Re: Snip 1/2A Combat plan

getback Tue Mar 17, 2020 6:32 am

batjac wrote:I love the old diamond ribs. You can build the whole wing on a flat surface in just a few minutes using CA. I may have to build one of these really quick, even though I have far too many planes as it is. Be a good way to use up some of the scrap wood I have overflowing everywhere. I saved the pics and will print them out with Tile Print tonight.

The Weak Mark

Mark have you flown this plane yet / built it Very Happy

batjac Thu Apr 02, 2020 7:23 pm

Sorry, Eric. Had too many projects that needed attention to get to this. Once I got some of the other stuff done, I made some time for this.

I had the plans printed out to size and cut out the rib templates. I thought about using the scroll saw for the ribs, but since there were only a few I decided to do them by hand, the way that a kid reading the magazine in the early 70’s would do it. I used a glue stick to stick the templates to some scrap 1/8” light ply and cut them out. Then I used some thin CA to harden the edges so the X-Acto knife wouldn’t cut into them when I cut the ribs. I found some pieces of balsa big enough in my scrap pile to make all the ribs.

The engine nacelle is 1¼” wide, so I grabbed a piece of ½” scrap and a piece of ¼” scrap and made a sandwich with the ¼” piece in the middle. I glued the engine nacelle template to this and then shaped it. For time’s sake, I decided to just use power tools, rather than hand form it.

Then I used more…. wait for it…. scrap wood to make the rest of the small parts.

Tonight I’ll look through my longer scrap pieces to find what I need for the spars and L.E./T.E. pieces. A scavenged bellcrank from one of the old 1/2A models I’ve scrapped should complete this.

The Scrappy Doo Mark

batjac Thu Apr 02, 2020 11:45 pm

DARN IT!!!!!!

Looking at the ribs gave me an idea for another plane! I don't have time for this!!!

The Cornucopia Mark

getback Fri Apr 03, 2020 7:34 am

Looking good Mark , it amazing what you can do with the scrapes around the table Wink

andrew Fri Apr 03, 2020 9:44 am

Nice build thread!! Anxiously waiting the next installment.

I use counter laminate for rib templates (since I have a quantity on hand), but your plywood with CA hardened edges is a great idea.

batjac Sat Apr 04, 2020 4:34 am

My birthday treat to myself is that I’d do no cleaning, no chores, and no responsibilities today. Just finishing a book, surfing the internet, working on the plane, and watching The Good, The Bad, and The Ugly.

Looking in the scrap boxes, I had almost everything I’d need to finish. What I didn’t have was the exact spar material. I needed 1/8” x1/4” balsa sticks, which I didn’t have. But I did have a 1/8”x1/2” stick that was long enough, so out came the balsa stripper. If Y’all haven’t got one of these in your tool kit, you should get one. It’s something that I waited entirely too long to acquire.

Then it was just putting it all together. Here’re the L.E/T.E./bottom pieces installed:

And the upper spar installed:

And ready to cover:

The Birthday Suit Mark

getback Sat Apr 04, 2020 9:02 am

Sounds like a day of chilling and Fun , I must say you bhild quickly and precise , and Yes the balsa stripper is a handy tool , i had one for a long time till something came up in building and needed the same pieces you did seen where another person was using one and remembered that i had seen that animal in one the boxes of stuff i acquired , done the trick . Clapping

Ken Cook Sat Apr 04, 2020 9:52 am

One thing that's always a good idea when building combat planes. Make provisions in the outboard wing for bladder. Very simple to do and it will suit other engines if the reedie isn't your cup of tea. Midwest offered and has the compartment shown on the plans. In addition, offering a 1/2" wide strip of lightweight glass cloth and heated epoxy around the ply firewall. Relying on epoxy or glue to hold the ply usually results in the entire engine and ply mount coming off in case of a ground strike. The Kamteknic radial mount works well for TD useage on these applications. Far superior to a Dave Brown mount which does nothing more than vibrate and break.

