Cheaper 3D Prints

Intro: Cheaper 3D Prints

Have you ever uploaded a 3D design and been shocked at the high cost of production? Well I just spent the last few months getting one rude shock after another from various printing services. But I learned a few things the hard way during the process.

Getting your prints manufactured in laser-sintered nylon has a lot of advantages over printing at home. But for the first few weeks (okay, months) I was very confused. Two similar prints could vary in cost from $5 to $50. I tried making walls thinner because I thought all the costs were based on the amount of material used. Slowly I started understanding where a lot of the hidden costs were, and how to eliminate them to lower my prices

These tips are going to seem laughably simple to an experienced designer, but by using these very basic tips I reduced my average print-cost by over 70 percent since my first attempts at 3D printing through a service provider. For example, one of my very first designs dropped from $38 per print to less than $5, with no loss in quality... so I'm sharing the lessons learned.

These Tips are For...

These tips apply mostly to selective-laser-sintered (SLS) materials such as the Strong and Flexible line of products from Shapeways. Other materials and manufacturing processes have different methods for minimizing output costs, but many of the concepts can be applied to other materials, and even your home printer.

Helpful Outlook

The printing services are your employees. They are your team, your crew and your best partner. Treat them well and make their work days better. Read and follow their guidelines. Your costs will go down as a result.

Understand the difference between your breathtaking, groundbreaking portfolio pieces and your cost-sensitive production pieces that you want to sell for a reasonable profit.

Design Software

I am migrating quickly from the beginner-friendly "123D-Design" to the much more powerful "Fusion 360" program. Both programs are free to makers, students and even professionals who earn less than a certain amount of money per year. They are both from the venerable Autodesk folks, a company that has led the design software industry for decades (and runs Instructables). But the tips apply whether you are using SketchUp, Rhino, Maya, SCAD or anything else.

Printing Service

I tend to use Shapeways for my 3D printing service provider. Ponoko -or- iMaterialise -or- Sculpteo and other services provide nearly identical high quality prints in similar materials, and they might be a better fit for your production needs. For example, Ponoko also does laser cutting. So if your project needs 3D printed parts and laser cut parts, you could source both from the same manufacturer.

And don't forget your peers. Check to see if some shops on 100K Garages or 3D Hubs can produce what you need.

STEP 1: Avoid Dead Space

Space = $$$ for both you and your print providers.

Dead Space Is Your Enemy

Your 3D print company tries to use every possible cubic centimeter of space in every batch of prints. They charge you for the space your design takes up whether it becomes part of the print or not - they have to.

The printing service will overlap parts, nest parts, rotate them and generally try to put as many parts into every print-run as they can while maintaining quality. It's basically like creating a giant 3D jigsaw puzzle.

Then they have to disassemble the puzzle by hand, identify each part for each customer, carefully clean each part, check each part for successful printing, and finally package it safely and ship it.

Try to make this complex process as easy as you possibly can. This keeps costs low for your partner-providers and for yourself. You will get a financial benefit from careful designing

No Dead Space - None, Zero, Zip Nada

Avoid dead space. If your print-service cannot print in a space, they still have to charge you for the useless dead space in your design. Never make designs with spaces your print provider can't use for other objects.

"Complexity is free," is a popular phrase right now - and it's true at certain levels. Unfortunately, nylon-powder, machine time and labor time are definitely not free - so design accordingly. Avoid dead space.

And BTW, dead space is bad.

STEP 2: Provide Access

Your costs will go down if you can give your printing-partner some sort of access to the unused space in your design. They can then print someone else's design in that space, reduce their cost and pass the savings along to you.

Can you add a door or removable lid? Can you make a hole bigger? Can you break apart the design so the empty interior is accessible for other people's use and not wasted empty space?

And make sure, when you arrange your parts for printing, you keep that door or lid open. The print service will rearrange parts, but they will not modify geometries - they will not open that lid for you.

Oops... My Bad

I once designed an object that looked to be affordable all throughout the development phase. I posted early designs and they all came back at a few dollars combined. But when I submitted the design for final output, the full design was triple the cost of the sum-of-all-the-parts. Ouch, what happened? I was out of time and had to order the part, so I paid full price. It came back beautifully printed - and incredibly expensive.

