Phototoxin

Physical Limitations of Metal

41 posts in this topic

Another issue with resin is that it's a "batch production" process where even with strict quality controlls the resin mixture can alter between production runs meaning the quality of a cast can vary.

One batch of casts will be very soild and without bubbles while a second can be softer with many bubbles. 

I've even heard of local atmospheric conditions like humidity effecting the quality of resin casting batches.

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5 hours ago, Col said:

Hawk Wargames are truly masters of their craft, if only all producers were up to their standard.

Starting out they weren't too hot, I had a few slipped mould lines, but I think as they've grown they've upped their QC and production values.

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I hope CB will still be loyal to metal - the manufacturers that I know and went into plastic in most cases decreased in quality of minis (Rackham, Games Workshop). I don't see any chances to make such great, Infinity sculpts in other material.

 

12 hours ago, Vaulsc said:

One thing I liked about plastic was the opportunity to kit bash, convert, and create your own poses a lot more easily. But metal is pretty straightforwardly better for the reasons people have mentioned.

Yeah, plastic seems easier to convert, but metal gives more satisfaction ( http://www.coolminiornot.com/390200 )  ;)

 

PozdRawiam / Greetings

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7 hours ago, Deep-Green-X said:

I've even heard of local atmospheric conditions like humidity effecting the quality of resin casting batches.

This is the case with plastics and rubber. Humidity plays a big part. I've seen companies need to reformulate when they moved a tool, for example, from Germany to Mexico. 

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CB usage of metal for minis is pure economic reason. Plastic has very expensive technological steps and will give your money back only if you are producing and selling a lot. And as Deep-Green-X said - you can do metal casting at your garage (what basically CB did in yearly years). Just to let you know guys, CNC machined matrix for some of plastic model kits can easily cost you 80 000$.

also from collectible side of view - metal is more preferred over plastic.

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2 minutes ago, Kwisatz Haderach said:

CNC machined matrix for some of plastic model kits can easily cost you 80 000$.

Holy jeez!!!! I didn't realize it was THAT expensive. Wow. 

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That would be for a very extensive or complex kit, though. It's substantially cheaper for a single sprue, and even cheaper if done in-house like it is by GW.

It's still orders of magnitude more expensive than setting up for spincast metal production, though.

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The big problem with plastic minis is the fact that you can't do undercuts.  The only way to have a detail that is an undercut on the finished model is to do multiple pieces.  And I mean like 20 pieces.

There's a lot of hate and discontent about the parts count for the Robotech RPG Tactics minis, which are all plastic models with lots of details.  20 pieces or so per model, not counting accessory pieces like the missiles for under the wings.  A GW space marine is 10 pieces, not counting belt pouches and stuff.

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Modern plastic injection can do undercuts... more or less. The mold has moving parts that move in and out of position when the big parts meet. Of course, it means more money.

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11 hours ago, MoPaint said:

Holy jeez!!!! I didn't realize it was THAT expensive. Wow. 

A single machine is that expensive, yes.  There's more to doing industrial scale injection moulding than just owning a machine and the dies, though.
You need to have the power setup to handle it, too (3 phase at a minimum, usually.   I could run one from my inlaws' place because they are set up for it, family of boilermakers and all that.).  This usually necessitates an industrial zoned area (or at least light industry).
As well as major league coolant systems, and the rest of the infrastructure and overheads in place just to keep the machines running.  They have to melt the plastic pellets and inject the goo under high pressure.  All of that creates heat that has to be controlled.  If the machines get too hot, they burn the plastic, not just melt it.  That's bad.

For all that, you're probably pushing it to get it started for under $1M. 

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On 3/21/2017 at 8:08 PM, Mob of Blondes said:

Modern plastic injection can do undercuts... more or less. The mold has moving parts that move in and out of position when the big parts meet. Of course, it means more money.

Slide molds are a lot more expensive than simple 2-piece molds.  And also require a different machine, too.

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14 hours ago, Section 9 said:

Slide molds are a lot more expensive than simple 2-piece molds.  And also require a different machine, too.

Different machine? In what sense? There are molds that work like plain two side ones, the slide cores are just Rube Goldberg machine wannabees. More complex things may need more complex presses, but if the thing can be made with normal one... This animation shows two extra blocks to create undercuts, one (orange, center) just works with the same mechanism than ejection pins, the other not (black, top).

mold_structure_002.gif

But yeah, price goes up, all the extra parts don't come for free, and they must close as tight as the main ones.

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21 hours ago, Mob of Blondes said:

Different machine? In what sense? There are molds that work like plain two side ones, the slide cores are just Rube Goldberg machine wannabees. More complex things may need more complex presses, but if the thing can be made with normal one...

I'm talking the slide pieces that make hollow gun barrels and/or muzzle brakes, which come in from the side of the mold.

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55 minutes ago, Section 9 said:

I'm talking the slide pieces that make hollow gun barrels and/or muzzle brakes, which come in from the side of the mold.

For very long things, maybe (haven't seen any such machine). For not very deep holes, the action of the two main blocks is enough and common machine is enough. Some cases use extra side powered actuators as part of the tool, but the machine is still a plain press. Animation above has a full hole created by top actuator. Bottle caps can be done with two big parts and a lot of smaller moving parts in them.

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If Infinity went plastic it would be the end of days........

 

quality skirmish level minis minis should be metal. End of story.

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