F-705 Keeps on going..

For some reason, the F-705 bulkhead is taking much longer for me than I ever thought, it also seems to be taking longer for me than other builders which is really weird.   I do think most builders sort of move on before it is completely finished which might be part of it.  Actually I will probably do this as well since I am going to be waiting for some parts from Van's anyway.

I think I am mostly done with the fabrication and drilling etc. at this point.   I just need to get the parts on order, do a few things with them; then do the priming/riveting thing.   I am going to go pretty light on the primer with this section since it will be painted in a few months anyway.

Tonight I worked on the flap bushings and they turned out OK, but I might have been a bit aggressive with them.   I think I might do them again (i.e. buy new ones) and actually put them together in assembly like you see here THEN drill them into the F-705 side supports.  I think this is the only way you can get them perfectly straight to the flap weldment and hopefully ensure no binding etc..  But for now it looks pretty good, we will just see if I can make it better.

WWII Reunion in Tucson - F-705 continued

I have been out of town for a bit with my grandfather visiting Tucson for a "Mighty 8th" Aircore WWII reunion.   He is now 88 years old and was a Tail Gunner during the war in a B-24 Liberator of the 392nd Bomb Group.  His group was called the "Crusaders" and he flew in 35 missions total.  Towards the end of the war he was involved in 3 missions where they bombed Berlin itself ("The Big B").. It was an interesting reunion, hearing all the stories from the old guys who were there.  We also toured the Pima Air Museum and Airplane Bone Yard down there in Tucson.  It was a great time for sure; here are some pics of my grandfather next to his plane and gunner's seat during WWII on the B-24. 

While I was down there, I also got some ideas about decals and paint jobs for the RV.  Lots of guys use Military Style paint jobs and they look pretty good..  While I might not do a full military job, I am sure I could fit the 8th airforce historical society insignia on my plane somewhere.  Or the 392nd bomb group and the crusaders insignia somewhere.

Regarding the RV, I have been continuing to work on the F-705 bulkhead and have all the top seat supports complete except for the piece of metal where I messed up the bend.   I have a new piece ordered from Van's and hopefully will be here end of week.  I think I may be able to finish this part up by the weekend and move to F-706, the next bulkhead down the line.

F-705 Upper Seat back supports

I ran into my first snag on the F-705 bulkhead.  The plans call for a 4 degree bend in an aluminum plate that sits on the top of the bulkhead.  This is used to support the seatback for both passenger and pilot.  Under-estimating this task I tried to rig up a make shift bending brake and had no success, the bend was OK I guess, but missed the centerline all together as you can see on the right.   Learnings here is that you need the right tool for the job...   Since there are two pieces and I only ruined one, I went to a friends place where he had a cheap, but effective bending brake.  It worked great, and as you can see the results were worth it in the below pictures.   Now I need to order an extra part from Van's to replace the one I messed up so I can have both complete.  

This work will effectively finish the F-705 bulkhead apart from priming and final riveting.   I will be doing that next week.  There is some trick to the riveting though as many holes get left open for future riveting in assembly. 

F-705 misc work

F-705 is turning out to be more work than it first appeared, imagine that...   I continued drilling the main bar, mounted and drilled the right seat belt anchors, as well as removed, shortened and shaped the bar doublers to proper fit.  Note, some of the bar doublers have countersunk rivets, so they are now finished as well.

After that I started match drilling the rest of the 704 structure as well as opening up the tooling holes so that bushing can be installed for the rudder cables.

The final task of the day was drilling the support angles that anchor the upper corners of the bulkhead, and provide a place for the canopy to anchor to.   Drilling went well, but was kind of a line it up and clamp it type of routine to get the first few clecos in.   Once I got a few in, it went smoothly.  Even drilling the opening for the canopy latch was not too hard.   I used the F-705 assembly as a guide and drilled an upper and lower hole.  Then using a chainsaw sharpening file I was able to file an opening between the two holes fairly quickly and it turned out really nice.

F-705 continued

Other builders have said it and I will repeat, you definitely need to look at the plans while building the Fuse.  It becomes most apparent when building the F-705 Bulkhead..  The directions have very little detail and it is now all showing up in the plans.   For example, on the bar and reinforcement doubler, there are some rivets that have universal heads, some rivets that are countersunk, some holes that go through all layers and some holes that go thorugh only some of the layers.  After you study it for a while, it makes sense, but there is definitely the opportunity to miss something.  

