8th Scale Aviation's, "CzechMate" Short-kit, Group build
01-16-2017, 04:48 PM
#277
Thread Starter
Thank you!
The prototype cowls are laid-up, as well; but I didn't take any pictures of them. Now that I've shown Tim how I do the various lay-ups, he is making more CzechMate cowls for the other two of us. Once done, we can finish the planking of the bottom fuse. (Eric and Tim wanted to get together to continue this weekend, but I came down sick. Just bad timing!)
The prototype cowls are laid-up, as well; but I didn't take any pictures of them. Now that I've shown Tim how I do the various lay-ups, he is making more CzechMate cowls for the other two of us. Once done, we can finish the planking of the bottom fuse. (Eric and Tim wanted to get together to continue this weekend, but I came down sick. Just bad timing!)
01-17-2017, 10:48 AM
#279
Thread Starter
Well, as you already know, Tim sells very accurate scale kits and accessories. This now allows him to produce fiberglass parts himself, rather than have to sub-contract out for them.
I intend to retire in just a few years, and am currently developing my own line of kits,as well, to supplement my income while keeping me busy in retirement.
The most enjoyable and rewarding part for me is how a core group of us here in Sacramento help and support each other's efforts in these endeavors. (Similar to the group in Redding at the Cottage industry they call "The Mustang Ranch."). Together, there will be multiple offerings of kits, including cowls and other accessories. Many of Tim's are available right NOW!
I intend to retire in just a few years, and am currently developing my own line of kits,as well, to supplement my income while keeping me busy in retirement.
The most enjoyable and rewarding part for me is how a core group of us here in Sacramento help and support each other's efforts in these endeavors. (Similar to the group in Redding at the Cottage industry they call "The Mustang Ranch."). Together, there will be multiple offerings of kits, including cowls and other accessories. Many of Tim's are available right NOW!
01-22-2017, 06:21 PM
#282
Hi Guys. Sorry for late reply I'm not getting notifications to my emails..
As of now there are,
Ta 152 With a 71 1/2 "span
Me 209 with a 59" span
Tstonami at 51 7/8" span and a smaller one at 46 1/8" span
in the works
F8F bearcat
Conquest 1 Bearcat
Rare Bear
and others in drawing stage..
As of now there are,
Ta 152 With a 71 1/2 "span
Me 209 with a 59" span
Tstonami at 51 7/8" span and a smaller one at 46 1/8" span
in the works
F8F bearcat
Conquest 1 Bearcat
Rare Bear
and others in drawing stage..
Last edited by tdstaf; 01-22-2017 at 06:28 PM.
12-01-2019, 07:37 PM
#283
Thread Starter
It has been awhile, but we are back at the build, again!
I am going to take you back to post #234. We had already installed the tailwheel assembly, and ran stringers from the last fuse former to then back of the fuse. Now, we are going to fare it all in, in preparation for sheeting the bottom of the fuselage. Scrap pieces are glued in-place, as pictured. Note that the blocks match the width of the side stringers, to allow for the thickness of the sheeting/strip planking.
Tim's rear fairing block.
Here the author (Ollie) carefully checks fit and alignment of the block, prior to gluing.
Another angle
Two lengths of scrap stringer material installed; and, started sanding to "round" the bottom.
Sanding roughly completed.
I am going to take you back to post #234. We had already installed the tailwheel assembly, and ran stringers from the last fuse former to then back of the fuse. Now, we are going to fare it all in, in preparation for sheeting the bottom of the fuselage. Scrap pieces are glued in-place, as pictured. Note that the blocks match the width of the side stringers, to allow for the thickness of the sheeting/strip planking.
Tim's rear fairing block.
Here the author (Ollie) carefully checks fit and alignment of the block, prior to gluing.
Another angle
Two lengths of scrap stringer material installed; and, started sanding to "round" the bottom.
Sanding roughly completed.
12-01-2019, 07:45 PM
#284
Thread Starter
The first of the bottom strip-planks is glued. Before going further with additional sheeting -- and before we enclosed the tailwheel assembly, Eric and I used a piece of sharpened brass tubing to cut a hole wide enough to insert a hex wrench. This allows us to be able to easily adjust the tailwheel alignment.
(Tim enclosed his. I guess he is choosing to take his chances.)
)
(Tim enclosed his. I guess he is choosing to take his chances.)
)
12-01-2019, 09:44 PM
#286
Thread Starter
Thanks, OKC Flyer!
