Barge design 2014-04-12 : More 3D modeling and off to the home improvement store ...
My previous 3D models of the barge were solid models which can be seen as a single "mold" in which material would be injected.
Essentially a hollow "inside" constrained by surfaces. That's how models should be created for 3D printing.
Except that this barge won't be 3D printed but built from plywood sheets ...
As I'm learning 3D modeling for 3D printing I went that way (to a hammer, everything is a nail, right ?).
What I need is actual "blueprints" of the various parts I'll have to put together. The previous 3D models were not a complete waste as I've been able to "draw off of them".
Exploded view
From top
Exploded view
From bottom
Assembly "helper"
To keep two pieces of plywood square
Here's a short animation on YouTube.
All the various parts (sidewalls, frames, bottom, transom ....) are individual components which can be modified, duplicated (draw one frame, all other will reflect changes). Individual components can be moved as "units". Or can be hidden.
You can also make sure you end up with something you can actually assemble ...(although SketchUp has no "mechanical" processing abilities; it's not a CAD engineering software)
Sharp eyes will have noticed that two notches are missing on the deck beams. I missed them and will be easily added (didn't want to re-process the video, lazy me).
Extra "open frames" will be added every 200m (or maybe less) and have been accounted for.
Once everything is designed that way, it's easy to get measurements and ... get to the local home improvement store !
I decided to go with 5mm plywood. Just basic ply, not the marine type which is significantly more expensive and much harder to find around here.
Castorama (think Home Depot, only more expensive ...) has actually two policies when it comes to cutting wood to custom dimensions:
- Lumber: Pay a full board (usually 227cm by 240cm or 7' by 8') and then pay one € per cut (you'd better carefully plan how you instruct them to cut it up)
- Engineered wood (ply, MDF ...): Cuts are free of charge and only actual board surface is billed
That essentially meant I could get them to cut my plywood parts for free and not even pay for any leftovers. There was just a 250mm by 100mm (10" by 4") lower limit. No big deal.
I handed over the measurements for all my 15 parts and went my merry way. 24 hours later I collected all my plywood parts (and gave a little extra to the guy for all the dust my apartment never saw).
Cost for ply (excluding tip): 23.30€
I also go some oak and beech (took whatever I found dimension wise ...) square dowels as beams.
Dowels will be added to most corners (not shown above) to strengthen them. I think I'll nail and epoxy everything together. Or maybe use simple white wood glue (which is easier to work with than epoxy) and then add epoxy fillets all around. Not sure yet.
Considering my views on epoxy ...
... I see where this is going.
I'm also 3D printing some helpers to hold parts together during assembly and curing.
But before assembly starts I'll have to figure out all the deck stuff: bollards, bitts, ...