JW Büker Jungmeister build
07-26-2022, 01:21 AM
#126
Insetting the panel into the opening was a fairly easy modification from my original method and REALLY worth the trouble. I just love the way it looks. On the full scale Bucker the aluminum panel lays on top of the fuselage but it is MUCH thinner (scale-wise) than this one so this one needs to be inset to look right.
I recommend the builder of this kit does NOT cut the stringer that spans this opening. There's still plenty of room for access and it avoids that unfortunate "sunken" look on the panel. And it stronger of course.
I installed a .8mm flange all around the inside and a 1/4 balsa flange on the bottom to screw into. I have since trimmed away most of what the screws didn't screw into.
Only modification from my original is I had to add some .8mm shims to my clips to account for the movement to the inside by that much.
It looks fantastic in person
I'm so happy with the way things are turning out.
I recommend the builder of this kit does NOT cut the stringer that spans this opening. There's still plenty of room for access and it avoids that unfortunate "sunken" look on the panel. And it stronger of course.
I installed a .8mm flange all around the inside and a 1/4 balsa flange on the bottom to screw into. I have since trimmed away most of what the screws didn't screw into.
Only modification from my original is I had to add some .8mm shims to my clips to account for the movement to the inside by that much.
It looks fantastic in person
I'm so happy with the way things are turning out.
Last edited by mitchilito; 07-26-2022 at 01:24 AM.
07-28-2022, 04:21 AM
#129
Originally Posted by JohnHab
Mitch, Are the struts laminated ply? What does the hardware ends on the struts look like? Will there be Cabine wires?
It certainly is turning out quite nicely.
It certainly is turning out quite nicely.
Yes, the struts are laminated (see pic). This aircraft is wire rigged exactly like the full scale. As soon as I finish the struts, that will be the next step: final rigging.
Then it’s time to cover - YAAAAYYYYY!!
There are aluminum fittings that will have to glue into the ends of the struts so there cannot be any extra glue in the pockets. Will be challenging to get right.
Last edited by mitchilito; 07-28-2022 at 01:22 PM.
07-31-2022, 01:32 AM
#130
As I said, the application of glue needs to precise so I made this little applicator based on these nifty little rollers Ive been using for composite layups.
I band sawed them in half so I get two for the price of one
These tiny rollers have a very nice rolling mechanism inside. Its conveniently almost exactly half the length of the roller so after use it can be knocked out and inserted into the other half.
I band sawed them in half so I get two for the price of one
These tiny rollers have a very nice rolling mechanism inside. Its conveniently almost exactly half the length of the roller so after use it can be knocked out and inserted into the other half.
07-31-2022, 05:35 AM
#133
Struts
The tiny roller did an AMAZING job. I just cant see how you could glue these things up as well or as fast/accurately without this tool. See the pics for comments
I couldnt operate without this sticky-backed release film in the shop. Each strut gets it on one side.
Properly stacked and ready for glue-up
The glue-up takes a lot of time so I used SLOW hardner.
Again, I have to say the roller made this job a breeze. The little ply stick you see in the foreground is my pocket cleaning tool. I was prepared to have to make several layups depending on time. It went fast so I finished in one pass.
I couldnt operate without this sticky-backed release film in the shop. Each strut gets it on one side.
Properly stacked and ready for glue-up
The glue-up takes a lot of time so I used SLOW hardner.
Again, I have to say the roller made this job a breeze. The little ply stick you see in the foreground is my pocket cleaning tool. I was prepared to have to make several layups depending on time. It went fast so I finished in one pass.
08-05-2022, 12:01 AM
#135
Originally Posted by mitchilito
They came out fantastic. Phase one complete. Now I need to find a woodworker to route the edges round. . .
Is there any room inside the struts ( cabanes) to run the servo wires for the top aileron servos?
08-05-2022, 03:09 AM
#137
I spent two days sanding struts! If you can find somebody with a router table DO IT!
I thought a lot about how to proceed with the assembly of the cabanes/top center section and wound up doing it like everything else on this kit: dry assembly. This part of the build was pretty intimidating (only because I had no real idea how to proceed) but when the dust settled it worked out GREAT and now I'm really impressed with the design/execution of this kit. It's hard to believe but the only thing holding the top center section LOCKED in place in these pics is the cross wires. No glue anywhere.
