As reality sets in....
08-09-2006, 08:57 PM
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As reality sets in....
I've spent so much effort in using only the lightest materials, that it seems I lost sight of the regular materials. Well, the need came around for a pretty DNU. I used transparent red monokote and got an AUW of ~11oz. After thinking about it, the first version came out right at 12oz. Well, this time I used a 300mah nimh instead of a 270mah nicd. (there's one oz) And eliminated the 1oz (in weight) fuel tank in favor of a balloon tank. That's two oz of equipment missing right there. The Monokote was only slightly heavier than Black Baron. (not an oz worth on this airframe!) If you kept up with the math, the built-up version is ~1oz heavier!
But, the monokote didn't really add that much weight over CP's minimalist version of 10.5oz. So where am I going? The Ace core would be a lighter option?! So I put the RTF wing on the scale. Yep, 4oz. If memory serves the cut down AFW came out ~3oz.
Now, if this seems incoherent, I fell earlier (from a moving vehicle... don't ask) and hit my head.[:@] Most of these measurements are approximate at best, but it proves the "airworthyness" of the new AFW's!
But, the monokote didn't really add that much weight over CP's minimalist version of 10.5oz. So where am I going? The Ace core would be a lighter option?! So I put the RTF wing on the scale. Yep, 4oz. If memory serves the cut down AFW came out ~3oz.
Now, if this seems incoherent, I fell earlier (from a moving vehicle... don't ask) and hit my head.[:@] Most of these measurements are approximate at best, but it proves the "airworthyness" of the new AFW's!
08-09-2006, 09:33 PM
#2
RE: As reality sets in....
When it comes to making the most out of a plane with a $7 engine, this one is right up there with the best. How have the balloon tank runs been for you? I have heard that a little talcum powder on the balloons keeps them from chafing in the plane [if they ever become a problem]. When I get time, I'm going to rig up a finnerator on my DNU, instead of having a fixed fin, and get a Norvel up front. This time the idea would be to carve a good 3D prop, like a 8x2 or so and see what happens.
08-10-2006, 08:22 AM
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RE: As reality sets in....
CP, this will be my first use of a balloon tank. What amazed me is how little it weighs compared to the alternatives. I cut a 1/2" diameter by 1/4" thick aluminum disc out. After putting a groove in the outside just wide enough for a tie wrap and a 3/32 hole in the middle, I slide a length of brass tube in there. Fully assembled, balloon and all, it wouldn't register on my postal scale.
To keep the battery from interfering I made a tube from 1/16 balsa to hold it.
Sneasle, it won't be. I made you a balloon tank, too.
I'm not even going to reread last night's post. It probably doesn't make a whole lot of sense. The gist of it was that the newer Thunder Tiger Ace Foam Wings are lighter than the built-up. One reason may be the basswood spars. It was definitely overkill, but is what's going in the kits. I'm still a little amazed by the revelation that an injection molded wing could be as light or lighter than a built-up...[X(]
To keep the battery from interfering I made a tube from 1/16 balsa to hold it.Sneasle, it won't be. I made you a balloon tank, too.
I'm not even going to reread last night's post. It probably doesn't make a whole lot of sense. The gist of it was that the newer Thunder Tiger Ace Foam Wings are lighter than the built-up. One reason may be the basswood spars. It was definitely overkill, but is what's going in the kits. I'm still a little amazed by the revelation that an injection molded wing could be as light or lighter than a built-up...[X(]
08-10-2006, 08:37 AM
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RE: As reality sets in....
It's an "Ugly Stik" that I put in .pdf form. You can see it and other efforts here: www.ulmer-rc.com
08-10-2006, 09:35 AM
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RE: As reality sets in....
I'm so glad people are still making progress in 1/2A (It will never die unless we all let it) 
Foam is my material of choice unless I'm just in the mood to build.
Foam is my material of choice unless I'm just in the mood to build.
08-10-2006, 10:13 AM
#8
RE: As reality sets in....
I'm not even going to reread last night's post. It probably doesn't make a whole lot of sense.
Is CC your secret decoder[X(]?Please post a pic of your ballon tank. I am getting ready to do one for my Rivets.
08-10-2006, 09:01 PM
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RE: As reality sets in....
Here's a couple pictures of my balloon tank. Vic, thanks for the idea! The nipple worked out fine and eliminated the brass tube I've been using. It will also make "burping" the tank much easier. Take a good look Sneasle. I'm slipping this in the envelope. Don't forget the new address!
08-10-2006, 09:09 PM
#11
RE: As reality sets in....
