Update on the board I'm making. All the foam was glued up and perimeter bands were added. I hand shape the blank to get it squared up. This is the top before the rail bands were added. The shaping is done and I laminated the bottom, but I didn't take new photos. I will get more photos later.
@sharkcountry that looks very cool. Do you expect the board to be as strong as the one made from a single foam block?
I usually add a balsa deck skin either 1/16" or 1/8" thick sheets of model airplane balsa. I also try to keep the laps going all the way around the rail. So far, I haven't had issues with the boards. The balsa decks are very strong against pressure dents.
I believe the glue joints add a lot of strength compared to a single piece of foam. They are spaced just under 2 inches apart. The foam is about 1lb density, when I get foam that is softer, I don't use it.
If anything, this process is much more complicated compared to a single block of foam. I do it because I had all these small EPS coolers coming to our house and gave away as many as I could. I believe this is the best way of recycling that foam. Sending it to a place that breaks it all up then fuses it back seems to require a lot of energy. I use a bit to cut up the coolers and a little more in the shaping.
If I was making boards for other people, I'd buy a good PU blank and do it right.
This is just something I can do with excess foam that would end up in the trash bin. I've made 5 now and 3 are used quite a bit.
karolis: the best CAD software is probably the one that you're most familiar with, and the one that exports a toolpath your machine can use. Unuseable toolpath = useless software. And that's all I know about CAD/CAM.
OK so the CNC homing issues are fixed and machine is almost ready to cut.
I also played with Board CAD, AKU shaper and a few other programs. From all the apps dedicated to surfboard design, AKU Shaper seemed like the most promissing one, but in order to use it with my CNC machine I would have to pay $45/month and still get an application with very limited features. Meh. I went back to good old Fusion 360 and after a few days of tracing the slices and outlines I have a virtual copy of my current board.
I still need to add fin box positions, cleanup the design a bit and buy a compressor to blow off the foam dust. The foam is going to be everywhere! Hopefully I can do some test cuts in the next few days.
EPS gets everywhere.
I babysit with a shop (25 liter drum) vaccuum cleaner and suck foam bits up every few minutes.
Support your blank at the ends. The foam will bend away from the cutter.
I use Shape3D on Mach3, but there are Euro involved in the S3D CAM license.
First attempt to cut a scaled down version of a board. There are some small issues but in general the concept works fine. With the current settings it would take around 2.5 hours to cut a full size kite board. I think after some tuning I could bring the time down to around 1 hour.
It is amazing to me how nice those blanks turn out once you've shaped them. Impressive. The balsa deck is good insurance. Ever do one in which you did both the deck and bottom. You know; just to the cutlap?
That which can be assorted without evidence was read in an illegal magazine.
I used to put wood on both sides, but those were the compsand boards we did. Probably been 4 years or so since I did both sides. The balsa wood decks keep the pressures down.
I think the main strength is in the glass because most of the boards I do are stringerless. I do double lams on the bottom, one before fin boxes and one after the deck is done and the boxes are set. Comes out a little heavier, but not as heavy as a strong PU/PE build. I'm just about done with this one, I really hope this one does all I expect for a 7' board.
Yes sir! As I said; "I am impressed".