Conference vmszoo::rc

I'm working on my Balsa USA Citabria Aero Pro and am planning putting in an on 
board smoke system.  I've never seen one used at the fields I've flown at but 
I'm told they work all-right.  Has anyone had any experience with them.  The 
one I bought is the Harry Higly Lots of Smoke....  I'm not sure what type of 
Smoke "juice" to use, or how to mix it if necessary.  Any ideas???  I'm using 
the Super Tiger .90 Two stroke.

/Brian 

    There is an article in RCM (September Issue, I think) on smoke systems
    and making your own smoke fluid.
    
    lotsa luck,
    
    Chris Spohr

    
>    It is possible that it may be in the August issue, but I believe
>    its the Sept. issue under one of the monthly columns.  Near the
>    front if I remember.      

  The article is in the September issue on page 6. It gives diagrams
of several different setups.


  Jim C

    But, after reading the article, there is still one question...
    
    Can smoke be used on 4-strokes??  It should be easier to burn the
    smoke mixture because the exhaust temp is so much higher.  Or is
    it too high??  Also, is there enough crankcase pressure??  My OS-61
    already has a fitting on the crankcase.  Can I use that??
    
    Thanks,
    jeff
    

    HI
      SEEING HOW THIS NOTE IS ABOUT SMOKE SYSTEMS,I'M WONDERING IF
    THERE IS A SMOKE SYSTEM OUT THERE FOR WING TIPS.I HAVEN'T HEARD
    OF ANY,SO I WAS JUST WONDERING THAT'S ALL.
    
                                       KEEP'EM FLYING
                                       JERRY

    Jerry,
    
    The only ones I've ever seen were of the "smoke-bomb" variety.
    
    Al

    I'm here, and I am also interested in smoke systems.  Unfortunately,
    I don't have any experience with them.  I would like to put one
    in my next plane, a Sportster 90.  I am going to use a 4-stroke
    in it.  I have heard that it is easier to generate smoke with a
    4-stroke because the exhaust temperature is much hotter.  I would
    like to see a working smoke system before trying to design one myself.
    Getting the smoke mixture to the proper temperature and dispensing
    it into the muffler at the proper rate must take some good planning.
    
    Charlie
    

    Charlie, I just bought a Super Chipmunk and there is a part on smoke
    systems.  It says that more heat is generated from 2 strokes and
    that a special heating coil would be necessary with a 4 stroke.
    I'll double check tonight!
    
    The plans tell me what I need as far as an extra servo, oil (smoke)
    tank, switch device etc. but what I'm after is info on specific
    brands and the complexity of installation and use and price.  The
    one thing that has always bothered me about this hobby is that you
    always need more than is shown.  For example, when you buy a plane,
    "...and now sir, would you like the accessory kit too?  You know,
    the wheels, gas tank.........."
    
    As far as the smoke system, I would like to hear from someone who
    has one and exactly what was needed and how much the TOTAL price
    was.
          * ** * *
    Ken  *** * *   * **
       * ** * * * ** * ***    \____----__|
      * * * * ** ** ***************-/\---|
                                        
                                      
    

    re-.2 
    Ken,
    	I would be surprised if anyone could say that a 2-stroke exhaust
    is hotter than a 4-stroke.  I think that the tricky part of a smoke
    system would be the preheat coil that goes into the muffler.  I
    haven't seen what one should look like.  If you have any info on
    this, I would like to hear more about it.
    
    Charlie
    

        Re:< Note 131.9 by BRNIN::SOUTIERE >

                Smoke systems  have been covered several times in RCM and
        MA.  The simplest  consist of a tank containing diesel fuel, some
        kind of pump (e.g.   Perry)  and  a  servo controlled valve.  The
        diesel fuel is simply dumped into  the  muffler  where  the  heat
        turns it into smoke. Some day I will play with one.
        
