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Jay Burkart's blog
Posted by Jay Burkart | Jun 14, 2015 @ 02:02 PM | 836 Views
These are some pictures of how I go about joining the whole wing tip section to the main center section. This is a removable joint using 1/4' CF rods and a 3/32 wire locator pin.
I use my wing jig to hold everything in alignment. The joiner sockets holes are predrilled in the ribs, Since the wing sections were cut on the correct angle on the radial arm saw, this gives me the main spars, TE and LE to align the very end ribs on to both the center sections and tip sections so I can glue it in place then run the joiner tube with a dummy kerf rib sandwiched between, through at the right angle for the joint. The main tube within the main spars are tacked into place with CA glue, then the rear locator pin tube is put through the ribs and supported on each side by some balsa pieces.
When all this is in place and well tacked in, I take a razor saw and cut right through the 1/16 kerf allowance rib and on through the joiner tubes.
This then gives me the two wing sections with the tubes installed. I then box in the spars with 1/16 ply and fill in with some end grain balsa with gaps and back filled with epoxy and microballons. Then the end ribs are capped over with 1/16 ply end cap ribs....Continue Reading
Posted by Jay Burkart | May 30, 2015 @ 01:24 PM | 1,576 Views
I've rough framed up the Center Sections of the three wings. I added shear webs all the way the length of the main spruce spars. The center bays shear webs are 1/16 ply as that forms the box for the joiner tubes. I then filled the gap between the vertical grain balsa filler pieces with long set epoxy filled with microballons to
still give it structure but no so much weight. I immediately capped all those spaces between the ribs where the wing joiner box with 1/16 ply to make the other side of the joiner box.
After the joiner box was done then I added two more sets of shear webs at the front sub spars and the rearmost sub spars to try alleviate a flutter problem seen in these wings. Then the center section bottom was sheeted with 3/32 balsa.
At the TE there was some additional pieces added just in front of the TE made out
of trailing edge stock, this is to reinforce where the rear wing mounting bolts are passed through. Then the top of the center section is sheeted also with 3/32.
Posted by Jay Burkart | May 20, 2015 @ 05:26 PM | 1,772 Views
I've come a way on the build of the center section for the three wings.
The Center section on the Racer is about 5.5 ft span. It is built in one piece and then bisected after it is framed and the center section planked. I cut right down the center where I place a dummy rib for kerf allowance right thru the brass receiver tubes for the joiner CF rod.
Note that the ribs are all provided with a little extra platform piece where they join onto the TE to allow for the TE to follow the curve of the under camber wing section. I will build the tip joiners after framing the tip sections when I have the center section halves mounted on my wing jig.
Posted by Jay Burkart | May 11, 2015 @ 09:08 PM | 2,934 Views
I've been quite a while getting all the parts ready for the Wing build.
I've bonded .014 Carbon Fiber strip to the 1/2" Spruce main spars, both center section and tip sections. Also the 3/8 ID brass tube for the center section build.
This involves roughing up the exterior of the tube for a good epoxy bond and end caps in both ends of the tube so the carbon fiber rod has an end stop.
Also the TE pieces needed to be laid out and the rib notches milled.
Also the TE needs to be spliced to make them long enough with scarf joints and a butt joint at the center where the wing will be cut in two panels.
Posted by Jay Burkart | Apr 23, 2015 @ 04:50 PM | 2,454 Views
I have finally started mounting the gear in the fuselage and landing gear mounts.
Main landing gear will consist of a 5/32 front gear and 5/32 rear angle brace.
I mounted the maple hardwood slotted mounts in the fuselage and will be actually bending the wire later. I also came up with a way to easily change the motor battery without having to remove the wing each time and also keep the battery as far forward as possible. I made a battery tray that slides into the fuselage from the front under the motor and the tray allows adjusting the battery fore and aft to best adjust the CG....Continue Reading
Posted by Jay Burkart | Apr 08, 2015 @ 09:58 PM | 2,403 Views
I started building the fuselages for the Racers and have built 5 of the six sides so far. I found that this is slow going as I have to soak the 5/16 longerons in hot water with a little ammonia for about 6 hours or so to make the front 1/3 pliable enough to make the bends in the front section of the fuselage. There is a fairly severe curve from the top and up from the bottom and using hard balsa required a long soak. Anyhow there are No cracks and no buckling. After gluing in all the verticals and diagonal braces plus gussets I let the longerons dry thoroughly overnight to take the form. Nice thing about CA is that it glues wet balsa nicely.
the fuselage longerons are almost 5 ft. long so I had to join on extra pieces to all the longerons, so not the extended scarf joints in the pictures, I am using about a 4" long joint, I also learned to prime each piece in the joint with a little thin CA first let that cure and then do the actual joint with medium CA. I also do all joints for all the other structure with Medium CA, then I will re-glue every joint after the fuselage sides are joined.
I am fighting having an issue with this model being tail heavy so you see that I even cut the firewall to where the Lipo is even as far forward as possible....Continue Reading
Posted by Jay Burkart | Mar 31, 2015 @ 08:00 PM | 6,925 Views
Next on the board is the building of the Horizontal Stab and Elevator and mounting the V.Stab onto the Horizontal to make it removable.
This H. Stab is very much different from the Airborn since this H. Stab is a lifting stab. So that makes it much thicker plus having an airfoil to it.
This stab is about 1.125 thick at it highest point. I wanted to make the slot mounting of the Vertical stab about the same as I used for the Airborns.
