Posts Tagged F-711 Bulkhead
More Aft Fuselage Work (2/17/12)
Posted by Ethan Jacoby in Aft Fuselage, Construction, Fuselage on February 17, 2012
1.7 Hours -
I received a couple of new toys in the mail, which gave me a good excuse to work on the plane a bit. The first new toy is an electric aileron trim kit. I finally decided that if the plane is going to have electric pitch trim, it should have electric, not manual, roll trim as well. Since I decided to go with electric trim for both axis, I took the plunge and bought some CS-8 stick grips from Tostenas well. I could have saved some money by purchasing cheaper grips and using rocker switches on the panel for trim operation, but I really like the idea of having a little more functionality on the stick. Plus, the Tosten grips look really cool! Now, I just have to figure out what to use all the buttons for. The hat switch will be trim, and the trigger will be my push-to-talk, but that still leaves me with 3 open buttons.
The Tosten grips are really nice! Now to figure out what to use all the buttons for.
Tosten grip from the side.
Tosten grip from the front.
Once I quite playing with my new toys and went into the garage, the first thing I did was to drill the F-712 bulkhead and the WD-409 tail spring mount for the two “keeper” rivets called for in the plans. With little information in the plans, I decided to drill the holes 1/2″ from the center of the bulkhead, and low enough to where I was sure they wouldn’t interfere with the bolts that will eventually be installed in this location.
The plans don't give much guidance on their location, but I drilled the two keep rivets in the F-711 bulkhead and WD-409.
Next, I decided to remove the F-710 bulkhead, as well as the F-711/F-712/F-779 assembly, from the aft fuse so I could re-work some of the bulkhead flanges a bit. My goal was to get the flanges to better match the angle of the side skins, resulting in a better fit for the bulkheads. After messing with these for a while, I reinstalled everything and re-checked the fit. The overall fit is better, but I’m still having trouble getting about 1/4 of the F-711 bulkhead to skin holes to line-up. The flanges still have some room for improvement in the area, so I’m probably going to remove this whole section one more time the next time I work on the plane.
I removed, adjusted, and re-installed the F-711/F-712/F-779 assembly. The fit is better, but not yet perfect.
The angle of the flanges on the F-711 and F-712 bulkhead matches the skin a bit better now, but I'm still having trouble with about 1/4 of the holes on the F-711.
The aft fuselage is completely clecoed. I'll check for "straightness" before drilling anything.
Aft Fuselage Clecoed (2/11/12)
Posted by Ethan Jacoby in Aft Fuselage, Construction, Fuselage on February 11, 2012
2.5 Hours -
I started off by trimming the ends of the J-channels. On the lower four J-channels, both ends require trimming. However, I’m still not sure on the upper two, so those will have to wait. The actual trimming was completed by drilling a hole in the bend on the channel, enlarging the hole to the desired radius with a step-drill, and then finishing the cut with a Dremel and cut-off disc.
Once the J-channels were finished, I slid them back into place on the aft fuselage assembly. I then when to work clecoing the F-706 bulkhead to the aft fuselage. This took a little time since the F-706 assembly is a little bulky, and it took a little brute force to get things to line up at times.
With the F-706 in place at the front, I turned my attention to the rear and slid the F-710 bulkhead into place. The plans say to put the F-710 in last, but it is obvious that it would be a real pain to get the bulkhead in after the tail assembly is in place. With the F-710 loosely in place, I next started trying to cleco the F-779/F-711/F-712 assembly to the rest of the aft fuselage. At first, I couldn’t get the assembly to fit, but I quickly realized that the J-channels were interfering with the F-712 bulkhead. To fix this, I had to remove the tail assembly and trim a little more off the ends of the J-channels.
Once the J-channels were trimmed a bit better, it still took a little work to get the tail assembly to fit into place, but, eventually, I got it. I was able to cleco everything in the tail section except for one side of the F-711 bulkhead. The flanges of the bulkhead aren’t bent quite right. So, I’ll have to remove this part and re-bend the flanges so that they better match the angle of the fuselage side skin. Hopefully, this will take care of my fit problem.
The aft fuselage seen from the F-706 bulkhead looking back toward the tail.
A side view of the aft fuselage. The upper J-channels are just sitting on the top for storage...that's not their actually positioning.
The tail of the aft fuselage. The tail assembly is a real pain to get clecoed!
The flanges of the F-711 bulkhead still need some work. I'll have to remove the bulkhead and bend the flanges to better match the angle of the skin.
Tail Spring Mount Work (2/5/12)
Posted by Ethan Jacoby in Aft Fuselage, Construction, Fuselage on February 5, 2012
4.0 Hours -
Today was another day where I spent a lot of time on the airplane, but didn’t seem to get much done. The instructions for the fuselage have become so vague, that I spend more time studying the plans or looking at other build sites on the internet, than I actually spend building.