                      _ 
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        |-/____________|
        |    |        o \
             O           \ 
                          O
         Hang in there! o_|_
                          |
             Anker      \_|_/

        

    The best smoke that I seen was from a oil called ALMAG which is
    a Aluminum/Magnesium cutting fluid.  It is available from most bulk
    oil distributers by the 5gal can.  I have about 4 gals of this stuff
    left since I sold my 1/4 scale plane.
    
    I thought that the smoke was most fun about flying.
    
    I used a DON HARRIS pump which is a small self contained pump that
    runs from 2 AA batteries and is controled by a seperate
    servo/microswitch.  Pull up, roll inverted, pull under, smoke on,
    accross midfield, slow roll, smoke off, pull up.  It was great!!!!
    
    Be carefull about diesel fuel and rubber products.  I once ran some
    diesel through my pump in the winter when the oil was too thick
    and it caused all the rubber seals to swell.  Diesel/Gasoline are
    alot different than alcohol based glo fuels.
    

    
    Also use a check valve of some kind as close to the muffler as possible
    to keep the back pressure from forcing the smoke fluid back down
    the tubing.

    Ahhhh... finally someone that has run one!!
    
    Tell us more about the pump...  Where did you get it?  What kind
    of check valve did you use??  I was thinking of using a check valve
    from my aquarium, but I was not sure how the latex (?) valve would
    stand up.
    
    Is this oil as detrimental to rubber as gas/diesel??  Did you use
    a preheating coil or was the exhaust temp high enough??
    
    How much does it gunk up the plane??
    
    ----
    
    I had planned to install a smoke system in my SS-40.  I bought the
    DUBRO smoke system.  I was never very happy with the installation
    and I was not thrilled with drilling the back plate of my engine.
    Plus, there is limited room in an SS-40.
    
    What I had recently decided to do, but am still in the design stages
    of, was to make a removeable pod that contains the oil tank, server
    and switch.  This would attach right under the wing.  A tube would
    run up to the muffler through the fuse.
    
   
     jeff (starting to get excited about smoke again)

    The pump was made by Don Harris out of California.  Now remember
    this was in a large 1/4 scale plane so room and weight were not
    a problem.
    
    The whole package came from Don Harris which included the check
    valve.  Any check valve would work.  You just dont want the muffler
    pressure to force the oil back into the tank.  You want it so that
    when you send Oil to the muffler it will only be a inch away and
    wont have to prime the whole line each time.
    
    The pump that I was using was a little pump unit that was about
    1.5"x1.5"x3" and that included 2 AA batteries a small motor and
    a small gear driven pump.  The micro switch would turn on  the motor
    and it will suck the oil out of the tank and push it into the muffler.
    
    HEAT.
    
    The engine was a Zenoah G-38.  I think there is a problem with glo
    engines not being hot enough to vaporize the oil but I cant comment
    on that.
    
    Like I said be carefull of gas/diesel around rubber.  It will generaly
    swell up any rubber that it doesnt like and ruin it.  The Oil did
    not effect any of the rubber like gas/diesel.
    
    I would give Don Harris a call if you can find his number.  I am
    sorry I dont have it.
    
    I think that covered it.  I dont know how to manipulate the
    "notes$scratch" buffer so that I can see your last reply.

    Thanks for the info..
    
    weight is not a problem for me...  The SS-40 is powered by a K&B60.
    Size is of concern, but not a major one as I will not be constrained
    by fuse dimensions.
    
    Heat - I think I am going to wrap a copper pipe around the muffler
    a couple of times to pre-heat the oil.
    
    Anyone have a simple design for an on/off switch directly connected
    to the Rx to avoid size and hassle problems with servo's and micro
    switches?
    
    thanks,
    jeff
    

    RE: < Note 131.15 by WRASSE::FRIEDRICHS "Go B's!!" >

>    Anyone have a simple design for an on/off switch directly connected
>    to the Rx to avoid size and hassle problems with servo's and micro
>    switches?

    RCM had such a beasty in a short article complete with plans a couple
    of issues back.  If you'd like you can borrow my copy.  I'll look it up
    tonight and post the issue date and page number tomorrow.

    Later,

    Don

    HERE ARE TWO IDEAS FOR PUMPS:
    
    1.  About a year or two ago, Model Aviation ran a construction article
    on the Super Doubler II.  It used a Perry pump, an oscillating pump
    that crankcase pressure.  For control they used a servo operated pinch
    valve.
    
    2.  If you want to use an electric pump  then I would suggest
    controlling it with a Jomar Universal Electronic Switch ($35.00).  This
    way you don't have to mess with a servo activated switch.
    
                --|--             Happy (con)Trails!
                 (O)             
          _______/ \_______       Scott Cox
    

    The servo will now operate continuously in one direction at the
    flip of the gear switch.
    
    Now what I need is ideas on how to convert/build a pump on the top
    of the servo.  Tonight I tried a basic "six-shooter" style pump
    where the tube was squegeed.  This worked OK, but I am having trouble
    getting all of the pieces to stay together....
    
    Any ideas are welcome, either enhancing what I am trying to do or
    a different design all together...
    
    I am going to call Don Harris and I might order his electric pump...
    
    cheers,
    jeff
    

    How about trying to run it off of muffler pressure. (with a check
    valve)  That might save the weight of a pump.  Most suitable pumps
    that I can think of would be big and heavy.  The other possiblilty
    would be to use a perry pump either off of crankcase pressure or
    one of the oscillating types that works off of engine vibration.
    These are fairly light.  The only problem withe the oscillating
    one is that it must be mounted to the engine rear cover and there
    is often not room there.
    
    Charlie
    

Re .19

>    How about trying to run it off of muffler pressure. (with a check

	That's not going to work since that's the force you need to 
overcome to get the oil in there. "Every Action Has An Equal And Opposite 
Re-action" and all that Newtonian stuff.

Re .8
	Dave,

   If you are looking for a smoke system in the UK, try the Ghost Squadron.
I saw these guys at a show in Oxford last year where they flew a couple of 
nice beasts with smoke on. I believe they flog all kinds of gizmos and 
gadgets (failsafes, battery monitors, etc.) but I can't recall the real 
name (or address) of the company. I'll have a hunt through the mags. 'cause 
I'm sure I've seen them in there SOMEWHERE.    

Ken Lee.

P.S. Dave, if you are putting smoke on your chopper, I hope it doesn't 
disappear in the hover!!!

    Not to argue too much, but muffler pressure is not constant and
    depending where you inject, there may even be a vacuum. 
    
    Charlie

    Well Charlie, you may have hit the nail on the head with this
    statement...
    
    "    Not to argue too much, but muffler pressure is not constant and
    depending where you inject, there may even be a vacuum. "
    
    Last night was my first attempt at using smoke...  I ended up buying
    the Don Harris pump and using a modified servo to turn it on/off.
    
    I used straight kerosene for both flights..
    
    Flight 1 - I had a restricting collar on the line going to the muffler
    as I thought that the dump rate would be too high.  However, during
    the flight the application of the pump did not change the amount
    of smoke.  There was a lightly visible smoke stream for most of
    the flight.  I believe (although I have yet to prove) that a venturi
    effect was happening and the kerosene was being sucked through.
    My other theory is that the tank vent placement is creating positive
    pressure in the tank and pushing the kerosene through...
    
    Flight 2 - For some reason my "servo-switch" (my modified servo)
    was stuck in the on position.  I had removed the restricting collar.
    During this flight the smoke quantity was better, but since I could
    not control the pump, I could not examine what was going on in the
    pump off condition.
    
    I couldn't play with it anymore, as on the second flight I went
    deadstick during the downwind to base leg turn on approach and I
    ran out of altitude into a small pine.  Minor damage but I needed
    a monokote iron before I could fly again...
    
