wascamp

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A pal of mine sent me a Jim Ryan P-47 Kit to build for him. At a 31 inch span it is a lot smaller than I usually build, and being electric it is a real depsrture for me. Ryan designs and produces some very nice lazarcut warbird kits. And this is one of his best. Most of his kits use foam wings but this particular model has builtup wings. The best thing about this kit is that it can be built as either a bubble canopy version or the earlier Razorback variant. I perfer the Razorback and it turns out my pal does too. The kit contains all the parts required to build both versions, including precut skins for the fuselage and both canopies.
I need to get in to Spokane to visit my LHS for goddies and supplies so the build will officialy start tomorrow night.

I will be building the airframe only. I will glass it, and send it to the owner in primer. While not yet a builder he is capable of painting and finishing the model. He will continue the thread to completion and test flight. One reason I am building it is that this is not a kit for the novis builder. In a rare case of honesty, Jim told him that it was not a kit for the first timer. Its not that it is overly complex, on the contrary it is pretty simple. But it does require some skills not usually found in the first timers skill set. The whole airframe is glassed with the exception if the tail feathes which we will do in silkspan and dope. Ryan designed the Jug for a geared 400 motor but the owner wants to use a brushless motor that weighs a lot less. In order to be sure she will balance I want the aft section to be as light as possable as I want to add a few scale details.

In a departure for most small electrics Ryan designs his planes with ailerons rather than rudder control. He provides a servo tray that will take the rudder servo so we will build the optional rudder for a full 3 axis airplane. This little plane is a real gem and I think we can have some fun with this build. As always, I welcome any tips and or comments as we go along.

See you tomorrow night with the first days photos.

alienx

Looking forward to this one. Those finished planes on the Ryan site all look beautiful to me. Ah, but then so do most of the planes I see in here. Good building!!!

wascamp

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Hey guys, I'm sorry for the delay. I was very late returning from Spokane last night adn returned to a very stressful situation. While I was gone my wife was the victim of a home invasion. She was in the basement and heard the guy upstairs. She called 911 and confronted the crook with a .357 Mag. He took off and she stayed in the house till the cops arrived. She was not hurt but it shook her up. Needless to say I had to stay with her so the shop remained dark last night.

Those of you who have built a Ryan kit know about the fuselage crutch. for the rest I will explain the process of building the fuselage.
The fuselage formers are mounted on a crutch that aligns them in the proper location. Each former has a slot that fits on a corresponding notch on the crutch. The formers are not glued to the crutch as it is removed after the fuselage is sheeted. This makes it very easy to build a straight fuselage assembly. One trick I use is to rub a candle or crayon along the edges of the crutch to allow the formers to slid down onto their stops. Once the formers are aligned 3/32 X1/8 stringers are glued into notches in the formers at eight locations from nose to tail. Very simple.

I'll post some photos tomorrow that will make this process more clear. I may need to pull the crutch prior to compleatly skinning the fuselage because I will need to install a new motor mounting plate. Our motor is a rear mount model and the plane was designed around a front mount type. I will need to build a new former to fit a little farther aft. Once the mount is installed the skinning can proceed.

Go Huskies!!!

F-16WpnsTech

Sorry to hear about the home invasion...Mr. .357 is the best home/life insurance policy around...sounds like the guy is very lucky to be alive.

I'll be watching this thread with interest, I just received Ryan's Rare Bear, so I'll need a little know-how in building it...first short kit that I've done.

wascamp

My Feedback: (1)

Things have quieted down so I was able to go out to the shop this morning and work a few hours. I had assembled the formers to the crutch on thursday so all I had to do today was add the stringers. I cut a piece of scrap 1/8 th ply into a 90 degree triangle to use as an alignment tool. This insures that all of the formers are square to the crutch. You can see from the first picture that only two stringers run the intire length of the fuselage per side. I started with the bottom one as it is the longest. The stringers fit like a dream. I layed them in on both sides and starting from the front I made sure each former was fully engaged with the crutch and square. CA at each contact location and they were secured. I glued first one side and then the other at each former nose to tail. After the full length stringers were installed the nose and tail sticks went on. The drawings and instructions make no mention of how far to run the tail stingers past the last former. I cut them long but that is probably not needed. The skins povide a location for the horizontal stab baseplate and a balsa block fits behind the last former to complete the tailcone.

