small_rcer

While waiting for the choke to arrive, you might try twisting the 3 conductor ribbon cable. I carefully twist all my servo leads or if they are separate and not twisted I braid them. It is also very important, to me anyways, to twist the wires going to the motor from the speed control. Long parallel runs are great antennae for radiating or collecting RF. Twisting them minimizes this "feature".

Well it works for me and it costs nothing and is easily done. YMMV

Jim H

SGC

Bipe Flyer,
Is the motor in your zoomerang brushed? has it got a cap from each brush to the motor case ? also on the esc (brushed/brushless) there should be a 10uF electrolytic capacitor across the battery leads , is it there ? is it ok ? the esc may also benefit by adding a 0.01uF ceramic disc capacitor across the battery leads in parralel to the 10uF electro.
With some brushless combos the esc program may need an adjustment/update to better suit the motor as the back emf/possition sensing can be a source of problems.
Stewart

Bipe Flyer

I thought about twisting the wires, but I was worried about them untwisting.

The motor is an AXI 2820/12 brushless with a Castle Creations Phoenix 35. The receiver and ESC are as far away from each other as possible. The range problem is still there even with the motor disconnected. I tried different receivers (PCM and PPM), servos batteries, ESCs and the problem only occurs with the Phoenix 35. I borrowed a Phoenix 35 from a friend and it did the exact same thing. I was going to isolate the BEC, but I called Castle Creations and they suspected the noise was on the signal wire. I should hook it up to my oscilloscope to see what's really going on. If the problem is on the BEC, I might be able to solve it with a cap between the +5 and gnd.

Bipe Flyer

OK, I just tested it on my oscilloscope. I can see a nice clean servo signal coming from the RX and a clean +5 from the ESC, so no problems there. I did find the problem though. Even with the ESC disconnected from the RX, battery and motor, there is an induced signal when the transmitter is on. I was not able to induce the same signal with a servo, extension or another brand of ESC, only with the 2 Phoenix 35s.

I've attached 3 pictures. It's only a 60MHz scope, but you can see enough to know what's going on. The first picture shows the BEC on the bottom and the signal wire on the top. This is with nothing attached to the ESC, so both are actually at ground - I separated them for clarity. The second is with the TX turned on and sitting near the ESC with the antenna down. The third is with the TX and ESC in the same position, but with the homemade choke between the ESC and the oscilloscope. Bingo!

BMatthews

It looks to me like you're getting some RF pickup and retification in the ESC or the voltage regulator or something. Perhaps try a .01 across the power leads and see what happens.... Or did you try that already?

On a brighter note I've managed to finish off my own Cricket between bouts of coughing and napping. I've been off all week with a bug I brought back with me from out of town. I now know for certain that the East will be the death of us all.... It really sucks when you glue a couple of things and then have to stop to blow your nose before it drips on the wood. Summer colds SUCK!

I'm a bit worried that it came out a bit heavy. As it sits here it's 3.5 oz RTF but that'll likely go down a touch overnight as the excess Nitrate Parfume gasses off. It'll fly OK but I'm just thinking that it won't be the slo flyer that I was hoping for. I may need to do another version but with a rubber model like stick built up fuselage and lighter wing. I used 1/8 x 1/4 hard balsa for the spar and there's just NO flex in that wing for any reasonable load. And of course the all wood fuselage and tail sections add a lot over a fully built up model as well.

If it needs the speed then it may be time to haul out one of the Johnson 250's like your's and set it up as a little speeder.

I'm looking forward to it darkening the skies this weekend out at Chilliwack.

Bipe Flyer

I called Castle Creations and they were very appreciative of the information. They are going to do some tests and rectify any problems they find - hopefully it was just a bad run. They really have excellent customer service.

Your Cricket looks great! What battery and motor are you using? You're not serious about the Johnson are you? A Johnson 250 is nearly 3 times the power of the motor that I'm using in mine.

BMatthews

... maybe ......

I don't know why I had the Johnson in my mind. I just re-read the first post and noted the LPS motor.

On mine I'm running the following....
GWS LPS-BRC 12 gram motor and gear
http://www.zebrahobby.ca/cgi-bin/cp-...OME:motors:lps
A Plantraco parkflyer Rx with a built in 7 amp ESC.
two 4.3 gm Bluebird servos
Apogee 300 mah x 2 Lipo. I think it was about 25 gms.
7x6 GWS prop.

I ran some very rough thrust measurements by rubber banding a stick to the model and supporting it against the torque while resting the tail stick on a scale. The motor puts out better with the 7x6 at aroun 1.7 to 1.9oz of thrust. The cut down one seems to be around 1.4 to 1.5 oz of thrust. If I can I'll run the smaller one for more ground clearance. Hopefully the baby buggy wheels will let me take off from short mown grass. I tried it last night on my own lawn and it moved but gets kicked around too much to stabilize for takoffs.

Bipe Flyer

It should be interesting to see how it will fly with a gearbox. I opted for the simplicity of flying with direct drive and flying on airspeed. Mine has an IPS, not an LPS.