Parts From Flexible Cutting Board

Hello everyone,

This article is about making accessories from flexible cutting board.  These ideas and techniques have been shown scattered in some of my articles but here they are compiled in a more focused and compehensive form here.

The raw material is available from many sources and is pretty inexpensive.   I recently looked at several products on Amazon.  There are several options starting at under $2.00 per sheet.  More than likely you could find one for free in the nearest kitchen.  The product is usually packaged with several sheets color coded for different food products; meat, fish, vegies, etc.  The colors can add a nice accent to your project.  They are also available in all clear or white if you prefer a non-intrusive appearance.  The ones in our kitchen came from Aldi's and look like this: 

What can you make?  Well, basically anything that you can make from used gift cards can be made from this material, including:

Control Horns

Attachment tabs

Reinforcers of several types

Achoring points.

Hatch pulling tabs

Landing gear skids

Here are soome examples:

CONTROL HORNS:

Various sizes of control horns can be made based on first cuttting 1", 1 1/8" or 1 1/4" strips.  The strips are cut using a  straight edge and hobby knife.

First trim the edge so you have a straight line to start with:

Then cut the width of strip you need based on the size of control horns you will make:

Here I have used the grid on the building board to cut 1" , 1 1/8" aand 1 1/4" strips.

Next use the grid again and scissors to cut the strip into squares (or longer pieces), one for each pair of horns you need.  Like so:

 It is a little tricky to get the scissors and piece lined up with the grid at the same time.  If you get off too much just toss it and do another.  Practice, practice, practice.

Then use the scissors to carefully cut corner to corner to make two equal triangles:

Next take one triangle and trim the corners with the scissors to make the final control horn shape.  Like so:

Make the first one by eye and use it as a pattern to cut the rest.  Just hold two together with the pattern on top and cut the second one to match.  Repeat with all that you are making for the set.

Note: You should mark the pattern "P" with magic marker and save it future use.  Always use the pattern for trimming so they don't "grow" by progressive adding of small amounts.

Next take the pattern and drill three evenly spaced 1/16" holes leaving at least 1/16 " of material to all edges.  It should look like the last step in the picture above.

Finally, stack up to 6 horn blanks carefuly aligning the edges where the holes will be drilled (right in the picture above) and the edges that will be embedded (down in the picture above).  Use a pair of vice grips to hold the stack in alignment with the pattern on top.  Drill through the pattern and into the rest in the stack to a make a uniform set of matched holes.  It does not matter if the diagonal edges or corner cuts do not a match exactly.  This is the only time you will have them close enough to  tell.  Your drilling set-up should look like this:

The completed group should look like so:

These holes are slightly uneven but not enough to worry about.

Here is a display showing the progressive steps with all three sizes:

Note that there is room for more holes on the two larger sizes, 4 and 5 each respectively.

The two pairs on the bottom are made from 1" strip but the pieces were cut to 1 1/4" (left) and 1 1/2 " (right).  These are the same as the 1" ones at the top of the picture but have longer embedded legs for larger or wider control surfaces.  The largest I have made are 1 1/4 X 2".

For larger models I have glued as many as 3 of these together (using hot glue) for more stiffness. Two thick is probably enough for most cases.  If you are stacking it is best to drill one before assembly and drill the rest of the stack after assembly.

This is a 3-ply installation on my 80" flying wing. They were made with 1 1/4" X 2" blanks.  The ailerons are 31" long and 2" average width.    

Here is a picture of a typical installed control horn:

Make sure to align the holes with the hinge point.  You may have to run the drill through the holes again as you install the control rods. 

Well, that is it for control horns.  Just install them the same as you would the plywood ones from FliteTest.  I like to fill the slot completely with glue, insert and adjust and then run a small bead in each side.  They end up rock solid.  They will flex to the sides which helps getting the control rods inserted.  I have never had one of these fail in use. 

ATTACHMENT TABS:

I use very small pieces of cutting board to make attachment tabs for linkages to connect paired rudders so they can be operated with a single servo.  The linkage is a piece of flag wire that is attached to each rudder trailing edge with the attachment tab:  They look like this:

Here is the fabrication sequence using a 1" strip of cutting board:

The tapered pieces are cut from the 1" strip with scissors.  The thicker end is about 3/16" wide so that it will just fit into the foamboard.  The 1/16" hole is carefully centered so that there is 1/16" of cutting board all around.  The thinner end is 1/8" or a little less.  A hole is made about 1" deep with the pointed end of a skewer.  The hole is filled with hot glue and the tab is inserted.  With this type of linkage with "Z" bends on both ends you have to attach the second tab to the linkage before inserting it.