I wanted to start by trimming the ends of all the J-channels. However, after looking at the plans and looking at the assembled bulkheads, I was having a hard time figuring out which ends get trimmed on which J-channels. So, for now, I decided to hold off on doing any trimming until after I start assembling the aft fuselage and can see exactly where the channels go. In the meantime, I used a piece of scrap J-channel to make a template for trimming the ends. I should be able to lay the template over the end of the J-channel and mark the trim pattern. This will save some time over measuring every single time.
I used a scrap piece of J-channel to make a guide for trimming the ends.
Next, I located the F-779 skin and started trying to cleco the F-711 and F-712 bulkheads to the skin. I say “trying” because this was a real pain. Pretty much every other build site I’ve looked at has a complaint or two about the fit of these pieces. My kit is no different. The bend in the skin doesn’t match the bulkheads very close at all, so I spent a lot of time trying to add a little more bend where needed, and messing with the bulkhead flanges to get the right angles on them. Eventually, I got to the “good enough for now” stage, but I may work on it some more or even add some shims. I’ll wait until the aft fuselage is assembled for the first time before I go too far on this though.
Once I got the F-779 skin to bulkhead fit reasonable, I took the assembly apart so that I could make the cutout on the skin for the tailwheel spring. I traced the cutout drawing from the plans, taped it to the bottom of the skin, and marked the area to be removed. I then used my Dremel to make the initial cut. I didn’t spend much time finishing the cut at this point, because it will likely have to be widened once I see how the tailwheel spring mount fits.
The F-779 tailcone skin needs to have a cutout made for the tailspring. I traced the template from the plans.
The rough cut for the tailwheel spring is finished, but this will probably need adjusting after I see how the tailspring mount fits.
Next, the WD-409 gets bolted to the F-711 bulkhead. The two open rivet holes in the bottom of the F-711 are used for the bolts, but the plans don’t mention anything about how to position the weldment on the bulkhead for match-drilling. Fortunately, Brad Oliver’s great website explained that the bolt holes needed to be positioned 12/32″ below the top of the weldment.
Once I knew the location, it was easy enough to mark both the weldment and the bulkhead. I drilled the first hole in the weldment to #30 while the weldment was on the bench. Then, I clecoed the weldment to the bulkhead, aligned some marks, clamped it down, and drilled the second hole using the holes in the bulkhead as the guide. I then gradually enlarged the holes until I hit 1/4″ for the AN4 bolts.
The WD-409 tailwheel mount is drilled to the F-711 bulkhead. The plans are pretty vague here!
The WD-409 to F-711 holes get enlarged to 1/4" for AN4 bolts.
After bolting the WD-409 in place, I re-clecoed the bulkheads to the skin to check the fit of the cutout. The cutout needed to be enlarged a bit, but I also couldn’t get the F-712 bulkhead to seat properly. After a lot of fidgeting and swearing, I finally realized that the “mouse hole” in the bottom of the F-712 wasn’t big enough and was interfering with the weld fillet on the WD-409. Once I realized this was the problem, it was easy to enlarge the hole and get everything to fit properly.
I had to do a little trimming of the cutout in the F-779 skin in order to get the tailwheel mount to fit.
With everything in place, the next step in the plans called for drilling two holes for “keeper rivets” in the F-712 bulkhead and the aft face of the WD-409. Again, there is no guidance in the plans for determining where to locate these holes. So, it was back to the internet for some researching. Eventually, I found the consensus is that close is good enough in this case, but to wait until after the aft fuselage is clecoed together. So, I’m calling it a day because I’ve had enough fun with the tailwheel for one day!
The F-711 and F-712 bulkheads sandwich the WD-409 tailwheel mount. Now I need to figure out how to drill the WD-409 to the F-712 bulkhead.
Bulkheads Finished (1/22/12)
Posted by Ethan Jacoby in Bulkheads, Construction, Fuselage, Longerons on January 22, 2012
1.0 Hours -
With a Penguins hockey game and two NFL playoff games on TV today, I only planned for short work session. Priorities, right!
Since I had already primed my F-711 and F-712 bulkhead parts, all that was left was to rivet them. The F-711 needed the bulkhead halves, as well as the F-711C bars riveted together at this time. The F-711D angle won’t get riveted until later in assembly after the skins are on. All of the bulkhead rivets could be reached with the squeezer, so I was a happy camper.
The completed F-711 bulkhead. The F-711D angle doesn't get riveted until after the skins are on.
A side view of the F-711 bulkhead.
The F-712 bulkhead was even easier than the F-711. For the F-712, just the bulkhead halves are riveted together (it’s a bit more complicated if you’re building a tri-gear model). As with the F-711, the squeezer could reach everything, making my short work session that much easier.
The F-712 bulkhead is riveted together with flush rivets on the aft side.