When I had time, I rethought the process and discovered a really stupid mistake. I had put the pieces together almost like they would be when assembled. That meant the lid was on, and I had effectively created a giant, inaccessible money sucking void at the center of the object. Double ouch!!!

I took three minutes or less, rearranged the parts for printing so the dead space was gone, and the costs once again plummeted to a third, a 66% savings for 90 seconds of work and a tiny bit of smarts.

STEP 3: Break It Up

Portfolio vs Production

It is often easier to avoid expensive dead spaces if you break apart your design into smaller pieces. Yes, these days you can design amazing single-body objects that were impossible to create just a few years ago - and your print provider will happily print them - dead space and all. And they will charge you for every cubic inch of space.

As a show-piece for your portfolio, these types of objects are fine. But for production of sellable mass-market objects it might be better to break apart the design. This often reduces your production costs enough to make the object affordable while giving you a better profit margin. Plus, it gives the end-user the enjoyable experience of building something.

Knowing when each approach is appropriate is up to you.

Opportunity Knocks

We all seem to be fascinated by the ability to print single-object, all-at-one time prints. At the same time, 3D printing is also still very expensive, and we hesitate to experiment with new, unfamiliar materials. Yet most commercial products use multiple materials, and increase their attractiveness while doing so.

What if we used this design challenge as an opportunity to explore different materials, or give us opportunities to explore different post-processing finishing techniques? Or as a way for end-users to customize their product?

STEP 4: Piggyback and Bonus Parts

Sometimes, you have to print a model as-is, there just isn't any way to redesign it using the previous tips. You cannot break apart your design into smaller pieces, there are no panels to leave open, and you cannot increase the size of any holes or openings.

There are still ways to reduce overall costs, especially if the model comes back to you before going to the final client or retailer.

Drama Free Doodles

I always have a large collection of techniques I want to try. But I often have a hard time justifying printing untested ideas or incorporating them into designs.

Those dead spaces in your design are actually great places to embed tiny test models. That hinge you want to test, the flexible joint, the test of subtle engraving - fill that dead space with your doodles. They will cost pennies each instead of dollars each as standalone models.

Add to Your Collection

I also have a collection of my favorite tiny objects that I fill dead spaces with. Letters and numbers, light diffusers, knobs and button covers, plus a collections of nifty giveaway items that I like to keep on hand.

Advertisements Enter Stage-Left

What about the times when the product goes directly from the print-house to the customer? Slip a 3D business card into a space you can't remove from your design - or a puzzle or gadget, or an entertaining spring or hinge. How about a simple toy ring or flexy-bracelet or hair tie. Something your customer can give to their kids or a friend and provide new interest though word-of-mouth and first-hand experience of 3D printing. It can add only pennies if done well, and make the unboxing experience even richer for everyone.

STEP 5: Combine Your Parts

Time is also $$$

Every free-standing part in your design has to be hand-cleaned, identified and coordinated with an order, then packaged indidually. So the print-service charges you a small fee for each separate model. Remember those helpful folks at your printing service also have to keep track of hundreds, maybe thousands of objects in each print run - your design is just one of them. Help your partners out and keep your own costs low by collecting the parts of your model into one easy-to-handle package..

Most service bureaus encourage you to attach, connect or enclose your parts. That way, they only nave to identify one object instead of 5, 10 or 20 oddly shaped pieces out of 1,000s.

Three Basic Methods

1. Sprue - A "sprue" is a connecting part that joins parts together. If you have ever assembled a plstic model you have likely snipped your main parts out of a framework of sprues.
2. Key and Loop - A "key" is anything that sticks through an opening in parts and holds parts together. A "loop" is what in sounds like - basically a key ring.
3. Enclose - Sometimes your parts just need to be enclosed in a cage or bracket to keep them all together.

Conclusion

That's it... as simple as promised. These basic tips can reduce your 3D pint costs by dramatic amounts. There are lots of subtle ways to reduce costs and simplify printing, so keep designing and keep learning.