I digressed from the plans on part of the ways of fastening the V. Stab to the
Horizontal, the plans called for two nylon screws going up through the Horizontal and up into the bottom of the vertical. But I worked out a way to use a carbon fiber pin in the Vertical so that it just pins it at the leading edge and only one screw goes up through the Horizontal and into the base of the Vertical at the Rudder hinge line. Also I had some problems with the 5/16 thick balsa at the hinge joint.
This piece had to be 11/8 thick and the length of the H. Stab 48 inches. I had several pieces of 5/16 X 3 stock and when I ripped it to size down its length the pieces of stock would immediately warp badly. This is probably because the wood was cut too green when it was made into 3" planks. So I had to steam the pieces and warp them back straight.
One issue that comes up with the Racer is that it has a short nose moment and the
size and weight of the tail feathers may be a problem to be able to get it too balance. With it being electric...Continue Reading
Posted by Jay Burkart | Mar 24, 2015 @ 10:08 PM | 2,759 Views
This evening after finally sanding and fitting all the parts from the short kit, I started to build the Vertical Stab and Rudder.
Pretty conventional build except for my way of mounting the V. Stab. to the H. Stab.
Notice the bottom of the V.Stab that there is a sandwich of balsa and 1/16 ply base with a modified blind nut where a 8-32 nylon screw passes up through the H. Stab. The front LE of the V. Stab will have a carbon fiber pin sticking out.
More on that as I get through the build.
Been doing it this way for about the last 15 years on many Airborns.
Posted by Jay Burkart | Mar 18, 2015 @ 09:53 PM | 2,994 Views
With the demise of the 2316 Sq. in. Airborns being disallowed by the new SAM 2015 rule book, I've decided to build another Lanzo model that will fly as well as the former Airborns.
This Racer is actually an earlier model design by Chet Lanzo by about 2 years or so but close to the same size. The Racer is not scaled up but is being built at the original size of 144" span and 2216 flat layout or 2206 projected.
I worked with Jim O'Reilly using the original Chet Lanzo plans and made some modifications to it to allow easy disassembly and transport plus add provisions for modern RC equipment.
Since the model is very large I've made the wing disassemble into 4 sections, the H. stab removable and the V. stab also removable plus the landing gear will come off easily, The model will easily fly with either Electric or fuel with it's roomy open nose section. The models I am building will be setup for SAM Texaco event.
The full size plans with all these mods is available from Jim O'Reilly Model plans and a short kit from Bob Holman Models.
This is the first build of the model from these new plans and it'll give a pretty good step by step procedure for building the model.
As usual I'll be building 3 of the models at once since I can't ever seem to build just one of any model anymore........I guess I'm just a production line builder for some reason.
Shown in the first pictures are the two Full size Racers that got my interest from seeing them last year at Dayton and the SAM Champs. Tom Ryan and Tom Boice have been most helpful in checking measurements on the original model built by Chet Lanzo which you will see as the Red White and Blue model shown in the pictures.
Posted by Jay Burkart | Jun 24, 2013 @ 09:29 PM | 4,670 Views
Here's some pictures of our new 2316 sq. in Airborns that I built for the SAM Texaco event.
I built 5 of these during the past winter.
Now that we've flown them, they seem to do well.
Seems like the bigger we make the Airborn the better it flys.
Setup for the Texaco event with 3S 2700mah Lipos they weigh in
at 165 oz RTF and some are heavier. With that battery the minimum
weight is 162 oz. so they are quite close.
The first flight at the Ft. Wayne contest one of my buddies had his skied out
to a spec and brought it down after 38 minutes to win.
Unfortunatley I lost my motor for some reason so I didn't do well at all.
Posted by Jay Burkart | Oct 14, 2012 @ 12:22 PM | 4,264 Views
My new Airborn 1600's performed well at the 2012 SAM Champs at the AMA Muncie site this year.
I was forunate to win the Grand Championship for Electric and my buddy Hank Gullet came in second with his Airborn 1600 that I built for him over this past winter.
My LMR Airborn showed an altittude of over 4100 ft. after the second flight even at this size it was just a red speck in the sky. I attribute a lot to the color scheme I use and the fact that the transparent color back lites from the sky making it more visible at high altitudes. The red shows up against haze and clouds and the white transparent shows up against blue sky.
On the Texaco second flight, I got a total flight time of over 70 minutes on a total motor running time of 4 minutes. I got up to over 3600 ft. on that flight.

Here are a few of pictures:
Posted by Jay Burkart | Feb 21, 2012 @ 10:35 AM | 4,883 Views
Just finished another Lanzo Airborn 1600 setup for LMR SAM event.
Virtually the same as the previous shown model but the hatch was made shorter and moved back over the CG because the motor is considerably heavier.
This motor is optmized for LMR and of a much higher wattage and then thrust output.
Everything else on the model is the same since I think I've optimized the building and setup of the model....Continue Reading
Posted by Jay Burkart | Aug 07, 2011 @ 10:44 AM | 6,183 Views
Attached are a couple of pictures of me holding my 1600 that gives a perspective of its size.
Also at the first contest on the first flight the performance of this model was
The flight was 1:07 hours on just 10 minutes of motor run, thermaling was
of the best I have seen and it's ability to work and center into the thermals
was remarkable.
The setup on the models was SAM legal at 110 oz. with a Thunder Power
1800mah 3S lipo pack and a NEU 1107/6D with 6.7:1 P32 gearbox.
Using my Aurora 2.4ghz radio system and a 2000mah 5 cell Eneloop receiver/servo battery pack.
I am now starting to build 3 more of these models for fellow SAM flyers
during the next few months.
Jay Burkart