Foam Cutter
I built a foam cutter. Here's the part list, and the prices of the various pieces. It's put together, and has produced a nice core. It still needs some refinements, but it's basically working.
Some notes:
- I couldn't find ceramic insulators, so I made something out of a ballpoint pen case, a couple cup hooks and some epoxy. Seems to work fine.
- The arm rotates on some plastic bushings, but seems to be operating smoothly.
- One time I put the template too close to the edge of the foam. Unfortunately, the aluminum acts as a heat sink, so the foam tore at the edges. 1/2" gap seemed to work fine, less might be OK too.
Items marked (n/t) were mail ordered and not subject to CA taxes.
| Table parts | ||
| 6 plastic screen door rollers | $5.34 | |
| Nylon pulley standoffs | $3.30 | |
| Pulley screws | $0.78 | |
| Window locks with thumbscrews | $1.77 | |
| Drop arm (C-channel aluminum) | $7.41 | |
| Drop arm bolt | $0.37 | |
| Table edge (C-channel aluminum) | $7.41 | |
| 30' pull wire black (non-conducting) (used 1/16" aircraft cable instead) | $2.40 | |
| 1/4" roller bearings (2) | ? | |
| 3/4" Melamine table top (to be 72" x 40", cut from 4' x 8' section) | $23.74 | |
| 2 1"x6"x6' pine boards for edging & arm support | $7.60 | |
| Tee nuts | $2.00 | |
| Hot wire bow parts | ||
| 12' extension cord | $6.98 | |
| 1"x4"x7' poplar (enough for one 4' bow + one < 3' bow) | $9.52 | |
| Screw eyes (bunch) | $2.47 | |
| 5/16"x36" music wire tensioners (enough for 3 bows) | (n/t) $7.99 | |
| 5/16" ID wheel collars (4) | (n/t) $1.50 | |
| 10'x1/8" bungee cord | $4.00 | |
| Stainless steel wire, .020 dia (actually 8' of .018 wire from NESail) | (n/t) $4.50 | |
| 2 ceramic insulators (built from scrap parts + epoxy) | - | |
| 2 torpedo fishing weights, 6-10oz (used vise instead) | - | |
| Template parts | ||
| .020 Lithographic aluminum | $2.00 | |
| Power supply | ||
| Variable AC transformer, 10A | ? | |
| Step down transformer, 100 to 30VAC, 10A | ? | |
| Power cord | ? | |
| -- or -- | ||
| Automotive batter charger, 10A max | (own) $0.00 | |
|
Taxable subtotal |
$83.09 | |
|
Tax |
$5.96 | |
|
Non-taxable subtotal |
$12.49 | |
|
Shipping charges |
$2.00 | |
|
Total |
$103.54 | |
Possible sources for blue or spyder foam:
Superior Balsa
- cheapest foam price so far, this is where I ordered from.
The Composite Store -
these guys also sell bagging systems and kits.
ACP Composites