    Next time I hope to try some cutting oil....  The people at Don
    Harris suggest mixing cutting oil with mineral spirits for the best
    smoke.  I also have to sort out my switch problem..
    
    Getting there!
    jeff
    

    The best Oil that we found for smoke systems was "ALMAG" made by
    TEXECO (sp) you know the gas station people.  ALMAG stands for
    Aluminum/Magnesium Cutting Oil.  It worked just great and put out
    more smoke than you can believe.  There is nothing more fun that
    to pull up verticle with smoke on to the point of a stall and then
    tail slide back thru your own smoke to the point that for 1-2 seconds
    you cant see your plane for the smoke.
    
    The ALMAG oil can general be purchase thru a bulk distributor in
    a 5 gal can for around $20.00.  This is the same Oil that is used
    on Pitts and the such while they are performing in Airshows.  
    
    Also as the Don Harris shows a restrictor I too found that it didnt
    need one.  Just pump it in full force, fully concentrated.  You
    may find that in the winter you may need to cut it with a little
    mineral sprirts to help the viscosity due to the cold.
    
    Keep us posted....
    

    If you could, explain the connections to the muffler.  I'm still
    confused on this part.  Do you have to drill a hole in the muffler
    for the smoke connection?
    
    Ken

    
    Does the smoke system make a real mess all over the plane, or is it
    comparable to the mess you get from a 2-stroke engine?
    
    Bill

    Sorry, I was out on vacation for the last 1.5 weeks.  Over 300 unseen
    notes in RC alone!!
    
    
    re .24 - Yes, you drill a hole in the muffler, tap the hole and
    screw in a standard brass nippled fitting (just like the one that
    is there for as a pressure takeoff).  The key to this is to make
    sure that you have the proper tap for the fitting that you have
    (Thanks Al!)
    
    re .25 - Using kerosene alone, I did not notice any additional goop
    above what I already get from my 2 stroke.  The whole theory is
    that is is vaporized easily.
    
    This week I need to repair my plane and locate some cutting oil.
    Perhaps I will be able to give it a try this weekend.
    
    cheers,
    jeff
    

    Thanks Jeff, but I have one more question;
    
    	Does it matter where on the muffler the hole is drilled?  Should
    it be towards the front or rear of the muffler or would it hurt
    to put it right next to the existing one?
    
    Ken

    Unknown at this time.  I added mine right next to the existing one.
    But I am not comfortable that it is working correctly yet.  (see
    previous reply).
    
    cheers,
    jeff
    

    The best smoke system I've seen was in NY state. The guy was running
    a .60 sized engine and installed a water cooling jacket to the head
    of the engine. The fuel for the smoke was feed into one side of
    the jacket and extracted on the other side adjacent to the muffler.
    He then had a copper tubing that he ran from the header end of the
    muffler inside the muffler to app. 1" from the exhaust end of the
    muffler. The end at the header end protruded outside and picked
    uo the heated fuel from the jacket attached to the cylinder. At
    the end of the copper tubing near the exhaust end of the muffler
    he had a piece of the copper tubing bent over the open end of the
    copper tubing. Much like the enlement of a spark plug. As the heated
    fuel came out of the copper tubing it hit the piece of metal and
    was atomised. With the  fuel heated to such a degree and the atomization
    the burning of the fuel was intense. He commented  that the systems
    that dump the fuel into the muffler at the header of the muffler
    have a problem with the fuel being sucked back into the cylinder
    of the engine. All I know is that this worked mint.
    
    
    Tom

    Lets re-awaken this topic.
    
    Now that the MUNK is flying I want to pursue the smoke system again.
    ALMAG cutting oil was suggested as the smoke mixture, but I just
    called a Texaco dealer and he said he can only get it in 55 gallon
    quantities which costs $250.  Does anyone know where to get this in
    5 gallon quantities?
    
