Total hours to date: 40 hrs (plus 3,000,000 hrs reviewing plans)
Note: I received an E-Mail from a chap that was concerned with the quality and complexity of the Pica kit. My intention in posting this page was not to scare people off of building this kit, but to share and disseminate information so that new builders may gain from my experience and past builders will share their experiences.
I am also attempting to create a very scale Spitfire Mk IX. If you are looking for an airplane that looks like a Spitfire and is easy to fly, this is still a good kit. The modifications I am making, I would have had to make to most of the 1/6 scale spitfires I looked at. ( I just hope the thing flies when I'm done )
To follow the complete construction start from the bottom of the page and read up.
I have been making the aileron and flap and other scale measurements from a scanned image of the plans against a blow up of the 3 views. This is a very effective way measuring scale features. Unfortunately this is a 12MB file. Completely impractical for the web.
| Date | Time | Photos |
Description |
| Feb 27, 1999 | 3 hrs | I decided to use a RADS linkage very similar to the aileron for the flaps. I was going to use a torque rod, but this would pass right through the wing hold down block. I am really beginning to like the RADS system. I am currently half way done the linkage. I am trying to rig it so that both flaps will run from the same servo much like the ailerons. | |
| Feb 13, 1999 | 1.5 hrs | Started construction of the Flaps themselves. I am using the original W22 trailing edge sheeting with a small piece added to the inboard side, and a piece of scrap for the small inboard flap | |
| Feb 6, 1999 | 2.5 hrs | Wow, I spent 2.5 hrs fiddling with the aileron linkage making sure that worked smooth without binding. The left aileron is now complete, except for securing the hinges which I will do at finishing time. | |
| Jan 31, 1999 | 2.5 hrs | Completed the RADS linkage with a modification. The servo sits infront of the
main spar. I am using only one servo for both ailerons. I ran a flexible rod
out to the middle of the aileron. The torque rod for the aileron is bent with a 45
degree angle in the aileron and a 90 degree bend where it meets the flexible push rod.
I then created two bushings for the torque rod. One where the rod passes
through the trailing edge, and one for where the rod passes through the shear web.
One of the reasons I choose this method was the ability to easily alter the aileron
throw. I will create an access pannel in the wing, so I can lengthen or shorten the
coupling on the torque rod (if required). Now here is the important part. The torque rod must be at least 3/4" longer than the distance from the bushing at the shear web to the back of the pocket for the torque rod. This is so you can actually remove the aileron from the wing. The problem is that the torque rod has a 45 degree angle and the hinges are at 90 degrees. You must slide the aileron on at 45 degrees first (with the torque rod pulled out 3/4") and then slide the hinges and torque rod into the wing. |
|
| Jan 25, 1999 | 2.5 hrs |    |
Finished creating a new rear spar for the new flap position. Had to
cut into the trailing edge block that was already glued to the center section. If
you are going to add flaps to the Pica kit do not glue this trailing edge on until the
flaps are finished. It will just make life a lot easier. I am going to use a
torque rod for the flap that will run inside the cockpit. They will probably be
visible from a close inspection of the cockpit, but better that then a visible control
horn on the exterior. I need to add the riblets to the inside of the flap so that
when they are extended they have the scale like appearance. I believe they should
retract a full 80 degrees to be scale. The spits flaps were for breaking, not lift. I have reached another quandry in regards to the wheel well. Should I frame in the wheel well before sheeting or after. What got me thinking about this was running the aileron linkage. I want to make sure it will clear everything. My solution so far, is that I am going to move the servo mouning position to in front of the spar. In the original design the wheels were in front of the spar, and the servo's behind. Since I have moved the wheels behind the spar, the servos should move to the front. So it looks like a lot of the time in the center section, building the servo tray is going to have to be undone. (Took another roll of film in for developing. But I am too cheap to pay for 1 hr. The 3 day stuff is a lot cheaper) |
| Jan 1, 1999 | 4.5 hrs |   |
Well it seams like an eternity since I found some time to work on the Spit
again. I have hinged the aileron and done some tests on the RADS method of
deflecting the aileron. This is the way to go. The hard part I found was
making the slot to an acceptable tollerance. I actually made 3 of them before I was
satisfied with the fit. But the arborite samples they are made out of are free so...
