Some of you may know that I’ve used Shapeways a lot over the last 5 or 6 years, especially for model-making for my full time job. I’ve generally used their (cheapest) SLS nylon, because it’s… cheap. Not fantastic detail, but very rugged, and the build volumes are large. I don’t use FDM much, because my machine no workie, and the SLS doesn’t have the layered effect.

Recently (for a couple years?) they’ve offered “engineering plastic,” which has finer detail and better strength. And it can be had in black material: not just dyed white, but black (or gray) all the way through. This is important when you sprue parts together and then need to cut the sprues off.

But, the Shapeways’ “engineering plastic” ain’t cheap: 2 to 3 times the SLS nylon (they now call it “versatile plastic”) cost.

Their “engineering plastic” is the product of Hewlett-Packard’s Multi-Jet Fusion printer. Still nylon, but a better process / material type. So, if you find another place that prints with that, you should get the same outcome. 3DHubs started using it, but their prices quickly got even higher than Shapeways. Xometry also does HPMJ, but they’re even more. The good thing about 3dHubs and Xometry is volume pricing, which SW doesn’t have. 3DH & Xom are going after production markets, not just one-off’s.

OK, I’m finally getting to the point. I don’t need volume pricing for now, just good HPMJ product (in black; not everyone does that) for my one-off projects. I finally found a place to try out, Jawstec. Here’s the comparison for 2 different parts, using the same process / material / models.

Shapeways: Part 1: $151; Part 2: $55

Jawstec: Part 1: $58; Part 2: $18

About 1/3 the cost! So I placed my order with JT, and will post on the quality when I receive the parts.

BTW, the above prices were based on sprued models: no loose parts, all connected together. If you don’t do that SW pings you extra for each separate “body,” no matter how small. For grins, here’s the pricing on part 1 with no sprues, all the parts loose.

Shapeways: $221

Jawstec: $58

Wow, almost a 4:1 diff! JT’s price didn’t go up with it being a multi-body part, so I don’t even need to mess with that tedious process, at least because of price. I might still though, to keep small parts together and not (as sometimes happens with SW) get lost in the process.

Here’s the part I’m talking about, all loose bits, about 6" long:

Cheers,

===>Cliffy

A little follow-up. I received the parts, and am happy with their finish (good enough for this project; I didn’t pay extra for the smooth surface) and detail. No pieces were missing, yay! So the bargain is, for me, true: less than half the price as Shapeways.

Furthermore, I ordered on 11/29 and received them on 12/6 – 7 days for printing and shipping, vs. at least 2x that with SW.

Not saying this will be the solution for everyone, but I’m grateful for this new avenue for HPMJ parts.

Hey Cliff,

First off, thanks so much for letting us know about JawsTec. I have a very nice FDM printer that is “dialed in” and produces minimal layer lines (especially when using Pro PLA). I still need to spray and sand a few coats of Rust-Oleum Filler & sandable primer to get things smooth.

I had been considering the purchase of an SLA printer for some time now but my experiences with SLA resin parts (Shapeways Ultra-frosted detail) and conversations with the folks at Formlabs have led me to the conclusion that SLA resin is less suitable for Outdoor Garden railway use than the PLA I’m using.

So, what are the MJF Nylon parts like? Have you painted or stained them? I assume the parts you have been getting for your job have been “functional prototype” and not production parts but can you give me some insight as to the durability and effects of exposure to the elements?

I’m sure I won’t be purchasing an HP MJF printer any time soon, but this may give folks a way to get the parts I design without the need to fill and sand at a very reasonable price.

Hi Dan,

About your FDM, have you considered XTC-3D by Smooth-On? You might call them and ask for a sample kit, I know they have them…

About SLA, yep, I’m also considering one of the cheap ones. But as you say, and I agree, probably not best for rugged / outdoor use. But, I’m eyeing it for detail parts of rolling stock projects that I’d keep indoors. Here’s the Anycubic, and they have a deal now for over $100 off… Hmmm…

OK, back to MultiJet, this was the material/process that Shapeways called “engineering plastic” for quite a while, as opposed to their “strong & flexible plastic” (now “versatile plastic”). Here’s the material page for “Industrial strength” MJPA12. Basically, it’s stronger and better-detailed than “versatile plastic,” but, I’m sorry to say, still nowhere near as detailed as in SLA.

