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Building Tips and technical articles. => 1/2 A building. => Topic started by: Andrew Tinsley on July 15, 2013, 10:00:45 AM
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Hello everyone,
I have been able to buy a number of Norvel 0.061 Big Mig start up control line engines. They were new and unused and at a good price. My query concerns the tanks on these engines. There is a pick up line that goes to the rear outside wall. This finishes up about a third the way up the tank rear face. There is a vent that goes from top to bottom of the tank and is bent to face into the slipstream. OK it looks a sort of stunt tank of the old fashioned kind, but without a vent going from the tank bottom and finishing just below tank top.
Does anyone know if they work or not? If not, has anyone tried a modification to make it work? Seems a pity to throw them away! I know the answer is to try them and see, but the combination is meant to be fire wall mounted and the tank adds about 1.25 inches. So the engine is that much further forward. Short of ripping apart a good 1/2 A stunter, I have nothing to try the combo out on! Anyone got any experience with these engine / tank units?
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Everyone I know of that's used them, said they work very well. Some of them have a spring loaded vent for fueling, and I think others don't. I have a couple, but like you, so far I have no use for them... yet. It's something I would certainly build around so as not to extend the nose too much. I use pressure bladders on my Norvels, since it gives such a flawless stunt run.
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Andrew, they work fine, just don't hold much fuel for the .061. You can move the tubing around if needed to get better runs. Heman at Aeromaniacs posted how to make a uniflo with one, i believe they were using .049's and got longer runs. Cox medallion and tee dee's will fit these tanks also.
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HI Andrew,
Not much help here on the Norvel C/L tank. I have beam mounted all my Norvels and gone with a separate tank. Mainly because of the extra length you mentioned.
Never a problem this way, so sorry that I cannot comment on the tanks.
BIG Bear
RNMM/AMM
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Thanks Everyone!
Interesting to learn that such a simple tank set up works so well. the Aeromaniacs site was a good read, almost forgot to read the article on the Norvel tank setup!
Bill I am with you on the problem of lengthening the nose. I would do a special build to accommodate this. Pity it is only a 1/2 oz tank. Really a bit too small for the 0.061 although the Aeromaniac article did say that their mod upped the laps available.
I suppose I am a cheapskate in wanting to use something that I got essentially for free. I only paid $50 each for the Norvels brand new in box and that is CHEAP this side of the pond. Very interesting that the tanks fit the Cox TD, a possible use there, but with my luck at fuel feed problems with TDs I doubt that this tank would work. Maybe try them out on my surplus of Wasps!
Thanks again,
Andrew.
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...Very interesting that the tanks fit the Cox TD, a possible use there, but with my luck at fuel feed problems with TDs I doubt that this tank would work. Maybe try them out on my surplus of Wasps!
Thanks again,
Andrew.
Or Medallions. They run great on suction.
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I have never been able to get hold of a Medallion, this side of the pond they don't come up very often. I am going to cause ripples, TDs run well but unless on pressure they seem to be very touchy. Anyway that you could make them a bit more user friendly by sacrificing a bit of power? Don't tell me to put a Medallion cylinder on them! They are even rarer than Medallions!
Andrew.
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The touchiness of a Tee Dee is mostly due to crankshaft timing, not the cylinder. If you want to try the cylinder change, the Medallion used the standard ready-to-fly cylinder and piston, nothing special about it. You could also try reducing the compression with more gaskets or the standard head.
My own preference is to use the crankshaft pressure port and a Kirn Kraft style needle (still available from specialty suppliers).
The Medallion I am currently flying on a Baby Clown has a Galbreath fine thread needle and crankshaft pressure. There have been some problems with the engine, but it is getting sorted out.
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...There is a pick up line that goes to the rear outside wall. This finishes up about a third the way up the tank rear face.
On the first one of these tanks I had to remove the pickup line and bend it a little to reach all the way to the outside rear. Later they came with two pickup tubes.
There is a vent that goes from top to bottom of the tank and is bent to face into the slipstream.
My first ones were like that but when they put pressure nipples on the mufflers they faced the vent toward the muffler and included a piece of silicone tubing for muffler pressure.
Does anyone know if they work or not?
Used them mostly as break-in mounts but yes, they do work. As you mentioned, they stick the engine way out there.
Yes you can use Cox engines in these mounts but if you use a NORVEL in a Cox mount you must remove a little near the top because the NORVEL crankcase is just a slight bit wider.
Good luck with them.
George
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I've used these mounts a number of times, here is one of my more successful configurations with it
(http://i52.photobucket.com/albums/g3/Adduckted/planes/LoneWolf003.jpg) (http://s52.photobucket.com/user/Adduckted/media/planes/LoneWolf003.jpg.html)
Can't remember the exact details, something like a 30" sparless span, maybe 180-190 square? Weighed around 10 oz I believe. Running an 061 Wasp, I think I could get about a 2 minute flight. Nowhere near what a decent bottle or ballon tank can give, but was still a lot of fun and easy to build
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A side view. Please excuse the poor edge sealing. I later repaired it with a better heat gun
(http://i52.photobucket.com/albums/g3/Adduckted/planes/LoneWolf002.jpg) (http://s52.photobucket.com/user/Adduckted/media/planes/LoneWolf002.jpg.html)
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A side mount with a 2 oz bottle tank rigge for pressure like this arrangement is much more effective
(http://i52.photobucket.com/albums/g3/Adduckted/planes/pics009.jpg) (http://s52.photobucket.com/user/Adduckted/media/planes/pics009.jpg.html)