Last modified: 2026-07-27 10:00:13
< 2026-07-25 2026-07-31 >I just woke up with maybe a good insight: would I have been better off printing these weights out of tungesten-filled filament or something?
Firstly let's look at density. I got codex to add https://incoherency.co.uk/jesref/material-densities.html
Lead is about 11.3 g/cm^3, a 75% by-weight tungsten-filled filament is 4 g/cm^3, so already it's only about 1/3 as good. That may be enough to rule it out already.
As for costs: I already had the lead shot so we can call that 0, but I had to buy the pouring ladle which cost £10, and a pack of end mills for machining the mould which cost £18 for 3.
I still have the end mills so you can amortise some of that cost, and I used up some of my lead stock so maybe that ought to be worth some cost as well.
Prusa's tungsten-filled PETG is currently out of stock and is not showing a price.
OK, on second thoughts: forget it. The cheapest tungsten-filled filament I found is $500/kg, and remember at 3x the density of PLA it won't go very far. Most of the sources are over $1000/kg.
I have mocked up a design for the tractor trailer:
And ordered the materials to make it. I already have a couple of sack truck wheels to use.
It is a steel frame and will have 9mm plywood bottom and sides.
I'm thinking of doing a folding tailgate.
I've pushed the rest of the key weights into place.
https://www.youtube.com/watch?v=JWY9zmYGR-s
Most of them went in with a good push and seem like they won't fall out. One of them cracked the plastic as it went in, so that one is currently gluing back together.
And about 5 of them were too fat to go in, so I put them back in the mould and trimmed with a hammer and chisel, which worked very well:
A couple more of the balls fell off, which are gluing back on now.
Current issues are: