saramos

Tubig,

It looks like you are on track with another great build. I tried the iron on technique on my Spit wings. It came out pretty good. I've made progress on my workshop and hope to get back to my Spit soon. This BT plane looks to have much lighter construction that the TF Spit. At 68", it looks like it'll be close to the weight of the 64" Spit. As for ducting and cooling, I've been toying around with the idea of using a small electric ducted fan to aide in airflow. If I find that I need more weight in the nose to balance, I'll test it.

Scott

tubig

wulf and scott, thanks for the comments. yes, this does build lightly especially when i'm using mostly contest grade balsa. after wrapping the TF Spit this model feels like a feather for what i have so far. it's also a fast builder, not the myriad of parts that TF uses in their kits. i believe most kit manufacturers design for liability not flying. i'm getting really hooked on BT's methods. i just wish he had some larger size plans. i want to start getting into the 80" ws models which will probably be my limit.

scott, the "ironed" glue method is pretty slick i think. sure, you have to wait about 30 minutes before actually gluing, but then you don't have to wait a couple of hours (or overnight) to wait for the aliphatic to dry normally and the sheeting doesn't pull up in places as it has on me in the past.

tubig

added a couple of bulkheads to aid with the cowl and canopy attachment. to get a better fit for the canopy to the fuselage i made another former (that will eventually be support for the instrument panel). i then trimmed away both bottom corners to allow the former to sit slightly lower to accomodate the canopy.

tubig

next was to add the horizontal tail. in order to get the angle of incidence right, first i drew a line below the fuselage on the plans parallel to the fuselage centerline. then i glued the fuselage above the work top as measured from the drawn line on the plan.

then i cut a couple of sticks used to measure from the work table to the stab leading edge and again from the table to the trailing edge and adjusted the stab seat until they were equal setting the correct angle of incidence with the fuselage (in the photo they are being used to support the rear of the stab). i couldn't get the stab seat sanded just right so i used a mix of epoxy/microballoons on the stab seat, set the stab on top and weighted the stab down while checking alignment. what i liked about the epoxy/microballoons is that the sand bags continued to squeeze out the excess epoxy/microballoon mix until just the right amount was left to create the perfect stab seat.

saramos

Was your epoxy/microballoon mix used for jusst forming the saddle or for permanant attachment? I see what looks like wax paper or tape in the photos. Or is that for protection of the fuse sheeting?

Scott

tubig

sorry for the confusion scott. i used the mix for permanent attachment. i made it slightly runny having more epoxy than balloons so it would get a good grip on the wood. it's very sturdy and i think will hold the stab well.

i ran tape along both the stab and stab saddle to protect the adjacent areas as the excess balloons oozed out. i marked the edge of the stab saddle on the bottom of the stab and ran the tape along that line so that it doesn't actually get caught by the stab. i really should have removed the excess while it was still gelled but didn't want to disturb the stab before it was completely set. i will sand off the excess balloons with the tape still in place to protect the balsa sheeting.

tubig

back to the 109. spent a little time today mounting the engine to the firewall.

the second photo shows the backplate that is supplied with the engine used for mounting to the firewall. a template is also provided to help in positioning the engine for correct thrust lines. the two smaller holes in the mounting bracket allow for screws that keep the mounting bracket in place when the engine mounting bolts are removed. since i only have a 1/4" firewall i'm having trouble finding screws small enough to just screw into the ply without hitting the engine on the other side.

the third pic shows the firewall just tacked onto it's bearers.

fire@forthall

it is called a slurry mix in the full size world! the slightly runny epoxy mixture. just had to say what a great looking build! I would sure like to build something like this but am unsure of my build abilities. some day though!

Katchmarek

My Feedback: (29)

fire@forthall, Ah heck...don't let that stop you! If your new to building warbirds, or not ready for a larger model just quite yet, try one of the SkyShark kit's. From what I've seen and heard, if I were a newcomer to warbirds, that's where I'd start for sure! Or, if you really want a bigger warbird, Meister Scale kits are big, and not too difficult at all...look and fly great too!
Rob / katchmarek

tubig

thanks.

i agree with rob. just start somewhere. this is my 7 or 8th build and second built from plans. if you do a thread here there will be plenty of people to help you along as necessary.

tubig

began work on the fin and rudder. the 109's vertical fin is unsymmetrical to allow for engine torque instead of offsetting the fin on the fuselage centerline. the left side of the fin is slightly larger with more curvature. Bob Holman's laser cut parts include two 3/8" fin halves. however, i needed to add another 1/8" piece to the left side to allow for the unsymmetrical shape of the fin. after that i traced to shape of the fin onto the bottom of the fin block and began shaping. this is a slow process of sand, check, sand, check, etc. to get the correct shape.

tubig

for the rudder i diverged slightly from the plans. BT shows a 1/16" balsa core. in an effort to get a thin trailing edge i decided on using 1/64" ply. after cutting out the shape i added rib locations and cut out spaces for the hinges. the hinge cut-outs was a good idea but i still did not get enough space and had a little problem when drilling out for the hinge points. if you go this route, do yourself a favor and give yourself more space.

here is the rudder in the rough.

tubig

before shaping the rudder's leading edge i needed to install the hinges so i tacked the rudder in place and marked the hinge locations. i had forgotten about the cutout for the elevator control linkage and added a middle hinge to the rudder but there isn't a place in the fin to accept the middle hinge.

pic 2 - hinge points added.

pic 3 - now i could shape the rudder. i re-tacked the fin and rudder together and again slowly shaped both together.