    I've also got a Perry oscillating pump....is this strong enough to
    pump the oil into the muffler?  I plan on mounting it on the fire-
    wall....would it vibrate enough there?
    
    Ken

                         <<< Note 131.31 by ICICLE::SOUTIERE >>>
    
    > I've also got a Perry oscillating pump....is this strong enough to
    > pump the oil into the muffler?  I plan on mounting it on the fire-
    > wall....would it vibrate enough there?
    
    Ken, I would mount it in the arc of the prop attached to the engine if 
    possible so that you get the maximum ability of the pump. They
    recommend direct attachment to the engine, rather than involving the
    damping effect of mounting it off the engine on the firewall. But then
    if the pump was an afterthought one doesn't always have the space. Thats
    when the fun starts...
    
    I am, like youself, setting up a smoke system. I have a question
    related to the size of tank that would be adequate to hold the smoke
    producing oil - 2oz,4oz,...? - any recommendations ? 
    
    Regards,
    
    Eric();

    Eric,
    		I plan on using a 4oz. tank (since it is all I have
    available).  Granted it won't give me alot of smoke time, but 
    enough to make a few good passes.  Again, looks like we'll have
    to expirement.
    
    		The location of the pump is another trial and error
    thing.  Maybe I'll glue it to the cowl!  It'll surely get some
    vibration there.
    
    		Do you have a switching device yet?
    
    Ken

    >		Do you have a switching device yet?
    
    Hi Ken,
    
    Yes, I got the Dubro (spelling?) valve. Its OK I guess.
    
    The valve allows two tubes to be shut off by rotating the arm which
    pinches the tubes. They supply a good length of rubber tubing. If I
    recall they also supply the nipples to fit into the back of the
    crankcase, and other bits & pieces.
    
    They recommend that you lubricate the pinch mechanism - mine is really
    tight. I hope it will loosen up (haven't lubricated it yet) as the
    servo will have a job pulling & pushing otherwise.
    
    As you said, a bit of experimentation will get something working.
    I hope to run in the engine and then try the smoke system on it soon.
    
    Regards,
    
    Eric();
    

    I am using an OS.90FS.  It has a drain nipple coming from the back
    of the crank case.  I don't believe there is much pressure developed
    there.  I will be using the pump method.
    
    Is there something in the hardware stores that will act as a shutoff
    valve?  I think I'll take a trip to the pet store (fish section),
    they have alot of weird valves.
    
    Ken

                Diesel or regular #2 fuel oil smokes great.
        
        Anker

    Anker,
    	Is the diesel or #2 oil mixed with anything else?
    
        In an older RC catalog, they suggested mixing 1 to 1 diesel
    with some Texaco Corvas form oil.
    
    	By the way, I am using an 8oz. tank for my smoke fuel.
    
    
    Ken

        Re:                     <<< Note 131.37 by ICICLE::SOUTIERE >>>

        Ken,
        
                I believe  straight  diesel is just fine.  At the back of
        my mind there  is  something,  but I'm sure its not any kind of a
        risk.  It has  something  to  do  with  the  density  of smoke vs
        consumption.  Anoth wonderful smoke  generating  fluid  is  power
        steering fluid.
        
        Anker

  If anyone is interested, I have copies of the Sept. 1987 RCM article by 
Chuck Cunningham that talks all about smoke systems and has some illustrations
of different set-ups.  
  If you want a copy send me a VAXmail with you mail stop.

                  Jim

    I'm getting ready to put a smoker in the Extra 300.  I have several
    questions that I could not find answers for in this note.
    
    First, where do you mount the tank for the smoke fluid?  Seems to me
    its best to put it at or close to the CG to prevent changing the
    balance as the fluid gets used up.  
    
    Second, what kind of tank do you use for the fluid?  Is it the same as
    used for glow fuel, or the ones used for gasoline?  I would think that
    most of the fluids capable of being used for smoke are petroleum based,
    and therefore would be in the same category as gasoline.  
    
