Hi, i am in the research phase of my first hollow wood build and i have questions about stringers that are over 8ft long. Marine plywood comes in 8 foot lengths, i beleive, so how do i create a stringer longer say 9 or 10 ft? I plan on using a cnc machine to cut the ribs and stringer out since i have access to one. I am using aku shaper and the template i looked at creates one solid stringer. So what am i missing?
Not trying to be flippant or a smarta$$ but, it seems what you are lacking is creativity and vision. You are relying heavily on machines to do what the mind can easily do. Have you never heard of a scarf joint? Plywood can be bought off the shelf ten feet long or can be ordered to any size you want. Money is the only constraint. The issue here is that you have to build it in your mind first. Having done that, you can see that it is possible to do all on your own. No machines, no programs, only you, your eye, and the shape you want. The eye is the first and foremost thing to train. If you can’t see it…how will you know it is done? Also, it doesn’t have to be marine ply. Exterior grade plywood and a thinned out coat of epoxy will get you the same thing for less dough. I realize it is the age of the machine, program, drone, apps and all that other superfluous crap, but ya need to walk before ya run. If you are stuck on what you want, look up Wood Joinery for suitable joints. I wish you luck and not trying to be a dick.
I know what scarf joints are, yes. I appreciate the sage advice but my mind is already made up. I have a cnc machine at my disposal and using it would save me a great amount of time.
If you dilute epoxy with rubbing alcohol to a consistency of thin paint or thick water (ambiguous I know) you can seal all the ply with it and forgo the added expense of marine grade. Brush or weeny roll it on. Gets good saturation. And thanks for not putting the phrase; “sage advice” in quotes. Just trying to help.
Jigsaw puzzle joints…
Does Aku ouput what you need or do you have to post-process to get the HWB stringers and ribs?
Thx for the input, and that is definitely an option I didnt consider. Can I somehow edit AKUShaper and HBTM (hollow board template maker) so i can save money and trees by creating a single 2 part stringer on an 8ft plywood board? I’m new at this so I dont know how this is properly done.
jrandy, that is exactly what I am asking. I am using the HBTM add on to calculate the ribs and stringer. How is the puzzle piece you show above done on AKUshaper?
It’s manual CAD work done in Draftsight.
Once you figure out how to get clean CAD data from HBTM you would have to draw in the features to split the stringer.
wow, ok this is getting a bit more complicated. Thank you for the answer. I’m guessing I have to convert the .brd file to a readable file for draftsight? is this something you usually do?
Honestly, the stringer’s significance is very different in a hollow wood surfboard than in a foam board. The longitudinal strength in a hws comes from the skins, and the rails, not from the stringer.
The stringer is only significant to building the bones, and having a structure strong enough to hold shape while adding the skins. Depending I guess on your chosen methods of construction, which I don’t really know at this point.
In other words, it seems to me you are overthinking the wrong things. You could cut the stringer in two pieces, with a butt joint or a 45 degree scarf, and a popsicle stick on either side, and probably be just fine. I have done just that.
This is an old pic of an old board, but its 9’ 6", and as best I recall that’s exactly how I built the stringer. No computers on this one tho, I just built it with my head and hands.
My point being use the computer to simplify the job, not to complicate it. If the computer can give you a template for the front half of the stringer and the back half, thats all you need.
I do not know of an easy way to get from the HBTM PDF file to clean CAD data. The one or two times I tried it was time consuming and I pretty much had to redraw everything. Maybe someone else knows a better way.
edit: added pictures
Huck, that is a beautiful board. I hope to get to that level of mastery one day.
i could very well be overthinking this process as I usually do when taking on new projects, so all my stupid questions will make its way to the internet. I am hoping that someone will come forth with an easy answer to my question, which is how does someone who has used AKUshaper to make a longboard over 8 feet CNC’ed a stringer?. The stringer dictates the board’s rocker so obviously this is important to get right. I wouldn’t be here asking how a template was made for anything under 8 feet, because of course the stringer and template will be able to fit on that single sheet of plywood.
Again, not trying to be a dick but, what is so wrong with simply drawing it out by hand on a roll of paper? After you have what you want, then maybe you can put that in your robot. You really want to see how Huck has done his rails. THAT…is genius. His rails made the full board and have the most integrity of any wooden board I’ve seen. With his system, you can get closer to a decent rocker throughout. Most come out too flat for real waves.
okie doke, have fun and post pics.
and maybe pop over to woodboardforum.com and run it by them guys, tell 'em huck sent ya.
Cut the stringer on the diagonal of the plywood sheet. The hypotenuse should give 8.94 feet. Or don’t do the entire continuous length. Cut the stringer in two pieces. Then cut another stringer, but have the break be in a different place than the first stringer. Glue them all together and match the rocker. Think of how a hardwood floor is layed out. Just a stab in the dark.