I also trimmed the aileron a little to match the outline of my 3 view. It
seams they cheated a little and made the ailerons a little bigger. I used Robart Hinges in the friese ailerons. My concern is that I will have to anchor the aileron hinges before painting and detailing. In fact, before sheeting. I will fuel proof and paint the slot for the aileron before sheeting. I also started construction of the W22 trailing edge between the aileron and the root. The wing did not have flaps on the kit, but I am again making modifications. My first step was to mark off the flap position on one of the W22's. I then cut the bottom W22 and will use it for the flap. I will have to cut some more of the trailing edge away and add some more sheeting to W22 to make the full flap. |
| Dec 12, 1998 | 3 hrs |    |
Put together the aileron. Everything went acording to the plans
except the die cutting of the mini ribs. The slots cut in the ribs are not all the
same, but definately for wood larger than the 3/16" planking for the aileron.
This was easy to fix. I also blocked on some light block scrap to make the
nose of the friese aileron. I also had to trim a little off of the outboard part end of the aileron to maintain a match to my 3 view. I added a 1/4" strip of sheeting to the top of the wing trailing edge so I could taper it to a nice edge to fit the aileron properly. I may have to cut this off when I sheet, but for now I will leave it attached. I may be able to sheet upto it. The bad news is that my film wouldn't develope. Just a bunch of blank photo's. I will snap a bunch more quickly |
| Dec 7, 1998 | 3.5 hrs | Created the well for the friese aileron. This is an aileron that is
hinged on the bottom surface and sticks the nose of the aileron into the airstream to
offset the adverse yaw of aileron deflection. The original outline for the upper surface of the aileron is accurate enough, but the Friese aileron used in the spitfire meant the under surface was much larger than the upper. This meant keeping the same outline on the top of the wing, but cutting the trailing edge back 3/4". Now the wing does not have a solid trailing edge. I was worried about creating this as it meant cutting the trailing edge before the new trailing edge could be added. This could throw out the 2 degree washout that was created with the washout jig. What I did was tack glue some stringers to the top and bottom of the wing to give it some rigidity before cutting the trailing edge. I then notched out the trailing edge and the ribs back 1" and left 3/32" of the top of the trailing edge. A new trailing edge was glued in and 1/8" light balsa was glued between the old trailing edge and the new trailing edge. (A picture will really clear this up once I get the film developed). I then removed the stringers that were tack glued in place. A check of the washout with the wing jig, still showed 2 degrees of washout. |
|
| Nov 28, 1998 | 1 hr | Cleaned up the bench a little. Started making the wing skins. Should have a few pictures by Christmas. Still trying to figure out what I am going to do with the ailerons and flaps. The wing is going to need some modification to allow for the scale positioning of the the ailerons and flaps. | |
| Nov 24, 1998 | 1.25 hr | Started gluing the left gear mount together. This is proceeding just
like it should. Started to think about how to hide the control linkages for the ailerons and the flaps. I put a message in rec.models.rc.air and got a wonderful response. RADS/RFDS This appears to be the answer. Harley Michaelis designed and used this on large gliders. I would like to hear from anyone who may have tried this on a power model. Mail me if you have any info and I will post it here as well. Mail Me I will run some tests in about 2 weeks. My only concern is flutter at the higher speeds. This is a concern only from my lack of knowledge about the speed and control forces on a glider. I.e. a glider appears to fly much slower. |
|
| Nov 8, 1998 | 1.5 hrs | Cut all of the pieces for the left gear. Laminated the two rib reinforcements. | |
| Nov 1, 1998 | 3 hrs | Copied all of the ply parts to make the left gear mount. Glued all of the right gear parts in place, and cut the rib to allow for the wheel to retract. It is a REAL tight fit using the Robart 3 1/2" scale wheels and struts | |
| Oct 4, 1998 | 3 hrs | 
|
I now have completed the plywood parts for the right wing's gear
mount. It only took 3 tries! Anyone want a few scrap pieces of plywood? My
next plan is to duplicate the parts for the other side, trying to remember that all of the
angles go the other way. Should take another 3 tries. 12 out of 24 pictures taken. I should have some film developed in about 2 weeks. |
| Sept 28, 1998 | 2.5 hrs |  |
I think I now know why the kit does not put the gear in the scale
position. You really need to remember that High School Trig. The gear rakes forward 16
degrees and backwards 20 degrees. This means that the mount for the gear must be angled on
two different planes. (not airplanes). I spent all of this time figuring out the angles
and made one piece of the cardboard mockup that I will use as a template for the plywood
pieces. The cardboard mockup thing works wonders for doing this kind of work because it is rigid enough for testing, light, and easy to cut, but most of all, a lot cheaper than aircraft grade ply. |
