1/2 scale Sopwith Tripehound

ProfLooney · 13 January 2010, 09:44 PM

Step 3: Label your part to make it easy. I label the bottom layer as "A" the middle layer as "B" and the top layer as "C"

after you do all the uprights for the bottom layer you want to repeat the process once more to give you the top layer.

Note: you can just use a butt joint on the top and bottom longerons as it will be a lamination so will be a strong joint.
Secondly your center layer will be different from the middle layer so be sure you only make the top and bottom uprights.

As soon as I do the next part and take pics will show you how to do the center layer which is just as easy. then we will add some glue and jig it all together with wire staples.

This same technique can be done with any regular WWI plane that used the sq longeron method.

1/2 scale is 1/2" wide strips, 1/3 scale is 3/8" strips, and 1/4 scale is 1/4" strips. you can use 1/8" thick strips for the 1/3rd and 1/2 scale and 3/32 for the 1/4 scale or if you like you can use 1/8th. it may not be 100" scale but it will be bulletproof and weigh the same as if you used sqware stock just stronger.

ProfLooney · 13 January 2010, 09:45 PM

ok I got a couple emails from some younger guys asking what a mortise and tenon joint is so I think I better explain it for the youngsters out there.

in the beginning there was no glue and was no nails. so the millwrights of the old days which were the jack of all trades in those days and did everything for the community, had to put buildings and furniture and everything else together without the glories of glue or nails.

so lets say they were putting a building up.

they would have the large beam running across the ceiling to hold up boards etc to put their grass roofs on. Well you cannot just sit the beam up there on top of posts, so what they did was cut a square or rectangular notch in the beam. then they wouldtrim the upright beam so that it fit super tightly into that notch usually needing beaten on. that is a basic description of a mortise and tenon joint. Usually they would then drill a hole in the side of the beam and all the way through the joint and pound a peg into the hole to act as a nail. they would then douse it with water which caused the wood to swell and there was no way you were getting that joint apart.

we are creating the same thing here. but instead of the tedious job of cutting into our longerons several rectangles and trimming our uprights we are doing it as a lamination. the bottom uprights fit inside the longerons, the middle layer go across the longeron which strengthens the connection of the first upright which is butted to the longerons. then the third layer is the same as the first.

this means that every joint connecting the uprights to the longerons is reinforced and when complete with withstand literally tons of force before it gives. Actually the wood will break before the joint and being laminated means that in a crash you probably wont do any dmg to the fuse unless you really brought it in hard.

and that kiddies is the very basics of a mortise and tenon joint. if you look around the house a lot of cabinets and wood furniture is still jointed in this way as it is the best joint out there.

ProfLooney · 13 January 2010, 09:47 PM

ok after doing the grocery thing with wifey poo today I was able to continue on the fuse.

When we left off I had shown how to set up the first layer and the last layer, so we will start with the middle layer.

for the middle layer we want to go the entire width of the longerons. What we do here is to lift the top longeron this time and the bottom and slide our upright under BOTH of them until it butts against our shelf frame. as you can see in the first shot this upright is where the longeron joint for the top is located. so what the middle layer will be doing is acting as a backing for the longeron joints. on a smaller plane you can stagger all the joints if you want and is a good idea, however if you noticed my building board is 8 ft long and 3 ft wide and the fuse barely makes it on there. so I am just using 2 sticks 48" long and since everything is laminated I am not worried. especially since the cross members will be jointed into the longerons similar to the bottom with the only difference being that we will only go through the last lamination instead of the entire thickness.

So back to the subject at hand. Once you slide the upright under the longerons, you mark it to the outside edge of the lower longeron. this way it will go full length.

ProfLooney · 13 January 2010, 09:48 PM

Now here are the clips I use as clamps so that i can pull everything tight against the building board. these are 1/2" and will cover all models. That being said I should have went with the 3/4" wide ones as they come in 1/4, 3/8, 1/2, 3/4, and 1" wide. but like I said if you get the 1/2" unless you doing a 1/2 scale plane you can use them for any plane and 100 of them only cost me 2 dollars and 50 cents.

ProfLooney · 13 January 2010, 09:51 PM

in the next 2 pics you can see I have the middle layer uprights in place and you can see how I use the clips to evenly clamp the uprights down.

ProfLooney · 13 January 2010, 09:53 PM

Now after the uprights are done we do the longerons. These have to fit in between the uprights so the best thing to do is use the process we used for the uprights. so I slide my longerons in place underneath all the middle uprights and mark them. once marked be sure you put some kind of marking or whatever onthe longerons so you know which order they go in place.

ProfLooney · 13 January 2010, 09:58 PM

Ok the next photos show the finished product with the top layer added. on the end shot you can see the little gaps between the layers and that is what the white clamps will bring tightly together. I have them on the uprights but have to add them on the lower longeron, I will put lead weights I have on the top longeron due to the Jig.

ProfLooney · 13 January 2010, 09:59 PM

Now I have both sides prepped and will take a couple days to get both sides glued up due to the slow drying time of wood glues

'14-'18aviationcollector · 13 January 2010, 10:35 PM

Quote:

Originally Posted by ProfLooney

Well I got back from dads with his draw knife.

For those of you youngsters scratching yer heads wondering what a draw knife is, the first pic is of an old belguim draw knife dad let me borrow.

The cool thing about using a draw knife on these struts is that more than likely thats what the craftsmen used to shape the struts on the original airplane.

As you can see a draw knife is basically an 8 inch wide hand plane but uses 2 handles to "Draw" it to you and makes for some really nice curly cues hehehe

As you can see from the second picture I got the shape pretty close just need to spend some time hand sanding the edges in so that they are all even. From the end view it looks thicker than it actually is.

For the most part it is a knife edge but I didnt want to go all the way to the end and chance taking a large hunk out

Hi Joe,

What an absolutely fantastic project!

I have some photographs taken at the Waring and Guillows furniture factory at Hammersmith, London. They built DH9's, and might have built other aeroplanes, I don't know. The struts seem to have been shaped on a jointer, which makes sense because it would have been a very quick method for shaping the streamlined section. Draw knives were used on aeroplanes though, particularly on propellors. I have observed some marks on the original Fokker D.VIII propellor which I think were made with a draw knife. I love to find original items in original condition. If this particular propellor had been restored, the marks would not be there to be seen.

Regards and congratulations on a very inspiring project!

David.

ProfLooney · 13 January 2010, 11:07 PM

thanks David. I have a lot more work to do on them and might redo them as I got some gouges in them from where the wood pulled a strand out where it was a lot harder than the reast so peeled a strip out. but I can use them for a jig and to make my fittings. I just got up from the basement shop where I glued the first side together. I still have to do the laser parts tomorrow since i got too busy with shopping etc today and i have the struts set up to be laser vut and laminated together so prob have them cut with the rest of the fuse parts just so I make sure the kit all fits etc.

since this is a prototype got a lot of reworking here and there til I am satisfied as I want it to look perfect when done as it will be going to a museum when finished after ive taken it around and done some flying with it. As the museum wanted a flying model.

I have another museum in texas wants a 1/8th scale ford trimotor so they can do Byrds polar trip version, but I only need to do the plans for that as they are going to build it.