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Thread: Cool new CNC tool for plywood boat construction

  1. #1
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    Default Cool new CNC tool for plywood boat construction

    Hi everyone,

    I've been building a custom design plywood flat-bottom dory for the last 6 months or so, after a year+ of planning and scale modeling. I had been using a traditional 4x8' CNC rig at a nearby maker space to cut the wood, which was a lot of fun, but also a lot more work and stress than I was expecting. Those machines are pretty intense, and not always the easiest to use.

    Then in November, the maker space (TechShop, if you've heard of it) went bankrupt overnight, and I was suddenly without a means of production. I live in a big city (San Francisco), so space is at a premium and I didn't exactly have a nice back yard or garage of my own to start tooling up. I've been building in a tiny warehouse space barely big enough for the boat.

    I wanted to share my experience with a new tool I've encountered to solve my tooling problem, because I think it's going to be a very empowering tool moving forward for the amateur boat builder. It's made by a company called Shaper (https://shapertools.com), and is basically a handheld CNC machine that allows for pretty precise woodworking, called an "Origin".

    It uses cameras to track its position on your plywood sheet, and lets you "watch" what you should be cutting on a virtual, heads-up display. They have some pretty nifty mechatronics built in that correct the drill position for you as you move. This means you just need to sort of push it in the right direction, and it handles the cutting down to 1/36-1/50th inch precision (I can't really verify exactly where the tolerance is, but it's around there).

    Here was my boat the day the TechShop closed. It was maybe 40% complete, with all the parts to that date having been cut with the traditional CNC rig:
    IMG_1383 2.jpg

    And now here's my boat as of a few weeks ago, before I embarked on fiberglassing the interior structure:
    IMG_1576.jpg

    The parts cut with this new tool ("only" about $2,300, compared to the $10-20k CNC rigs I had been using) fit perfectly with the existing parts. It was a perfectly smooth transition.

    Now I can literally cut the rest of the boat in my kitchen, if I wanted to.

    The way the tool tracks its position is with these strips of tape, which the camera can identify. You lay them out of the plywood sheet, scan it, and then overlay your part in the virtual workspace before you start cutting:

    IMG_1479 2.jpg

    Here's what it looked like when I put a few pieces into place after cutting, before I removed the tape:
    IMG_1500 3.jpg

    Once I finish fiberglassing the inside, I'm going to use the Origin to finish the seating, railing, bow cover, and some strip hull planks for aesthetic effect. Wanted to share with others how much fun its been using this thing on my project, especially for those who may be looking for a low-cost, safe, smaller CNC machine for their own wood boat projects!

    IMG_1573.jpg

    I'm also chronicling this project on Medium, for those curious for more detail:
    https://medium.com/@cwsullivan/boat-...n-202ca5b4cb95

  2. #2
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    Default Re: Cool new CNC tool for plywood boat construction

    Wow. That seems too simple to work. When you say you "scan" the ply after applying the tape, how is that done? I assume the tape placement does not have to be precise, just no less than X inches apart? And how does the router adjust the final fraction of an inch -- does the bit shift left and right in the tool?
    -Dave

  3. #3
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    Default Re: Cool new CNC tool for plywood boat construction

    Quote Originally Posted by Woxbox View Post
    Wow. That seems too simple to work. When you say you "scan" the ply after applying the tape, how is that done? I assume the tape placement does not have to be precise, just no less than X inches apart? And how does the router adjust the final fraction of an inch -- does the bit shift left and right in the tool?
    Yeah so the display is pretty intuitive, and there is a "scan" option on the screen. When you click it, the software will show you what the camera can see, and you basically move the tool across the sheet, slowly, and watch it gather up information about the plywood and tape. It highlights strips of tape it is able to identify clearly, so you know when you've scanned the whole sheet well enough.

