3d Stuff

[Ein]

I think Moddler is the way to go. Following this very closely...

[Lane]

[Joey]

Jon, these are amazing! You've certainly come a long way in 3D modeling in a short time.
I'm astounded that the rivets came out so well on the Moddler print -they look so small. Care to share the diameter you used?

-Joey

[Joey]

Oh, and please keep us posted on how the underside comes out.
As I'm sure you saw with the Shapeways parts, the underside usually has much poorer detail than the topside. Very apparent at Shapeways, but I've never tried Moddler so I've no idea about the results there.

[paulson games]

Thanks Joey I've been plugging away at the programs pretty hard and also had one of my friends who's much more experienced with modelling is going over everything to clean up errors before sending it out. I'll have to check on the rivet dimension but I think it's right about .5mm maybe slightly smaller?

The parts showed up yesterday, I did a mold of the shield last night and here's the first casting which I'm quite pleased with.

(sheild is 20mm in diameter)



The cast was made direct from the printed part, no sanding or clean up work. Needless to say it's incredibly clean and there's no visable stepping or laying marks. The printed underside surface (the back of the sheild ) has no discernable differance in quality. I was blown away with how much better this came out than the shapeways version.

The very slight ridges on the shield face are part of how the model's wireframe is constructed (not the printing), I'll be tweaking that a bit so that it'll be completely smooth on the next print.

The handle is a little clumpy looking due to my messing with it and over applying superglue, the printing was really clean but I messed it up while trying to fill the small gap behind the handle with styrene so that it could be cast as one part. With such a tiny bit It was an exercise in frustration and I think I will be having the shield reprinted with a seperate handle (when I submit the tower shield) that way it'll be two parts. Which will improve the molding step and won't wear on the production molds as much.

Totally blown away with how clean these came out and will definately be using moddler again.

I have both axes molding at current and will hopefully have an update later tonight.

[paulson games]

Apparently the printed parts are a semi porous material that are grabbing the silicon really badly which resulting in my first set of molds tearing when I was attempting to remove the parts. The silicon was bonding with the surface like it was superglued in place. The shield came out with a lot of resistance but managed not to tear, the axes however bound too tightly and ripped.

Fortunately the parts were strong enough not to break and I was able to carefully scrape all the silicon off. The rubber to rubber release that I use to keep the mold halves seperate seems to work well at preventing the silicon from binding with the part so I'm just about done with round two of the mold attempts.

I've also been looking at the parts and they are a bit large in scale, works great if you want a giant two handed weapon of doom for your hereo but a bit large for average line troops so I decided I'd also do some scaled down copies as well. The downside to that choice is that I have to go in and manually reposistion all the points as simply scaling the model down would render the rivets and details too small for the printing. Not quite as painful as building the weapons from scratch but it does take some time to rework the models.

I also decided to do a roman style gladius to go with the shield and spear, reworked axe is in the middle, original axe is on the right.




Also did a bunch of clean up work on the mech autocannon, most of it was tweaking the wireframe and making the body watertight so I'm not sure how apparent it'll be based simply on the renders. Internally it's shaping up nicely. WIll be adding an ammo port shortly and some more surface details.

[Lane]

I don't remember seeing any mention of the material being porous, would have warned you if I had.

It could be that the people recommending Moddler were priming, sanding and sealing the models before casting so they never had your problem.

[Ein]

Which brand of RTV did you use?

[paulson games]

I use smooth on brand stuff.

Only the inital face had the problem with the silicon sticking, the backside which normally gets a light coat of the rubber to rubber release had no issues with sticking. It may not be porous but there's at least some sort of material bonding with the raw material, where in compairsion the stuff that's been coated in release agents is fine and doesn't grab.

As I'm doing everything in two part molds I was able to salvage the back pieces, pry the piece out of the front part, cleaned off all the silicon and I at least was able to salvage half the molds. For future models I'm just going to give the part a light brushing of release while it's in the clay prior to molding the first face.

Initally I thought it was porous but if that were the case the I'd see micro beading into the surface of the model after removing the large chunks. Release agent wouldn't block it from getting into the faces as the air pressure would force it in. After thinking about it for a while I think it's a chemical/material reaction. I've had issues with micromark and smooth-on materials sticking like this as well so some materials may not be compatible. Smooth-on resin binds up inside micromark silicon really bad, although the micromark resin works fine with smooth-on silicon for whatever reasin.I use the micromark R-to-R release on both their silicon and also on smooth-on silicon and it works great on both products.

