Jim Henley

Found it, the number is fairly well obliterated all I can make out for sure is 3 and 2 the first and last numbers the others could be one's or seven.

Stickbuilder

Well, Good news, and bad news. Between F-5B, F-6B, F-7B, I have been able to reduce the weight of the parts by a whopping 2.25 ounces. The bad news is, I had to make the firewall which becomes F-4B. This is made from 5/16" aircraft ply. The original piece (with the tank access cutout was 1.0 oz. The new F-4B weighs exactly 3.0 oz for a gross weight gain of 2.0 oz. So, all that work to save .25 oz. On the up side, if I had not done it, the plane would already be 4.25 oz heavier than it is now, including the new F-4B. That's over 1/4 pound. I'm happy. [8D]

Bill, AMA 4720
WACO Brotherhood #1

WacoOne

My Feedback: (3)

Bill

What happens to the 1" thick nose block (F2) when you add the 5/16" ply firewall? Is it eleminated? I've never been able to understand exactly how you do this conversion.

I already had my fuse built per the plans when I decided to cut off the beam mounts and use an FT-160. I need to modify it some how and would like to hear more details on how you do it.

Bill Hogue
WACO Brotherhood #21

mobyal

Stickbuilder Bill --
Looks like the good news here is not so much the weight (1/4 oz) you've saved so far, but that the weight distribution has changed. In other words, though you've added 2 oz weight back to the fuselage it's in front of the cg, if I'm visualizing it correctly. So not only have you saved the total of 4+ oz you noted, but you're not gonna have to add as much nose weight as might otherwise be necessary.

Bill H --
And re the constructed fuse w/ the beam mounts cut off, that's exactly what I did w/ the 1/6 scale I built years ago. I simply epoxied a 1/4 piece of ply on the front end, cut it to provide a passageway for the fuel lines, and bolted my mount to it. Can't remember whether I needed spacers behind the mount or not. Worked great and it wasn't very hard to do.

Stickbuilder

The new firewall replaces F-4B. The Balsa cowl ring still goes in place, and you can make/purchase standoffs to mount the engine. You could probably leave the center cutout in the balsa cowl ring in place, since the wood is so hard. The reason for the heavier F-4B is to be able to safely mount the engine to this piece rather than trusting the 1/8" light ply unit that is furnished with the kit.

Mobyal,

You need to read the post again. If I had simply recut F-4B and used it, there would have been a 4.25 oz weight penalty (if I had not put the other formers on a diet). Using the O.S. 160 twin, you don't have to add lead to the nose. You do, however need to be fairly judicious in mounting the servo's and flight battery. I am also making a new F-14B to be able to mount a scale tailwheel, and need to save every gram forward of the C/G. I would like this one to be as light as safely possible (keyword is safely), remember, lighter flys better, and as Dick Pettit says, "A heavy airplane just makes a deeper hole in the ground when it crashes."

As I said, the net weight saving so far is .25 oz with the heavier parts figured into the equation. That weight so far is ahead of the C/G. Also part of the formers around the fuel tank box will be removed, in order to be able to have a larger fuel tank, and to make the tank accessible from the wing saddle opening.

One other area that will be beefier, is the landing gear mounting, and there will be a working shock absorber with this one. Before, the model is prone to bounce on landings, since the gear is very ridgid.

Bill, AMA 4720
WACO Brotherhood #1

damifino

Forgive me for being such alate entry in this thread. I'm sure you guys have covered the answers to my question(s) through this thread but maybe you could briefly re-cap for me?

If I buy the 72" plans from AMA, will you be able to supply all the stock parts' outlines and instructions (PICA's) via this thread or other means? I am watching with interest your mods and improvements. I've only seen, in person, one 1/5 size PICA WACO and it was built, years ago, according to the plans. My building skills are up to the task of a project such as this and I'd like to make it happen. Thanks.

Stickbuilder

To be brief, I am currently in the process of cutting one, and am copying the parts. When I am done, I will make the tracings of the parts and the callout for the sticks and sheeting available at no cost. Please allow me some time, as these parts do not just fall out of the sheet. They are die crunched, and must be cut carefully so that they will be usable to everyone.

