Subject: Re: [harryproa] 3D printed harryproa models? |
From: Mike Crawford |
Date: 11/9/2012, 2:49 PM |
To: harryproa@yahoogroups.com.au |
Reply-to: harryproa@yahoogroups.com.au |
I recommend sending Shapeways your sketchup file just for kicks.
You might be surprised with the actual cost versus your current
estimate. Or, you won't be surprised, but at least you'll know.
You can also probably get away with 1mm. High strength plastic is
pretty strong, especially for a model that won't have to take any
real abuse. Seriously -- how many consumer devices do you own that
have a wall thickness of 1mm or less? And those are devices that
are designed to be thrown into backpacks and dropped on the floor...
Or, think of it this way: 870 cc is almost a liter of resin. It
would seem unlikely for a hollow 20" model is going to take that
much material.
A 12" model might also cut your surface area by a factor of six or
more. Technically a factor of eight (half the width, length, and
height), but let's say six for the sake of discussion. In which
case a foot-long model with a 1mm skin could cut the original
estimate by a factor of 18. Or $6.
That's not the same as your $12 wish, but it's not out of the
ballpark when building a $80,000 boat from $4,000 plans.
---
Darn, now you've gotten me wanting to do it.
But we're due to start construction of our new house next year, so
I'll remain resolute about no new boats for now.
- Mike
I was just thinking about the cost. I recall that the foam panels average about 1 lb/ft^2. The harry weighs in at 1800 lbs. If we go with a 1"=2' scale, so the model is 20" long, that would be 1800 sq ft => 450 sq in => 2900 cm^2. With a 3mm skin thickness, it would be 870 cm^3. That would be pricey! I checked shapeways.com, and their high strength plastic is $1.40/cm^3, which would work out to just a bit over $1200.
I guess the price needs to come down a bit before this is practical. Would it be worth it for really tiny models? I am not sure if it is worth the trouble for one that is 2" long, instead of 20" (but if someone makes one for $12, I would buy it <grin>).
- Gardner