    Third, what are the pros and cons of using a pressure tap from the
    crankcase vs. a pump to pressurize the smoker tank?  I have heard two
    stories on this.  One says that crankcase pressure will work, but won't
    give you lots of smoke, therefore use a pump.  Others have told me the
    crankcase pressure is going to be more than enough.
    
    Finally, how do you arrange the filler for the smoke fluid?  Is it done
    like the fuel tank, or are there some special ways to set up the
    plumbing?
    
    I'd appreciate any of the collective wisdom out there on this subject.
    
    Thanks,
    Joe

    Joe,
    	I have looked into smoke systems and have purchased a pump and tank
    from B&D.  You do need a tank and fittings made for gasoline.  No
    silicone tubing!  Some people use muffler pressure and a check valve
    but many use either an electric or engine driven pump.  The pump I
    bought runs off of the variable crankcase pressure of a 2-stroke.  I 
    intend to use it with a Zenoah G-38 but I can't fit the stuff in my
    Ultra-Hots easily so it's sitting in a box.  To get good smoke, you
    need good fluid flow and some sort of preheat coil to get it hot
    enough.  The best results I've seen were with a Gas burning engine -
    high exhaust temperature.  The smoke tank can be set up just like a
    fuel tank for filling.
    
    Charlie
     
    

    Re: -.1
    
    Charlie, thanks for the very useful information.
    
    I started the smoke installation by mounting the Dubro smoke switch and
    its servo behind the firewall.  Plenty of room in there, but as luck
    would have it, the servo _just_ touches the wing when it is bolted in
    place.  I don't know if this will be a problem or not.  It doesn't seem
    to represent any danger to the wing or the servo, so I may leave it the
    way it is.
    
    I decided to mount the smoke tank on the CG.  This will require a tank
    about 1" thick and about 4"x6" along the other two dimensions laying on
    its side under the servo tray.  I'm not sure there is such a thing
    commercially available, but I will try to find one close to these
    dimensions.  The square configuration won't fit anywhere.
    
    For starters, I'm going with the direct crankcase pressure method.  If
    this proves unsatisfactory, I can add a pump later.  However, the idea
    of drilling and tapping the crankcase cover seems like a "violation" of
    the tight-fitting, gasketed and sealed engine chamber, and if it
    weren't for the fact that this is standard operating procedure, I would
    have major reservations about doing this.  I won't argue with success.
    
    The rest of the Extra 300 is coming along just fine.  This is a very
    nice kit.
    
    Regards,
    Joe

    I have a similar problem with fitting a tank into a smaller Chipmunk.
    I bought a sheet of blue styrofoam at the lumber yard the other day and
    am going to try making a small tank with a fairly peculiar shape by
    overlaying the foam with fiberglass and epoxy and then melting the foam
    out with gasoline when it cures.
    
    Does anybody know if a .46 motor runs hot enough exhaust to make smoke
    with?
    
    Will

    I was in Tom's Hobby Korner the other day looking at all the fuel tank
    configurations, when lo and behold, I spotted a tank that was exactly
    what I was looking for.  It is 1 3/4 high with a rectangular shape of
    about 4" x 6".  I've never seen this before in any of the catalogs or
    trade mags, so I asked what it was for.  Nobody in the shop knew, and
    Tom wasn't there.  As it turns out, it is a speed boat tank, made to
    fit inside a low-profile hull and sit right on the centerline of the
    hull.  In fact the bottom of the tank is gently sloped from each side
    to the center just like a hull. Dubro refers to it as the VEE TANK
    line.
    
    Well, its already fitted into the fuse and it went in beautifully. 
    Right on the CG!  Turned out to be a neat installation.  An with 16 oz
    of capacity, I should be able to get considerable duration from this
    smoker.
    
    I'm takin' my time with this baby so it comes out right.  Maiden flight
    sometime in the spring of 1993.
    
    Regards,
    Joe