We continued sheeting, bending each strip plank to match the contour of the fuse. We were sure to use the softer, most flexible pieces of material, and wet the balsa to allowing it to bend, without splitting; and, gluing gradually, to ensure the more forward sections did not separate as the rear portions had to be contoured more sharply behind the tailwheel assembly.
2nd strip plank adhered with thin CA to the first.
Once dried, I began bending the strip plank to match the fuse contour. Gradually gluing the bottom of the plank to the formers and other existing structures.
Here, a dampened shop towel is used to moisten the balsa, allowing it to flex even more, without splitting.
We continued sheeting, bending each strip plank to match the contour of the fuse. We were sure to use the softer, most flexible pieces of material, and wet the balsa to allowing it to bend, without splitting; and, gluing gradually, to ensure the more forward sections did not separate as the rear portions had to be contoured more sharply behind the tailwheel assembly.
2nd strip plank adhered with thin CA to the first.
Once dried, I began bending the strip plank to match the fuse contour. Gradually gluing the bottom of the plank to the formers and other existing structures.
Here, a dampened shop towel is used to moisten the balsa, allowing it to flex even more, without splitting.
12-01-2019, 09:57 PM
#287
Thread Starter
Before the last part of the strip plank was glued, it was folded around the rounded scrap blocks and held in-place with a metal ruler. The ruler's edge began at the tailwheel wire, running back, aligned with the centerline of the bottom of the fuse. A #11 Exacto blade was used to trim away the extra material. Then, the strip was glued to the rounded filler blocks.
The sheeting on the far side has been trimmed, and the matching piece on the near side is trial fitted, before gluing.
The sheeting on the far side has been trimmed, and the matching piece on the near side is trial fitted, before gluing.
12-01-2019, 10:07 PM
#288
Thread Starter
Our planking continues . . .
I stop to take pictures of Eric working diligently on his CzechMate's sheeting.
One piece of strip planking resisted the attempts to manipulate it into an even curvature. If you look closely, you can see the split. It will be CA'd, filled, and sanded.
I stop to take pictures of Eric working diligently on his CzechMate's sheeting.
One piece of strip planking resisted the attempts to manipulate it into an even curvature. If you look closely, you can see the split. It will be CA'd, filled, and sanded.
12-01-2019, 10:27 PM
#289
Thread Starter
Tim states that before the bottom-most layers of planking can be applied, we must fit the wing to the fuse, and mount the cowl. Recesses in the cowl must be trimmed away, in order to fit it around the leading edge of the wing.
I sanded my cowl ring slightly to fit snuggly inside of the cowl. I placed the cowl's trailing edge down on a flat work surface, & pressed the ring lightly to ensure it lined up perfectly with the edge of the cowl. In the next picture, you see me with the assembly flipped over, tack-gluing the ring to the cowl from the bottom. I applied the thin CA very slowly & carefully, just inside of the edge -- ensuring CA did not run over the edge to the outside of the cowl. Then the inside was glued.
I sanded my cowl ring slightly to fit snuggly inside of the cowl. I placed the cowl's trailing edge down on a flat work surface, & pressed the ring lightly to ensure it lined up perfectly with the edge of the cowl. In the next picture, you see me with the assembly flipped over, tack-gluing the ring to the cowl from the bottom. I applied the thin CA very slowly & carefully, just inside of the edge -- ensuring CA did not run over the edge to the outside of the cowl. Then the inside was glued.
12-01-2019, 10:41 PM
#290
Thread Starter
The fuse was set upside-down in a cradle. The wing was set onto the wing saddle and centered. One of us held the wing tightly in-place as another drilled two 5/16" holes through the firewall and into the leading edge of the wing. The holes were spaced 1" apart, each a half an inch from the centerline; and will accommodate leading edge wing dowels.
Eric holds Tim's wing in-place while Tim drills.
I hold the front part of the wing and drill my wing dowel holes, while Tim holds the rear of the wing secure.
Eric holds Tim's wing in-place while Tim drills.
I hold the front part of the wing and drill my wing dowel holes, while Tim holds the rear of the wing secure.
12-02-2019, 06:47 PM
#292
Thread Starter
Back 20+ years ago, a 50/50 solution of water and vinegar seemed to be regularly recommended in some of the build articles in popular magazines I was reading at the time (such as Radio Controlled Modeler and Model Aviation). I tried it, and it worked fine.
Once I was feeling lazy and didn't want to have to run into the house to get vinegar; so I used water only. I did not notice any significant difference; so really do not know what benefit the vinegar is supposed to add -- especially beings the authors of the articles I read recommending it, never offered specifics.
