Introduction: 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.
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.
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.
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.
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.
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
- 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.
- 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.
- Enclose - Sometimes your parts just need to be enclosed in a cage or bracket to keep them all together.
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.
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