    I think the bulk of the patent is in the actual gearbox that controls that fine motor correction to fractions of an inch, but it looks like two servo motors that move the entire drill assembly. There's about an inch radius of error it can tolerate, so if you don't keep the tool within an inch of the cut line, it will retract (pretty quickly, but not unsafely) and wait for you to put it back over the line before it will continue the cut. The tool does a good job of showing you that radius tolerance, and most of your job is focusing on keeping the tool within it.

  4. #4
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    Default Re: Cool new CNC tool for plywood boat construction

    I'm pleased that you got your boat built.Can you explain how you derived the shape of the components and generated the program that told the machine where to go?

  5. #5
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    Default Re: Cool new CNC tool for plywood boat construction

    Congrats on a great looking build ! a real 21st Century WOW!! ,
    surprised the drive wheel/roller/what-ever does not suffer excessive slip especially when tool dulls and/or dust gets thick on adjacent surfaces but I look forward to reading/looking more.
    This is the first lesson ye should learn: There is so much good in the worst of us, and so much bad in the best of us, it doesn't behoove any of us to speak evil of the rest of us.
    E. Cayce

  6. #6
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    Default Re: Cool new CNC tool for plywood boat construction

    Quote Originally Posted by John Meachen View Post
    I'm pleased that you got your boat built.Can you explain how you derived the shape of the components and generated the program that told the machine where to go?
    Sure John. The CNC tool can read any "SVG" vector file. So you can draw these up in Adobe Illustrator (for example) if you wanted, save as .svg, and the Origin will read the file and turn it into a tool path for you if you insert a USB drive with an svg file on it.

    I really like that it figures out the tool path for me. This was something I spent a lot of time on and screwed up many times with traditional CNC.

    I've actually been writing software myself for my boat design. It probably would have been a lot easier to just do it in CAD, but instead I've spent the last several years developing a system that works out the geometry of boat parts (given a handful of input parameters like LOA, max beam, etc) for me, and generates the cut files. I go into excessive detail here: https://medium.com/@cwsullivan/boat-...n-580541e77f99

  7. #7
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    Default Re: Cool new CNC tool for plywood boat construction

    A tool with possibilities. Not to be picky but it uses a router not a drill. Nice boat.

  8. #8
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    Default Re: Cool new CNC tool for plywood boat construction

    Im really not getting it. Whats the advantage over a batten and a standard router, the fact you dont have to manually transfer any drawn lines? I cut the plywood planking for my last 12ft development model using a jigsaw. I guess if you use computer generated numbers, boat plans, then its a usefull tool.

  9. #9
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    mt vernon, ill. usa
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    Default Re: Cool new CNC tool for plywood boat construction

    It's obvious you're having fun using this new mix of computer and camera and servo technology, BUT, it's only doing what a measuring stick, a batten and pencil has been doing for hundreds of years. I'll admit it's very interesting and could be useful on more intricate projects.I'm gonna stay traditional for now but thanks for sharing.
    PS,, you need a lot of that tape don't you?

  10. #10
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    Default Re: Cool new CNC tool for plywood boat construction

    Quote Originally Posted by pelicanbuilder View Post
    It's obvious you're having fun using this new mix of computer and camera and servo technology, BUT, it's only doing what a measuring stick, a batten and pencil has been doing for hundreds of years. I'll admit it's very interesting and could be useful on more intricate projects.I'm gonna stay traditional for now but thanks for sharing.
    PS,, you need a lot of that tape don't you?
    Exactly my thought as well. And after all the expense of CNC programs, CNC routers, and that proprietary tape, ... well, at the end of the day, you still have a fiberglass covered plywood boat. One would have to build a lot of dories to amortize the cost of all the CNC software and tooling. CNC woodworking may be great for repetitive operations, but it's a dory, not an IKEA bookshelf.

    As they say, "Whatever floats your boat." I guess. Good luck with your project.

  11. #11
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    Default Re: Cool new CNC tool for plywood boat construction

    I can see that this gadget does a little of what a CNC router is capable of.I don't see it as a substitute for one,except for approximate cutting of flat panels.Given that you have to generate a file that the machine can turn into a toolpath,you might as well use the toolpath generating feature of the Inkscape program to do just that or you could send the .svg or .dxf file to a fellow with a real CNC as the panel will only take a minute or two to cut out.You can even find free software to generate the G-code yourself -look for dxf2gcode-although I suspect most router owners would prefer the .dxf as they are then free to choose which cutter to use.