Comments

[Edgar]

A pity I cannot do Multiple Favorites! Thanks!

[wizodd0]

If you need mass for the base of an object, design it with a void and fill it after manufacture with sand, if you have designed a void, you can leave screw plugs for this purpose or just plug the holes with epoxy or the like.

If you need strength, you can design a void and fill it with expandable polyurethane foam, or design internal cross members.

Always ask your maker if they have suggestions, as they want to have you as a customer, and reducing your costs increases the chance you will stay a customer--and it can also increase their throughput which means the most profitable use of the machine.

If costs are based upon swept volume, remember that many parts can be designed easily to be printed in such a way as to be folded into final position, and held with anything from designed in snap points to adhesives.

In all cases, the costs will depend upon: machine time cost, materials cost and overhead. Minimize therbligs.

In every case, the problem with things you don't know is that you have no way to know the depth of your ignorance.

[markk7]

Fantastic tips wizodd0. Flat pack and old school tricks like dovetails and bending-kerfs are worth a whole other Instructable just to begin to explore. I've seen good guides on doing this with laser cutters, but with stainable/sandable wood and bamboo filaments now available it could be a great time to create a hybrid style.

And how's this for ignorance: I have, more than once, actually increased my costs by applying these tips poorly,,, and still don't understand exactly why the cost went up. I'm a total noob, so I really appreciate you sharing your expertise freely with me and the community.

[Pkranger88]

Very good tips. I used to run the 3D Prototyping Lab at NIAR at Wichita State University.

Not all printers work well this way. If you are doing powder prints, such as on a ZCorp printer, you won't likely nest parts inside of parts.

I can totally see these nesting methods working on prints on other printers though.

Kudos for putting in the time to include some CAD screenshots.

[markk7]

Wow Pkranger88, can I just say I'm jealous... and thanks for the feedback and knowledge. Every vendor seems to have a different method of optimizing their efficiency and lowering consumer costs. I would love to know the strengths of different machines and methods, but I concentrated on the one I am most familiar with. The scary part is that even these will probably be obsolete in a few months. I know Shapeways is constantly evolving and they can now spot errors, alert me and even fix some automagically. Two years from now these tips could be as relevant as extending the ribbon life on a daisy wheel printer. But what a wonderful time to be involved with this technology. Thanks again.

[gcheintz]

Thanks for posting but you should fix your title and says "tips for 3dprinting at a service" rather then 3dprinting tips. You can buy a 3dprinter for 200$ now so I read this assuming there is something that I should be aware of on my 299$-printer but this was just how to take advantage of some 3dservices strange charging systems. Our school has a 3dprinter that charge us but it only charges per weight which is a good method and almost none of your tips will apply for that charging method.

[markk7]

Absolutely correct gcheintz. - I totally see your point. But "How to save money on one out of several materials at (mostly) one out of several vendors in the months surrounding mid-year 2015," well dude that just seemed too long.

So help us out. I know other technologies, like FDM, and other materials like resin, have totally different ways to maximize efficiency and minimize costs. I would love to see more Instructables tips on how to cut costs on other printers.

FDMs can have low material costs, but the clean-up labor costs can be high. And the time spent cutting large, complex projects into well behaved chunks and designing supports can add up. If you had to pay $35 per hour for clean-up and design, how could we save money... and is it really that much cheaper than the free-form SLS when those costs are factored in? I'm pretty sure that would be a popular guide. I know I would read it.

Thanks again, and sorry about the fake out... my bad.

[MikB]

Great tips. For one service I've used for this, I don't think they'd count your "key" example as a single item, all parts MUST be connected. In which case, I would suggest a hybrid of key-and-sprue.

Use the key method as shown, but put the weakest possible sprues from the KEY to the MODEL. That way -- it's all connected. So the computer says "Yes!". But a tiny force will break apart the faux-sprues leaving it all retained by the key. The fact that they may break in handling isn't a problem, the parts are still retained.