I shotend the motor shaft, installed the prop mount and motor mount so I could locate the firewall. It turns out that the firewall goes in just behind the first former. I have started the firewall/motor mount and will install it after the ship is skined and the crutch removed. One more note. The floor of the battery box must be installed before the upper nose stringers are glued on. You must cut a 1.5 by 4.5 by 1/16 th part from the supplied balsa sheet and glue it to the 2nd, 3rd, and 4th formers. Three pieces of supplied triangle stock are added to strenthin the whole thing. So far the fuselage build is pretty straightforward. The lack of a detailed assembly manual makes this kit a little beyond the average new builder.

Tomorrow we will start the skins.

wascamp

My Feedback: (1)

I started the skining today and will finish it tomorrow. I worked about 3 hours today and you can see it went pretty quickly. This kit was designed using Auto-cad and it shows. The parts fit is supurb. The skins are precut and lay on almost perfectly. I have skinned all but top two pieces and have not had a gap that will require more than a dab of filler.

The skining is pretty easy. I wet each skin with a mixture of water and household amonia, about 75-25 and let it soak for about 5 min. My work bench has a rounded edge so I roll the wood aginst the edge to give the part a little curve. This keeps the wood from resisting once one edge is glued to the stringer. The plans call for the skin to be fit and glued from the center. This works, but I like to align the part to the lower stringer, pin it at the forward lower end and work my way aft. I glue the lower edge to the stringer fo its whole length. Wet 1/16th balsa is quite flexable and it is easy to pull and push it into a tight joint along the stringer. I glue from the backside and pin in place till the CA has set. At this point remove the pins. You will be handling the plane and you dont wnt to snag a pin as it can damage the skin. Speaking of pins, I use very small pins. T-pins are a little too big and you risk splitting the stringers, plus they leave largwe holes in the skin. The smal gauge pins leave almost no hole. The balsa closes over the puncture and the hole all but disappears.

Most of the skins are glued from the inside. Once one edge is set I press the skin to the formers and glue to the top stringer. It is easy to hold the skin to two or even three formers at a time and wick some thin CA at the former/skin joint. Just be careful with your fingers that you don't press too hard on the structure around the work area. These stringers and formers are quite thin and won't take a lot of pressure.

As during the stringer installation, I skin in the same order. Left side part and then right side part. I put the middle skin on both sides and then the upper skin, followed by the lower. The only trimming I have had to do was on the bottom skins along the joint. I will do the last two skins tomorrow as they are the ones that make up the razorback portion and have compound curves.

PS. The last picture is my assistant shop foreman. Please excuse the dirty jeans, we had just come in from cutting firewood.

alienx

It's already looking really good! I love the lines of the razorback, even though it isn't even skinned yet!!

PS. That's a really nice looking helper you've got there. He's got huge paws.

wascamp

My Feedback: (1)

Ok, the easy work is done. I fit the last two skins and we now have a razorback. The skins on the belly extend only to the last former so a balsa block must be shaped to complete the lower fuselage. I located the tail block, marked the outline with a thick pencil line. Cut to shape with a coping saw staying outside the line. The plans tell you to tack glue the block on while you carve and sand it to shape. You then remove the block and hollow it out. A drumal with a ball mill makes short work of it. Glue it back on and finish sanding it to match the body conture. At this point you can pull the crutch. You can pull it if you havn't gotten any CA between the crutch and a former or two. Luckily I only glued one former to the crutch and it was where I could get a knife at it. A little cutting, some tugging and out she came. Well, all the pieces came out anyway. I think I should have used more wax on the contact points.

I worked on the motor mount and got it to fit just right. Some lightening holes will finish it up.

I will set the fuselage aside for a while and build the tail unit. It is a snap but I will be finishing it with dope and silkspan. once the tail is installed there are two more filler blocks to carve to finish off the fuselage. Then we will build the wings.