For me though, if something’s being left outdoors and viewed from a couple of feet, the level of detail (especially with my not perfect eyesight) in HPMJ is more than adequate.

As for painting, I’ve only stained black parts with rust color; I can not [edit] say how white parts take paint, and which paint works best. There’s probably forum threads on that, but I just haven’t needed to go there yet.

Maybe a good thing to do would be to upload a small sample part, and have it printed in the materials of interest, from Shapeways or 3D hubs or JawsTech (whoever is cheapest). Or, maybe one of those has a sample set for comparison, perhaps free with a phone call, who knows.

[edit] Since the HPMJ part material is a type of nylon, I’d think it would be fine for outdoor use, though I haven’t yet read that specifically anywhere.

Your thoughts?

Cliff

Cliff Jennings said:

Hi Dan,

About your FDM, have you considered XTC-3D by Smooth-On? You might call them and ask for a sample kit, I know they have them…

I have not used XTC-3D but I have used something else that works in the same manner. It’s called Mr. Hobby Mr. Dissolved putty. It’s essentially a brush on self leveling putty and works quite well. However, It’s not cheap so I find the Rust-Oleum to be much more economical for larger areas like my 4" diameter tank car ends.

About SLA, yep, I’m also considering one of the cheap ones. But as you say, and I agree, probably not best for rugged / outdoor use. But, I’m eyeing it for detail parts of rolling stock projects that I’d keep indoors. Here’s the Anycubic, and they have a deal now for over $100 off… Hmmm…

I’ve looked at the Anycubic and as cheap as it is, when you take into account the cost of the resin, Parts that currently cost me pennies now would be dollars and not as durable. The SLA process is much more “messy” and involved so I feel I wouldn’t really gain overall time either.

OK, back to MultiJet, this was the material/process that Shapeways called “engineering plastic” for quite a while, as opposed to their “strong & flexible plastic” (now “versatile plastic”). Here’s the material page for “Industrial strength” MJPA12. Basically, it’s stronger and better-detailed than “versatile plastic,” but, I’m sorry to say, still nowhere near as detailed as in SLA.

For me though, if something’s being left outdoors and viewed from a couple of feet, the level of detail (especially with my not perfect eyesight) in HPMJ is more than adequate.

I agree. How many parts on a commercially produced 1:29 scale model are > 1mm?

As for painting, I’ve only stained black parts with rust color; I can say how white parts take paint, and which paint works best. There’s probably forum threads on that, but I just haven’t needed to go there yet.

Maybe a good thing to do would be to upload a small sample part, and have it printed in the materials of interest, from Shapeways or 3D hubs or JawsTech (whoever is cheapest). Or, maybe one of those has a sample set for comparison, perhaps free with a phone call, who knows.

I’ve been poking around the forums and there are mixed opinions regarding painting/dyeing. I plan on placing an order soon with JawsTech. It’s cheap enough for me to pay for the samples!

Thanks for the insights Dan. Regarding the painting, the lightest color that JT has is gray, fwiw, so you might try that (vs. black).

Let us know what you learn!

Cliff Jennings said:

Let us know what you learn!

Here are the prints I received from 2 orders from Jawstec . The first was a few plows, Brake Wheels and an NW2 roller bearing sideframe. After speaking to them in chat I decided to see what they could do with my more highly detailed Nathan horns.

Most parts I had made black, tumbled and polished. The Hopper hatches, LGB Genesis plow and one NW2 plow are raw(gray) and tumbled only. I find the parts that I paid extra to polish are really not much different then those that were only tumbled. They all have a texture almost like surface rust. Not sure how much of that will be noticeable after a coat of paint but I may try sanding and/or scraping a bit. Overall, I’m not disappointed as the parts will certainly pass the 10ft - probably 5ft rule. They seem to be very durable and can’t beat the prices. 10 Brake wheels $2.53. 4 Nathan K5LA horns $2.76. 8 Truck sideframes $19.26. LGB replacement plow $5.88

Thanks for posting all that Dan. I’ve been working with my parts (same material / source) over the last few days, and was somewhat disappointed with the graininess. But, for larger parts or ones having less detail, they seemed ok. And as you say, the price is great.