70 Series - F4U - Build Log

May-15-2010     75% F4U Project Version 2 of the tailfin and rudder are finally good enough to cut out. I can already see where improvements need to be made. I'll call it a night, and start version 3 in the morning.
Apr-30-2010     75% F4U Project More smoothing...
Apr-25-2010     75% F4U Project I took the cowling off to work on the bottom of the cowling.
Apr-24-2010     75% F4U Project The bottom of the cowling being foamed. NOTE:  There are no photos for the last week or so due to time spent filling and smoothing out the body and the anomalies between the body and the cowling.  When complete, you will not be able to tell where the cowling ends and the body begins.
Apr-14-2010     75% F4U Project Foam is cut for the bottom of the cowling and laminated into place.   I need to find a supplier that can cut the nose bowl...
Apr-13-2010     75% F4U Project Tilting the bird up to start foaming the under belly. The first photo shows the second coating applied to the cowling and sanded down to meet the body.  This time we got the cowling to mate to the body without any issues. The second photo shows the new "top" tail alignment piece being dry fitted and the last photo shows the gray coating that is used to seal the interrior.
Apr-11-2010     75% F4U Project The final Crutch strip is laminated into place and I reshaped the tail cone template just slightly.
Apr-10-2010     75% F4U Project As you can see, I got a ton of work done today.   Not only did I get 25% of the foam glued in but I started so early in the morning tat I managed to hot wire it and add the first surface coat.   While waiting for it to cure, I started working on the tail and designing alignment ribs that you will see later. The final two photos show that I'm adding the final crutch strip.
Apr-08-2010     75% F4U Project Version #2 of the Cowling plug.   I re-measured everything and notice I added a horizontal rib to hold the shape a little better this time.
Apr-04-2010     75% F4U Project Here are images of the first cowling plug before I destroyed it.   I'm trying to show you how it comes to a point and its supposed to continue the body's shape.  Unfortunately these pictures don't do a good job of showing you what I mean.
Apr-02-2010     75% F4U Project AHHHHH NUTS!!!   Turns out that the cowling is too narrow at the nose bowl.   There's no way to save it, so I'm invoking RULE #1: Never be afraid to start over.    ...So I did.   I cut all new pieces
Apr-01-2010     75% F4U Project only had time to smooth out the first surface coat and add another
Mar-28-2010     75% F4U Project Dry fitting the infrastructure that will become the cowling plug.  The last photo shows the first layer of the surface coating.
Mar-27-2010     75% F4U Project Assembly of the cowling inner structure
Mar-26-2010     75% F4U Project
Mar-25-2010     75% F4U Project
Mar-24-2010     75% F4U Project
Mar-23-2010     75% F4U Project
Mar-21-2010     75% F4U Project
Mar-17-2010     75% F4U Project
Mar-15-2010     75% F4U Project
Mar-14-2010     75% F4U Project
Mar-13-2010     75% F4U Project
Mar-12-2010     75% F4U Project
Mar-08-2010     75% F4U Project
Mar-06-2010     75% F4U Project
Mar-01-2010     75% F4U Project
Feb-28-2010     75% F4U Project We put the first layer of fiber glass on the first elevator today.   In the last photo, the side was added.   The non-functioning instruments are merely there for looks as this F4U is just the plug and will not actually fly.
Feb-19-2010     75% F4U Project The elevators are coming along nicely.   The leading edges of both elevators are a mess.  I'll have a lot of work ahead of me to straighten them out
Feb-15-2010     75% F4U Project The first 2 layers haven't come out as nice as I expected as you can see by the first two photos.  The third and forth photos show a hand crafted filler piece for the inner wall of the elevator trim tabs.
Jan-25-2010     75% F4U Project Smoothing out the Horz. Stab.  The ends of the leading edge are scultped with various sanders.  The second photo shows the early stages.  Then ends will be covered with resin and smoothed out several times before the correct shape is achieved.
Jan-03-2010     75% F4U Project New and improved version of the Horizontal Stabilizer.  Sections are completed at different times due to the size of our largest hotwire bow.