REINFORCEMENTS FOR SKEWER CONNECTIONS:

Josh has shown us how to reinforce the holes made by skewers in power pods using gift card material.  The same thing can be done using cutting material.  Just cut a 1" square and drill the center slightly bigger than the skewer (Most skewers are 1/8"so 9/64" or 5/32 would be good).  Spread a generous ring of glue around the hole and use the skewer to center it as you install it.  Here is one (dry fit) in place:

For installations where the skewer is closer th the edge of the foam a triangle cut from a 1" square works well.  Here are the two shapes that I generelly use:

Here is a triangular one installed and well used.  The skewer was installed closer to the top edge of the power pod with a zip tie through the wing to make more room for the battery :

This one has gone through a few rough landings with no movement (There were a couple of broken skewers).

WING TIP HAND LAUNCH DOWEL REINFORCER:

I use a short piece of dowel mounted at the left wing tip as grip for hand launching many of my designs.  The dowel goes through a hole in the foamboard near the wing tip with a piece of cutting board on the bottom to reinforce it.  It looks like this:

The reinforcement was cut from 1" strip with the right angles to match the folds in the wing.  A 3/16" hole was drilled in the reinforcer leaving about 1/4" to the wing tip.  The reinforcer was glued into place.  A skewer was used to make a hole through the foamboard starting from the bottom and just piercing the top.  Then the hole was finished with the skewer from the top.  A 1 1/8" length of dowel was tapered slightly at both ends and inserted from the top with a generous ring of hot glue placed on the dowel and then twisted down to spread it like a donut on top.  Then a ring of glue was applied around the dowel at the bottom.  Nice and secure. 

LANDING GEAR ATTACHMENT POINTS:

I wrote an article earlier about making retractable landing gear from wire hangers.  The attachment points were made from cutting board.  Here is a picture of the completed installation:

The larger pieces were trimmed from triangles made from 1" squares.  See the related article below for details.

This method could be adapted to attach any sort of moving accessory that requires a pivot point.

HATCH OPENING TABS:

Several of my designs have hatches covering the equipment bay.  The hatch is generally made flush and secured with velcro so a handle is needed to pull it open.  I use cutting board to make small tabs for the purpose.  Here are some pictures:

This one is made by cutting a piece about 3/8" wide from a 1" strip.  A slot was made in the end of the hatch, filled with hot glue and the tab inserted.  A bend was made in the tab by holding it down with needle nose pliers and bending about 3/8" of the end up at 45 degrees.  The longer end was then inserted into the glued slot.

This one was made to glue onto the inside of the hatch:

Again, the tab was bent up before installing.

Both methods work equall well.

LANDING GEAR ANCHOR POINTS:

Some of my designs use a landing skid made from flag wire to avoid scuffs on the bottom while belly landing.  These use a conventional landing gear attachment at the center with two dowels and rubber bands.  The gear is made in an arch with spring tension and inserted into an anchor point in the wing on each side.  The wing anchor points are where much of the landing force is applied and they are reinforced with cutting board triangles cut from 1" squares:

For more details see the related article "One Sheet No Waste Twin Tail Boom #3" below. 

BELLY LANDING SKID:

On my "Half Sheet No Waste Flying Wing" I used a piece of cutting board to reinforce the lower corner of the underslung gear pod.  It has a hatch for gear access that attaches at the same point so it would be subject to damage on even normal belly landings.  The cutting board skid is made from a 1" strip running the full width and hanging down about 3/8".  I have not tested it yet but it should soften the force of a normal landing.  It looks like so:

Hopefully this will save the pod.

I am sure there are many other possible applications.  These are just a few that I have used,

The sheets are 12" X 15" and cost under $2.00.  If you cut all 1" squares and cut those all to triangles for horns, etc,  you would have 360 horns at about 1/2 cent a piece.  OK, so you would have to build 90 planes to use them all, but I am just say'in!  Pretty good economy whatever the application.

Please let me know if you have any other ideas for using this stuff.  

Have fun building!

Dan