pic 4 - now all that is left is to shape the rudder's leading edge and fin's trailing edge to match.

tubig

back to work on the tail. i made a couple of rudder control horns from computer board. i prefer this stuff to g-10 because it's a lot easier to cut.

then i cut some slots in the rudder, added the horns and then drilled through them for some toothpick pins.

then temporarily mounted to add the pull-pull controls. with that i could add the remaining fuselage lower side pieces and bottom piece. i filled in the smaller gaps with microballoons. i'm beginning to wish i hadn't glued the horizontal stab on so soon as it would make it much easier to shape the rear end/vertical fin without the stab getting in the way.

ramcfarland

My Feedback: (44)

Always liked this one posting so I can follow along (can you PM me about the glass building surface) Thanks

tubig

richard, was going to pm you but just decided to post here anyway.

my glass surface is 1/2" x 4' x 6' tempered glass. (wish now i had gone with 8' long but it would be very cramped for my shop)
bought in philippines (where i live) for about US$150. i like it very much. i used to be a pin person (something about pushing pins in corkboard was satisfying) but no longer. i can do everything on the glass; build, glue, cut. saves me a lot of time walking back and forth between old build table and and workbench. all glues (epoxy included) just pop right off when dry. fairly flat, could use some newspaper shims in a few spots but don't think i'm going to fool with it.

if you (or anyone) has more questions on it feel free to ask.

glad you're enjoying the build.

tubig

spent the last couple of days adding the vertical fin and sanding. i mixed up some microballoons and troweled them in the planks on the underside of the fuse and around the fin/stab area and started sanding. pretty much done. just a few touch-ups here and there.

i also figured out that i could not use the aileron strip linkage for the elevators as there simply was not enough room for smoothly operating elevators. so i canned the store bought links and made my own from brass tube soldered to the wire. should have done this in the beginning and it would have saved me a lot of time fiddling with the mechanism.

tubig

i put together my exhaust today to see how it would work and i think it's going to work well. i had to get a 90 deg. exhaust header pipe (OS), 2 motor adapters and flex tubing from Macs Products (all ordered from Tower). once i was happy that the engine/exhaust was going to work the way i had hoped, i removed the engine and finally epoxied the firewall in place. i think that pretty much completes the basic fuselage construction. still just a few things left to do on the inside with radio and wing mounting.

oh yeah, and added the "what-ever-this-thing-is-called" for attaching the aerial to the fin. still needs a little filler.

wulf190

My Feedback: (19)

Neat setup Tubig. The plane looks nice and smooth. Looking forward to "the other half" of the build now that the airframes coming through to speed. Seems like things slow down after the big stuff is complete. But we're all enjoying your thorough posts on the thread. All the parts that I've cut for this bird sit shamefully in a box with all the rest of the wood necessary for completion.

tubig

thanks wulf. maybe this build will motivate you to put those parts together. it's really a nice building model.

tubig

i'm making the mg gas exhaust and engine bay vent outlets now prior to covering because i think it will easier this way. pretty simple. just marked out the area and, using my diamond files, cut and sanded the scoop shape.

(sorry for the fuzzy pic on this first one, i guess the camera has a thing for Helmut's boots)

pic 2: prior to sanding the shape i added some balsa doublers to the underside to give support for the sheeting as i was sanding.

pic 3: the right side. not bad. after glassing (which will give the balsa added strength), i will come back and sand a fine pointed edge on the "top" side of the scoop to give it a sheet metal look.

tubig

for the 'intake to the mg firing gas' i am making this the location for the radio switch. i will have to enlarge it slightly from scale (1/2" vs. 3/8" scale) to get my fingers in to move the switch but i can live with that. after cutting out the slots (undersize at first) i made some balsa supports that will allow the ply switch plate to be screwed to so i can remove it if necessary.

pic 2: with the ply plate mounted.

pic 3: from the top side. i believe i will cover the ply and balsa inside with plastic and paint flat black to sort of hide the inside.

pic 4: finally, with the engine bay exhausts included which are on the right side only. again, after glassing i will try to remove the 1/4sq. stringer which is in between the gap for the mg firing gas inlet.

tubig

added the tailplane struts today. i made them from basswood. to get the correct length and shape of the ends i first made a template strut from balsa.

pic 2: then just redid it with basswood.

pic 3-4: both have been tacked in place. i will remove them to glass the fuse.

BT shows a dowel drilled into the end of the strut which is then glued into a block in the tailplane. i really don't see the need for that as the tailplane has been epoxied to the upstand so i will just epoxy it to both the fuse and tailplane without the dowel insert. going to try to add an aluminum cover at each end and complete them with a bondo base at each attachment point.

tubig

spent the last couple of days covering the tail group controls and half of the fuselage. using Dave Brown's Skyloft for the the open bay rudder and elevator halves. as of now i have 2 coats of thinned nitrate dope on the covering. it will require several more to fill the weave.

for the fuse i'm using .6 oz glass cloth and polyester resin. this is the first time i've tried polyester resin and cloth and have mixed feelings using it. it's dries very quickly which is good for keeping the project moving but this also means it gives limited working time. apparently, i'm using a lamenating resin because it remains slightly tacky when cured. i've tried adding more activator but that seems to make it cure to fast to use. so after the whole fuse is covered, i'll put on a flow coat of Zpoxy finishing resin. just one more side to cover.

Baldeagle

My Feedback: (7)

Tubig I don't know if they have it over there , you might want to try Mimwax Poly U. It is a water base and a lot easier to use than fiberglass or epoxy. It dries pretty quick to. your 109 is looking good. Rich