    Every couple of weeks this type of gadget gets an airing here and I wonder how many of the people trumpeting their virtues consider that by the time you have generated the shape of the panel,you are most of the way to being able to create a file for using a rather more accurate and faster CNC machine.We have come a long way from the days when some poor devil had to sit at a machine control panel and type in G and M codes from coordinates and include tool diameter and length compensation.We would now expect to select a shape,describe which side of the line to cut,total cut depth,maximum cut per pass,simulate,post-process and send the file to the machine in a couple of minutes.We can walk over to the machine and simply select and load the program and have the job ready to go instantly.No sticking tape or peeling it off.Something like a used ShopBot might cost twice as much as one of these substitutes,and is so much more capable,not to mention saleable at the end of the project.I know which I would prefer.
    Last edited by John Meachen; 02-15-2018 at 04:51 PM. Reason: hit the enter key too soon

  12. #12
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    Default Re: Cool new CNC tool for plywood boat construction

    Quote Originally Posted by John Meachen View Post
    I can see that this gadget does a little of what a CNC router is capable of.I don't see it as a substitute for one,except for approximate cutting of flat panels.Given that you have to generate a file that the machine can turn into a toolpath,you might as well use the toolpath generating feature of the Inkscape program to do just that or you could send the .svg or .dxf file to a fellow with a real CNC as the panel will only take a minute or two to cut out.You can even find free software to generate the G-code yourself -look for dxf2gcode-although I suspect most router owners would prefer the .dxf as they are then free to choose which cutter to use.

    Every couple of weeks this type of gadget gets an airing here and I wonder how many of the people trumpeting their virtues consider that by the time you have generated the shape of the panel,you are most of the way to being able to create a file for using a rather more accurate and faster CNC machine.We have come a long way from the days when some poor devil had to sit at a machine control panel and type in G and M codes from coordinates and include tool diameter and length compensation.We would now expect to select a shape,describe which side of the line to cut,total cut depth,maximum cut per pass,simulate,post-process and send the file to the machine in a couple of minutes.We can walk over to the machine and simply select and load the program and have the job ready to go instantly.No sticking tape or peeling it off.Something like a used ShopBot might cost twice as much as one of these substitutes,and is so much more capable,not to mention saleable at the end of the project.I know which I would prefer.
    These are all good points, I'd just add:

    1. A larger, faster CNC machine is great if you can afford one, if you have the space for one, and if you're willing to fix/re-calibrate them. This tool does everything I was previously doing on a full-sized CNC for a fraction the cost. I definitely miss the speed and autonomy of the ShopBot (I actually do get tired after an hour with this tool). But I don't miss the maintenance. And I don't miss the time sunk trying to generate good toolpaths for the ShopBot. The simplicity of the handheld tool is paying off so far. We'll see how it ages, and how the warranty holds up!

    2. I wish I was a talented enough woodworker that the pencil/measuring stick/batten approach was fast and accurate for me. Obviously, learning takes years of making mistakes, but it's been really nice to know the precision cuts are always "just going to work" with my handheld CNC. I imagine that as I get more comfortable with woodworking, I'll offload more and more of this stuff to my own intuition and handiwork, but for now it's very reassuring that I won't waste good wood cutting things that don't end up fitting. Especially with complicated geometries.

    3. As Pelicanbuilder pointed out, it can take a lot of marker tape (and that certainly takes time as well) with this approach. I've heard (and am trying to move towards) a setup where the tape is actually set up *around* the sheets, instead of on top of them. Depending on what you needed to cut, you could possibly keep the same tape setup, drop in a new sheet, and the cameras would know where to move if the old tape is still visible. At most, you may need to put a strip of two down the middle of each axis, to keep a continuous field of vision for the machine.

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