And that brings up the key to success with this part of the build. In order for all the geometry to work out correctly the builder MUST: 1) bend all the fittings as close as humanly possible to plan, 2) assure that the front and back bracing wires are EXACTLY the same length side to side. This part is vital because those wires, in conjunction with all the built-in fittings and pockets etc, are what's holding the center section plumb. I even built a bracing wire measuring jig to match lengths exactly (just two headless nails in a long board to hold one end of the wires side by side).
After the dust settled it had been a simple (but time consuming) process. And FUN. Now I have to prime the struts for paint before I glue the cabanes together because I don't want to do that with them glued up. I will final paint them glued up and primed.
Fittings
I knew it was going to be a looooong process after I finished that first strut!
I was really nervous bending these up. They need to be as perfect as possible
It's a trick getting all the pieces in the right place. (if you build this kit you'll see what I mean)
First step in dry fit.
Once the wires were balanced I measured from bench to each corner of the center section and was AMAZED to see that the whole assembly was perfectly plumb on all four corners. Amazing kit.
Wow
I thought a lot about how to proceed with the assembly of the cabanes/top center section and wound up doing it like everything else on this kit: dry assembly. This part of the build was pretty intimidating (only because I had no real idea how to proceed) but when the dust settled it worked out GREAT and now I'm really impressed with the design/execution of this kit. It's hard to believe but the only thing holding the top center section LOCKED in place in these pics is the cross wires. No glue anywhere.
And that brings up the key to success with this part of the build. In order for all the geometry to work out correctly the builder MUST: 1) bend all the fittings as close as humanly possible to plan, 2) assure that the front and back bracing wires are EXACTLY the same length side to side. This part is vital because those wires, in conjunction with all the built-in fittings and pockets etc, are what's holding the center section plumb. I even built a bracing wire measuring jig to match lengths exactly (just two headless nails in a long board to hold one end of the wires side by side).
After the dust settled it had been a simple (but time consuming) process. And FUN. Now I have to prime the struts for paint before I glue the cabanes together because I don't want to do that with them glued up. I will final paint them glued up and primed.
Fittings
I knew it was going to be a looooong process after I finished that first strut!
I was really nervous bending these up. They need to be as perfect as possible
It's a trick getting all the pieces in the right place. (if you build this kit you'll see what I mean)
First step in dry fit.
Once the wires were balanced I measured from bench to each corner of the center section and was AMAZED to see that the whole assembly was perfectly plumb on all four corners. Amazing kit.
Wow
Last edited by mitchilito; 08-06-2022 at 01:29 AM.
08-05-2022, 04:34 AM
#138
The last check before gluing the cabanes: incidences. Credit to JW: its PERFECT. 3 degrees bottom, 2 degrees top. This using the cockpit sides as zero.
Thats with nothing but the wires holding it together. Just amazing.
Thats with nothing but the wires holding it together. Just amazing.
Last edited by mitchilito; 08-05-2022 at 04:37 AM.
08-06-2022, 01:24 AM
#141
Originally Posted by JohnHab
That is impressive. With no means to adjust the length and having to precisely bend the attach points. Excellent work. Are the metal parts Aluminum? Did they bottom out on the center ply when you installed? What did you pin them with?
Nicely done.
Nicely done.
The miracle of computer design/manufacturing. . . .
Last edited by mitchilito; 08-06-2022 at 01:26 AM.
08-08-2022, 02:38 AM
#143
Originally Posted by tmac48
Interested to see what you are going to use for a motor and how it is mounted, hope you are going with a Moki!!
tmac48
tmac48
NOTE: the prop in the vid is for my 3W Rare Bear project - not the Bucker. Bucker gets a big black two blade prop.
Last edited by mitchilito; 08-08-2022 at 03:12 AM.
08-08-2022, 03:00 AM
#144
I'm running out of things to build. As I said, I need to get all the struts primed for paint before I glue the cabanes together. I decided to try something a little different. Instead of putting 3/4oz fiberglass finish cloth over the 10 of them (soooooo time consuming) I elected to saturate them with Minx Polycrylic water based clear coat. I applied three good coats, sanding in-between. Now I'm going to top coat that with Klass Koat epoxy primer. I will say this: of all the parts of this kit, I like the way the cabane struts look the least: they are the same size as the wing struts but on the full-scale Bucker the cabanes are a smaller gauge tube. It's quite noticeable. Also, they are always going to look like wooden assemblies - because they are. Functionally they are fine and I can see why JW adopted this method - in keeping with the computer-designed/routed style.
