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I have a friend who owns a CNC machine. Quite a big one actually, capable of handling 4x8 plywood sheets.
I was wondering. Is there any company that sells plans for stitch and glue kayaks in the form of a CNC file?
I don't know exactly which type of CNC he has, or what file format it takes, but I imagine it wouldn't be too hard to convert the file from one format to another. Am I wrong about that?
Seems like I've seen a company from the UK which does. I believe the name is Jordan Boats, check WaterCraft magazine, a UK publication. Available at most B&N's. Also check the classifieds in WoodenBoat magazine.
Good luck, Mac
CNC files are usually specific to the machine on which they are used. You need to be looking for a DXF (Autocad) file format that can be imported into most 2-D CNC router tool path generation programs with very little effort. Actually, it would not be particularly difficult to create a usable file from published paper plans. If the drawing contains enough information to cut the pieces out with a jig saw, then it contains enough information to create a CAD file.
Obviously one doesn't want to put the cart before the horse. What counts is the plan, not how it is cut out. I am currently designing, and translating plans for a CNC machine I hope to have. There is no value to the process for one boat. It takes a long time to get the plans formatted (though it would be fine and fun for some small dingy).
I am currently translating plans from pdf for this boat plan I have. It takes an evening to get one sheet out, and I haven't even started to work on the tool paths. The work I am currently doing, I am good at, but the tool paths will have a learning curve (your pal would probably be a wiz at that). The software automates it, but it is like hiring a house designer, they still have a thousand questions they have to run past you.
So for example, the PDF is set up with the assumption that boat length panels will be made up, to which the drawings will be applied. But it is a large router than can handle one 4x8 sheet, let alone multiples. So even one sheet has to be reformatted into as many individual panels as are required, like 3-6. A drawing per panel. And the wastage in wood is huge, because one is taking the continuous drawing and pulling sections apart and placing them like islands in a 4x8 sea. Of course one still packs them in tightly, and that is something cad is good at visualizing. It is also possible to come up with products that can be dropped into bare areas and cut at the same time as the boat is. And if the plans were designed with CNC in mind there would be enhanced efficiencies, though not necessarily compared to regular plans.
When it comes to making the boat, I wonder how great that will be. I will have to cut out a lot of panels, In some cases, common parts could have been cut that were paired together up to four at a time, if I was just using a jigsaw. Also, one of the advantages to CNC will be the cutting of dovetail joints, but one can cut the scarphs a lot faster, and there are fast ways to join them, then you have full length panels. Those joints would be made with and at panel edges. But the machine will be creating complex patterns where those parts meet. The idea is the machine works while you aren't there, but I wonder how realistic that really is. The point being I need to learn more, and take the journey.
On the pro side, I didn't like writing by hand, my results were messy, and less well spelled, and it was laborious. I think there is a chance that more ideas will make it off the drawing board if I have an integrated machine to cut them out.
There is also a branding opportunity, where you can professionalize your work with CNC. Lots of ways.
The reason I am doing this is because I have been designing in CAD for 20 years and the only output I have is on my printer. Also, there is an assumption that the time spent on getting familiar with the elements is going to pay off in something. Boats are naturally curvy, and that is something CNC does well.
It is taking time for cad files to be offered because at the moment there really isn't any way to get paid for your creativity, and the far larger value you are putting out there, and not getting paid for. It would be a bad deal for the the Stones to deliver their next album exclusively over Pirate Bay, but at least they wouldn't have to produce 5 times the songs. Cad plans are 5 times the songs, or a lot more. Once one plan leaves you have no further control.
Recently I was designing a new ukulele, and I decided to do a version of my own, then I did a version using an online parametric modeling program, and I ripped off a PDF file from a business and converted it to CAD. I was able to use a preview from their website. All three plans came out about the same. Basically you could lay them on top of each other, and that means I know where the business got their plan too. But the point I am getting at is that when you get to this point in the process, they aren't getting paid for their property anyway, and they might as well sell their PDF as a CAD plan for more money. They are getting more money for the formating, than the design and they borrowed that anyway. But guitars, etc... Are a different deal than boats.
The reason I'm asking is because many of these companies that sell the plans often sell kits with pre-cut plywood parts, flat packed, ready to assemble.
As far as I can tell, they just cut them from 4x8 panels, and charge hundreds of dollars for the process.
The complete kits, with all the accessories, epoxy, fiberglass etc... are usually around $1000, But the "Wood parts only" kits are still around $700
http://www.clcboats.com/shop/kit_opt...ak-kit/68.html
4mm 4x8 Okuome marine plywood sheets are $54 each at my local lumber yard, so even if it's a 3 sheet boat, that's less than $200 for the plywood if I can cut it myself. Even if I can't buy the CNC file itself, it's well worth the trouble of scanning a pdf or paper plans into a CAD program.
Roderick,
I suggest you do some in depth research on CNC software before doing much more work. You don't have to figure out how to place individual parts on multiple sheets of plywood. The CAM software will do that for you automatically. You won't have any use for a single drawing per panel. You want to import all shapes of a particular thickness plywood into the program at once so it can figure how many sheets of plywood you need and the absolute best way to arrange the parts on multiple sheets.
Christopher,
If you're going do a price comparison, make sure it's apples to apples. Make sure the Ply and structure parts you're pricing are identical to "CLC's" or whoever you're dealing with as there's unlimited variations in wood quality. Also have you priced quality epoxy/cloth lately? A S&G boat requires quite a bit and it gets expensive very quickly. The pre-cut structure parts will also save a lot of time and waste, especially if your shop isn't equipped to turn out these items. I'm not stating you can't save a few bucks, I will state it's typically less than most realize, especially considering the convenience factor.
Mac
Quote:
Originally Posted by Christopher Collins
I live in an area with a pretty active amateur boat building community. Right near Lake Ontario, the Finger Lakes, and the Erie Canal. I'm also luck enough to live near a really great local lumber yard that caters to the boat builder market. They sell the very best marine plywood on the market. Joubert BS (British Standard) 1088 Okoume. And they have the epoxy too. I'm not sure about the fiberglass. Having a supplier about 5 minutes away helps save on shipping too.
I've put together a cost spreadsheet. It's looking like around $600 total, for wood, fiberglass epoxy, varnish and accessories like seats, etc...
Christopher,
Sounds like you're doing things right and in a idea geographical area to build boats.
Enjoy the build.
Mac
If/When I eventually start it, I'll be sure to keep everyone posted.
The point is there aren't parts, there is a PDF drawing that is not designed for CNC production. I has to be reduce d to parts that will fit on a sheet. Sure once those parts are created the software can puzzle them out. Though I don't know they would take all the issues into account. The problem is that the parts are designed around modules of scarfed ply, and that basically means parts designed to fit on 20 foot panels,in this case, that when taken apart now need 3 sheets. It's not a big deal, but it isn't as though everything about the process is like bunnies in a field of tulips either. Of course if the designer had decided to design from scratch for CNC I wouldn't have these problems because he never would have released the plans. :)Quote:
Originally Posted by Art Mann
Thanks for the head's up though, since I have a lot to learn about this stuff. At this point, I am putting it off another year, as it is just too expensive.
True, but how were they planing on getting paid? First, the hundreds of dollars they are getting paid includes the cost of the plans themselves, which normally are way too cheap if the boats are any good. Plus the CAD set-up is huge, as I tried to point out. If you have someone who will do it free for you that is great, but essentially like him giving you the epoxy for free, good deal for you. Then there is the cutting time. CLC is competing out there for projects aside from their kits in the general CNC word, and that is the cost they tack on for cutting out their boats. So it is a competitive price that lands them jobs in industry when they are not the architect, just the CNC team. You can see the hourly rate they bill for cutouts of plans on their site, and their CNC business rates on their site. So again, that's cool if you have someone who will do it for you for free, but they aren't getting paid, no reason why CLC should do that.Quote:
Originally Posted by Christopher Collins
As pointed out, if they send you the plans, you clearly don't think any of this is worth anything, so why wouldn't you (or others of the same mindset just post the plans on TPB). I am not making moral judgements, but practically that is how the world today thinks. The reasons the kits business is the biggest part of the small boat business, is that it preserves the value, in a way that nothing else does, and they aren't going to shoot themselves in the foot.