aspeed Sat Apr 04, 2020 10:06 am

I used the beam mount option in my plane many years ago. The radial mount would allow any motor. Surestart, Bee, TD or Fora? even. By having the bladder compartment, a Bee tank could be drilled out a bit larger than the .082" and some nitro added. (A big hole needs to be drilled in the side of the tank) Surestarts can be filed a bit larger too if you remove the needle assembly first. If you could fit the "little red cap" it might be good. There is a bit less pressure than tubing bladders. At any rate, it is good that someone is actually making one again.

batjac Sat Apr 04, 2020 6:12 pm

Oops! Looking back at the plan, I just realized that I built this wrong. Now I'm not sure if it'll fly at all. The plans state most emphatically, in underlined letters, "Use White glue". I used CA glue. Now I dunnit.

I like running bladders, but I think I'll stick with a stunt tanked Bee for this one. I'm not going to be flying combat, just fun, so a tanked Bee should be just right. Also, I tried a couple of the red caps from Ace in the past. I could never get a leak-proof seal on them. The surgical tubing just works better for me.

The Bare Headed Mark

aspeed Sat Apr 04, 2020 6:21 pm

I hate bladders. I never seem to be fast enough to unclip the line. Takes a few tries and makes it hard to fly alone or at the RC field. I guess I need more practise or make up a switch that can flick quickly. I read somewhere that a toggle switch works but details make it look difficult. The F2D shutoffs are ok, but not for everything. I had a long skinny hard tank in my old Snip that worked well on the TD.

batjac Sat Apr 04, 2020 9:02 pm

aspeed wrote:I hate bladders. I never seem to be fast enough to unclip the line.

I can't unclip it fast enough, either. Watching Rusty's videos made me feel inadequate. It was by accident that I figured out what works for me when I did my bladder fueled Testors pipe bomb engine. Ideally, the bladder is on the inboard side, and the fuel line goes forward and under the fuselage. I have a cheek block that I can pinch the line against with my left forefinger. I clamp the fuel line while filling and when priming. I flip the prop on prime to make sure it's going to fire, then re-prime. I pinch the line against the cheek block on the left side of the plane, and then remove the clamp. Flip the prop, or use a starter spring, and when the engine burps I release my forefinger. The engine will catch, but usually rich, so after a couple of seconds of run time I pinch the fuel tubing again to lean it out and it's ready to go. I've done it with the bladder on the outboard side and pinching with my left thumb, but I feel more secure holding the plane when using my forefinger.

See the following video clip. I didn't do a prime run since I had run the engine a few minutes earlier:

The Slow Fingered Mark

aspeed Sat Apr 04, 2020 9:27 pm

Yours seems sensitive to the needle considering it is a fine thread. There are a lot of combat guys around here. Most of them use the thumb, sort of like your method, or hemostats. I have the leadout connector and slide it. Another guy closes the needle and quickly opens it when it fires up. The F2D shutoff has an arm that can squeeze the line when you let go. Some guys scare me when they hold the plane between their legs and point the plane at their head. I have stiff tubing on my bladders so the thumb method is a bit hard. I guess I should go out and play a bit.

batjac Sat Apr 04, 2020 10:09 pm

aspeed wrote:Yours seems sensitive to the needle considering it is a fine thread.

It was like that with the Testors needle also. Unfortunately, the engine had a very narrow band between blubbery rich shutoff and too lean cut off. Just looking back at my original Testors engine thread, it was 3/4 turn from blubbery to too lean. The band was better with the fine needle, but still only about 1/4 turn in the two-cycle power band. I had considered playing around with drilling out the venturi to see if I could get a wider band, but too many other things interested me more.

The Quickly Distracted Mark

Basswood Sun Apr 05, 2020 8:15 am

Nice thread Mark. Lots of detail. I was just thinking about building a combat plane for one of my new engine builds. I noticed you only used one cent on the outer wing tip. on some kits they recommend two cents,some use a nickel. Is that where the old phrase "Throw in your own two cents" comes from?
Ok maybe I'm over thinking this. Laughing

Basswood

aspeed Sun Apr 05, 2020 8:54 am

I guess we have to use a nickel up here. No more pennies, we just round up to the nearest $.05 on the bill. Oh ya, no more one or two dollar bills either for quite a while.

batjac Sun Apr 05, 2020 12:44 pm

Basswood wrote: I noticed you only used one cent on the outer wing tip. on some kits they recommend two cents,some use a nickel.
Basswood

Actually, I used two cents. I glued one on top and one on bottom of the outboard wingtip. Not enough room for two on top.

