All FAP Panls Joined

The fourth, and final, Fold-A-Plane (FAP) panel has finally joined the other three. I have colored them in this image so that they are easier to distinguish.

Right now they are only bonded together with micro (a thick paste made from epoxy and glass micro-ballons), but soon the joints will be overlaid with 4" wide strips of BID to make them secure.

Time Spent Today: 2.0 hr

All FAP Panels Completed

Yesterday we glassed the last side of the last FAP panel.

Time Spent Today: 4.0 hr

Back On Track

Over the Labor Day weekend I managed to cut out the broken panels, make new ones (including a layer of UNI and BID on one side), and get them glassed in place. Today I glued the three completed panels together again, which is where we were when we discovered the issue with the fractured foam in the original panels.  I used some super glue to attach a couple of sticks across the assembly to keep those panels (shaded green in the photo) from being damaged again.

Time Spent over the Holiday: 6.0 hr
Time Spent Today: 1.0 hr

Oops

When using the Fold A Plane (FAP) technique you only glass one side of certain panels until after the folding task is complete. As mentioned in an earlier post, even a light coat of epoxy, even without glass in it, is enough to prevent the panels bending in the way they need to.  One thing to note is that a properly prepared, glassed-on-one-side panel is still a fragile thing; prone to bending the wrong way and breaking. That is what has happened in the pictures. Two smallish panels, that have heavy panels on their outboard ends bent backwards and the foam snapped. One obvious issue with the break is that the panel does not bend in a smooth radius any more.

Bent this way until the foam snapped.

Now looks funny when bending.

 Nothing to do but replace the broken panels with two new glassed-on-one-side panels.

  

Time Spent Today: 1.0 hr

Getting Ready For Bending

It was an unusually cool day for August in Texas, so I spent all day on the plane. Once the last side of the last FAP panel is completed (Monday?) we will be ready to use the Hinged Panel Tool to fold the sides up on the fuselage. Before that could happen I needed to correct a mistake. We had accidentally applied epoxy, but not cloth, to an area that needs to bend, and I needed to remove that layer. Even without cloth there was no way that area of the panel was going to flex like it needed to. Ordinarily that would been sand paper and a lot of elbow grease, but I have The Machine, the 4'x8' CNC router table I built. I built it because I was originally planning on building a metal airplane and wanted to make my own 'kit' rather then using tin snips. The Machine is what I have been using to cut out my foam panels accurately.

 After aligning the panel on The Machine's bed and measuring the X and Y coordinates of the area I needed skinned, a software package I use with The Machine was only too happy to create a tool path for the router to follow. I chucked in a 3/4" mortising bit and, with my hand hovering over the emergency stop button, let The Machine skin off  the 1/25 of an inch thick layer of epoxy. It worked out perfectly.

 
I next let The Machine trim and straighten all of the sides of the 3 finished panels. Basically I had it make multiple passes along each side, each maybe 1/100" deeper than the last pass until I was happy with the resulting edge. Four passes was usually enough. Here is a before/after pair of pictures. The Machine only needed to remove 0.040" to get that edge clean and dead nuts straight.

Lastly, I mixed up some micro (epoxy and glass balloons mixed into a putty) and joined the 3 finished panels together on the HPT. The screws and fender washers are to keep the seams tight as the micro cures.

Time Spent Today: 8.0 hr

First Side of Last FAP Panel

There are four FAP panels, each with two sides. Each side must be sealed with slurry and then layered with one ply of UNI and one ply of BID. This is side number 7...  one more to go!

Time Spent Today: 4.0 hr
I realized today that I have been totaling clock hours and not man-hours, so I am making an adjustment to account for my wife's added time. All future hour reports will be man-hours.

Time Adjustment: +12.0 hours

Starboard Fuselage FAP Panel Glassed Other Side

Kinda skipped out of the groove there for a bit. WE are now in a full-on push to get the other fuselage panel done and the whole thing on the HPT and folded into a basic airplane shape.

It takes two people  about two hours to pre-cut the fiberglass cloth (one ply each of UNI & BID), seal the foam with slurry, and then position and wet out the cloth.

One picture shows the excess epoxy being squeezed out of the layup by the use of a vacuum bag.

