littlera

I have over forty years experience with glow, but my first gas engined plane is nearing completion. It is a Skywalker II and will have a Mintor 22. I guess I am a real noob with gas!

My question is this. In this plane, I have plenty of room inside the plane where I could mount the ignition module. I can see the advantage of it being in a cooler place, but it could be worse as there would be no airflow over it. I don't know how much heat must be dissipated from the ignition. Mounting on the outside of the firewall is an option, but this would be behind the engine and would be at a somewhat elevated temperature. Also, if mounted inside, can I wrap it in foam like a receiver to protect it or would this cause it to overheat? Putting it inside the plane puts it a bit closer to the receiver, which I would think would not be desirable.

So, I just don't know which way to go.. Your thoughts??

All Day Dan

My Feedback: (5)

For the past 15 years, I have mounted my CH ignitions in a plywood box with a 1/2 inch of latex foam enclosing the module. The box is screwed to the rear of the firewall inside the fuselage. There have been no problems with heat or vibration. Dan.

earlwb

I usually just use some self sticky velcro and stick the CDI unit wherever it will fit OK. You are limited to how long the spark plug wire is though. The instructions I read, about some of the units, say to leave the CDI unit open to the air and not to enclose it in foam padding as it might overheat. Other instructions say to pad the unit in foam. So far the velcro works well protecting the unit from engine vibration. But if your instructions do not say to keep it open to the air, then go for it with the foam padding.
ref V2 RCEXL unit <cite>http://www.cncengines.com/rcexelcdi.pdf
</cite>

pe reivers

I use velcro mounting, preferably in the cool air behind the firewall.

dirtybird

My Feedback: (5)

The trouble with mounting it behind the firewall is you have to cut a big hole in the firewall to get the spark plug lead thru. I mount mine on the firewall.(in front)

daveopam

My Feedback: (9)

Inside the plane has to be cooler than on the engine box inside the cowl where a lot of them get mounted.


David

Truckracer

My Feedback: (19)

I mount mine where the plane's design allows me to mount it!

Some airplanes such as CUBS, etc. just don't have cowl areas large enough to contain the ignition box. In these cases, the box goes inside the fuselage just behind the firewall and yes, I do cut a big hole for the plug cap to pass through. I don't consider this a problem as gassers run fairly clean and if the hole is located in the right place, no residue will enter the fuselage. When inside the fuselage, the box is usually mounted in foam as it has to be pushed up where a tank would have been if the plane was glo powered. Of course the tank is relocated back near the CG.

On larger aerobatic planes there is usually plenty of room to mount the ignition box on the outside or inside the engine box. I prefer outside if at all possible. I usually use a small piece of foam under the box and retain the box with (2) Velcro straps. I avoid putting the box near the exhaust or just behind the cylinder. Round cowl planes are especially good as you can usually mount the box on top of the engine box well away from the engine.

Where ever you mount the box, protect the plug lead in every way you can to prevent damage! I prefer the black split lomb material rather than the supplied spiral wrap as I believe it gives better protection. I've also used small pieces of silicone tubing in addition to the split tubing in areas where the lead has to pass near exhaust pipes. Split foam air conditioning line insulation is also handy for protection. McMaster Carr has dozens of different tubing styles that can serve to protect plug leads and prices are reasonable.

mikes68charger

My Feedback: (34)

I got all mine on the motor side of the fire wall as I was told they make interfearnce even when you use an opti kill swich.

Even on my CMP spifire it was real I mean real tight, but with the motor inverted, I went to lows got a some cheap alummum 90 angle brackets, put it over the the top of the motor and then used velcrow rapd throw the top 2 long motor mounts to hold it tight. Just keep it a few mm off the carb and your good to go.

I think I read some were on here that you have to keep that box 12-18in away from your recivers. IS this still true? with 2.4?

captinjohn

I like this Idea using Velcro.....may work nice on my profile. Thanks Pe R

dirtybird

My Feedback: (5)

No, but you don't want to hide the receiver behind the motor from your transmitter.