The Extravagant Mark

roddie Sun Apr 05, 2020 6:26 pm

aspeed wrote: The tip usually hits the ground on the crashes. We have to use a nickle because we don't use pennies any more.

Regarding U.S. coins/pennies; they are no longer minted in copper. They are minted in lighter-weight aluminum and then copper-anodized. I keep/save odd steel flat-washers to use as possible o/b tip-weights. A tip-weight "box" can be constructed so as to be easily "buttoned-up" at finish.. and easily-accessible for adjustments. Postal scales (consumer-digital) are cheap.. and an accurate way of measuring your model's outboard wingtip-weight.. which is worth notating on the plans.

Here's a 1/2A combat design called the "Whetstone IV"..

aspeed Sun Apr 05, 2020 7:43 pm

I seem to be a charity case for F2D wrecks lately I have been using spruce triangle stock and gussets on the outer tip to repair and strengthen that area and add tip weight at the same time, Previous planes from coroplast I used a couple nails for tip weight. Whatever is around.

Ken Cook Sun Apr 05, 2020 8:25 pm

Alan, I was just given 4 of them. They should've went into the trash. I had to rebuild almost all of the ribs, tips and recover. My son flew one two weeks ago and it had a very minor warp which I can easily iron out. For as bad as they were, it was amazing it flew this well. Foam leading edges had to be rebuilt and I even wrapped the foam back in paper. They're repaired so well the original owner was just in awe. It can be very time consuming, but I find it relaxing at the same time as long as you don't need the planes.

63expert Mon Apr 06, 2020 8:37 am

Having a line pincher mounted to the airframe makes the bladder thing a little easier.

aspeed Mon Apr 06, 2020 11:15 am

I think I have 9 F2D planes now. Using 1 Fora, 1 AP .15, 1 ASP .21, and 1 Ucktkam .15. I need a couple of those slanted motor mounts to run a couple old Rossis or Conquests. I don't have any clear covering, so my planes won't impress anyone, but they are more solid than original. Got a couple 1/2A combats that need some time to get ready. Probably use a Fora .049 and a Norvel. One is a foamy and one is a Russian one. I get the new planes and accessories from Yaro. He is fairly local here. Not sure if there will be any contests this year. I don't fly combat with others, just the racing.

OhBee Mon Apr 06, 2020 3:01 pm

What is F2D?

aspeed Mon Apr 06, 2020 3:12 pm

F2D is the combat class of FAI rules. FAI is the "world" class like AMA. There are speed classes F2A, and racing classes F2C, and free flight and RC classes F1A, F3A B-C-etc https://www.youtube.com/watch?v=N7loHjrssQg

batjac Mon Apr 13, 2020 12:28 am

First off, let me apologize to Aspeed for hijacking his thread. These things happen, Ya know….

I finished this off a couple of days ago, but didn’t have time to take pictures and post this. The yellow covering is the last of some of the new, poor quality MonoKote I had, and the red is something that was in the bottom of the box, but I don’t know exactly what it is. No markings on the roll.

The finished weight is a little more than I was hoping for at 5.25 ounces, but it’ll still zip on an .049. I’m not sure if I’ll stick with this engine. I have a Golden Bee, or I have an anodized red stunt tank I can put on something. Don’t know how I’ll go with this. Maybe I’ll just leave it as is. Who knows. I was right when I said it looks nose heavy. I cut the nose down 1/8” from what the plans said, and it’s still a tad nose heavy. Ah, well. It’s done now.

This is why I like scratch building from old plans. I get a plane that looks like no other. And using scraps helps get rid of the materials laying around. So now that it’s finished, it needs a name. What name for a plane built from leftovers that I scratched from a magazine page? Why, "Scrap ‘N Snip" of course!

The Highwayman Mark

Sponsored content