gas engine ignition question
 

I realize there should be 10-12" between the ignition and the radio-switch etc for interference problems, but does that include everything- like the throttle servo or kill switch servo (or electronic kill switch) or can those servos ( and there leads) be closer as long as the rcvr-battery- switch has seperation

gas engine ignition question
 

This includes everything that has wire going back to your receiver. I had this problem of glitches a few months back because I had mounted the servo for the throttle up front of the firewall. I knew better but I wanted to see if it would really make any difference. Believe me it did, I had the mother of all glitches. Also watch out for tail wire braces that are metallic and form a closed loop. James Goss

gas engine ignition question
 

As much seperation as possible is best between the ignition components and RX, battery and wiring. The servos and kill switch themselves need the seperation as well.

I use a nyrod or something similar for the throttle, choke and or kill swich and then locate the servos as far away from the ignition components and wiring as possible. I have found that 6" inches works fine. Anything that is capable of picking up ignition generated "RF" needs to be seperated. The wires, servos and battery carry the noise back to the RX.

gas engine ignition question
 

I have to agree with MGlavin that 6" will work just fine. I have a 1/4 scale cap with the throtle servo only 6" away and it works flawless. In fact it is less than 6" from the switch for the ignition. I also agree with everyone that has ever said that you want to mount it as far away as possible, just because.... You can also use a fiber optic to connect the servo and mount the servo right next to the ignition source if so desired. I will also suggest that you range check EVERYTIME you get ready to fly. Good Luck
Jeff

Tail wires
 

James, thanks for the tip about the tail wire braces, I'm ready to intsall the tail wires on a Giant Stinger I'm building. I'll use wire on the top and Kevlar on the bottom. Will this suffice? Thanks, Dave

Separation
 

I just got off the phone with Brison and the man there said I could mount everything side by side as long as I had a bosh (not sure about spelling) spark plug cap with a metal lead going to the plug held on by a hose clamp. He said with the bosh I would not have to worry about RF but suggested to still go back 3 to 4 inches. My 80" Lanier Cap 232 is tail heavy and I would like to fix it without adding lead. I bought this plane used and it has the bosh. I am new to gas. Has anybody heard of this before? Thanks for the help.

interference
 

My son was having an intermittent interference problem and found that the hose clamp that was holding the ground onto the spark plug was just a little loose and this was causing the problem as certain RPMs. Tightened the clamp and everything has been fine since.

gas engine ignition question
 

Bosch is one brand of a shielded spark plug boot. It is a metal boot that covers the plug. Electromagnetic waves generated by the spark are "captured" by the metal boot. The standard boot is rubber and radio waves travel through the rubber and can interfere with your receiver. If everything is installed properly, a shielded ignition will protect your receiver better than an unshielded ignition. It's standard technology on full-scale airplanes, 3W, ZDZ, and DA motors.

Tail feathers braces
 

Try WEED EATER nylon , instead of metal wires/rods.... it even comes in colors & sizes.

gas engine ignition question
 

You can thread the nylon with a 4-40 die and screw a clevis right on....

gas engine ignition question
 

That will be fine Dave, I have used that combination. Anything that breaks up the conductivity of the wire. I have a 1/3 scale Staudacher that I am using nyrod for the tail wire, works fine. You can use all metal wire and nylon landing gear straps to anchor the clevis to also. I like to use these straps with metal wire and faslinks (Great Planes) to anchor them. It is a really fast installation. James Goss

gas engine ignition question
 

Im not radio smart enough to know the reasons,but electronic ignitions seem more likely to cause interference than flywheel and coil setups,and you must be much more careful about seperation with the electronic type.On my first CH equipped gas model I did all the right things but for some reason I mounted the two on/off switches side by side......and instant hit was the result.
CH sell Bosche caps to which you solder the ground wire from the plug lead.These work very well but are large and very ugly.Im going to try to find out where the ZDZ caps and armoured leads are made and try to adapt one to one of my weeder conversions with a CH ignition.I use weeders in 1.20 sized models and the smaller neater cap would be a real help for more sightly installations.......

gas engine ignition question
 

I once watched a model go out of control - (it was obviously throwing all urfaces in wild flail mode.
The post mortom showed that the Bosch metal cap -which was clamped tightly at its base, had fatigued around the slit above the clamp then the cap vibrated around the plug- you could see the scuffing.
The single cyl engine really was a vibrator and tho the owner used a dual RX setup -and had everything else done correctly - the hash generated by the engine running -with intermittant grounding, was too much.
As long a every thing is well grounded ad shielded - you can get away with some pretty spooky component placements.
On my own models - I have had the cap come loose a few times - I use the ZDZCap setups - and they simply flip off the plug and the engine kills.
Never even a momentary glitch.
Even tho the fully captured setup they use , may not appeal to everyone - it sure seems to be the best "trade off " of all the types I have seen. :eek:

gas engine ignition question
 

Say DH:
You can use a 4mm screw with a nylocknut to hold that ZDZ cap on. The locking nut up against the steel shell.

gas engine ignition question
 

yes -and a good idea - -my point was that should it loosen - it instantly is off and creating no "hash"