Bill, AMA 4720
WACO Brotherhood #1

pimmnz

Master Stickbuilder, If I may be so bold, but as you are attempting to loose weight at the front, and trying proper legs for the old girl, then you can actually make the U/C mounts much lighter cause the shock loadings will be much less with the springy legs...Beefing up is not required, just a few sticks to distribute the load around the structure...
Evan, WB#12.

WacoOne

My Feedback: (3)

Bill: You say that the new firewall replaces F-4B. (I can't figure out how to do a quote here) Now I understand what you are talking about. Thanks for the clarification. However, my fuse is already built per the plans so I can't replace F-4B without tearing the whole nose section apart. I think I read in one of your earlier posts that you epoxied a 1/4" ply to the original F-1 and bolted the engine mount to that. Is this an alternative way to do it? I'm wondering if I can do this if I can get some blind nuts behind F-4B. What do you think?

Bill Hogue
WACO Brotherhood #21

Stickbuilder

Bill,

You are a little far along to replace F-4B, with a heavier firewall. If you do not have the cowl ring on yet (the 1" thick Balsa thingie), then stand the fuse on it's nose and trace around the circumference of the fulelage. Transfer that to a piece of 1/4" ply, and dut it out. Sand it to a near perfect size. and epoxy and pin it to the existing F-4 structure. Bolt it together with at least 4 bolts equally spaced around the structure. Then drill for the engine and mount it in the conventional manner. I do not like Blind nuts, since they can strip, and you are in deep doo-doo at that point. You will probably need to remove the rear of the tank box and convert the tank to a tail loader. This means that you will need to cut away part of F-7B to gain access. You can use a tie bar from ply to restore the strength to the former (Bolt it in place)

If you have the Cowl ring already in place, consider routing the center out, and adding the 1/4" piece to the firewall, and use standoffs to get the distance that you need.

Bill, AMA 4720
WACO Brotherhood #1

Stickbuilder

Evan, in addition to the springy L/G legs, I am going to Bungee the center support, using a spring, and plunger arrangement to the inside of the fuselage, where it will be supported by a plate laminated from ply, and glassed to the fuse bottom. I am changing the bottom front stringer to 5/16" spruce, to help bear the load. The shock load area will be triangulated to spread the stress loads evenly to the Fuselage. The tailwheel will be a plunger type, shock dampened unit as well.

Bill, AMA 4720
WACO Brotherhood #1

damifino

Thanks Stickbuilder. I'll keep up with this thread. Are you going to post them as you do 'em or all at once? I'm in no hurry because I've got this to finish- A Sig Hog Bipe modified into a Der Jager, presenting for your amusement, der Hog Fokker................

Stickbuilder

I haven't considered how I want to do it yet. I may post all the pictures of this Fokker at once , or I may actually do them a few at a time. At any rate the WACO parts will be posted in a format that will keep the size correct.

Bill, AMA 4720
WACO Brotherhood #1

damifino

I made a pair of plunger type dampners for some wing mounted, fixed landing gear legs on a plane that had a nasty habit of punching holes in the covering with the wheel pants. It was a .40 size Super Sportster so tubing sizes are relative. The outer 'housing' of the dampner was 6061 aluminum tubing of about 3/16" ID, the plunger was stainless steel tubing that telescoped freely in the aluminum housing. The dampning component was a piece of rubber O-ring material approx. .070 diameter X 3/4" long inserted into the body ahead of the plunger. The whole unit was about 4 1/2" long. Made landings and take-off runs very smooth and predictable, she was a squirrel before. I slipped a small O-ring over one of the plungers as a travel indicator and saw 1/2 to 5/8" of travel. That was with about 3/32" of pre-load on the rubber. Worked like a charm.

skylarkmk1

damifino,

Could you possibly post a diagram of your damping set up? Inquiring minds want to know . Thanks

Stickbuilder

Happy camper here. I finished cutting all the bottom formers, and using the standard formers and weighing them all prior to any weight reduction, they weighed 13.5 oz. After putting the formers that I kept from the kit, and performing the lightening regimen, and adding F-4B from 5/16" plywood, and F-1 from 5/16" ply, and replacing F-14B from 5/16" ply (for the tailwheel mount). The total weight for all the bottom formers is 10.0 oz. That is a whopping 3.5 oz reduction in total weight, and I now have the formers that are strong enough to mount up to a 40cc Gasser. With the further reductions, and eliminating the Maple engine bearers, I should be able to reduce the fuselage weight by 10 to 12 ounces.

