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#1 stephavee Oct 02, 2012 06:37 PM

pop pop boat issues
 
I have been playing with these little things for a few days now. The coil type was my 1st. but as i moved on to the "boiler" type i ran into a problem. It starts to run but then it has one good puff and it stops. its like i flashes out or something? I started with a two tube setup but had the same issue. so i went to a boiler made out of a old mini paint can with 4 tubes. i see some online that use drinking straws so i dont think i have too much flow through the tubes but it still will "flash" out. so i made a two burner a alcohol lamp to use instead of candles. It doesnt matter if i use both burners or not same problem. what do you guys think? this is what i made tell me how to get this running right.http://i1138.photobucket.com/albums/...0-02154018.jpghttp://i1138.photobucket.com/albums/...0-02154029.jpghttp://i1138.photobucket.com/albums/...0-02154048.jpg

#2 SenorNeekers Oct 02, 2012 08:18 PM

I find this happens as well with some of my putt putt motors. What I found to be useful, is for there to be a dip in the 'motor' tubes at some point.

Something where the water won't all run out. This seems to help especially with multiple tube 'boiler' types. Coils, due to their nature, have low spots in the run of the pipe anyways.
There is a certain balance to be struck with these things. Too much heat and/or too large a diameter of tube, and too much water will be expelled, then sucked in. This results in one good push, but then the systems is over cooled and stops.

I can't say I've figured out the science, but those are some of the observations I made. My best putt-putt boat was also my smallest.

S.S. Buggerlugs (2 min 23 sec)

#3 Brooks Oct 03, 2012 10:44 AM

A couple comments, don't profess to be an expert, though.
1) boiler is angled, not flat. Perhaps all water in boiler is expelled on first puff, none left to cool, and suck water back in.
2) Is burner inserted backwards in photo? At any rate, flame may be licking the tubes. If they get, and stay, flame hot, then perhaps no suction available to refill them. Easy to check, just put a barrier between burner flame and the tubes.

Neat hull; I make bottleboat sailboats, but hadn't considered a bottleboat popper :-)

Mogogear is an expert, you might mail him, though I expect he'll see your thread eventually.

http://www.rcgroups.com/forums/member.php?u=221719

#4 ooyah Oct 03, 2012 03:40 PM

Quote:

Originally Posted by Brooks (Post 22902298)
A couple comments, don't profess to be an expert, though.
1) boiler is angled, not flat. Perhaps all water in boiler is expelled on first puff, none left to cool, and suck water back in.
2) Is burner inserted backwards in photo? At any rate, flame may be licking the tubes. If they get, and stay, flame hot, then perhaps no suction available to refill them. Easy to check, just put a barrier between burner flame and the tubes.

Neat hull; I make bottleboat sailboats, but hadn't considered a bottleboat popper :-)

Mogogear is an expert, you might mail him, though I expect he'll see your thread eventually.

http://www.rcgroups.com/forums/member.php?u=221719

Brooks,
you-tube video of a Canadian who makes Put Put boats (
Part 2 -Canadian Putt putt Boats -YT (4 min 41 sec)
) this chap I think is a friend of Mogogear, Fascinating stuff from so simple materials.
Much easier to make than the brute of a flash steamer that I have and not so dangerous.
George.

#5 steamboatmodel Oct 04, 2012 09:23 AM

There is a lot of information on pop pops on this forum, which Daryl is a member;
http://modelsteam.myfreeforum.org/index.php
We built some of the tube type for Scouts a few years back.
Regards,
Gerald.

#6 Brooks Oct 04, 2012 10:16 AM

Couple poppop threads here at rcgroups:
http://www.rcgroups.com/forums/showthread.php?t=1240012
http://www.rcgroups.com/forums/showthread.php?t=1295920

To expand on the boiler-angle-is-bad comment I made: The angle sends liquid water to the low point of the boiler, naturally. The location of the tubes at the low point allows the water to be expelled on the first pop. If the boiler were level, the water would not pool at the tubes. Or, if the tubes were moved away from the low point, or simply stuck up through the floor of the boiler so they did not act like funnels, then my hypothesis problem would be solved.

Solutions: Moving the tubes would be hard, I think. But, depending on how hard it is to break the tube-transom seal, you might be able to level the boiler just by sliding all the tubes aft. This would lower the boiler, so you'd have to adjust the wick lengths of your burner, of course. For testing, a short stub of birthday candle would serve as a quick and easy burner.

Ooyah, I've seen Daryl Canada's videos, they are neat and he is an Expert. But I lost my downloads of the videos in a computer crash, so thanks for posting :-).

Building the diaphram style boiler appears to be an art: A friend built 2 seemingly identical boilers - one ran like the dickens, one was a complete dud. So, persistence is required to succeed with pop-pops, I conclude *smiles*.

#7 stephavee Oct 04, 2012 02:37 PM

Thank to all! I put a dip in my tubes, this in turn lowered my boiler and flatend it out. I trimed my burners and ran it on one. I worked well but when i lit the other burner my solder joint failed... I wanted to play with these boats but only had silver solder for lower temp applications. So i'll take a trip to Airgas and get somthing more appropriate.

#8 Brooks Oct 04, 2012 06:11 PM

Hooray! Huzzah!


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