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SMOKE ON! — Make a Cheap & Easy Smoke Muffler

Posted: October 18th, 2016, by AircraftWriter

A good approach to supplement fad to your RC flights is to supplement a fume system. Do a loop or a hurl and afterwards supplement a dense, long-hanging fume track and we have an airshow! You can save some bucks by modiflying your batch scarf instead of shopping a blurb one. Then we can take that income and request it to a cost of a fume siphon and compulsory hardware. Here’s how we did it with my Zenoah G-20-powered Hangar 9 1/4-scale J-3 Piper Cub.

Before we can make fume with your new smoke-muffler, we need good peculiarity fume fluid.

 Robart Manufacturing’s Liquid Sky oil is accessible in 5- and 1-gallon qualities and it provides excellent, long-lasting smoke. Liquid Sky is used by pros and Joes for turbine as good as piston engine-equipped aircraft and is froth safe. Liquid Sky creates unequivocally unenlightened fume and there is also a pointed Root Beer smell to assistance facade that automotive gasoline smell we get from a good day during a drifting field! (

Step 1: Here’s a batch scarf private from a engine and spotless adult with some MEK well-off to unequivocally degrease it. we used a new single-edged razor blade to mislay a aged dull gasket. Here we can see a new one we will supplement after a scarf has been modified.
Step 2: The plumbing indispensable is a brew of Tygon gasoline fuel line and heat-resistant silicon tubing that binds adult good to a feverishness of a muffler. To cgange a scarf all we need is a vast coronet tube that fits into a categorical dull siren to be used as a perplex tube, and a skinny coronet or copper for a oil preheat and injection tube. we use Du-Bro and KS collection to purify hook a tubing. For a fume oil tank, we use a sullivan 10-ounce tank set adult with a customary two-tube setup. Be certain to use tie wraps to secure your tubing.
Step 3: The initial thing to do is to cut, hook and prepared a finish of a Injector tube. To make a excellent atomized mist of oil into a muffler, we use a knife to clip a finish of a copper tube. This seals a finish and shapes it so it resembles a fish tail. we afterwards use a skinny cut-off hoop with my Dremel to scrape a center of a fish tail. This produces an opening about half a area of a batch tubing end. The tube is afterwards focussed so it’s prolonged adequate to enter a side of a muffler, pass by to a other side, and afterwards hook 180 degrees to re-enter a muffler.
Step 4: Drill 3 holes in a side of a muffler. Depending on your scarf and engine installation, these holes have to be tradition laid out. On mine, a singular entrance hole is on a muffler’s abaft side, and a dual others are on a front side. Drill a holes somewhat incomparable than your injection tube’s diameter. For my oil-injection tube we drilled 3 holes afterwards used a rat-tail record to increase a holes slightly. Now use a drum-grinding bit with your Dremel and grub divided a black finish on a muffler. This will yield a purify aspect for a steel glue to hang to.
Step 5: Here we see a injection tube commissioned and prepared to be hermetic with JB Weld steel epoxy. Be certain to purify a injection tube as good as a aspect of a muffler. Build adult fillets around a tubes/holes areas. Smooth a fillets with a soppy finger and afterwards set aside for 24 hours to entirely cure.
Step 6: To yield a perplex tube, a vast coronet tube is slipped in to fit into a scarf and a fit should be snug. The tube is longer than a inner tube already in a muffler. Slip it into place, bottom it out and afterwards symbol a length. Use a KS Tubing knife and cut it to length.
Step 7: To get a length of a inner tube, we used a focussed square of handle or welding rod. Slide it into a muffler, trip it over a finish of a inner tube and with your thumbnail, use a handle as a abyss sign and send a length to a coronet tube. The area during a finish of a coronet tube will be a perplex territory and will need to have several holes drilled into it! Drill several holes in a finish and afterwards silt smooth. Slip a perplex tube into a scarf until it bottoms out and is flush with a dull pipe. Drill a hole and secure a coronet tube in place with a pan-head square steel screw.


Step 8: To track your fume lines into a cabin area, cavalcade a hole in a firewall and slip a unbending handle into a hole. Guide a handle until it enters a cabin and afterwards insert your fume line to a handle and lift it into place. At a finish of a fume line, implement a 1-inch-long square of feverishness fuel silicon tubing with a brief length of aluminum tube. Silicon binds adult to feverishness many improved than Tygon gas tubing. Connect a silicon tubing to a oil injection tube and shaft a scarf behind into place on a engine. Reinstall a engine cowl. Notice that we had to grub divided a small bit of a cover to transparent a injection tube.
Step 9: Now it’s time to implement a plumbing, tank, siphon and a approach to scale a fume oil flow. we done a removable tray to secure all a hardware. Velcro binds a tray in place, double-sided fasten attaches a tank to a tray, and some froth stuffing protects a siphon and engine from vibration.
Step 10: we use a fuel filters for a purify oil flow, a check valve to forestall scarf vigour from pulling oil behind into a siphon tubing, and many importantly, a remote needle valve public to umpire a oil flow. If we don’t scale a upsurge properly, a oil can cold off a scarf and revoke a volume of fume it generates. 
This is many improved than regulating a clamp on a oil tubing. we used a needle-valve public from an aged O.S. .61 engine. It works great!
Step 11: Smoke oil pumps are accessible from several sources. Two that we have used are a TME (requires 12V battery) and a Don Harris pump, that can be powered simply by plugging it into a receiver. There are others as good from Sullivan and from Slimline Products. A bit of recommendation here is before we implement a pumps and insert a plumbing, be certain to check that siphon wise is a “IN” and that is a “OUT.” This will save a lot of grief if we were to go forward and implement all and afterwards find out something is bending adult backwards.
Step 12: Here’s a finished designation in my Hangar 9 Piper Cub. Notice that we use a lot of wire ties to keep a plumbing neat and forestall it from relocating around. we used a T-fitting to fill and dull a fume tank and placed it between a siphon and a tank. Note a positions of a needle valve public and a check valve. Be certain to place a needle valve in a available place to make it easy to adjust. In this installation, we run a opening tube out along a filler line. This automatically allows a crawl to brief out divided from a indication while stuffing a tank. For tighter installation, use apart Fuel Dots to fill and dull your fume system.
Step 13: Check out a fume density! This is what it looks like with a oil upsurge roughly totally close down (only one spin open). This environment gives a lot of “smoke-on time” and a 10-ounce tank lasts some-more than 10 minutes. The complement works good and when we switch a fume off, it takes about 5 to 7 seconds for a fume to stop completely.


Heat equals smoke! Whenever possible, preheat your fume liquid before it is injected into your muffler. Using a elementary vigour wise to inject a liquid is not a good setup.

Regulate your fume liquid flow. Too many fume oil is worse than too little. Excessive oil cools a muffler, that reduces a volume of fume it generates and shortens smoke-on time by blazing adult a liquid faster than is needed.

Do not switch a fume siphon on when we engine is during low stifle or during idle. You can means a engine to drown on a unburned oil that increases behind pressure. A good thought is to brew a fume switch with your stifle channel and set a on position to anything over half throttle.