Dec-26-2009     75% F4U Project
Dec-25-2009     75% F4U Project
Dec-05-2009     75% F4U Project The elevator foaming goes well, but cutting the inlay was murder.  I'm not conviced that installing the inlay will actually works. If the inlay doesn't work, I will take it out of the design and re-build again. I have a feeling there will be a 7th version.
Dec-04-2009     75% F4U Project Foaming the first elevator.  The foam turned-out better than I expected, but I see more improvents.  I won't make anymore more changes in this design, however, I did update the drawings for the next time.
Dec-01-2009     75% F4U Project Foaming the first elevator.  The foam turned-out better than I expected, but I see more improvents.  I won't make anymore more changes in this design, however, I did update the drawings for the next time.
Nov-29-2009     75% F4U Project I found too many area for improvement so I created and cut new version 7 of the ribs.  This picture shows everything fitted together.    The last pictue shows the new HStab glued and clamped together.   This new design took 25 minutes to put together and glue.
Nov-28-2009     75% F4U Project The new ribs are being fitted onto the spar, with the new trailing edge alignment spar sitting just above the new spar.   The last picture shows the new reinforced leading edge.
Nov-15-2009     75% F4U Project On the far left, you can see the new spar being laminated.  In the middle you can see the new Leading edge design and that the ribs of the elevator now include the rivet holes for the bearing.
Nov-13-2009     75% F4U Project A design flaw was found and I had to go back and try to figure out what the elevators appeared to be so small. It turns out that the Spare was exactly 1.5" too far aft. Unsing the lessons learned thus far, I started completely over from scratch and improved the design.
Oct-10-2009     75% F4U Project Today we laid in the 2nd layer of glass.
Oct-07-2009     75% F4U Project Now that the surface is smooth, we laid the first layer of fiberglass.
Oct-6-2009     75% F4U Project Right HStab tip still needs work, but is almost complete.
Oct-5-2009     75% F4U Project Left side started and almost finished.   Needs to be sanded into final shape after the curing.
Sept-27-2009     75% F4U Project
Sept-26-2009     75% F4U Project
Sept-25-2009     75% F4U Project
Sept-24-2009     75% F4U Project
Sept-23-2009     75% F4U Project
Sept-22-2009     75% F4U Project
Sept-21-2009     75% F4U Project
Sept-20-2009     75% F4U Project
Sept-19-2009     75% F4U Project
Sept-7-2009     75% F4U Project Pardon the mess!    These two pictures give you a good idea on how big the stabilizer is in relationship to the rest of the plane.
Sept-6-2009     75% F4U Project We cut the spar for the stabilizer and decided to lay it into approximate position.
Sept-5-2009     75% F4U Project The new version of the ribs fit much better and notice that I added an newly designed alignment piece to the nose.   This new piece not only keeps the ribs straight, but it also helps with the spacing.  This thing is Big!   ...and I haven't even got the elevator attached yet.
Sept-3-2009     75% F4U Project Several improvements were found when we assembled the ribs, so we went back and made changes to the master drawings. We will re-cut all ribs again tomorrow.
August-30-2009     75% F4U Project Cutting of the all new redesign of the Horizontal Stabilizer begins! While waiting for the Horizontal Stabilizer part to be cut out, I stuck in old gauges in to the instrument panel for fun.
August-22 & 23 of 2009     75% F4U Project Nothing but solid work for getting a new stabilizer designed.   There was nothing wrong with the old design.   However, the former design works better for a 1/5th scale aircraft than it does a 3/4 scale.   So I decided to pull out my original design that I created a few years ago for the old 70% scale project (which we will not be building) and scale it up and improve it.   My old 70% design called for fewer ribs but more support than I felt was needed to make the plug.   So I changed the design to add more ribs and have most ribs evenly spaced.  This will make the foaming process even easier and the whole piece stronger. The solid modeling software used does not do all the work for cutting the Elevator, so I exported the drawing into CAD and did all that work separately. (No pictures of that process shown)
July-04-2009     75% F4U Project The top half is almost complete. So much to do to get the outer skin smooth and free from dimples. We are still waiting to hear back from the canopy manufacturer about making changes to the WAR Aircraft Replicas Canopy I had molds made for several years ago. If he can stretch/shape the demo canopy to the desired shape, we can make a mold in a fraction of the time it took to make the WAR Corsair.