Once I was feeling lazy and didn't want to have to run into the house to get vinegar; so I used water only. I did not notice any significant difference; so really do not know what benefit the vinegar is supposed to add -- especially beings the authors of the articles I read recommending it, never offered specifics.
12-07-2019, 11:00 PM
#296
Thread Starter
5/16" diameter dowels were epoxied into the leading edge of the wing; and, then we broke for lunch. After lunch, the epoxy had cured well enough for us to finish installing the wing.
The wing was put in-place, with the front wing dowels inserted into the firewall. We took turns, with one of us holding the wing securely, while the other carefully measured from the end of the fuse to the inside corner of the aileron, nearest the wingtip -- re-adjusting and re-measuring as necessary, until the measurements were identical. Thus, ensuring the wing was square to the centerline of the fuse. Then, we drilled 3/16" holes through the rear center of the wing, and into the wing mount blocks. We did mine first, but no one took pictures. Eric was next, so I took pictures while Tim held his wing. I held Tim's wing; so again, no pics -- sorry.
We advised Eric that he should hold the drill perpendicular to the angle of the airfoil, to ensure that the heads of the wing retaining bolts would be flush with the wing's surface, once installed. But this being his first time, he unfortunately started his hole slightly too forward, and exaggerated the forward angle necessary; so, did not get sufficient "bite" into the plywood wing mounting block. He was completely successful with his next two holes, but will now need to fill and sand the original hole (forward, right).
The wing was put in-place, with the front wing dowels inserted into the firewall. We took turns, with one of us holding the wing securely, while the other carefully measured from the end of the fuse to the inside corner of the aileron, nearest the wingtip -- re-adjusting and re-measuring as necessary, until the measurements were identical. Thus, ensuring the wing was square to the centerline of the fuse. Then, we drilled 3/16" holes through the rear center of the wing, and into the wing mount blocks. We did mine first, but no one took pictures. Eric was next, so I took pictures while Tim held his wing. I held Tim's wing; so again, no pics -- sorry.
We advised Eric that he should hold the drill perpendicular to the angle of the airfoil, to ensure that the heads of the wing retaining bolts would be flush with the wing's surface, once installed. But this being his first time, he unfortunately started his hole slightly too forward, and exaggerated the forward angle necessary; so, did not get sufficient "bite" into the plywood wing mounting block. He was completely successful with his next two holes, but will now need to fill and sand the original hole (forward, right).
12-07-2019, 11:09 PM
#297
Thread Starter
The 3/16" bit was exchanged for a 1/4" bit, and holes that would clear the threads of the nylon 1/4-20 bolts were drilled. Pictured below, Tim enlarges his holes (probably drilling into my work surface! 
). Then, Eric does the same -- thankfully, no threat to my workbench.
). Then, Eric does the same -- thankfully, no threat to my workbench.
12-07-2019, 11:22 PM
#298
Thread Starter
Next, Tim and Eric use a 1/4-20 tap bit to tap threads for the wing retaining bolts into the plywood wing mount blocks. Then, harden the threads with thin CA. (For the record, I do too; but apparently these guys don't seem to care enough about what I do, to take a picture of me. I mean, the camera is laying "right there," guys -- come on. 
)
The wing is then mounted to the fuselage.
Tim installs the 1/4-20 nylon wing-retaining bolts.
)The wing is then mounted to the fuselage.
Tim installs the 1/4-20 nylon wing-retaining bolts.
Last edited by Iron Dog; 12-07-2019 at 11:48 PM.
12-07-2019, 11:40 PM
#299
Thread Starter
Pictured is my wing, mounted. It fit the wing saddle of my fuselage, beautifully!
Tim wanted to try using fiberglass arrow shafts as wing dowels. It might be a good solution to the problem of wood dowels often compressing and otherwise succumbing to the effects of vibration; or in some cases, the holes enlarging. BUT, only if we insert and glue another smaller diameter wood dowel inside the arrow shaft. I am concerned that if we don't reinforce it, the brittle arrow shaft will crack sooner or later, and eventually fail.
Tim wanted to try using fiberglass arrow shafts as wing dowels. It might be a good solution to the problem of wood dowels often compressing and otherwise succumbing to the effects of vibration; or in some cases, the holes enlarging. BUT, only if we insert and glue another smaller diameter wood dowel inside the arrow shaft. I am concerned that if we don't reinforce it, the brittle arrow shaft will crack sooner or later, and eventually fail.
Last edited by Iron Dog; 12-08-2019 at 12:22 AM.