Also, your tip for leaving things open. Not all services will discount on that. For the one I used, it was based on swept volume. A closed unit cube would cost X. An open unit cube (no lid) would cost the same. Printing the lid alongside (sprued) would add a small cost (extra volume). If stood close. If stood flat and alongside, it would double the cost -- twice the swept volume.

And other models were not stacked inside "your" volume +2mm around. So use it, as you're paying for it.

So it really pays to experiment with multiple layouts, as every company has slightly different parameters and charging.

[ted_ferguson]

if you make the sprues too fragile won't it fail QA when they pick it up and it breaks apart?

[MikB]

I don't know -- the point is the KEY holds the parts together so that it doens't cause the 3D printing house to fish for parts. The sprue-to-the-key can break, or not, it's only there to convince the computer it's really ONE part. You still have only one component, just a slightly more partial one.

I would hope the 3D fab wouldn't reject it out of hand,just because a component of below-recommended size broke. I suppose you could add a note to the job :)

[markk7]

Thanks MikB, great reply. I've had connections break, but only had one part to completely separate. They didn't charge me, but I don't want a flag on my account either so I still try to make solid connections. I'm learning as I go. Flat parts catch the "air stream" more, spend an extra penny and connect top-and-bottom to make a more rigid joint... stuff like that. Thanks again.

[markk7]

Thanks Ted - MikB is right on the money. Sprues etc. do break, and a lot of the reason I use them is really just to save the handing fees, especially on projects with lots of small parts. And his point about making the staff's life easier is a great one. Imagine having to sift through several cubic feet of dust (In a haz-mat suit) just to find one little part and then match it to one out of a hundred unfamiliar models in that print batch... arrgh!!!

I'm getting better at sprues and such, and I've never had a model damaged because a sprue broke. But someday soon (no really) I intend to sell models. So I want the customer to get a perfect print, not something with parts dangling or detached. Shapeways does their job really well, so it's up to me to make sure the customer will get that feeling of quality.

[MikB]

"for this" -- instructables ate my link :(

www.instructables.com/id/Raspberry-PI-Camera-Spinner-3D-Print/

[markk7]

Now that's a nice, tight design. Really well done!!!

[MikB]

Thanks -- my first 3D printed object! But not the first iteration of the model (it did take a few goes submitting/quoting/editing to get it down to that packed size. And the obligatory "you missed a non-manifold face" error, even after checking).

Yes, there's a fair bit of cleanup, and trapped SLS dust!

[markk7]

Great points MikB and really important ones.

*** Study the manual for your service provider!!! Understand their needs***

*** Stay up to date on any changes to their policies and capabilities!!!***

***Take advantage of any tools and free estimating abilities to test for the best layout!!!***

*** Learn, refine, adapt - but do it - it's easy and fun!!***

I fretted over balancing generic-vs-detail etc for what I anticipated to be a beginner audience (even more beginner than me). I also worried that the policies will change next month, or that technology will make these tips obsolete. I know making a drain hole larger, or a mesh less dense could achieve the same results as adding a lid. Many paragraphs and entire steps disappeared trying to find that balance.

So I settled on a "Please Read The Manual" approach with some of the biggest gotchas to look out for this week, mostly on Shapeways. Maybe I should have used a stronger, more traditional RTFM approach.

Note that the illustrations also have issues: overly wide spacing between parts, bad orientation of the stein lid, parts too thick or thin, no fillets. But I also didn't discuss how tight spacing and sprues increase clean-up time etc.

I would love to see more detailed tutorials from people like you. This is just a dusting on the tip of a huge iceberg. Hopefully this guide helps people avoid paying $50 for a $5 print, but I could sure use some help fixing those numerous 10 cent errors that could make it into a $2 part and really affordable.

And let's not forget balancing cost with durability, functionality and aesthetics.

Thanks again for the fantastic feedback. Your comment is featured and you followed. Cheers.

[opengreenenergy]

Wow nice tips.

[markk7]

Thanks deba168. They are really basic, but hopefully they help.

[EricTheTechShopMan]

I agree

[markk7]

Thanks EricTheTechShopMan. Hope they help someone make their 3D designs become real.