The tail group will be stickbuilt, and the Horizontal Stabilizer will be 2 piece, which will appear to be more scale like. I am going to use a hardwood tail post, which will extend forward at the top to house a tube that will allow the stabilizer pivot tube to be epoxied into position. The H-stab will use a tubular joiner front and rear. The rear joiner tube will be a slip fit through the locator tube in the fuselage, which will act as the stabilizer pivot. The forward tube will free float within it's track in the top of the fuse, and extend slightly into the V-stab. There will be a threaded trunion silver soldered to the forward tube. A capscrew will go through a threaded hardwood Boss mounted to a sub-former at F-13B (rear) and will utilize a jam-nut to lock the capscrew. The Horizontal stabilizer will appear more scale-like and will have the ability to have the incidence adjusted through a small hole in the bottom of the plane. I will probably install a small hinged spring loaded hatch to cover the hole.

I am extremely happy with the amount of weight reduction that I have been able to accomplish, and the knowledge that I have been able to facillitate the stronger mounting system for the Engine and undercarriage while reducing the overall weight of the airframe, and not sacrificing the appearance of the plane in any negative manner.

I will explain the plunger shock absorbtion system that I will be using in the next post. The hour grows late, and I am tired tonight. Talk with you guys tomorrow.

Bill, AMA 4720
WACO Brotherhood #1

damifino

I'll take a picture of them if I can find 'em. Or sketch it out. Don't want to muddy up STICKBUILDER's fine thread unless it's WACO related. I'll leave that up to you guys. I'll be glad to PM you though. You Fokkers have a good night.

skylarkmk1

damifino,

PM or email me ([email protected]) if you don't want to clutter up Stickbuilders thread. Thanks

Stickbuilder

You don't have to worry about muddying anything up. This is good information, and can be used by all. THIS IS NOT STICKBUILDER'S THREAD. THIS IS EVERYONE'S THREAD THAT LOVES WACO'S!!!!!

Bill, AMA 4720
WACO Brotherhood #1

Skinny Bob

My Feedback: (12)

damifino, please post your pics or drawings here. I'm sure a lot of us would like to see them.

Thanks

ClayH

Motor recommendations for the 1/5 scale Pico YMF

Has anyone run the OS 120FT twin four stroke in this plane. It's the same size as the current 160FT but 15% less power. My airframe weighs 10.5 lbs minus motor, receiver, and fuel tank.

Also, I've noticed recently on a few older 1/5 scale Wacos that they had damage to the upper wing at the rib joint where the center section sheeting stops. Is there something in the wing spars that would create a stress riser at that point?

Thanks,

Clay
Waco Brotherhood #18

khodges

My Feedback: (1)

Squeeeel like a pig. Boy, it's shore got a purty nose cone

WacoNut

Nice thread Bill,
Thought I would stop in and say hi I have always liked the WACO and may have to put one on my build list after finishing my Ziroli Stearman 87" and my next build after that will be a Ziroli P-40. I will be looking you up if and when I get around to a WACO.
Anthony

Stickbuilder

The problem in the wing to center section junction, is that the spar joiners are little bitty pieces of 1/8th ply that are about 3/8" high and 1" long from the center out. I always recut mine and go out at least 3 rib bays in the wing, and butt them together in the center section with a doubler overlaid. No problems.

CubNut,

When you want one, let me know, and I will see that you get a set of prints for the parts, and you can get your plans from AMA.

Bill, AMA 4720
WACO Brotherhood #1

Stickbuilder

Clay,

The 160 weighs 39 ounces, and I would suspect that the 120 twin has the same weight. The 120 twin should have about the same power as the OS 91 Surpass, so you should be okay there. It won't get in a big hurry, but I think you will be safe with it.

Bill, AMA 4720
WACO Brotherhood #1