??? It has to have a pick up line, or you will need to fly down hill all the time!!! That hard plastic tubing, even an empty ink pen cartride would work. In the past, I have just gathered the balloon around the pick up line without any adapter, but the adapter idea should work........it just needs a feed line.
08-10-2006, 09:29 PM
#13
RE: As reality sets in....
Nope, imagine what will happen when you go into a climb. The balloon tank should not be filled to the point where there is any pressure, or else you will need to position a tiny little man onboard to adjust the needle during each flight as the pressure drops. you should be able to put enough fuel into a balloon to get a decent length run, but you don't want to fill it to the point of expanding.
08-10-2006, 09:37 PM
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RE: As reality sets in....
Right, but a bladder (by definition) doesn't usually give the pressure. There's just no air to be sucked in. Don't get me wrong, I'm not positive it will work. Normally, the engine would be sucking from the back of the tank where G-force would be pushing the fuel. Would the fact that it's pulling from the front instead of the back make a difference? G-force would effect what's in the tube, too, right? I'm going to drill the back out for some tubing. By the time Sneasle get's his in the mail, we'll know whether the tube needs to be pushed in.
08-10-2006, 10:05 PM
#16
RE: As reality sets in....
I think it would work at least as good as a film can tank to drill out the stopper and force a hard plastic line into a grommet made from a short hunk of fuel tubing. without a pick up line, the runs will be pretty short.
You first suck all the air out of the tank, then pinch the line. Then you get the syringe set up with no air in it, just fuel, then go ahead and fill the balloon. The balloon should still look like a limp rag when you are done filling. 3/4 of an oz should just lay in a balloon [I'm guessing] without developing any pressure [other than head pressure]. You will know when you get the kinks worked out, when you can watch it go through a full tank [on the ground] without having to touch the needle to keep the engine from frying.
You first suck all the air out of the tank, then pinch the line. Then you get the syringe set up with no air in it, just fuel, then go ahead and fill the balloon. The balloon should still look like a limp rag when you are done filling. 3/4 of an oz should just lay in a balloon [I'm guessing] without developing any pressure [other than head pressure]. You will know when you get the kinks worked out, when you can watch it go through a full tank [on the ground] without having to touch the needle to keep the engine from frying.
08-10-2006, 10:12 PM
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RE: As reality sets in....
Darn CP. You just casually solved another problem for me. I've been fighting getting the brass tube soldered in. Since the aluminum won't take solder, the process is difficult and a little time consuming. Using a piece of fuel line is an easy solution!
08-10-2006, 11:38 PM
#20
RE: As reality sets in....
VIC, it has been a long time since I set up a balloon tank. The key is to eliminate the air as much as possible before filling, and to not over fill it. There is a side benefit of less fuel foaming if high rpm is causing a hard tank to fizz.
PT, the only way I know of to join brass tubing with aluminum is with epoxy or loktite and a press fit. I have made my own T fittings that have held up, and those backplate pressure regulators are done the same way.
PT, the only way I know of to join brass tubing with aluminum is with epoxy or loktite and a press fit. I have made my own T fittings that have held up, and those backplate pressure regulators are done the same way.
08-12-2006, 01:31 AM
#22
RE: As reality sets in....
PT, Pigg,
you can solder aluminium with standard solder, but you need to sand it under oil to remove the oxide layer, and then introduce the solder before you remove the oil.
This has worked the couple of times I have had to do it, but I am not confident it will work with every alloy.
Stefan
you can solder aluminium with standard solder, but you need to sand it under oil to remove the oxide layer, and then introduce the solder before you remove the oil.
This has worked the couple of times I have had to do it, but I am not confident it will work with every alloy.
Stefan
08-12-2006, 02:03 AM
#23
RE: As reality sets in....
ORIGINAL: combatpigg
PT, the only way I know of to join brass tubing with aluminum is with epoxy or loktite and a press fit. I have made my own T fittings that have held up, and those backplate pressure regulators are done the same way.
PT, the only way I know of to join brass tubing with aluminum is with epoxy or loktite and a press fit. I have made my own T fittings that have held up, and those backplate pressure regulators are done the same way.
Would JB Weld hold it? That stuff usually gets the job done where everything else fails for me.
Tom
08-12-2006, 10:48 AM
#24
RE: As reality sets in....
Ya, that's what I meant when I said epoxy, but JB is probably the best stuff. I have some other stuff similar to JB that is thicker. A hard line in a soft balloon is not a good idea, it will find a way to poke through. why not run a piece of fuel line to the rear of the balloon?