Whistling Death

Sometimes yes and sometimes no. Some planes are built in such a way that you can route the spark plug wire around the firewall. Others you will have to do through.
In the case of going through the fire wall you can take the end off the spark plug cap drill a 5/16"-3/8" hole then reinstall the plug cap on the other side. It adds another step to the build process but it works.

john josey

littlera

Nice installation, John. Very neat and clean.

What kind of fuel tank is that?

Truckracer

My Feedback: (19)

Very nice installation but I would secure the fuel lines with zip ties and use some type of protection on the plug lead such a split lomb or spiral wrap. Unless protected, it will rub through the copper braid where it touches anything on the plane such as that plywood tank floor it passes through.

john josey

Thank you for the kind words....As for the fuel tank, i'm really not sure, i get them from here -
http://www.glensmodels.com/2005.htm

I can certinally find out for you.

john josey

Hi there....yeah, i should have mentioned that it's not finished yet, theres not even an engine on the front of it yet

Truckracer

My Feedback: (19)

I kinda figured that was the case but some new people see a photo and think they should copy that install exactly as shown. Keep up the good work!

Oh yes, that tank is a Nalgene bottle .... commonly used in the medical community and chemical industry. Available from many sources these are commonly used for Heli fuel tanks.

john josey

Yeah, thats fair comment....I should also point out that the ignition module is mounted on two strips of 6mm foam tape at each end and not directly onto the plywood floor (to keep the contact area with the fusalage to minimum) and then the velcro strap.

littlera

John,

Thanks again. The Nalgene bottle has been fitted with metal fittings I have seen somewhere. Apparently Glen's Models is getting them from someone that goes ahead and upfits the bottles to make tanks from them.

I am familiar with Glen's Models of Scotland, even here in North Carolina, USA. They have a wonderful series of Maule airplanes that they get as ARFs from China. I have wanted one since they were introduced, but have not been able to get my hands on one. Chatter on RCU uncovered at least one or two modelers in the states who contacted Glen's about getting one sent from Scotland to the USA and were greeted with no return communication on their request or were quoted absolutely outrageous shipping charges (I think in the range of 500 pounds sterling.) I am a Maule fan, and bought a Powerplanes International kit of the Maule Skyrocket made in the early 1990's from a guy in the Channel Islands. HE only charged me USD 20 to ship it to me! Powerplanes International, you probably know, was a kit maker from Wales. They are no longer in business. The kit built nicely, and is a great flyer. It is only a small .40 size model.

My daughter lives and works in London at the moment, and is moving back to North Carolina in November. She is coming home on a cruise ship (cheaper than flying, believe it or not!) and I am considering having Glen's deliver a kit to her apartment in London and get her to float it to me on the ship.

john josey

Yeah, i remember powerplanes international.

500 UK pounds !!! EEEK.....i could probably get a return flight and deliver it to your door for less than that ! Glen is also a freind (i used to work for him when he first started the company) so i could ask him what the issue is if any ?

The maule is not really my thing, but watching glen fly his own....prop-hanging and even some crisp 8 point rolls, they do appear to fly really well

littlera

John,

If you know him and get a chance, please ask him what is the issue with shipping / selling his products to buyers in the USA. Depending on what you find, I may pursue the matter. I appreciate it very much!

john josey

Yeah, no problem...i'll give him a call tomorro and report back tomorro evening.

phakur

My Feedback: (13)

I just finished my Spacewalker 2-I mounted the ignition at the bottom of the area shaped like an L inside the cowl.

There is tons of room there and I used some tie wraps and foam under it to keep it in place.

Just make sure to keep the exhaust out of the cowl and have plenty of cooling air across the engine-you'll be fine.

littlera

Am considering that area on my Spacewalker too.

What engine did you use? Has it flown?

aerialsports

My Feedback: (130)

I always mount mine on the firewall on the opposite side than the muffler using a good velcro and then a zip tie just for security, ignition boxes do produce heat so it is best not to fully enclose them in foam or any thing else.