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June-22-2009     75% F4U Project The pics are a bit fuzzy...   I remember to clean the lens after I took the pictures, so Tuesday's pics will be clearer. I hot wire the foam by myself tonight and they came out great.  I'll add he two next to the firewall tomorrow.
June-21-2009     75% F4U Project I cut the blocks for all nine forward most sections, but I only glued in 5.   I thought my hotwire bow was not long enough so I stopped.  Turns out that it is plenty long enough and I could have glued them all in.
June-20-2009     75% F4U Project The back plates where install for the nose section.   Notice that I left some panels open.  I did that so we could study the gauge positions.   Turns out that we will have to modify the IP (Instrument Panel) so the gauges will not go through the top skin.   We will not modify this IP because is will be mounted to a pedestal and no one will ever see inside.
June-19-2009     75% F4U Project The canopy almost fits!!!   I took the WAR F4U (~50% scale) canopy that I had made a few years back, and stuck it on to see how close it would fit.    Photo 1:  If you click on Photo 1 and 2 you will see just how close it is.   The WAR F4U is Parallel with the Crutch line and the real F4U canopy angles downward like the 75% F4U does.   I called the Canopy manufacturer tonight and left a message to see if we could possible hand re-shape this canopy to fit.  If he's willing to do that, I could possible make a new plug from the stretched version. Over all the length is 100% dead-on.  The bubble needs to be stretched back towards the seat about a 1½". Photo 2 & 3:   If you click on Photo 2, you can see how far the back needs to be stretched downward. Notice that there is a bit of a gat between the canopy and the body.  Reviewing pictures of the F4U-5, the canopy actually had a very small gap.   I plan on re-shaping the body to remove some of that gap. The last picture shows the untrimmed canopy from the front where the windshield will go.
June-17-2009     75% F4U Project A bit more body work on the upper back and we started cutting the backing plates for the forward section tonight.
June-22-2009     75% F4U Project The pics are a bit fuzzy...   I remember to clean the lens after I took the pictures, so Tuesday's pics will be clearer. I hot wire the foam by myself tonight and they came out great.  I'll add he two next to the firewall tomorrow.
June-21-2009     75% F4U Project I cut the blocks for all nine forward most sections, but I only glued in 5.   I thought my hotwire bow was not long enough so I stopped.  Turns out that it is plenty long enough and I could have glued them all in.
June-20-2009     75% F4U Project The back plates where install for the nose section.   Notice that I left some panels open.  I did that so we could study the gauge positions.   Turns out that we will have to modify the IP (Instrument Panel) so the gauges will not go through the top skin.   We will not modify this IP because is will be mounted to a pedestal and no one will ever see inside.
June-19-2009     75% F4U Project The canopy almost fits!!!   I took the WAR F4U (~50% scale) canopy that I had made a few years back, and stuck it on to see how close it would fit.    Photo 1:  If you click on Photo 1 and 2 you will see just how close it is.   The WAR F4U is Parallel with the Crutch line and the real F4U canopy angles downward like the 75% F4U does.   I called the Canopy manufacturer tonight and left a message to see if we could possible hand re-shape this canopy to fit.  If he's willing to do that, I could possible make a new plug from the stretched version. Over all the length is 100% dead-on.  The bubble needs to be stretched back towards the seat about a 1½". Photo 2 & 3:   If you click on Photo 2, you can see how far the back needs to be streched downward. Notice that there is a bit of a gat between the canopy and the body.  Reviewing pictures of the F4U-5, the canopy actually had a very small gap.   I plan on re-shaping the body to remove some of that gap. The last picture shows the untrimmed canopy from the front where the windshield will go.
June-17-2009      75% F4U Project A bit more body work on the upper back and we started cutting the backing plates for the forward section tonight.
