As much as I’m blown away by the internal complexity of 3D printed rocket engines and the intricate detail of 3D printed medical models, I still think the unsung heroes of the additive world are jigs and fixtures. Needed to firmly hold a part in place while a secondary operation is performed, jigs and fixtures are necessary but non-glamorous parts in themselves. The term “jig” generally defines a part that holds and aligns another, end-use part (workpiece) so the latter can be machined, drilled, precisely cut, etc. A “fixture” is typically used to hold a workpiece in place while another manual or automated operation is done – more often inspection, assembly of two parts together (by welding or screwing/bolting) or to just more easily hold a part in a position that allows, say, applying an emblem or installing a side-window as tasks in an automotive assembly line.
For both use-categories (I’m going to call them J/Fs), the design work has traditionally been done in CAD by mechanical engineers. Once the designers have imported the CAD model of the workpiece, they typically offset surfaces in just the right area(s) and use the new surfaces as the basis to design a secondary structure that will firmly hold the workpiece in place. Depending on the complexity and possible organic-ness of the CAD model’s shape, plus the J/F designer’s experience level, this process can easily take hours. The final structure might itself need to be assembled (welded) from separate sections of aluminum stock, with separate handles and fine-adjustment positioners later bolted on.
Applying 3D printing processes to J/F design has already expanded the options for users to redesign and lightweight existing fixtures. The following images show an example created some years ago as a collaboration between Ford Motor Company and Stratasys, to improve the ergonomics of a rather heavy window-glass alignment fixture. The new design included ergonomically-shaped handles plus integrated pneumatic valve components and switch mounts, and cut weight by more than four pounds – a noticeable benefit to the assembly-line employee tasked with this repeated job.
Off-loading Fixture Design
What if this entire design process could be compressed from hours to minutes? And off-loaded from the traditional mechanical-engineering team to free them up for more complex tasks? These goals have been addressed and met by trinckle, a Berlin-based software company founded in 2013. Their expanding portfolio of products includes fixturemate, the software package I’ll focus on today; many more are available and in development – see the PADT blog post, “Exploring the trinckle Additive Apps Suite Software for 3D Printed Fixtures.”
I first encountered this software tool around four years ago when there was some talk about PADT becoming a trinckle reseller. I got the chance to test it out and was really impressed by the results. Fast forward to late 2025 – and fixturemate became available to everyone through Stratasys, as an app embedded in GrabCAD Print Pro (GCPP), the high-end software dedicated to setting up 3D print-jobs for all Stratasys additive manufacturing systems (with some tools now extending to other platforms). What a timesaver!
The workflow inside GCPP fixturemate results in either sending the design directly to a Stratasys 3D printer or exporting the model as a STEP file for further processing in CAx software (in case, say, you wanted to machine it). But 3D printing your fixture gives you light-weighting design-freedom, many material options and a direct method for producing oddly shaped geometry. Let’s check out some examples.
Simple Material-Handling Tray
A simple application of fixturemate is creating a material-handling or dunnage tray with conformal recesses for safely transporting one or more parts from workstation to workstation.
Simple conformal holding-tray for knee-replacement sample (3D printed “knee” stands in for actual metal part)
Launch the fixturemate tool from inside GrabCAD Print Pro, and make a fixture in three steps:
1 – Import Knee (CAD model) and set Z position to 0.35 inches:
2 – Select Baseplate (Convex Hull) and define part Height as 0.75 inches:
3 – Subtract Workpieces and see final part:
4 (Optional step) Hollow out the backside to lightweight the part: click on Save Material/Print Faster/Create hollow fixture
At this point, you Export the completed fixture to GrabCAD Print Pro for printing. (If you also check the “Fixture B-Rep (STEP)” box), it sends the STEP model itself to GCP Pro which can then be exported for additional design work or alternate production method):
I’ve designed a number of fixtures with this software and found that even for a complex shape, the basic framework only takes five minutes. Designing a structure to hold multiple copies of a part, or to hold one part in two orientations, might take ten or fifteen minutes – a far cry from the typical process in a CAD package.
Here are several fixtures where I set up the base to hold multiple parts, either as a carrier tray for a sample model we call an Omega Clip or as a mockup for a sterilization tray of respirator adapters:
Fixture with individual holding-supports
What if you want something a bit more complex? How about this fixture that holds a part for inspection and touches only at a few small areas, using “support posts”? First, here is a version done years ago at Stratasys to hold a prototype of an Oreck vacuum-cleaner head, using a standard design approach with CAD.
Now, here are two versions I did with fixturemate. On the left is a first cut I did in five minutes, creating three posts and adding labels for axes and a part number. On the right is the final version, light-weighted with several cutouts added.
The process for adding the posts is easy. After bringing in the CAD of my workpiece and selecting a Convex Hull baseplate, you just click on Supports and choose from rectangular, cylindrical, conical or custom, place them where desired, edit the dimensions and do the same Subtract to create the reverse shape.
Clamps, Organic Shapes and Other Fixture Options
Fixturemate offers many more possibilities for quickly crafting all sorts of fixture shapes, including designs where clamps will be mounted, all done with clicks and quick adjustments.
Here’s one I did with mounts for industry-standard clamps,
And here’s an example of a go/no-go fixture I designed as a fit-check for a fuel line part.
The basic fit-check design was completed in five minutes; I then spent an additional fifteen minutes to edit/remove material to lightweight the overall structure and save on model material.
Fixturemate has a few quirks, one of which is that the CAD model you import is from then-on termed the “workpiece” and another is simply that to reopen a fixturemate file you had previously saved, you click on the “clock” icon – aka “Restore session from your PC” which just doesn’t seem intuitive compared to File > Open. But you get used to it.
I’m finding fixturemate super useful, and the company is also responsive to user-feedback.
fixturemate: your time-saving solution to a lot of fixture-design challenges
If you’ve been thinking about getting a license of Stratasys GrabCAD Print Pro for its other cool features such as 3D Array, Labeling and Cost Estimating, the time-saving power of fixturemate should tip you into “buy” mode. Check out the 30-day trial of GCP Pro and put fixturemate to the test: design some fixtures of different styles, send them to GCP Pro, and export the STEP or STL/3MF file to print even if you don’t have a Stratasys printer. Done!
PADT Inc. is a globally recognized provider of Numerical Simulation, Product Development and 3D Printing/3D Scanning products and services. For more information on Stratasys printers and materials contact us at info@padtinc.com.
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