cad

133 Articles

Browser-based 3D Editor Covers The Basics While Staying Local

August 1, 2026 by 29 Comments

Got an idea and want to make a simple 3D model, but don’t want to install a full-fledged CAD modeling suite and queue up a few hours of tutorial videos? Check out SketchForge, a 3D modeling program that runs locally in one’s browser without any need for an account, or external services.

SketchForge takes a more WYSIWYG approach to 3D modeling by making it easy to put an object together with primitive shapes, and making it extra easy to specify dimensions and align parts with one another. There’s also a sketch feature that makes it easier to create more complex shapes by making a 2D drawing, then extruding or revolving it into a solid. We like that it has STEP format export as an option, making it easy to import your creation into another CAD program of your choice later. Most 3D printer slicers natively support the STEP format nowadays, too.

It’s a bit reminiscent of Tinkercad in concept, but entirely local. It’s still new, but there’s a demo online that gives a good idea of its capabilities if you’d like to give it a spin.

We’re reminded of CaDoodle, another project that takes the “Tinkercad, but local” approach but as a standalone executable, instead of browser-based.

Glue-in Hinge Design Tries Something Different

June 12, 2026 by 17 Comments

Need a hinge in your 3D printed design and would prefer not to re-invent the wheel? You may find [Alex Krush]’s glue-in filament hinge useful.

This design (shown in this simple box as an example) makes a very close-fitting hinge point.

This design prints half the hinge as a separate piece — the u-shaped one in the picture to the side — that must be glued into the target object after printing. It’s a bit of extra work, but doing it this way has a couple advantages.

One is that printing some of the hinge elements separately means one no longer needs to choose between a print orientation that best suits the object, and a print orientation that works best for the hinge. Also, the length of 1.75 mm filament used as a hinge pin is held captive after assembly so there’s no need to glue the hinge pin itself.

[Alex] helpfully provides the parts in STEP format, which makes CAD tweaks and adjustments easy. While incorporating the design should be doable even if one is just using .stl or .3mf files because boolean subtraction and merging is all that’s needed, having the model in STEP format is so much better.

Should you need some pointers on incorporating either into FreeCAD, we have you covered.

FreeCAD 1.1 Tutorial, For Beginners Who Like Clear Instructions

May 13, 2026 by 60 Comments

If you’ve been interested in FreeCAD but haven’t known where to start, here’s a wonderful video tutorial for FreeCAD 1.1 by [Deltahedra] aimed squarely at how to model a 3D part from scratch while also following best engineering practices for part design. It focuses on a concise and meaningful workflow that respects your time and doesn’t make assumptions about skill level. It even starts by taking a few moments to explain how to navigate the interface, a courtesy many will appreciate.

FreeCAD can do quite a lot, so a tutorial that focuses on a specific yet broadly-applicable task with a clear context is a great way to narrow the scope into something manageable, and be comprehensive without getting bogged down in minutiae. [Deltahedra] does this by exclusively using the part design workbench, demonstrating what to do to make a part step-by-step, and showing common mistakes that can happen and how to fix them if they occur. Beyond that, it’s left up to the curious hacker to delve for themselves into what else FreeCAD has to offer.

Since 1.1 is (at this writing) the latest stable release, one can also be confident that the tutorial will match the user interface and features one sees on their own screen. After all, it can be frustrating to attempt to follow a tutorial only to find out things are a few versions behind and nothing is where one expects it to be.

Best practices aren’t just fussy rules about how to do things, and [Deltahedra] demonstrates this by showing how certain procedures just plain make more sense when designing shapes. Our own Arya Voronova has also shared best practices for FreeCAD, so check that out for some added perspective. You’ll be wielding FreeCAD in confidence and comfort in no time.

Thanks for the tip, [Vik Olliver]!

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How To Avoid Failed Screw Holes In 3D Printed Parts

May 7, 2026 by 21 Comments

Screws are useful fasteners for 3D prints, but the effectiveness of a screw (not to mention the ease or hassle of insertion) depends on the hole itself. This comprehensive guide on how to design screw holes in 3D printed parts takes guesswork out by providing reference tables as well as useful general tips.

The guide provides handy tables saying exactly how big to design a hole depending on screw type, material (PLA, PETG, or high-flow PETG) and whether the hole is printed in a vertical or horizontal orientation. This takes the guesswork out of screw hole design.

There’s no reason to guess the right size of hole for a screw, just refer to some handy tables.