Time Spent Today: 2.25 hr

Starboard Fuselage FAP Panel Glassed One Side

Laid on the UNI and BID on one side and then vacuum bagged it.

Time Spent Today: 1.5 hr

Back in the Saddle

Haven't done any work on the plane in almost 4 weeks.  A SCUBA diving vacation to Honduras took up 3 weeks of that; one week to prepare, eight days there, and one week to get back to normal.

Things are back to normal so today I got back to work by getting the starboard fuselage FAP panel ready to lay up, including cutting the UNI and BID to shape.

Time Spent Today: 2.0 hr

Second FAP Panel Glassed Both Sides

Same job as yesterday, just the next FAP Panel aft. There are two FAP panels left. The first two form the cockpit and baggage area (both now finished) and the next two form the tapering part of the fuselage back to the tail. There is a port one and a starboard one.

Time Spent Today: 2.0 hr

First FAP Panel Glassed Both Sides

Finally back in the shop.  I ran out of bagging film and it took a week to get more. I need to get better at keeping items 'in stock' to prevent useless delays like that.

Not much to say tho, we just glassed most of the inside of the forward-most HPT panel. We didn't glass all of the inside, just the parts that are not going to bend when the sides of the HPT are hinged up. This will make sense later.

Time Spent Today: 2.0 hr 

HPT has Legs and is Right Side Up

Here is the HPT both up side down and then right side up. The legs have my usual 1/2" bolts and nuts embedded in the ends so that the rig can be adjusted level on the slightly uneven floor. The hinges are some 3' stainless steel hinges I picked up off of Amazon for about $5 each. A bit of over-kill for this application maybe, but for $5 I will find many other uses for them at some point.

Time Spent Today: 6.0 hr

Hinged Panel Tool (HPT) Layed Out

The most significant thing today had to do with a push broom.  I finally got the corner of the shop slated for assembly of the plane cleared and swept. I then laid the panels that make up the HPT out on the floor to check the fit. Tomorrow I start putting hinges and supports on the HPT.

Time Spent Today: 0.0 hr ('cleaning the garage' is something I should have done anyway and so I am not counting that time toward build time)

Glassing Side One of the Second FAP Panel

While the first large layup we did a week ago came out fine, we decided to change to the Aeropoxy PH3665 hardener for 120 minutes of pot life instead of 60 minutes of pot life. The idea is that any excess epoxy in the layup would be more liquid during vacuum bagging and thus more would be removed.

It has become apparent that the vacuum pump we have been using (a 'wet' type pump generally used for servicing air conditioning) is not going to work. It gets very hot after 6 hours and emits a fine fog of oil mist while running. We are switching to a Gast DOA-P101-AA pump from eBay.

Time Spent Today: 2.0 hr

Start on the Hinged Panel Tool

Today I un-bagged the layup we did on Tuesday and cleaned up the excess material around the edges. I hope to lay up the other side tomorrow afternoon.

I also started cutting out the panels needed for the Fold-A-Plane Hinged Panel Tool (HPT). The HPT is a construction technique invented by another Vision builder. The  basic idea is to lay the completed Fold-A-Plane fuselage assembly on the thing and then fold the sides and tail up to easily establish the vertical sides and lifted tail of the fuselage.

I am making the HPT out of 5/8" particle board. The stuff is stiffer*, straighter*, and cheaper than  1/2" plywood.  I bought some stainless piano hinges for a great price to hinge the panels together. Stainless is overkill for this task, but they were only 10% more expensive then the aluminum or steel ones and stainless will be useful on many other projects around here at some point.

Time Spent Today: 2.0 hr 

First Glass Laid

My wife, Lesa, and I tackled glassing the first side of the first FAP panel today. Things went really quite well even though it was our first time laying glass in many years.

First we cut UNI and BID to fit, then folded the fabrics and set them aside.

After vacuuming the surface of the foam and applying micro slurry (syrup consistency) first the UNI and then the BID were laid down and wet out with warm (30C) Aeropoxy using putty scrapers. Adjoining strips overlapped its neighbor by at least 1".  The picture on the right shows the wet out layers getting a layer of perf-plastic before an absorbent 'blotter' layer and a layer of vacuum bagging plastic. We realized too late that we forgot to apply peel-ply to the aft edge where it will join the next piece. Oh well, easily addressed with sandpaper and acetone.