While I'm waiting for my Klass Kote to arrive I worked on the wing struts. The instructions say make the bracing X's out of "3mm carbon rods" but JW provides white fiberglass rods. I won't actually glue them all together until they are completely finish painted. I machined the center connecting buttons out of aluminum. I would not have wanted to build this kit without my machine shop.
bracing rods will be glued up over this plan
Just in case you want to know, the hole angle in the button is exactly 37 degrees.
Ready to glue up - but not till completely finished.
While I'm waiting for my Klass Kote to arrive I worked on the wing struts. The instructions say make the bracing X's out of "3mm carbon rods" but JW provides white fiberglass rods. I won't actually glue them all together until they are completely finish painted. I machined the center connecting buttons out of aluminum. I would not have wanted to build this kit without my machine shop.
bracing rods will be glued up over this plan
Just in case you want to know, the hole angle in the button is exactly 37 degrees.
Ready to glue up - but not till completely finished.
Last edited by mitchilito; 08-08-2022 at 03:30 AM.
08-08-2022, 03:17 AM
#145
I'm running out of things to build. As I said, I need to get all the struts primed for paint before I glue the cabanes together. I decided to try something a little different. Instead of putting 3/4oz fiberglass finish cloth over the 10 of them (soooooo time consuming) I elected to saturate them with Minx Polycrylic water based clear coat. I applied three good coats, sanding in-between. Now I'm going to top coat that with Klass Koat epoxy primer. I will say this: of all the parts of this kit, I like the struts the least. Especially the cabanes: they are the same size as the wing struts but on the full-scale bucker the cabanes are a smaller gauge tube. It's quite noticeable. Also, they are always going to look like wooden assemblies - because they are. Functionally they are fine and I can see why JW adopted this method - in keeping with the computer-designed/routed style.
While I'm waiting for my Klass Kote to arrive I worked on the wing struts. The instructions say make the bracing X's out of "3mm carbon rods" but JW provides white fiberglass rods. I won't actually glue them all together until they are completely finish painted. I machined the center connecting buttons out of aluminum. I would not have wanted to build this kit without my machine shop.
bracing rods will be glued up over this plan
Just in case you want to know, the hole angle in the button is exactly 37 degrees.
Ready to glue up - but not till completely finished.
While I'm waiting for my Klass Kote to arrive I worked on the wing struts. The instructions say make the bracing X's out of "3mm carbon rods" but JW provides white fiberglass rods. I won't actually glue them all together until they are completely finish painted. I machined the center connecting buttons out of aluminum. I would not have wanted to build this kit without my machine shop.
bracing rods will be glued up over this plan
Just in case you want to know, the hole angle in the button is exactly 37 degrees.
Ready to glue up - but not till completely finished.
08-08-2022, 03:51 PM
#147
Good choice on the Moki 300. I will be using my 250 that I have fitted the single outlet exhaust ring to. Trying to keep the extensions on the twin outlets proved to be impossible for me and they always exited at a silly angle. Interested to see how you mount your motor to that firewall with such a big hole in the middle. Have received notification that my kit is ready to post!!
08-09-2022, 03:24 AM
#149
Originally Posted by Jaketab
Mitchilito, the 2 into I exhaust on the Moki. When you tack or braze it in place will it be removable? I considered using one previously, but it would appear from the angles to be permanent when its mounted.
J Tab
J Tab
They sure make the exhaust note nice though. . .
08-09-2022, 03:27 AM
#150
Originally Posted by tmac48
Good choice on the Moki 300. I will be using my 250 that I have fitted the single outlet exhaust ring to. Trying to keep the extensions on the twin outlets proved to be impossible for me and they always exited at a silly angle. Interested to see how you mount your motor to that firewall with such a big hole in the middle. Have received notification that my kit is ready to post!!
Your Moki 250 is PLENTY of power for this airframe - as you can see in all the videos of them flying with 250's. I'm only using my 300 because I already had it kicking around . . . .
Last edited by mitchilito; 08-09-2022 at 03:30 AM.
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