reyn3545

Does anyone know of a good electronic ignition cut-off that works with the Rainbow-tronics ignition module?

I've been using a smart-fly, but getting low voltage blinking lights on the ignition module (low voltage) and the engine is cutting out at higher RPM's (as designed). If I remove the ignition cutoff module, all works fine.

I like having the electronic cutoff, but not if it makes the plane un-flyable!

wphilb

My Feedback: (10)

I am using Smart Fly but no issues I am aware of? What battery type and capacity are you using?? Mine runs fine on ground with no cut outs with 3 cell A124. We have also found that unlike several other systems the Smart Fly works with only a single A123 battery on a G-26EI or G20EI engine so I know it is capable of handling lower voltages.

I recommend you contact Smart Fly, easy to deal with and good support.

Whitney

wphilb

My Feedback: (10)

reyn3545

Whitney... are you using the stock ignition module, or the rainbow-tronics?

I've used both a 3-cell A123 and a3-cell LiPo... both will start and run the motor using the Smart-fly, but I do get the low-voltage blinks and cut-outs.

wphilb

My Feedback: (10)

I am using the new R-T ignition. I have not checked the lights, I have them behind a panel, I will check next time I run the engine. Do you get the cut-outs immediately or after some run time?

Whit

reyn3545

After just a few minutes of run time... an "on" light, with brief "off" flashes about every second or so.

reyn3545

regenbieger

Dear all,

this is the information that DIS5*-M system detects "low voltage" of the ignition battery. If you look at the HP of Smart Fly it is mentioned that the ignition switch system runs up to 8.5V. Possibly this is the problem that the ignition switch will cut-off the 9.9V of 3 A123 cells down to 8.5V.

Please check this with the Smart Fly guys. It would be nice if you will post the results here.

Best would be to use a switch system which will provide the full voltage from the battery to the DIS 5*-M system without any nameable drop of the supply voltage.

Best regards

Uwe

Moebius44

My Feedback: (1)

Great info, thank you. I have a 215 going into an Airworld Sukhoi SU31. I'd like to install a composite 3-blade. What size and manufacturer please. TIA

reyn3545

I talked to Smart-Fly a few weeks ago when I was chasing this problem originally... they told me that the cutoff switch was rated up to 12 volts, but they didn't want to publish that upper end.

I may have a switch that works fine at 8 volts, but marginal at higher... who knows? I may just take the cutoff switch out and have a switch on the transmitter that kicks the throttle down to completely close the butterfly.

heinzulrich

Interesting subject. Personally I use old school method, incorporate a micro switch intercepting the power to the ignition and controlled by one of the channels as a kill switch.. The old KISS program is sometimes still the best way to go. Just my opinion...

Greg Wright

My Feedback: (6)

I am a new owner of a Moki250 and i will be installing it into a Comp-Arf P-47 Bubble canopy version of this plane.
I'm just happy that they came out with this new ignition module that i will be able to run the whole airplane on 7.4 volt lipo's

Maxam

My Feedback: (62)

These engines can swing big props but....That big???? -Tom

reyn3545

I'm glad somebody else said that.. I was thinking the same thing!

JPate147

It will swing it, depending on the pitch you set. Comp-ARF has a video of the prototype P-47 (same engine - Moki 250) and it is a screamer. It is 30 inch diameter.

Maxam

My Feedback: (62)

Good illusion. It looks like it is a 40 incher! I have my 215 swinging a 33x16 SEP two blade and it looks a lot smaller. Good luck with your fine project. -Tom

reyn3545

I know another builder who's doing the CARF -47... it's a great looking plane, can't wait to see it in the air. This guy crashed his Ziroli P-47 at Top Gun this year... and still finished in 2nd place!

Greg Wright

My Feedback: (6)

Yes it will swing this prop the diameter is 30'' and the pitch will be set at 14 degrees. The engine is to be set up to where it will only turn up to around 3800 rpm on the ground and then it will unload in the air to some where around 4500 to 5000 rpm.

heraldoboldrin

I also receive this ignition, but are you sure will handle 7.4 volts?

Detlef Kunkel

Greg,
be sure you will find 6000 during shallow dives in flight. 5500 straight out. I have the same setup and monitored the values via telemetry.
Careful on the throttle at full speed is all I can recommend here. The engine will always revv in its uppermost range

Greg Wright

My Feedback: (6)

Here are the instructions that came with the motor.

Greg Wright

My Feedback: (6)

Greg,
be sure you will find 6000 during shallow dives in flight. 5500 straight out. I have the same setup and monitored the values via telemetry.
Careful on the throttle at full speed is all I can recommend here. The engine will always revv in its uppermost range
[/quote]

Then it sounds as if you could add some more pitch to the prop.

wingstrut

Detlef, I read earlier in this forum that Moki recommended to set your servo to only open the throttle 3/4 of the way in order to keep the engine responsive due to it's design.

Won't that help to prevent the engine from unloading as much in a shallow dive because of the slightly restricted airflow into the engine?
I'm asking mainly for the guys having trouble with over-revving, I usually fly my planes with less than half throttle only opening for a loop or other vertical maneuver that needs the power.

I believe we shouldn't prop our Moki's just to keep the rpm in a specified range, we should prop our Moki's to match the aircraft and use the throttle to keep the rpm's down.

I think that is what I understand you are saying.

Thanks for your support,...........Ron

Detlef Kunkel

Ron,
good thinking in one aspect, yes. But to be honest, I myself think I have some experience with engines, and a "good" ear when it comes to notice upcoming troubles with an engine. But I would have been VERY wrong to estimate the rpm in flight of my very clear running moki 250. I would have given it around 5000 ( with 3600 on the ground) but is was a clear 6000 readout., serveral times per flight. I really was slightly shocked from that, and learned that I really fly a too fine pitch for the speed the aircraft gatheres in flight.
Only because I am aware of that now, and I apreciate the takeoff power, I stick with that, but it is no good general advice or setup since there are points to understand and accept..
I saw more than one CARF 32" three-Blade props on 250 engines, which lead to destroyed engines, with too fine pitch setups. People dont see orunderstand the consequences with a pitch of 12" or so. Porsche on the motorway in first gear, the best example I can give. What sense does that make....

Everybody can do with his engine as he likes, its not my case, and not my money. But I doubt if everybody would be careful enough on the throttle, when his setup is wrong, and tries to compensate that with the throttle stick.

I guess in general terms its much better and safer to fly the pitch that roughly suits the aircrafts top speed, not fly the wrong pitch and reduce the carb opening / servo travel.

heraldoboldrin

i will run mine with powerbox spark regulator.
I think they have to version 5.9v and 7.4v regulated and you turn on and turn off by a channel in the receiver