To drill the lower bar, I am working one layer at a time.  All holes do go through the bar itself, so no worries about making a mistake here, so just the lower bar was drilled first.  Next I drilled the spacers, by leveraging center line I drew and clamping them in place so they don't twist as I drill.  After that I added and drilled through the reinforcement/doublers, and "centered" them.  The directions call to cut them to size, but I have seen builders end up with them a bit short on the edges.  I am going with a centering technique and then drilling them before I cut them, or shape them.  This will allow me to get all edge distances correct.  I will try to post pictures as I go.  Also Some holes don't go through the reinforcements so I was able to cover them so as not to make a mistake here.

Once the Bar was drilled, I built a jig and drilled each left seat belt anchor.  The right one will be drilled in assembly using the lower bar as a guide.

F-705

F-705 is the bulkhead that sits directly behind the seats in the RV.  This bulkhead caries the flap mechanism, is where the rear wing spar attaches to the fuse, as well as provides for the seatbelt anchors.  Lots of cool things that go together with this part.   I was able to begin some work, but will also continue to research the internet to make sure no mistakes on this one.

Here you see I made the spacers that fit between the rear spar attach plates at the bottom of the spar.  Note metal grain direction is important here, as well as the very minor bevel on the edges of one of these.

I also cut to length the main bar that supports the seat belts and rear wing spar.  Drew a center line on it to help line it up with rivet holes on the bottom bulkhead channel assembly.  Here I have it clamped together and ready for drilling using the bulkhead assembly as a guide.

F-704 complete, starting F-705

I went a bit further than most with F-704 at this stage.  The plans tell you to take it apart, but I am just going to leave it connected for the time being.   I got some 4 inch 7/16" hardware bolts from Ace and they fit in the wing bolt holes perfectly for the build.  These will be replaced later once the wings are mounted but are needed now to maintain the structure.

I also drilled and installed, but haven't torqued the spacer bolts that goes into the Top of F-704.  These fit perfectly with the wood blocks that I created.  This structure is one solid piece of metal, and currently is just finger tight.   Great enginneering on this one for sure.  (Except for the stick weldments discussed earlier.)

Looking forward in the manual I started F-705 bulkhead.  It took me about an hour to locate all the parts, (Hope I got them all) but here you see them all on the table in their raw from the box condition.   Its kind of cool to see how they look at this state, then how they look after I put hours of work into them.

Control Column

I saw something disappointing when fitting the control column.  It appears that one (or both) of my stick weldments are not straight.   I will go back to Vans and ask them about this, because the sticks are very visible from within the cockpit.  If they look bad, It may reflect negatively on the overall construction..  ;-)    Here are a couple pics that outline this issue...

Anyway,  The control column did go together well, aside from the weldment issue.   I made some blocks per the instructions and temporarily attached the two bulkheads together with the installed control column.    ;-)

F-704 Bulkhead Riveting

I continued work on the center section F-704 A and B bulkheads.  It was interesting riveting the bulkheads, I found that squeezing these did not work at all without bending the rivets, So I drilled out a couple, then shot them all with the standard head rivet set and a snap sock to help protect the heads of  the rivets.  It turned out pretty nice overall.  When riveting the bars in place I found that even the -14 rivets were a bit short, only providing a very small shop head.  This is OK, because really the rivets are only to hold the bar in place until the bolts go in and secure it completely.  Overall it turned out fairly nice, I did notice that the anodizing has spider cracks very consistently and looks bad overall, but isn't structurally a problem.

Here you can see while riveting the flush rivets on the center section that attached the cover support brackets (Outer Brackets in grey), the anodizing splintered quite a bit, looking bad, but not providing any structural problems.  I would recommend possibly back riveting these rivets if possible, might take longer to set up, but you could possibly avoid messing up the pretty anodizing.

F-704 Center Bulkhead

Happy 4th Of July ! ! !

With the firewall mostly behind me, I have moved back to the center bulkhead.  Lots of little details so far on the fuse that all must get taken care of.  Its slower going than you think when you first look at it.   Working on the control column mounts, the bushings needed to be reamed just like the aileron bellcranks.  And the inside of the mounts needed to be sanded because the fit just wasn't quite as good as the aileron bellcranks.  I got those pieces working smooth together, then needed to polish the edges of the stick mounts so they would fit inside the control bracket.   Also, once the coloumn mounting angles were drilled, I removed them to remove excess material that Van's recommends to reduce weight. (that is the cut out section on the Grey angle pieces.

I also worked the black bushings a bit grinding off the sides as vans directions so they would fit cleanly in the hole that buts up against the side gussets.