June-13-2009 & June-14-2009    75% F4U Project Yet another week of body work, but we are very close to fiber-glassing.   I've been asked why there is a piece missing in the lower-aft section.  That section will get put in after the tail gear is installed.   This plug will have no need for gear, but we don't want to pass up the opportunity to fit the gear now, so when we build one what will need gear, we will no in advance that there will be no problems with our modified design. Photo 1:  Notice the shine on the skin.  The shinny areas are where the surface is correct and the dull areas are indications where epoxy filler is needed to fill in the low areas.   Both Pictures were taken on Saturday and by the end of the day on Sunday, very few dull spots remain. Photo 2:  Shows that the body formers were sealed with resin to prevent high moisture from destroying the inner structure.  This is the last step before we start putting the skin on We hope to fit the first canopy this next weekend. At this rate, we will not be ready to take the plug to Oshkosh.   Darn!  I was really looking forward to seeing the look on Paul's and his father's face when this monster gets dropped off at his tent.  Paul and his father are the founders of the Rotec Engines we plan on using.
June-06-2009 & June-07-2009     75% F4U Project Another weekend of body work and glueing stringers into the upper forward section.
May-31-2009     75% F4U Project Photo 1 - Mostly Body work.   I added several layers of glass bubbles and started smoothing out all of the hot-wire mistakes. Photo 2 - stringers in the forward section that were dry fitted were glued into place.
May-25-2009     75% F4U Project Most of the foam is now in place on the aft upper section of the body.  I hot wired all the sections as I worked alone this holiday weekend.  Notice the forward section has plywood on it.  The plywood was an experiment to see if I could get cheap door skins to take the shape without cracking.   There was some cracking and popping, but for the most-part the door skins fit fine.   If it's decided that we can finish the skinning process with this type of plywood, then that will save the project hundreds of dollars over using aircraft ply.   The aircraft ply we use cost roughly $149-$189 USD a sheet.  We will play with this a little more in the coming week.
May-23-2009 and May-24-2009     75% F4U Project Photo 1 - Show a bit more progress was made adding and cutting the block into shape. Photo 2 - While waiting for the block to cure, I spent a large amount of time playing with a prototype of the rear gear retract assembly.  We found a couple improvements we will try in future prototypes.
May-21-2009 and May-22-2009     75% F4U Project The first foam blocks where glued into place during a demonstration. I came back after the glue had set and hot wired the block. Before leaving cut 4 more blocks and glued them into place.   By the end of the Memorial Day weekend, I hope to have all panels that I do not need for accessing the center of the aircraft, in place and shaped.   Work was also dont to the tail fin (not pictured).
May-17-2009    75% F4U Project Photo 1 & 2: We started cutting and laying more backing plates into place. Photo 3 & 4: You can see that we started glueing the backing plates into place.  Not all plates will be glued in until the landing gear it fitted.   This aircraft will not have the gear but future versions will.
May-16-2009    75% F4U Project Photo 1: We added another layer to the leading edge. Photo 2: While waiting for the Leading edge to cure, we spent time designing a new rib to add strength to the Tail-fin post.  Also, the added rid will give us more surface area to mount the skin that will hold the Horizontal Stabilizer in place. Photo 3: With the leading edge finally cured enough, we added a very thin layer of epoxy to the out skin to seal the pours of the wood and provides a little more strength.   This also helps bring out any unwanted dimples we may need to repair before we start fiber glassing.
May-10-2009     75% F4U Project Photo 1: Time was spent increasing and strengthen the leading edge of the Tail fine. Photo 2: Additional Formers were added to hold the plywood that will hold the rear canopy slide rail. Photo 3: No matter which foaming system we decide on, we will need to add backing plates of some kind to help keep the foam in the correct position.  If Polyurethane is used it will help to cut down an the amount of foam used.  Most importantly these backing plates actually add more strength. NOTE:  For those of you that have not read the entire project, you need to know that this particular plane is NOT meant to fly.  This is a static display that will be mounted on a custom made pillar in Muskeegon, Michigan.  The plane will be painted in the colors of Ike Kepford's plane and be on display in front of the Muskeegon LST Museum.
Apr-18-2009 & Apr-19-2009    75% F4U Project The left side of the tail fin is glued into place and comes out of the clamps without any defects.  After adding the final stringer to the top left section, we dry fitted the horizontal stabilizer cradle into place. The former was about 1½ degrees out of place so we will make a custom part to help hold the cradle in place.   I'll focus in on that later.