The reason for different numbers is because multiple (but predictable) variables affect a 3D-printed hole’s final dimensions. Shrinkage, filament properties, and printing orientation can all measurably affect small features like screw holes; accounting for these is the difference between a good fit, and cracking or stripping.

In addition to the tables, there are loads of other useful tips. Designing lead-ins makes screws easier to insert and engage, and while increasing walls is an easy way to add strength it’s also possible to use 3D-printed microfeatures which are more resistant to distortion and don’t depend on slicer settings. There’s even suggested torque amounts for different screw and material types.

Sure, the most reliable way to get a hole of a known size is to drill it out yourself. But that’s an extra step, and drill bits aren’t always at hand in the desired sizes. The guide shows that it is entirely possible to print an ideal screw hole by taking a few variables into account.

If your design calls for screws, be sure to check it out and see if there’s anything you can use in your own designs.

A Trackball 3D Controller

April 27, 2026 by 33 Comments

We use CAD packages in our 3D work, and it’s likely that many of us have become annoyed by the limitations of controlling the view of a 3D object using a 2D interface, our mouse. Joystick-like 3D controllers exist for this purpose, but [David Liu] found them inconvenient. He tried a trackball, but that didn’t improve matters. His response was to take the trackball and change the way it controlled the software, turning it from the equivalent of a ball rolling over a surface to a ball representing the object on the screen itself. He can turn and rotate the object intuitively just by moving the ball.

He started with a Kensington off-the-shelf trackball and adapted its electronics and handy twin optical sensors such that it worked in the required fashion. There was a lot of iterating and tuning to get the control feeling right, but he’s ended up with a peripheral that replaces both mouse and 3D joystick, and leaves the other hand free for those keyboard shortcuts.

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One Sailing Pulley To Rule Them All

March 6, 2026 by 25 Comments

When thinking of humanity’s ability to harness wind energy, many people will conjure images of windmills from places like The Netherlands or Persia. But people have been using wind energy for far longer than that in the form of sailing ships. Using the wind for transportation goes back another four thousand years or so, but despite our vast experience navigating the seas with wind alone there is still some room for improvement. Many modern sailboats use a number of different pulleys to manage all of the rigging, but this new, open-source pulley can replace many of them.

The pulley, or “block” as they are sometimes called, is built with a polymer roller made out of a type of nylon, which has the benefit of being extremely durable and self-lubricating but is a bit expensive. Durability and lack of squeakiness is important in sailing applications, though. The body is made from CNC-machined aluminum and is composed of two parts, which pivot around the pulley’s axis to allow various ropes (or “lines”) to be inserted without freeing one end of the rope. In testing, this design outperformed some proprietary stainless steel pulleys of similar size.

Another perk of this design is that it can be set up to work in many different applications on a sailboat, whether that’s for hoisting a mainsail or pulling in a jib or any other task a pulley could be used for. It can also be stacked with others in many different configurations to build custom pulleys of almost any type, and can support up to 14 mm lines. For a sailor this could be extremely valuable, because as it stands each pulley on a ship tends to be used in only certain applications, and might also be proprietary from a specific company. This pulley is being released into the open-source world, allowing anyone to create them who wants one.

Thanks to [Keith] for the tip!

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STL Editing With FreeCAD

January 22, 2026 by 30 Comments

[Kevin] admits that FreeCAD may not be the ideal tool for editing STL files. But it is possible, and he shares some practical advice in the video below. If you want to get the most out of your 3D printer, it pays to be able to create new parts, and FreeCAD is a fine option for that. However, sometimes you download an STL from the Internet, and it just isn’t quite what you need.

Unlike native CAD formats, STLs are meshes of triangles, so you get very large numbers of items, which can be unwieldy. The first trick is to get the object exactly centered. That’s easy if you know how, but not easy if you are just eyeballing it.

If you use the correct workbench, FreeCAD can analyze and fix mesh problems like non-manifold parts, flipped normals, and other issues. The example is a wheel with just over 6,000 faces, which is manageable. But complex objects may make FreeCAD slow. [Kevin] says you should be fine until the number of faces goes above 100,000. In that case, you can decimate the number of faces with, of course, a corresponding loss in resolution.

Once you are satisfied with the mesh, you can create a real FreeCAD shape from the mesh. The resulting object will be hollow, so the next step will be to convert the shape to a solid.

That still leaves many triangles when you really want flat surfaces to be, well, flat. The trick is to make a copy and use the “refine shape” option for the copy. Once you have a FreeCAD solid, you can do anything you can do in FreeCAD.

We’ve run our share of FreeCAD tips if you want more. There are other ways to tweak STLs, too.

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