MarkNovack

My Feedback: (3)

Now that the fin is beveled to final dimensions, the elevator need to be relieved to allow for rudder throw. Mount the stabs and mark the edge of the fin bevel on both stabs.

MarkNovack

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Our false square is still set for the rudder throw, so we can use it to mark our elevator reliefs with perfect accuracy.

MarkNovack

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The line on the left elevator shows the actual place that the rudder will move to. The right shows the relief that the elvators will get. Remember that these relief cuts still need facing. They will get 1.5mm balsa facing.

MarkNovack

My Feedback: (3)

The band saw makes this easy. Only close, the sanding belt will take it the rest of the way.

MarkNovack

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Sand to the line.

MarkNovack

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Notice in the last post that the elevators where sanded together as one. We want our elevators exactly the same size. Now they are ready to be beveled.

MarkNovack

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Again, we make a double bevel here. The less one surafce is beveled, the stronger it is. I will not post a bunch of pics of beveling the elevators and stabs as it is all the same as the rudder. Slowly, checking constantly, and stopping when they are perfect.

After the elevators are beveled, we mount the rudder and elevators and move the control surfaces in all directions to ensure there will be no conflicts in range of motion. Remember to mentally add an extra 1.5mm into the necessary clearance.

Well, here is one airplane empanage set relieved and beveled. That took about 1.5 hours. Now I will take the elevators and face the new root edges. Then we will prepare our hardpoints and the mounting recesses and do the final gluing on the tail pieces.

We shall return shortly with a few more steps today.

Mark

gavoss

My Feedback: (16)

Acroman330, I can answer that question. I purchased a 10" cutter for about $500 ($600 list). The one they are using can cost up to $10K depending on the size. You can get a 36" model for about $2500-3000 + software. The software isn't cheap either, another grand actually. You can cut from something like CorelDraw! but it won't really be what you want or need.

I purchased my cutter as a "demo" model and saved $100. It was used at shows but it came with a new blade and full warranty. I had it for a while and something went haywire with it and they sent me a brand new one under warranty. Needless to say I was a happy camper.

Check out "Stika vinyl cutter" on your favorite search engine. That will give you a list of vinyl cutting machine companies that sell cutters. I've had my 10" model for about 2 years now. I haven't had enough business to pay for the machine, but then again, I don't advertise. The convenience is well worth the cost of admission.

Also, if you have your color scheme already on a computer, check you local sign shop and see what format they need and convert your file as needed. They should cut out your design for very little since you aren't using their material.

Hope that helps. gv

MarkNovack

My Feedback: (3)

The season it coming. These airplanes are not going to build themselves. We kept going with finishing up the gluing steps on the empenage.

The next step after relieving and beveling was to face the new cuts on the root end. A little job, but we properly block the 1.5mm facings to keep them from bowing away from the elevator. They dry in about one hour and then get snading flush with the sheeting. Easy step.

Here they are installed and block taped.

MarkNovack

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These are the horn mounting plate we will be using. Normally they come without the milled recess, but as all of these airplanes will use ZNLine aluminum horns, we use a file that cuts a 1mm depth into the plate that captures the horn nicely. I shall post a few pictures of the 3meter routing table at work on a small job.

MarkNovack

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This table cuts everything from these little parts, to fuselage sides for the 300XL Extra, and even wing parts for Mudry Aviation for their full size CAP aircraft.

MarkNovack

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These are some very nice horns. Specially made to use the MK ball bearing connectors. These screw into the plate with a 5mm wood screw. If that sounds like it's not enough, we have never had one pull out or heard of one pulling out. The plates are aircraft ply.

MarkNovack

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It is actually two 5mm wood screws that hold it to the plate. The plate itself will contact balsa all around for a very strong attachment to the control surface.

MarkNovack

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The number one way to do this job it with the router. It is depth locked at 3mm. The outline of the plate is drawn onto the control surface and the piece is routed out. The corners are then finished by hand and fresh #11 blade.

MarkNovack

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A little work with the knife on the corners and the plate goes in.

MarkNovack

My Feedback: (3)

The same method, routed out to depth. The hardpoint gets a little rounding to fit nicely into it's recess. At the point on the stab where the hardpoint sits is a balsa block. The stab tube is glued into a balsa block under the sheeting. It does not sit directly in styrafoam.

MarkNovack

My Feedback: (3)

OK, if it seems like I skipped something, I will show all in closeups tomorrow.

All of the hardpoints are mounted with 24 hour epoxy and a generous helping of microballoons. I fairly well load the recess with the mixture and let any extra ooze out and wipe it away. I also push the mixture into the foam a bit...I want this to be a very hard mounting. I then clamp it in place with balsa blocks covered with release tape. The epoxy/microballoon mixture will push the plate flush with the sheeting and the whole thing should require little filling with balsa filler.

Here you can see the clamping on the hard points (mounting plates)

Also seen here is the trailing edge. The basla stick you see is NOT the trailing edge, the trailing edge is a .4mm ply strip (1/64th ply). This creates a very ding resistant, durable trailing edge that adds a negligible amount of weight. The balsa strip is necessary to distribute even pressure along the thin strip of ply for a good glue joint. It is also glued on with epoxy. The very thin TE could warp with a water based glue, and CA is a little messy.

When all is dry, I shall get close-ups pf all of these mountings. Still left to do on these surfaces is filling any dings and imperfections, final sanding, and then store them in their saddles until they go to the coverer.

MarkNovack

My Feedback: (3)

Last photo for tonight. A long day to prepare three empanage sets. Ailerons are next.

rajul

My Feedback: (58)

Hi Mark, the double bevel angle is a nice concept. What is the angle like ? Looks like 15 degrees.

MarkNovack

My Feedback: (3)

Mike, the rudder gets about 30 degrees, the fin post about 15.

The elevator gets about 20 and the stab around 10. No 3D throws on this airplane. Now, a customer could take a basic kit (fuse and cores) and go 3D crazy. The results would be awesome with the side area sported by the fuselage and the incredible stability of the design.

OK, here are some close-ups of the almost finished empanage. A bit of NHP filler and final sanding, and we will take a drive to the coverer.

The first couple of photos show the 1/64th ply trailing edge. By the way, I put all of the trailing edge material for one airplane on the gram scale to see the actual weight and I could not get it to register. 4 grams for the whole airplane including the epoxy is my estimate, it may be a little less.

MarkNovack

My Feedback: (3)

This it the top tip of the rudder. It is very durable now. Not at all difficult to apply the TE, I can't see why use a balsa TE anymore. Just cut the cores to a taper and cap the back with the ply.

MarkNovack

My Feedback: (3)

The plate is almost perfectly flush with the sheeting. I will sand off the epoxy shine and poke a little NHP filler where it is still needed.

MarkNovack

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The ZN horns come in pairs of a left and right handed horn. They are very pretty, about 3 grams for a pair, and just too easy to mount.

This whole mounting set-up is really strong now. The plate will come out only by pulling the entire control surface apart.

MarkNovack

My Feedback: (3)

Here are a couple of shots that I wanted to include but it was too late the other day.

This shows all plates and recesses for the empanage.

MarkNovack

My Feedback: (3)

Here is an elevator. Before the router went to work, I positioned the plate and scored the outline with a knife. Then marked it clearly with a pen so that it was easy to see during the routing process. This creates clean edges and the router gives an even depth.