Here you can see the whole layup being vacuum bagged. On the right you can see Aeropoxy being squeezed through the perf-plastic into the blotter layer (the yellowish polka-dots). There is a lot more being squeezed out than I expected; I really thought we did and excellent job of removing the excess Aeropoxy with the putty scrapers. Maybe we did... maybe vacuum bagging is just that much better...

(Note: DO NOT put the vacuum port on top of the part like this. 

Epoxy will collect under it and leave a mark.)

What Ty thought about the whole affair.

Time Spent Today: 3.0 hr

Second FAP Panel Goes Together

Yesterday the first (of four) panels that make up the lower fuselage was assembled and this evening the second one was assembled, again using the piping bag technique to apply micro paste to the edges being bonded.

Time Spent Today: 1.0 hr

Cutting More Parts

The last couple of days saw the cutting of all of the 1/2" and 1/4" foam panels that make up the lower half of the fuselage. Work ended Sunday when the panels that make up the forward-most FAP panel were aligned and micro'ed together using the piping bag method of applying a bead of micro bonding paste to the mating surfaces. The white cloth strips running under the seams between the panels are made of Dacron and are there to keep any extra micro paste the squeezes out of the underside of the seam from bonding the panels to the work table.

Time Spent Over Weekend: 10.0 hr

Cutting of First Parts

Today I used the CNC router table to cut Last-A-Foam for the first time. That Last-A-Foam makes a lot of dust when sanded or machined. Thank goodness for the dust boot and the vacuum hose, which handled 99.9% of the resulting fine particle waste. The whole cutting job was done in about 15 minutes.

I also micro'ed another set of panels together so that they would be ready to go tomorrow.  I micro'ed them using a different technique than I used yesterday, which was to use a stir stick as a spreader and apply the micro 'bagel and cream cheese' style.

This time I put the micro in a ziplock bag and, after moving the micro to the bottom of the bag with a stir stick (toothpaste-style), I cut out the corner of the bag to make it into a piping bag. It worked quite well as I was able to run a neat bead along the edge of a sheet before mating it to the adjoining sheet.

 

Time Spent Today: 1.0 hr

Official Start of Construction

Construction had begun.
That first step on a journey of a thousand miles has been taken.
Epoxy has been mixed.

The first major milestone in the construction of the Vision EX is the lower fuselage (aka 'the boat'), consisting of the entire assembly of the sides and bottom of the fuselage from the firewall aft. I will be using the alternate 'Fold-A-Plane' method of construction so my first steps are to make about a dozen variously trapezoidal foam panels. While I could lay all of this out with a ruler and a Sharpie, that really isn't my style.  Instead I drew all of the panels out in Autodesk Inventor 2013 and nested them with Cut2D to get the most out of the sheets foam.

The nesting exercise revealed that I need to make three panels by joining stock 24"x48" foam sheets.

Panel 1 is 48"x96" (3 sheets)

 

Panel 2 is 48"x96"

Panel 3 is 30"x48"

I

Here are three of the stock panels being bonded together with a paste made from Aeropoxy and micro-ballons. The black things on the panel are mesh bags of lead shot (scuba soft weights). They are there to hold everything down while the epoxy paste cures.

Once everything is cured, I'll take this triple-panel to the CNC router table and let it accurately cut out the shapes for me.

Time Spent Today: 3.0 hrs (including CAD work)

Epoxy Hot Box

Warm epoxy is less viscous so it flows, measures, mixes, and wets out better. Keeping it in a 'hot box' so that it can be dispensed as needed already warm and ready is a great convenience.

Since I still have no supplies (same as yesterday) I decided to build a hot box.  I started by using the sheet metal features of Autodesk Inventor 2013 to work up a suitable design. I saved the unfolded parts as DXF files and then used Cut-2D to create tool paths and save them in g-code. Finally I sent the g-code files to my homebrew 4'x8' CNC router table and had it cut the parts out of some scrap 040 and 032 6061 aluminum I had laying around.









The Vision calls for using Aeropoxy, which comes in cans, and doesn't have pumps for metering, so I will be transferring the Aeropoxy parts into a couple of one gallon jugs with pumps I got off of Amazon. The hot box has a layer of foam insulation lining the inside and each jug is wrapped with about a foot of 4" Flex-Watt heat tape (that happened to have laying around). The resin jug is sitting on the temp sensor of this nice little temperature controller and the heat tapes are attached directly to the controller's A/C output. Very simple hookup.

Here is the finished hot box sitting on the mixing stand next to the gram scale for getting ratios correct and a temp/humidity meter for making sure environmental conditions are within limits for working with the Aeropoxy.

Time Spent Today: 6.0 hrs

The Build Table

I am still waiting for all of my supplies to arrive, which is OK, because as of 2 days ago I didn't have a build table on which to use them to make parts. That has been corrected. For a long time now I have been ruminating on how best to build the table. After all, your aircraft is only as straight as your table. A post by 'Little Scrapper' in the Workshop Tips and Secrets / Tools forum on HomebuiltAirplanes.com suggested that 16 gauge steel wall studs are 'dead nuts straight'. I found a retailer of such steel studs nearby and bought 4 of them with 6" webs for about $15 each. After another stop at Home Depot for a couple of sheets of 3/4" MDF ($30 each) I was ready to start my table.

The steel studs I bought were 12' long so I needed to make the table top 12' long as well. I cut one of the sheets of MDF in half and joined it to the full sheet using #20 biscuits every 6" and a bead of wood glue.

Next I pre-drilled some 1/8" holes in the stud flanges to make setting screws easier. Access to the flanges is a bit tight; you only have about 5" of clearance so I used my right angle drill motor and the super special drill bit you see in the picture (regular 1/8" drill bit snapped in half with a pair of pliers). The right angle drill motor made short work of driving the 3/4" screws through the flange into the MDF as well.




















I attached three of the studs as lengthwise runners left, right, and center, then cut the fourth one into thirds to provide the beams that the runners would sit on and that the legs would attach to. The legs are 2x6 dimensional lumber boards cut 38" long with 1/2" bolts and nuts installed in the ends to provide a way of compensating for an uneven floor.

Time Spent Today: 7.0 hrs

First Order of Supplies

Although I purchased my plans five months ago (November 2015) I haven't done much other than read them and prepare the shop. Preparing the shop did involve a lot of drywall repair, painting, and better lighting, so it was a lot more than just sweeping and setting things in order.

Yesterday things got a lot more real when I placed my first order for building supplies from Aircraft Spruce; foam, Aeropoxy, fillers, peel ply, and lots of miscellaneous consumables (see below). The stuff can't here soon enough. From Amazon I ordered a digital scale, some bottles and pumps to measure out the Aeropoxy with, a pair of stainless scissors and a 'pizza style' rotary cutter.

Qty Ship B/O Item Unit Price Total Price 1 1 0 01-25800 MIXING STICKS BOX OF 500 12.750 12.75 1 1 0 01-14700 3M GLASS BUBBLES 5 LB. 43.750 43.75 1 1 0 01-14900 FLOCKED COTTON FIBER 5 LB. 21.750 21.75 1 1 0 01-25700 12 OZ MIXING CUP (PKG OF 60) 14.750 14.75 2 2 0 01-24902 #3FR EPOXY ROLLER FRAME ONLY 6.750 13.50 2 2 0 01-24903 EPOXY ROLLER COVER ( ONLY ) 4.350 8.70 1 1 0 01-42150 PR2032/PH3660 GALLON KIT 138.950 138.95 50 50 0 01-00642 BID FIBERGLASS 38" RA7725 7.850 392.50 4 4 0 01-13500 LAST-A-FOAM 4.5 LB 1/4X24X96 35.700 142.80 5 4 1 01-13700 LAST-A-FOAM 4.5 LB 1/2X24X96 57.750 288.75 2 2 0 01-13600 LAST-A-FOAM 4.5 LB 3/8X24X96 44.750 89.50 1 1 0 01-12000 URETHANE FOAM 2" X 24" X 96" 73.850 73.85 10 10 0 09-00500 DACRON FABRIC 605 2.97 OZ 3.950 39.50 2 2 0 1080-50 LT.WEIGHT 1.45 OZ INDUS CLOTH 6.600 13.20 10 10 0 01-00641 UNI. FIBERGLASS RA7715/38W F16 10.500 105.00 Subtotal: USD 1399.25