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

Got my Maslow in about a month ago and set 'er up, went through calibration(s), and started in on a few small ‘starter’ projects. Quickly, however, I decided to start in on a Bolger Bobcat sailboat:

I’ve built small, wooden ‘stitch and glue’ plywood boats before, and this was the first time I wanted to go from fully-digitized plans in CAD to CNC milling.

I recreated the blueprints in AutoCAD Fusion 360, going painstakingly over each measurement and offset to get virtual panels. I then created puzzle joints from freehand splines to ‘cut’ the virtual panels to lay them out on 4x8 plywood sheets.

Taking the plans to g-code in Fusion 360 was not too hard, thanks to the video tutorials out on the Web. From there, it was a matter of cutting the frames, the side, bottom and bilge panels and the other bits and pieces.

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I’ve built small, wooden (plywood) boats before, but this was where I wanted to take the full plans, digitize them (via design parameters within AutoCAD Fusion 360) and go from there to CNC milling.

Then came the cutting…:

The Bobcat is now down in the shop, taking shape, with epoxy/sawdust putty in the seams now awaiting sanding and then taping with fiberglass strips:

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Oh my god…oh my god…oh my god!! I don’t even know that to say…this is amazing!!!

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I am literally speechless

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A stitch and glue something is on my Maslow list. You have made my day! :smiley:

Thanks, all! I will keep you updated.

Woops. Forgot to add a few pics for the ‘blueprint’ to digital conversion process!
Here we go:

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I have done quite a few stitch and glue projects: a 17’ sailboat, a few kayaks, a stand up paddleboard, and now this 12’ catboat. I, personally, love the method! I cannot say enough about modern epoxy and also about just using plain 'ol fine sawdust from your dust collector for making the seam putty.

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The boat build reminds me or Leroy Gibbs in NCIS. At least you don’t have to take out a wall to get the boat out. :slight_smile:

Great work!

I want pictures of it on the water.

Thank you

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…already took out part of the wall for a previous boat…! :wink:

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You rock! How much do you estimate the materials for the build? I’ve been out on a tall ship and done a bit of sailing with a crew. I was thinking I might want to learn to sail a small boat. This might fit the bill.

Thank you

I’m going to jump the gun - Sonny do you mind if the pictures are used in one of the Bi-weekly updates newsletter?

Thank you

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As the late, great Chris Farley would say…
download

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I hope the other side of the room has garage door on it :slight_smile:

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Amazing ! Crazy Good ! Keep it up !

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This is a large project using the full cutting size of the maslow, exactly the sort of thing it’s designed for.

What sort of errors are you seeing from your cuts?

This is a perfect example of perfect being the enemy of good enough as so many of us are worrying about the accuracy, while @Sonny_Lacey is not worrying about it, he’s just building it :slight_smile:

Especially after reading the one blog post about a commercial company doing the same sort of thing (with three or more generations of CNC machines, the last of which is expensive enough that he comments that the vaccum hold-down motor costs as much as a decent car), which said that they go through multiple router bits a day and find that the accuracy as the bit deteriorates is enough to affect the fit

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Is the door big enough to get this out? :stuck_out_tongue:

This is really awesome, glad it is working out for you.

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Amazing work, it gives me hope my plan for a teardrop trailer won’t be an issue.

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Sure thing @Bee go on and use any pics you like.
As for a materials cost, it’d be something like:

  • plans: $100
  • epoxy and cloth: $400
  • plywood (marine grade Okoume shipped down from Boston): $500
  • spruce, fir for spars: $200
  • various hardwoods: $100
  • brass sheetmetal and various fittings: $200
  • sail (made by Doug Fowler of Ithaca, NY who is one of the best): $750 [alternatively, Sailrite has kits for around $350 if you want to do that bit yourself, but Doug did my last set of sails and I like to support the thing he is good at]

I’m also using lots of scrap pieces here and there from other old projects, etc.
Hope that helps.

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