new experience for me having never seen a working example prior to converting mine to 2.4.
I learned very quickly some new lessons & reminded of some old.

1 I became very lazy over the many years of proportional flying by simply "trimming out", in flight, building and slight C of G errors.
2 When flying with proportional control I did not realize how many very subtle control inputs are used during flight.
3 Free flight modeler's are pure geniuses!
4 Neither pushing forward or pulling back on the aileron toggle will help one bit.
5 A 2" wide 27" span elevator surface is a lot when you use all or nothing throws - must get better on pulsing!
6 I now know why the old multi channel models had such small engines compared to what we use now (IE Astro Hog, 72" span, 6Lbs 4 oz. with a K&B 35
or the Taurus 71" using a Veco 45 with intake restrictor "as we have more than enough power" was a quote from the original build article.
7 If you have never flown reeds before, in my opinion - for what its worth - I would select a very easy to fly beginners model & if possible have it so ugly the ground will repel it making it double crash proof - and oh yes check for warps and be fussy about balance.
8 It is very rewarding to have your first transmitter conversion work to perfection even if the pilot doesn't.

Despite all of the above after various range checks, reducing controls throw, engine run-ups & the flights all worked out well with the model returning home in one piece and a very happy modeler. I think this will see a lot of use over the next season.

I am looking forward to my single channel set conversion done.

Here is an after the flight photo with the plane still in one piece. As I took the photo you cannot see the grin on my face!!!!!
mjf
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Re: Kraft Custom 12 All transistor Transmitter Conversion
Postby Phil_G » Mon Dec 04, 2017 1:43 am


Thanks Mike thats great news, its great fun once the shakes settle down!
Back in the day™ I only ever flew gliders on reeds, so I never had to deal with throttles at all.
Consequently the throttle caused me the most trouble when coming back to flying reeds in a powered model.
I re-learned reeds on a Junior 60, which I sold and regretted, so now I have another waiting for the gear to be installed.
By the way, for anyone puzzled by Mikes internal build shots, he has the old PIC encoder, not the Reeduino.
I like your list of lessons learned, funny but true :D
Cheers Mike
Phil

Re: Kraft Custom 12 All transistor Transmitter Conversion
Postby ceptimus » Sun Nov 05, 2017 5:29 am


Great looking transmitter Mike! It's in wonderful condition for its age and you made a lovely neat job of the installation inside. You should be proud and I'm sure you'll have many happy flying days with it.

Martin.
ceptimus
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