Just take it the next step and design the boat yourself. You can do a lot better job than CLC can do since you can take your exact service into account. I designed the first boat I ever made back around 79. It turned out fine, and as you point out, you can probably make several for what one from CLC will cost. Then you will have actually learned something.Quote:
The complete kits, with all the accessories, epoxy, fiberglass etc... are usually around $1000, But the "Wood parts only" kits are still around $700
http://www.clcboats.com/shop/kit_opt...ak-kit/68.html
4mm 4x8 Okuome marine plywood sheets are $54 each at my local lumber yard, so even if it's a 3 sheet boat, that's less than $200 for the plywood if I can cut it myself. Even if I can't buy the CNC file itself, it's well worth the trouble of scanning a pdf or paper plans into a CAD program.
It isn't necesarry to use 1088 for these projects. Thousands of these boats have been made of humble doors skins. My tri is made of doorskins that didn't even have the marine glue in them, and it is fine 25 years later. 1088 is an option obviously, but it is designed for uses where the panel is not sheathed and gets saturated by water. If one is epoxy sheathing everything, as one should, high end material are not required. I can get marine grade panels of 6mm for 13 bucks. Unfortunately I don't currently have a source for the thin stuff that is as nice. Since the 6mm stuff is balance ply, it might be possible to plane it to 4mm, some of it is 5mm so with balanced plies, that should come out fine.
Maybe as a company who sells plans and kits, I can offer a different perspective on this. I should note that I don’t produce S&G plans or kits for personal reasons.
For the most part Christopher you are correct. The cost of producing your own stitch and glue kayak kit is anywhere from $400 to $600 depending on the quality of the materials you put into the kit, and as you alluded to , there is very little labor involved in the production of a stitch and glue kayak kit as the CNC does most of the work.
In fairness, there are other intangibles that are only fair to consider from a kit companies point of view. What you are paying for is actually the expectation of getting a quality design from someone who knows what they are doing and support when you need it. So the question you really need to ask yourself is if support, design considerations and the time it takes you to produce your own is worth the extra $500 bucks or so.
I cannot begin to tell you how many emails and phone calls we get from people who downloaded FREE plans off the internet. We get contacted from people who use the wrong glass, or wrong resin or cannot figure out why their knuckles hit the gunwales when they paddle because of a bad design.
I am not a big fan of S&G kayaks but if that is your thing then there are a couple of things you need to do to be successful in making your own design. You need to use a cad software which has an UNFOLD feature. This will take the panels and flatten them out for you in a way that CNC will understand. There used to be a great shareware program out there called “Hull Designer”. Not particularly fancy, but definitely sophisticated enough for what you are talking about. Once you have the design you like you can import the DXF file into a real CAD program and dissect the panels and lay them out on a 4 X 8 sheet of plywood. Then convert to G-code and you are off and running. For the record, I would not use scarf joints for a couple of reasons. First, they are difficult to calculate for a CNC when splitting up your panels. Second, a puzzle joint will work just as well if you are glassing and is infinitely easier to make a clean joint.
As Roderick suggested, I would see if you could get your hands on some door skins to do your prototyping. Just because you can make a kayak design, doesn’t make you a kayak designer, so spending $200 on a trial balloon is probably a good idea to see if you like what you produced. $50 worth of plywood, a little resin, glass tape and a can of paint is enough to get you in the water to test a design.
This much work wouldn’t be worth it for most people, but if you have the spark then go ahead and give it a shot.
As a little motivation, here is a picture of a freighter canoe that we will be launching is about a month and if you look closely, you will see a 10’ kayak in the background which should hit the water about the same time. No matter how you end up getting there, the important thing is to make some sawdust, and if I am going to build, I prefer to build something that floats.
Attachment 288351
Good luck, keep us posted.
JKB
Last year CLC did a long blog post describing in detail their process over the years for creating their kits. From the early pattern and router days, to today's CNC world. Sounds like quite the process. Even though they have hundreds of thousands invested in the best machines and software, there are still a lot of details that need to be caught and adjusted, to provide the kits in the current state of play. For instance they use bulkheads with tabs. Thing of that for a while, getting those set in the right position is probably easier to do through revision than getting everything perfect from the get go.
http://www.clcboats.com/life-of-boat...rvey.html?jm=1