I also noticed that the color of the original plastic part changes slightly after casting as well, there's some sort of minor reaction going on but it doesn't seem to affect the mold or the original part at least in regard to the material hardness or detail.

Anyways thought I'd post the info that way people are aware of the possible issue, just coat it with rubber release and it should work ok. A nice smooth priming it might also do the trick.

[Lane]

Thanks for the warning about smooth-on resin sticking to micro mark RTV. In general I try not to buy any "store Brand" resin or RTV since they are generally just another companies product repackaged and charge more.

Since it sounds like you are serious about doing 3D work and already were making conversion bits you should check out the yahoo group scificonceptsanddesign. They have several people doing RP prints of models, lots of good information even if you do not join.

When you contacted Moddler did they send/ link their tips for 3D prints? If not I think I have a copy from the yahoo group.

[mangozac]

Some great advice in here Jon! You're working hard and coming up with some good results. I understand if not but are you able to share any comparative costings?

Love the work on the gattling gun! I certainly know of some models where it would come in handy

[paulson games]

I'd submitted a sprue consisting of one of each weapon and the sheild to each of the companies, for shapeways it ran me $11 but the quality was also pretty piss poor. (useable but would have required tons of cleaning and recasting it to get a production suitable piece)

With moddler the same sprue ran $50 and IMO it's probably the best quality for the money.

Print-A-Part (or fine line now) ran $65.

Quality wise moddler and fine line are pretty much the same, I think that moddler did a slightly better job of cleaning the model after printing. Fine line for the most part was great but the rivets looked a bit odd to me, they also had a few small bit of excess material which scrapes off easy. The rivets are white for some reason while the main body is blue. I haven't really given the fine line prints a super detailed go over as I was already molding the moddler ones and they are what I'll be going with for future projects. Not disappointed with fine line parts, just for the slightly lower costs and lightning fast service time I think moddler wins out.

Both companies also had roughly the same shipping price of about $10, as they are shipped by priority mail. Shapeways includes the shipping cost in the price of their model but there's a $25 minimum order.

I talked a bit with Mark (nosegoblin/dreamforge) and his experience with the printed parts binding is due to the stepping effect that's created by the prints layering. From normal viewing the parts look smooth but if you put them under magnification you can see that they are basically made out of lots of squares kinda like a sculpture made from leos. The hard corners and vertical surfaces create a lot of friction areas on the part so the silicon doesn't want to let go easily. WIth the release they seem to let go ok, but I'll be cleaning up casts of the master part before I use them in creating production molds.

If you lightly run a blade over the part it'll peel off some of the high points on the layers edges and helps smooth down the piece without cutting into the body or ruining the detail. It's also preferable to do this to a cast that way you won't wreck the master part, additionally the resin is much easier to sand and see the surface detail on. The plastic these are printed on are semi-transparent and it's often hard to tell if you are seeing imperfection on the surface of it it's internal microbubbles inside the part. The plastic is also really hard and doesn't sand or scrape easily. It's more likely to scratch and damage the surface than when using a resin cast.

[Vaaish]

The white bits you are seeing on the printapart one comes from however they adhere the layers together. Over time you will see more white showing up but it doesn't seem to affect the durability of the print.

[paulson games]

I finally got off my lazy butt and got all the master molds finished. I'd wanted to get these done about a week ago but I've been in kind of a slump, casting for orders is tedious at times which makes it tough to get new stuff cranked out at the same time.

Here's a shot of the casts, I have to run a bunch more off give them a good cleaning under magnification to get rid of all the ridges left by the printer's stepping. They look fine to the naked eye but they have tiny ridges particuarly on the rounded surfaces which might show up when using ink washes on the parts. So before I can make the production molds I need to run off 5-10 copies of each weapon clean and them all individually. As long as I don't get too bogged down I plan on having them ready to post up my site within the next two weeks.

[mangozac]

They're looking great! Still a few print lines visible, but none so bad that probably won't be concealed by painting. The scale shots I saw on a mini they did look a little excessively large. I know 40k stuff is a bit exaggerated but the double headed axe was a bit too overboard for me.