| Sept 23, 1998 | 1.5 hrs | 
|
Built the right wing. The wings are built up, and the first step is
to build a tapered wing that fits inside of the elliptical wing. First some changes
to the kit. I still had to move the spar forward 5/8" to make room for the
landing gear. The wheel retracts where the spar used to be. Second, I changed the
dihedral. The kit uses almost a 11% dihedral, I used a 7.5%. The real Spitfire
Mk IXe had a 7% dihedral along the bottom chord, and a 6% mean chord dihedral. I am
probably sacrificing some stability here, I just hope not too much. Now came the figuring out. Once because of an illusion, and once due to unclear instructions. Step 22 has you pinning the Washout Jig to the plans. The wing is built with a 2 degree washout. The washout jig is fat at one end and skinny at the other. The jig is placed along the trailing edge. Now, at first, one would think that the fat end should go to the tip as washout would indicate the tip should "tip" down. Except, this is an elliptical wing (or tapered) and the X section of the wing continually gets smaller. Therefor the distance to the trailing edge of the rib at W5 (Center Section) is much greater than the small rib at W13 (tip). The jig needs to be placed like the book says, fat end at W5. I still did not believe this until I built the wing and did some measurements and confirmed these results. Problem #2 came when I now had to place the W14 trailing edge on the jig. W14 is skinny at both ends and fat in the middle, making a gentle arc one side of the trailing edge. My first thought was that the part was missnumbered. I thought the trailing edge should be fat at the root, and skinny at the tip. The plans make no mention of this, nor do they say which way the arc should face (up or down). After measuring the rib trailing edges against W14, it hit me. This is an elliptical wing (my forehead is getting sore by now from all of the slapping I keep doing). If you were to cut a boiled egg, the X-section of the cut IS skinny at both ends and fat in the middle. Now I just had to guess as to should the arc point up or down. W14 does not fit nice against the jig unless the arc is pointed up. Mystery session over. I moved the spar as follows. I used a spare piece of wood the same size as the real spar and pinned it to the original location. I wanted this in place as the Washout Jig based its position from the original spar position. When I did a trial fit of the real spar in its new position, I had to put shims under it as it did not fit snug against the board in its new position. As I placed each rib, I would trial fit the rib and cut a shim for the real spar.. Then put glue on the rib, lift the spar with the shim I had just cut. I would then Pin the rib to the dummy spar to make sure the washout jig was doing its job. Gluing the ribs, and top spar went very quickly, as the die cutting that plagued the center section ribs, seams to have disappeared. The leading edge went very smoothly as well. It is a laminated leading edge as it forms the front of the ellipse. Once the laminating is done, this makes for a very strong leading edge. Of concern I have noticed, is the lack of shear webs between the spars? Anyone ever built a built up wing without shear webs? I may add them later. The last thing I noticed is where the instructions for gluing the sheeting are placed. Right before you make the left wing. So it reads kind of like this. Make center section, check, make right wing, check, now with everything pinned to the board still, glue the sheeting together, oh by the way don't forget to make the other wing. I have not glued the sheeting yet and will not until the entire wing is built. My next task is to mount the Robert 606 retracts into their scale position before construction of the left wing. I want to see if my theories prove correct before I have to take apart both wings. The gear should rake forward approximately 18 degrees and should put the wheels just under the trailing edge. |
| Sept 22, 1998 | 1.5 hrs |  |
Finished the center section of the wing. This is a kit for an
experienced builder. The book does not do a good job of stepping you through each
phase of construction. Of notable problems:
I was going to mount my air tank for the retracts here, but my Robert tank is a little two large so I will be mounting it in the fuselage. If you mount your tank in this center section, I would suggest cutting the holes for the tank before you glue the ribs in place. I sure hope the rest of the wing goes a little easier. |
| Sept 21, 1998 | 1.25 hrs | Sanded the Center section ribs to the same profile and recut the lower
spar notch to move the spar 5/8" forward. This is enough so that the gear may
be mounted in a scale position, and that the shear webs between the upper spar and main
spar will glue to the front of the upper spar, and the back of the lower spar. Glued the center section spars to the main lower spar. Glued in the Wing Mount block. |
|
| Sept 20, 1998 | .5 hrs | Laminated ribs W3 - W4 - W5 together. Was a little disappointed with
the die cutting of the parts. The size of the plywood parts did not really match the
plans or the other balsa parts. Ribs W4 and W5 show to be the same size on the
plans, however my W4 is longer than my W5. Trimmed the W4 rib to match the W5 rib and sanded the plywood to match the balsa and plan profiles. |