The shot of the fuselage looking into the interior give you an idea of how much room we have for flight equipment.

alienx

Hey is that the battery tray in the front of picture number 3? If so, how wide is that? I'm wondering if it is wide enough to hold a battery that is 1.375" wide. It looks like there is a ton of room to slide the battery forward towards the firewall, and still get your fingers in to strap it to the tray with velcro??? I think that should be a big help in getting the plane balanced with the smaller, lighter motor.

Nice work!!

wascamp

My Feedback: (1)

Alianx, Yup. That is the floor, or roof if you will of the battery tray. It is 1.5 inches by 4.5 inches. There is nothing in front of it till you hit the motor mounting former. You could stuff the battery right up against the motor. Or move it back almost to the servos. I think the reciever must go in there though.

I'm going to take a day or two off from the build. I have come down with a cold and there is too much Football tomorrow to let me get out in the shop. I promise to get hot on the build Friday. See you all then.

alienx

That's just the right size! It almost looks like the esc and receiver could go on opposite sides of the battery tray. Either way, that long battery tray has to be a good thing for balancing anyway!

Have a good Thanksgiving!

wascamp

My Feedback: (1)

The plans show the ESC in the first bay forward of the wing. I guess that way you can hook everthing up with the ESC between the motor and the battery. I will glue some velcro to the battery tray and the owner/pilot can put his stuff were he wants it. Not being an electric flyer I have no prefference for componant location. What little I have read about it though aI know that you want to secure the ESC to something so it does not vibrate and come unplugged. Of course we wnt thigs to stay in place so the balance does not change in flight.

alienx

That seems like a good idea for the ESC. In all my other planes I have to wedge it up as close to the motor as possible to help balance the plane. It's also good to keep it away from the receiver too. At least this Ryan P47 was designed around a bigger, heavier battery. I think that will be a tremendous help when the flight system goes in! A small lipo will add some needed flexibility.

Off to get some turkey! Happy Thanksgiving everyone.

wascamp

My Feedback: (1)

Last week I said I was going to take a couple of days off. That's what I did but I'm back at it now. The fuselage is done with the excepton of the tail. I put the first coat of lite filler on the joints and small dings. Man you have to be careful sanding 1/16 th sheeting! It will break with any pressure at all. I started to carve the cowl but had to put that aside untill the hardware for the motor mount arrived. The package from Tower came friday but I had to go pick it up in town today. I finished the motor mount and installed it tonight. I got a bunch of brand new #11 blades so I was able to cut out one of the wing skins. The wings are built flat over the plans. The bottom skin lays down first. The main spar and ribs are assembled on it. Once the structure is glued to the skin the whole thing is unpined. A washout shim is inserted unted it at the trailing edge and the top skin is glued down. I was going to post some pictures tonight but it got too cold out in the shop. I was forced to come in. It is +2 degrees F. and even with the woodstove going it's a little tough to heat 56,600 cu ft. I will have to go out several times tonight and stoke the fire to keep my glues from freezing. Fotos tomorrow when it warms up.[&:]

wascamp

My Feedback: (1)

Sorry fellows, but this build is going to have to wait a few days. Our high temp today was 5 degrees F. I kept the fire going all day but never got the shop much above freezing. I could only work for 15 or 20 miniutes at a time because my hands started to freeze. I even hung a large tarp to close off the shop bay from the rest of the garage. It helped, but just barely. I mounted the cowl block and sawed, carved and sanded it to shape. I glued up the remaining wing skin sheets so they will be ready to cut out when I can feel my hands again. If anyone is interested I can explaine the process of shaping the cowl. This build reminds me of the old Royal kits. With having to carve the tail block, some fillers at the horizontal/vertical stab joint, the wing tips, and the cowl you end up with more chips and dust than wood on the plane. I like it! With all of the formed plastic and fiberglass parts now the art of shaping balsa is becoming a lost art. Shaping the parts by hand relies more on the eye and feel than any technical skill. You basically take off everything that does not look like an airplane. When it is almost perfect, you stop. Sure as heck, you will take off too much if you try for "perfect". At least that is my experiance. I promis to go out tomorrow and shoot some pictures of the progress so far. Such as it is!

alienx

I've seen you're weather on the TV. It looks pretty extreme!!!

