Building a Bolger Bobcat (Payson Tiny Cat) catboat from CAD on up

I would LOVE to share the files (they are all AutoCad Fusion360 files)… First, however, I really should check with H.H. Payson & Co., up in Maine, where I purchased the paper plans. I really would hate to get in trouble with them for redistributing something that they would consider “theirs.”

They may be amenable, as the files I have are definitely NOT the complete plans and you really do need those to assemble the whole cat.

In any event, let me contact Payson Co. and I’ll let you know.
Thanks,
Sonny

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First, I’m SO happy to hear that you’ve finished the boat! I didn’t want to pester you by asking again. I’m looking forward to your follow up posts. It’s remarkably gratifying to splash after all that work.

Second, I also would love a set of the files (if possible) and I totally understand and respect you checking with the author first. I would also like to clarify if we get the plans from the website or the book or both. Please advise.

Third, I’m a rigger at West Marine, so if you need any help at all with splicing, etc. let me know and I’ll see what I can do. I have written up several sets of step-by-step instructions with photos for various splices. For example, on my gunter-sloop rig, it’s recommended that you use a Dyneema cored line for the main halyard since it has to be pretty tight to get that yard all the way up and snug. I plan on using MLX, stripping the core, so that it’s only 3/16" up high going through the sheave and yard, but 3/8" down where you cleat it. This is much easier on the hands. The key is knowing where to bury the cover into the core and you can’t really know that until you’ve raised the mast and are setting the main. You want the bury to be above the cleat.

Anyway, I’m sewing my sails so I can raise my mast. I may set my jib flying (using the luff of the sail in place of the forestay) instead of an actual forestay and halyard setup, but we’ll see. The boat itself is getting close. Some more fancy filleting on the interior, then flip and finish the bottom with some graphite epoxy and paint.

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i understand, what i was more interested in was the layout of your file to see how you laid out the fusion files, trying to learn the system from scratch and its daunting at best an example with specifics to what i would like to do/ mimic would be very helpful.

Hey Jerry,

What boat are you intending to build? Another Bobcat or are you planning on doing your own takeoff of some other design?

i have plans for Amanda A stitch and glue kit. I have hand cut 2 plans from CLC and built one of their kits. I was hoping the maslow might be the way to get perfect lines cut. Im finding the programming aspect to be over my head but still trying to move forward. If I can learn how to layout Amanda, the Tenderly Dingy is next on my list of builds.

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I highly recommend the Tenderly, either the Classic or the XP. Both share the same hull. Only the interior and the rigs are different. You can sort that out much later in the build process.

The Amanda looks like a great boat to start cranking out CNC boats! Fewer parts will allow you to get your feet wet and reduce the amount of time to generate the offset data points.

BTW, there is no “programming”, only taking measurements from the plans, going into your favorite CAD program and connecting those dots with a Bezier curve (which should be built into the software). This can then be exported as a DXF file and imported into Easel or other program to export g-code.

It sounds easy, but you’ll need to figure out your own workflow and favorite applications to handle the various steps.

We should be having this conversation over on the boat builder’s thread…:wink:

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Red Letter Day. Just finished the first sea trial of the Bobcat in the Essex area of Middle River, here on the Chesapeake. Everything went as expected and the boat sailed beautifully. Not a ton of wind, but enough to test all points. She sails better than my old NE Dory, and has a much weightier ‘feel,’ which I wanted. I need to work out a few kinks on the rigging (e.g. the gaff needs adjustment to take out an unwanted sail wrinkle), as well as install the topping lift and lazyjacks (maybe). 100% satisfied!

IMG_1707

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Brilliant work! Well done :+1:

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Congratulations!

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She’s amazingly beautiful! Thanks for taking us on your journey. It’s very comforting to know that CNCing paper plans for any boat is totally doable. Only about 6 months of posts, you’re a faster builder than I am.

Hey @bar, I think you have your project of the month here…:sunglasses:

I love the white on the top of the mast, nice touch! Since you’re so close, you should swing by CLC and show John what you’ve been up to. I’m actually going to be taking my freshly finished boat down to Center for Wooden Boats in Seattle next month to show the end product to the guys building them in a class. There’s also some talk about me teaching some splicing classes.

I’m currently building my sails (jib finished, starting on main) and splicing my Dyneema rigging. It was really gratifying to see her with the mast up, finally. I’m going to use the luff of the main to determine where to mount the hardware on my mast.

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I’m not a sailor, so I only understood about 7 of the words in your post, but this is amazing work! Great job!

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@Sonny_Lacey Wow. Congratulations on a magnificent build.

I sailed when I was a teenager and only casually since but now my kids are just reading the same age as when I started and are out at sailing camp this week. This thread dropped by jaw. I’m a long way from being able to take on this project, as I’m still setting up my shop, but what an inspiration. Thank you for sharing all the details, I really appreciate it.

Beautiful work.

-Jeff

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If you like this awesome thread, you should check out this one:

I’m 95% done with a CLC Passagemaker dinghy at almost exactly 200 hours. In fact, just finished sewing my main sail kit from Sailrite. Tomorrow, I’m lacing the sail to the spars to determine where to mount the hardware on the wooden mast.

P.S. Thanks again @Sonny_Lacey for sharing!

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Very cool… I “stumbled” on the Maslow CNC machine when searching for something totally unrelated, and my first thought was that it would be PERFECT for boatbuilding. I’ve built a few of Phil Bolgers designs- And the lofting process even on the simple ones gets quite tedious. If you manage to get it all on the plywood correctly, you still have to cut it accurately. I can recall thinking more than once during my last build how nice it would be to have access to a BIG cnc router.

I’m getting more and more tempted to order one!

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Make sure to check out the thread below if you haven’t already. I actually love the lofting process, but you’re right, there’s a lot of pressure to make the parts in the nesting diagram actually fit on the sheet. A few months ago, I had to make six planks fit onto a 12’ scarfed sheet. I actually worried about it the entire previous night and it actually took some gumption to go into the shop that morning to begin. I kept checking and re-checking the measurements. On the second to last plank, I finally knew they were all going to fit. I ended up having 2" to spare across the 48" I started with. Whew! :sunglasses:

What boat(s) are you interested in? Would love to discuss it over here:

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How did you get a flat pattern from a compound curve in Fusion?!

The flat pattern is already in the drawings in the plans. That’s what you are purchasing. It’s not until you join the seams together that the compound curve develops (and my mind gets blown). Not trying to speak for Sonny, but he basically redrew the data points from the plans into the CAD program and connected the dots with Bezier curves or other tools that make smooth arcs or straight lines.

Damn! Lol
I’ve been searching for a way to do that!

Interested in the paddle boards you spoke of. Can you post pictures or info on any of the paddle boards you built?



SUP_handmade_md

@fajay,

Here is the finished board and the CNC-cut innards that I made. It’s a longboard design with medium rocker and a gentle deck curve. The fin is a single large, old-school D-fin made out of Okoume plywood. Nose and tail are some blocks of old yellow pine I had laying around.

The outer skin is recycled fence wood that I resawed down very thin and then made fair with hand plane. The rails are foam-core fiberglass built up from “pink” insulation foam. A layer of 4oz glass fabric covers the top and bottom, with 7oz. on the rails. The epoxy used is Entropy Resin’s Super Sap.

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