I just talked to a materials man in Columbus, Ohio. He pointed out correctly that at the travel rates of 4 mm/sec for a 0.5mm path, for a block 40mm long, 20mm wide and 10mm deep. It would be 20 layers of 0.5MM and a layer would take 10 sec/ length X 40 lengths/layer X 20 layers minute/ 60sec= 133.33 minutes or over two hours! His idea is to use the Reprap to build a hollow disposable mold to fabricate parts with. This would use less material and wouldn't need supports since it is a hollow mold. I am going to tinker together a motorized syringe with full and empty limit switches. A DC motor would only need one bridge, so I could send a catalyst at the same time with another syringe. I could then remove the syringe and use it to fill the hollow molds to produce part sets. I think we need a materials forum. Maybe we can use that JB weld that everyone raves about! I am of course joking, but the mold idea is sound. I wonder if it can be done in AOI?

Edited 1 time(s). Last edit at 07/25/2007 09:46AM by englewood.

> I wonder if it can be done in AOI?

I see no reason why it shouldn't, in theory, anyway. You'd just design your object and do a subtractive boolean operation with the object and a block that would contain it.

In practice it could be a little tricky. I've been finding that in Art of Illusion the boolean ops work better if you build an object by starting with a block bigger than your final object and then use boolean ops to take away the bits you don't need rather than building up your object from a bunch of smaller bits using the "union" option in the boolean op.

The boolean ops in AoI are fairly fragile, so you've got to be careful that they don't go crazy and reverse some surfaces to point inward during an op. You can see this happening when you look at the resultant boolean and see what appears to be polygonal holes in it through which you can see "blue sky". That's a sure sign that you got some reversed surfaces and need to start over.

Another problem is when you try to do a union and but two blocks just barely in contact instead of overlapping significantly. That can cause all sorts of drama when you try to slice and dice the resultant boolean object.

englewood Wrote:
-------------------------------------------------------
> I just talked to a materials man in Columbus,
> Ohio. ...../..... I am going to tinker together a
> motorized syringe with full and empty limit
> switches. A DC motor would only need one bridge,
> so I could send a catalyst at the same time with
> another syringe. I could then remove the syringe
> and use it to fill the hollow molds to produce
> part sets. I think we need a materials forum........

I agree! Having materials forum would be nice. There may not be hundreds of threads on this subject but quite enough and rather distinctive in their content. It's always nice to have a place where you can track back information from old thread. Otherwise we may have a lot of pertinent data that gets lost among other subject data.

Also, I'm very interested about hearing on your syringe setup. I need something similar for my UV setting resins. I need to be able to deposit very thin layers and have bought 20ml syringes with needles < 0,4mm. I have also seen cartridge guns that can hold up to 600ml of resin. It makes sense to talk about deposition methods when talking about different materials.

As for printing molds, it has such a high potential that we need to see how we can do those the best way. Not only software wise do we need to find the right solution, but we may need different mold materials for different object materials (metal, polyester, epoxy, thermosets....)

Sidebar:
Is there a software package for hosting a message forum that would allow the same discussion thread to be indexed in two different sections? This would help to make things more findable in situations where a discussion topic could apply to more than one forum section, and would cut down on crossposting and redundant discussions.