I would be interested in how you shape the cowl. I've seen the square block of wood that comes in these kits. I would say that that alone would almost be a deal breaker for me. I was wondering if there was some trick to it, or if you just have to have a bit of artist in you.

wascamp

My Feedback: (1)

Ok, since you asked, here is how to carve a cow block. In the kit you get an endgrain balsa block and a very thin ply former, F-!. On the plan you will find a representation of the block with the former located on it. See first image. The first thing to do is extend the centerlines out beyond the outline of the block. Draw them directly on the plan. Lay the block on the plan and mark the centerines on the edges of the block with a soft pincil or ballpoint. Use a carrpenters square to mark the lines on the edges and both the top and bottom of the block.
On the fuselage locate the horizontale and vertical centerlines of the first former. Mark the lines on the outside of the skin. I use a pen to make a small line at each point. You will find that on this plane the lines hit the middle of the stringers. Now locate the ply former F-1 on the block. The lines you have drawn on the block will help you place it so it replicates the plans. You can use CA to fix it to the block, but I like to use Tightbond Trim glue as it has a high tackynes and drys quickly. F-1 is not a structural member, it serves as a sanding guide. When the former has dried you can cut out the inner shape. In this case I had a hole saw that was an almost perfect fit for the upper radius. The lower radius can be removed with any toos that you have at hand. I rough it out and finnish with a piece of sandpaper around a dowel or tool handle. Take your time. Sand, look, sand some more, look.......Endgrain balsa will sand away to nothing faster than you would believe.
Locate the block to the front of the fuselage (F-2)Line up the centerlines with the tick marks you made on the fuselage that correspond to the fuselage centerlines. Before you glue the block on, mark the outline of the fuselage on the back of the block with a pencil. This line will be your rough cut line. Align the block and glue it to the front former. I use med CA to stick it on and then weep thin CA between the parts to hold it in place.

When your glue has set place the fuselage on the work bench with the nose down. Take a wide razor saw and cut down thru the block. You will be sawing with the grain staying just outside the line you drew around the fuselage. You will take big pieces at first and then smaller ones as the cown takes shape. Once you have taken all the material you can with the saw it is time to sand. I use a t-bar sander with 100 grit paper to do the initial shaping. !00 will cut very fast so only sand to the rough line. Try to sand with the grain and only cross the fuselage/cowl joint at 45 degrees. Switch to 150 grit paper to do the final shaping. You an hand sand at this point if you are gentle. Refer to the side and top views on the plan for the shape. It helps to have some photos of the real plane to help get the shape close. Sand the nose lip contour down to the edge of F-1. When you think you are almost there, Quit. The final shaping will come as you final sand the fuselage prior to covering. For that operation I use 200, 220, and 250 grit. You always want a little excess material so that final sanding does not take the shape too far. You can always sand some off, but it is tough to put some back on.

Take a look at the photos and see if I got close to the desired shape.

alienx

Roger,

She's looking really good. I'm glad you wanted to do this build. It's beyond me. I love the motor mount former too. Should be the simplest mount off all the planes I own. Especially with the blind nuts.

Thanks for the pics and explanation.

Andy

PS. I've been moving for the last two days. But not before sneaking out yesterday morning to get 4 flights on one of my P47's. What a great morning. And now I am settled in to a new place, so I can finally get back to spending money I don't have on planes I always wanted!!! I have a nice little dining room in the new place that is going to be converted into a hanger ...

Tripower455

My Feedback: (2)

The Ryan kits are great flyers....

They were designed around direct drive 6 volt speed 400 motors and nicd. I have been flying my Bearcat for over a year with a Mega 16-15-6 brushless, APC 7-5E, CC Phx 25 and TP 2100 lipos. It goes like stink and will run for over 35 minutes on that battery at 14-16 amps. You could probably use a 7 turn Mega and get even longer flight times..


The only CG issues I've had was when I tried to use a lighter battery, and I couldn't get enough weight forward and with the CG neutral, it was very snappy. The 2100 balances it nicely.

alienx

I love that plane too. It would have been my second choice.

What's your AUW with that 2100? I'm curious because I have no idea where we are going to come out with this P47. I hope to be under the 18 oz Jim targets, but we are adding a rudder.

How do you feel the heavy battery does inside a small airframe like this? I wonder if it is too stressful?

