Foam board

[john e. holliday]

Foam board as found in arts and craft stores,  has any one tried laser cutting it?

[MikeyPratt]

Hi John,
Sure you can, just slow down the speed and power of the laser and it cuts fine.  But it is so easy to cut with a knife it is almost as fast as the laser.  I've done that a number of times on built up wings and it works great.  It can be used on fuse formers, wing Ribs, and other places.  You can even vacuumed form it a little, that kind of foam I’ve used for free flight wings and stabs.  Really easy stuff to work with, so I know it would work well in other areas as well.  I’m trying cut out pieces to fill lighting holes in profile right now and it seems to be just great so far.  The old glue that was called PICA Glue It worked well but not sure it is made any longer. 

Later,
Mikey

[Paul Wescott]

Foam board as found in arts and craft stores,  has any one tried laser cutting it?

Doc - Laser will do it but melting any kind of foam or plastic produces nasty fumes.  There is a DIY article out there about a better way than laser cutting.  Someone made a $5 thing-a-ma-Bob like a tattoo gun on steroids.  A small brushless motor with a crankshaft and a music wire needle.  Mount the TAMBob on an X-Y system like a laser cutter.  Fire up the powered needle and it perforates the paper and the foam at high speed.  Push <GO> on the CNC X-Y system and it produces laser cut precision parts out of 99¢ sheets of foam.  I don’t have a CNC X-Y system of any type (laser, router, plotter, etc.) or I would have paid more attention.  But a couple minutes searching should unearth it.

Paul W.

[john e. holliday]

Thanks for the response guys.  I've been cutting ribs and parts for one of two identical planes I'm constructing.   Bought three sheets of 1/8 foam board for less money was asked for one sheet of balsa.

[john e. holliday]

Well this has been an experience I may not repeat.  Went through a dozen Ex-acto no. 11 blades cutting the peices.  Weighed each of the peices and foam is a little bit heavier.  The wings are both at the same stage.  plywood bell crank mount with three inch bell cranks from MBS Model Supply.  Lead outs are .027 cable doing swagging both ends.  The foam wing has balsa leading edge, wing tips and triangle braces to kepp it square.  Weighed the wings today:  Foam wing = 12 ounces,  balsa wing - 9 ounces using diet scales the wife has as my postal scales went on the blink.  More later after I get them covered.   They will be in the fuselages before I cover them.

Second pic is foam wing.