Resin spin caster.

[Blindhorizon]

Oh yes it will be on the porch i was saying apartment more to explain why i cpuldnt used a regular compressor to cast because of the noise.

[Blindhorizon]

So I'm looking for suppliers in the US for dental grade silicon, I found this product here i believe it is what you where referring to mango.

http://www.gcamerica.com/lab/products/P ... /index.php

The interesting thing about this is i was reading their instructions and they recommend using an alcohol based surfactant (debubblizer) to reduce bubbles in the mold. Has anyone seen or used anything like this for their molds before?

http://www.gcamerica.com/lab/products/P ... idAIFU.pdf

Blind-

[mangozac]

That Polypour stuff sounds exactly the same as the Pinkysil (other than the colour ). Would certainly be interesting to try out! Let us know how you go sourcing some!

I've not heard of using alcohol based surfactants before. I guess ultimately you're going to need to vacuum and/or pressurise the mould as it cures anyway so that you can deal with any air caught in undercuts and stuff, so the surfactant isn't really necessary in our line of use. Pinkysil is extremely thin anyway so I couldn't imagine thinning it down much more. Still, can anyone else further comment on the use of a surfactant with silicone?

[Deadmeat30]

saw this thread and thought ild add my 2 cents with playing about with it in the past.

With the right venting, spin cast resin (not restic) can be done. I did some trials last year as an experiment.

You can see the results are pretty good for a very first attempt into spin casting (yes that was the first ever spin).

Ive since brought a spin casting machine to trial further and perfect the method.

You can also purchase silicone discs, like the natural rubber ones made for metal castings. Ill get some photos of it when i can find it.

[Sazza Bee]

[Blindhorizon]

[Hythos]

I'll add more detail soon, but I've worked out a spin-cating machine out of a $50 Harbor Freight drill press (turn the whole thing upside down, and build a frame & plate); the whole thing costs less tha $100 (US), and allows for changing RPM through belts.

My intent is to pour lead/pewters, and be cast in either silicone or natural rubber, but also get the most out of resin
For now, I've been using SmoothCast & Oomoo 30 with decent results from gravity-pouring, but do expect better with using a pressure-system, or "spinning".

[Blindhorizon]

I'm really interested in how this turned out, including any pictures of stuff that was cast using this.

Cool, keep going!
blind-

[Hythos]

Thanks, Blind
I have a few components built, however I hope to have the whole thing worked out soon... So it's not yet functional.

I can show a "fixture" I've made - this is what I'll call an 8x2 (8x 2"x2"x1"deep cells with which to cast a radial-mold).

Other fixtures I have drawn would include 4, 5, 6, or 8 cells, in either 2" or 2.5" squares, which I can make out of various thicknesses. I've calculated the 8x2 to be the most cost-efficient, considering almost all of my pieces can be made within 2"sq.

Each of the 2" square will accommodate 1 miniature up to ~40mm wide and about 60mm tall, or, may support several small objects/pieces. The castings are made through "conventional" means (first pressed in clay, and pouring two-halves of silicone, each 1/2" deep) to form a full cast of a 1" deep mold, including all cells at one time (including a "gate" disk that's molded into it at the same time the mini's are cast).
The mold itself need not be placed back into the fixture when spinning - it'll be sandwiched between two disks in the spinner, so this mold can be used over and over.

I had calculated the volume of silicone needed for something like this, to require a bit less material than if using a circular mold. Cost-per-mold for an 8x2 would be about 1/3 that of the "sample" size Oomoo 30 (which is all I've had experience with, yet). So, assume ~$7.50.
Compared to Natural Rubber used by high-volume casting, the cost-per-cast is about 1/4 that of 9" casting disks (http://www.conquestind.com/s_s2.php)

[mangozac]

Wow this has become VERY interesting! I'm especially interested in your calculated cost savings! Please keep us posted as the project progresses (including more cool photos like that!).

[Hythos]

Still try'n to get time to get some real work done... 12" of snow in the last day hasn't helped.. LOL
Soon!

[Hythos]

I've been intending to get back to working on the spin-casting jig... life happens :/

Here's an update:
12" plate - Anything wouldn't have to be this elaborate; a plain 1/2" steel plate disk would work just fine - the key is with the MorseTaper taper to fit the Drillpress spindle.


This 12" plate took about an hour to work up the design & program, and about 6hrs to machine... My CNC generated a couple errors that produced some unintended features, but they hopefully shouldn't effect the performance.
I have a couple more things to add, mainly hold-down bolt-holes. The mold-frame I had machined (or in other cases, a round mold) can be placed atop, and held down with a 1/4" plate (yet to be built - more on this soon).



I had tried to find a simple A/C motor, but since most came at a cost of $100+, I opted for a drillpress that already came with a spindle, and picked one up for ~$65 from Harbor Freight (anything even if previously used should be fine). If anyone wanted to build one of their own in the same fashion, you could first use the drillpress to drill & ream the center-hole before repurposing it as the base for the spin-caster.


More to come, as I get the time for it...

[mangozac]

So cool!

Repurposing the drill press is a great idea - indeed there's no cheaper way to get such a motor drive setup with appropriate torque and speed adjustment.

Are your intentions to spincast metal?

[Hythos]