Apr-04-2009 & Apr-05-2009    75% F4U Project More stringers were added into place and we tried making a fixture to help hold the skin of the tail fin in place while it dried.  I don't like using clamps as they can depress the skin creating dimples.  After wasting all after noon on a fixture, we settled for using clamps any way.  We got lucky and the skin was dimple free. While waiting for the epoxy to cure we played with dry fitting the part that will hold the canopy track.   The fit is near perfect but we found ways to possible improve on the design.     We will take another look at a possible design change later.
Mar-28-2009 & Mar-29-2009    75% F4U Project Mostly finish-up work this week.  Pictures to come soon.   We finished adding the final layers to the crutch and also worked on the top most stringer which we call the back-bone.  We'll finish the back-bone next week. We need to finish up the re-designs of the tail gear so Gerry can start cutting the aluminum and we can get the hydraulics ordered.   Even though the pictured plane is for display only and will need no landing gear, we felt that we could not pass up the opportunity to complete any possible design changes to the tail gear now and save ourselves a little bit of work in the future.
Mar-15-2009   75% F4U Project The leading edge of the tail fin will need to have a build up of epoxy before we can shape it.   A new layer of approximately 3/8" was applied and will let harden.   Any more and the resin could over heat and cause a fire. No work Saturday meant that we had to make up for lost time on Sunday.   The final layer of epoxy was applied to the bottom section last week and was still not hard enough to sand due to the cold air in the shop.   Rather than waiting for it to cure after bringing the room up to 80°F,  we turned the assembly over and started dry-fitting the crutch and stringers.  We broke-out the laser and aligning the body.  The crutch is now glued into place and the stringers in the rear section are also glued in as well. While wating for the crutch and stringers to cure, we played around with three possible ways to create the outer skin.  The best option so far was to custom fit blue styrene foam.   The third picture shows the shaped foam dry fitted into place.   The styrene foam worked far better than we imagined. Using a technique we learned form Gerald Clark of EAA Replicas Fighters Association.   This method is especially good because we can now hot-wire the foam into perfect shape. The last two pictures show the tailfin  and rudder spine clamped into place for a photo-opportunity. The laser was still on and when we put the rudder on, the alignment was perfect.  Notice the laser on the table saw, in the back-ground.
Mar-08-2009   75% F4U Project The first picture shows the original rudder design.   At 1/5th scale, this design works well.  However, at 75% scale, the design doesn't really work unless we plan on designing some massively heavy/expensive hinges.  Also it leaves creating the leading edge very difficult to shape with foam or any other method.  Any way we would attempt to finish the rudder would leave it less then optimally strong.   So a redesign was called for.   I started by drawing the center-pivot-line (as you can see).  After a few seconds, we had a solution.   We reviewed how other aircraft tackled the rudder and I found that WAR Aircraft Replicas' design could be retro-fitted and slightly modified to work.   I won't spoil it for you now, I will cover the design changes in future postings. This week, I finally finished the skeleton of the tail-fin and I started shaping the leading edge too.   The next step will to add a fair amount of very hard resin on the leading edge and shape it to perfection, much the same way that we finshed off the front-bottom section that you see in the final picture. A ton of time was spent on smoothing out the first layer of resin that was used to fill in the depressed areas.   Once finished with that step, I added a health portion of easy-to-sand resin and smoothed it out in order to make sanding a bit easier (as seen in the last picture).   The next step will be to sand everything perfectly flat one more time and then add a thin layer of fiberglass for surface strength.   CarbonFiber could be used, but we felt it was a waist of money considering this airplane will be used to make molds and super strength in this section was just not needed.
Feb-28-2009 & Feb-29-2009 & Mar-01-2009  75% F4U Project NOTE: all pictures are of the Firewall and first fomer while the aircraft is upside-down. If the first picture, you will see the "spacer" being fused into place and clamped. The second picture shows the stringers in place. When building a 50% WAR Aircraft Replicas design, the plans call for sheets of polyurathane foam to be glued together and laminated to the fuselage.   Later, you would sand the foam down to the body formers.    Sheets of polyurethane foam are outrageously expensive.   We wanted to try the liquid version of polyurethane foam and see if we could get better and cheaper results.   ...better?   maybe...    Chaeper?  ...probably. What we found was that you had to mix up very small batches and immediately apply it to a small section.   Not once could we apply all of the resin without having sticky foam all over the place and as you can see on the last two images, it's impossible to get it on evenly.  Just to foam this small section, we went thru 1 set of bottles (resin and activator). One major benefit was that the foam was completely cured at 45 minutes and we could sand and apply the small batches more times per day than expected. Conclusion:  Liquid Foam will work,  but hand-appling just is not going to be efficient.   We will look into setting the pressurized spaying systems to foam.   Otherwise, we will be going back to polystyrene. DOW just released a Polystyrene system much like the existing urathan systems.   An email was sent to DOW, but we are still waiting to hear back from them.
Feb-28-2009 & Feb-29-2009 & Mar-01-2009  75% F4U Project Originally, the shelf between the two body formers that our CEO is working on, was meant to be nothing more that a device to keep the body formers properly spaced-out.  However, Joe Labert (Pictured) took the idea and turned it into a fuel tank shelf.   It turns out that the location will allow the fuel cap to be located in the same location the real one was.  We will try to turn this section into a compartment that will open for fuel tank removal/maintenance.   Remember, this particular Corsair design is a the static display version only.  So this idea will be transferred to the flyable version.    Kits of the smaller 1/5th scale will be available by another comapny soon!!! There are no plans to post development pictures of the flyable F4U at this time.
Feb-20-2009 & Feb-21-2009 & Feb-22-2009  75% F4U Project The center "Spine" for the Horizontal Stabilizer may look complicated but turned out the easiest to create tool paths for.  Click on the image to see how the program created the tool paths for our CNC Router.  These and many more parts will be cut out and prepared for assembly tomorrow morning.  We managed to get the tail fin 80% finished.   As some point I forgot the change dimensions after increasing the thickness of the support pieces so they didn't fit exactly right the first time.  This is actually the third version with the leading edge just laying on top while the Epoxy dries on the lower pieces.  We had better luck with the center cestion of the Horizontal stabilizer.  The pieces all fit perfectly the first time.
Feb-14-2009 & Feb-15-2009  75% F4U Project The wing saddle was reinforced with two more layers of plywood. We disassembled the entire aircraft and made some minor last minute adjustments and added clear coat to several of the parts.  The center photo shows that gluing has started with the firewall.  The second rib is not finished and will undergo another modification; however it worked well to help pull the firewall flat onto the wing saddles.   Aluminum fittings will be added to the final version to add even more strength. Many more parts were laminated (not shown),  while waiting for the parts to cure, we started cutting the vertical and horizontal tail feathers.
Feb-08-2009 - Late Eveneing - Late Eveneing  75% F4U Project The first photo shows the aircraft being dry fitted and we used that to check alignment.  The alignment was not perfect enough considering this aircraft will server an the master plug from wich to make the molds. The second photo shows the support beam directly behind the pilots head. The third photo shows the control panel with holes that will hold the tradition "Steam Guages".   The layout was modeled by way of overlaying an image of the real F4U-1A's control panel.  The fit was almost perfect.   Two of the guages had to be moved and two additional guages were added to monitor possible wing and or drop-tank(s).
	01-02-01-2009 - Late Eveneing  75% F4U Project Just for fun, we took a few layers of the crutch and put them into place on the rear section of the fuse and placed some of the remaining body formers into place, including the Tail Gear Structure.   This thing is starting to look like an airplane!
	01-02-2009 - Early Morning  75% F4U Project Tail Gear Mounting Structure complete.  For the prototype, we will leave the assembly made from 2 layers of ¼" Ply. because this particular version will likely never get fitted with any landing gear.  The next version will be made of aluminum.
	25-01-2009  75% F4U Project The crutch takes shape using an old multi-layer technique.  The crutch is fairly strong with only 2 layers and will be get exponentially stronger wtih each layer.  The cruch uses three species of soft and hardwoods.
	18-01-2009  75% F4U Project New improved parts were cut.  You can see the new version being assembled on the table.  Also note the Original 35% prototype in the background.
	17-01-2009  75% F4U Project Assembly of the first parts cut show many opportunities for improvement
	1-01-2009  75% F4U Project Begins The First parts are cut!