Tripower455

My Feedback: (2)

I am at 21 oz with the 2100 battery. I also have active rudder and wouldn't get rid of it to save any weight.

No issues whatsoever with that battery. I yank mine around like there's no tomorrow, and have had NO issues in uncounted flights. I did put some triangle stock around the battery mount. I can't remember if mine is stock or not, but my battery stick is a piece of 1/16" lite ply with velcro on it, and a double sided velcro "seat belt" that goes around the battery and stick.

The airframe was designed around heavy nicds, so it really isn't any heavier with a 2100 lipo than it would be with a 1500 nicd.

Mine is covered in Ultracote, and I don't think it could be made much lighter. My next one will be glassed and painted, but it's reallly easy to add a lot of weight that way.

It is definitely not a trainer, but it flies well at 21 oz. Tracks like a pattern ship......

The motor setup I am using is absolutely idiot proof. It hand launches nicely, I have a nice amp cushion and it is an animal.


I was using a 5 turn to begin with and the amp draw was around 22-24 with the 7-5E and 3s lipo. I ended up burning up an ESC (with subsequent loss of control..... ParkBECs are in all of my high draw applications now), and the airplane crashed right on the prop nut from 100' up! It took about 2 hours to repair it and I've been flying it every time I go to the field ever since. These things are very rugged.


Oh, and make sure that you make some cooling exit holes. I made 2 oval holes on the bottom of the fuse under the horizontal stab. I also added some holes in the motor mount to let air in to cool the motor and esc. The P-47 has the scoop under the motor, so you probably don't need any more inlet air, but definitely make some good sized exhaust holes.

alienx

She looks great. 21 oz is definitely a little higher than I hope for. I can live with about 18oz I guess. Even that seems a little bloated for a 31" span. My battery is about 2.3 oz lighter than yours probably is, so that should get the P47 down to at least about 18.5oz anyway. Maybe another half ounce for the motor (got a 400 XT going in this one). It's not going to be a rocket be any means, but it should make about 110-120 watts per pound.

Your covering came out very nice. I like the plane! Where did you get the star and bars decals?

wascamp

My Feedback: (1)

Tripower455,

She is coming along nicely. I have the wings sheeted and am shaping the tips now. I shot some pictures and will post them after dinner. Thanks for the tip on the exhaust holes. I think there is plenty of inlet area in the cowl, but no outlet yet. I had planned to mock up the turbocharger intercooler outlets in the aft fuselage but now I may have to make them functional. I hate to just open up the fuselage in the tail area. On the real plane there are oil cooler outlets just forward of the wing but I dont' know if I need to open them or not. I think they would let the cool air out rather than the heated air. If we put the ESC in the bay just forward of the wing they might work to cool it though. I'll need to think about that. Buy the way, that is a very nice looking F-8 F.

Tripower455

My Feedback: (2)

The 18 oz that Jim Ryan recommends is with no rudder and a 6 volt speed 400. I still think it would be hard to get one that light.

The problem with a lighter battery is that you will probably not get it far enough forward to balance. My TP2100 weighs around 4.5 oz, and I tried a Tanic 1550 which was about 1.5 oz lighter, and had major aft cg issues. I would have had to add weight to get it to balance. Other than it being a lot more snappy, the difference in weight was not noticeable in the air. If you are going lighter than a Mega, you are definitely gonna have to add some nose weight to balance, OR lighten the tail a bit. The rudder isn't gonna help in this respect.

Thanks! It doesn't look that good any more after a year of combat! I was going to strip it and glass and paint it, but I enjoy having such a low hassle, throw it in the car with the rest of the planes, fun to fly ship!




I got the decals from Guillows. Real cheap. I bought a whole stack of them for around $15.

Tripower455

My Feedback: (2)

My ESC is right behind the firewall, in the airflow created by the holes I put in the firewall. You also have to get some airflow over the battery too, as mine got kind of hot before I put the exhaust holes in it.

There are some cool scale openings in the aft part of the fuse that you could make functional on the P47. You want them behind the battery, and you want about twice the outlet opening as inlet for best flow.

The Bearcat is very clean, so I decided to just cut holes in it. They aren't obvious in flight though. It does make a nice whistle on high speed passes!