A side view of the F-712 bulkhead.
With these two bulkheads done, all of the bulkheads are finished (for now), and it’s time to move on to something new. Unfortunately, the next step in the plans is to cut and bend the longerons. This seems to be an area where a lot of builders get stressed out, but end up with satisfactory results. To make this a bit easier (I hope), I bought some longeron bending dies off a Vansairforce.net member some time ago. The dies are milled out of a relatively hefty chunk of aluminum, and the idea is to squeeze the longeron in the dies using a vise to make the gentle bend. I’m sure it will be a fun process.
Up next is longeron bending. I bought these dies a long time ago to assist with making the shallow curve.
The longeron dies bend the longerons by squeezing the dies together in a vise.
F-711 and F-712 Bulkheads Started (1/21/12)
Posted by Ethan Jacoby in Bulkheads, Construction, Fuselage on January 21, 2012
2.4 Hours -
Back to work on the bulkheads…
The F-710 bulkhead and F-710B angle received a coat of primer the other day, so, today, I riveted them together. Fortunately, all of these rivets could be reached with the squeezer, so it was an easy task.
The F-710 bulkhead and angle are riveted together.
Next, I finished up the F-711 bulkhead by trimming away a section of the bulkheads and making the F-711D angle. The bulkheads are trimmed to make room for the elevator pushrod, and it was an easy task to remove this material with the bandsaw. The F-711D angle was another easy piece to make because it just had to be cut to length, clamped to the bulkhead and match-drilled. With the angle made, I then prepped all the F-711 parts for priming.
A big chunk of the F-711 bulkheads gets trimmed away to make room for the elevator pushrod.
The F-711 bulkhead prep work is finished. After priming, this will be ready for assembly.
The F-712 bulkhead is the last bulkhead that I have to make. This one is like the F-711 bulkhead in that it is two halves that get riveted together, back to back. There are no angles or other parts to be made for this bulkhead, so it was as simple as final-drilling, deburring, dimpling and prepping for primer.
The F-713 bulkhead is made from two halves riveted back to back just like the F-711 bulkhead.
Finally, I put a coat of primer on all the F-711 and F-712 parts. Tomorrow, I’ll rivet these bulkheads together, and then it’s on to the dreaded task of bending the longerons!
The F-711 and F-712 bulkhead parts are ready for a coat of primer.
F-706 Finally Done, F-711 Started (1/19/12)
Posted by Ethan Jacoby in Bulkheads, Construction, Fuselage on January 19, 2012
1.8 Hours -
The primer on the F-706 sides was dry, so it was finally time to rivet them to the base and set the F-706 bulkhead aside. All of the rivets could be squeezed, but the base and sides are made from such thin aluminum that they were a bit of a challenge to rivet together. The challenges were mainly from the bulkhead being so light and flexible that it was hard to keep it in position. Oh well, the F-706 bulkhead has joined the many other partial assemblies in temporary storage. Hopefully, I’ll get to start putting the partial assemblies together at some point soon because I’m running out of storage room in the garage!
The F-706 bulkhead material is so thin that it is actually a little difficult to rivet. At least it can be set aside for a while now.
With the F-706 done, I wanted to wrap up the F-709 and F-710 bulkheads as well. Between the two bulkheads, there are only three parts. For tonight, I prepped and primed these parts. Tomorrow, I’ll rivet the F-710 angle to the bulkhead, and these parts will be finished (toss in my usual, “for now”).
There isn't much to the F-709 and F-710 bulkheads. Here, the parts are being primed.
On to the F-711 bulkhead. Van’s calls this a “double bulkhead.” Basically, it is two bulkheads riveted back to back. Since I actually knew where these parts were in the crate, it didn’t take me long to find everything I needed to get started. I clecoed the F-711A&B bulkheads together and then grabbed a length of AB4-187 x 1-1/4 bar stock and got to work fabricating the F-711C bars. The bars were simple to make…cut to length, draw a center line, drill three holes in each bar at the specified locations, and cut the outside top edge to a slight angle…easy.
The F-711 bars are fairly easy to make from the provided stock material. Just cut to length, drill a few holes, and add a taper.
Once made, the F-711C bars are clecoed and clamped to the F-711A&B bulkheads in order to drill the remaining holes. The centerline on the bars is visible through the holes in the bulkhead, and the bulkhead holes are used as the drill guides for match-drilling the bars. After the bars were fully drilled, I marked a section of each bulkhead half that needs to be trimmed away to make room for the elevator pushrod. However, I’ll leave the actual trimming for another day.
The F-711C bars are clamped to the F-711A&B bulkheads for drilling.
The blue centerline on the F-711C bars is visible through the holes in the F-711A&B bulkheads. The bulkhead holes are then used as guides for drilling.
The F-711C bars are drilled and the F-711A&B bulkheads are marked for trimming.
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