Could Non-Planar Infill Improve The Strength Of Your 3D Prints?

When you’re spitting out G-Code for a 3D print, you can pick all kinds of infill settings. You can choose the pattern, and the percentage… but the vast majority of slicers all have one thing in common. They all print layer by layer, infill and all. What if there was another way?

There’s been a lot of chatter in the 3D printing world about the potential of non-planar prints. Following this theme, [TenTech] has developed a system for non-planar infill. This is where the infill design is modulated with sinusoidal waves in the Z axis, such that it forms a somewhat continuous bond between what would otherwise be totally seperate layers of the print. This is intended to create a part that is stronger in the Z direction—historically a weakness of layer-by-layer FDM parts.

Files are on Github for the curious, and currently, it only works with Prusaslicer. Ultimately, it’s interesting work, and we can’t wait to see where it goes next. What we really need is a comprehensive and scientific test regime on the tensile strength of parts printed using this technique. We’ve featured some other neat work in this space before, too. Video after the break.

Continue reading “Could Non-Planar Infill Improve The Strength Of Your 3D Prints?”

Time Vs Money, 3D Printer Style

A few months ago, Hackaday’s own Al Williams convinced me to buy a couple of untested, returned-to-manufacturer 3D printers. Or rather, he convinced me to buy one, and the incredible success of the first printer spurred me on to the second. TL;DR: Lightning didn’t strike twice, but I’d still rate it as worth my time. This probably isn’t a good choice for your first printer, but if you’ve done the regular maintenance on your first printer already, I’d recommend it for your second or twelfth.

As background, Al has been volunteering with local schools to teach a 3D printing summer class, and this means outfitting them with a 3DP lab on the dirt cheap. His secret is to buy last year’s model which has all of the features he needs – most importantly for the kids, automatic bed height probing – but to buy it from the scratch-and-dent shelf at Creality. Why? Because they are mid-grade printers, relatively new, but on deep discount.

How deep? I found an essentially endless supply of printers that retail for $300 on discount for $90 each. The catch? It might work, it might not. I bought my son one, because I thought that it would at least make a good project for us to work on together. Those plans were spoiled – it worked absolutely flawlessly from the moment we bolted it together, and he runs 24-hour jobs on the thing without fear. From the look of the build plate, it had been used exactly once and returned for whatever reason. Maybe the owner just didn’t want a 3D printer?

The siren song of straightforward success was too much for me to resist, and I picked another up to replace my aging A8 which was basically a kit for a 3D printer, and not a particularly good one at that, but could be made to work. My scratch-and-dent Creality came with a defective bed-touch sensor, which manifest itself as a random absolute refusal to print.

I took it apart, but the flaw is in the design of the V1 touch sensors – the solenoid requires more current to push down than the 3DP motherboard can reliably deliver. It works 100% of the time on my bench power supply, but in situ it fails about 30% of the time, even after hitting it with graphite and making sure everything is mechanically sound. Creality knows this and offers a free trade-in, just not for me. The new version of the Creality probe costs $50 new, but you can get cheap knock-off BL Touch models for $14. Guess what I did?

And guess what bit me? The cheapo touch probe descends a bit slower than the Creality version should, and the firmware is coded to time-out in an extra-short timeframe. Thankfully, Creality’s modifications to Marlin are all open source, and I managed to tweak and flash a new firmware that made it work 100% of the time, but this was at a cost of probably eight hours of bug-hunting, part-ordering, and firmware-compiling. That said, I got some nice extra features along the way, which is the advantage of a printer running open-source firmware.

So my $300 printer cost me $105, plus eight hours of labor. I only charge one coffee per hour for fun hardware debugging tasks, but you may have a different valuation. Taken together with my son’s printer, we have $600 worth of printer for under $200 plus labor, though, which starts to sound a little better.

Is gambling on an untested return 3D printer worth it? For us, I would say it was, and I’d do it again in a few years. For now, though, we’ve got three printers running and that’s all we need. Have you gone down this perilous path?

Winter-Proof (And Improve) Your Resin 3D Printing

Was your 3D printer working fine over the summer, and now it’s not? With colder temperatures comes an overall surge in print failure reports — particularly with resin-based printers that might reside in outbuildings, basements, or garages. If you think this applies to you, don’t miss [Jan Mrázek]’s tips on improving cold-weather print results. His tips target the main reasons prints fail, helping to make the process a little more resilient overall. [Jan]’s advice is the product of long experience and experimentation, so don’t miss out.

With environmental changes comes the possibility that things change just enough to interfere with layers forming properly. The most beneficial thing overall is to maintain a consistent resin temperature; between 22 and 30 degrees Celsius is optimal. A resin heater is one solution, and there are many DIY options using simple parts. Some of the newer (and more expensive) printers have heaters built in, but most existing hobbyist machines do not.

An extreme case of blooming.

Temperature control isn’t the only thing, either. Layer formation and build plate adhesion can all be improved by adding rest times between layers. Yes, this increases print time. It also allows resin to settle before the next layer, improving adhesion and preventing blooming (a rough texture caused by an imperfect cure.) Since resin flows less readily at lower temperatures, rest times can help improve results. The best setting depends heavily on your particular setup, so [Jan] gives tips on finding optimal rest times.

Most common knowledge and advice from well-meaning communities online focuses on increasing exposure time or blaming the build plate. [Jan] feels that these are ultimately the wrong way to go about addressing failures. Usually, an environmental change (like the arrival of winter) has simply pushed a printer that was not optimized in the first place outside of its narrow comfort zone. A little optimization can set things back on track, making the printer more resilient and reliable overall.

Comparing Adhesives For Gluing PETG Prints

Testing every kind of glue with PETG, including wood glue. (Credit: Cosel, YouTube)
Testing every kind of glue with PETG, including wood glue. (Credit: Cosel, YouTube)

PETG is a pretty great material to print 3D models with, but one issue with it is that gluing it can be a bit of a pain. In a recent video by [Cosel] (German language, with English auto-dub) he notes that he found that with many adhesives the adhesion between PETG parts would tend to fail over time, so he set out to do a large test with just about any adhesive he could get his hands on. This included everything from epoxy to wood glue and various adhesives for plastics

TL;DR: Some superglues seem to weaken PETG, and a construction polyurethane glue is the absolute winner.

For the test, two flat surfaces were printed in PETG for each test, glued together and allowed to fully dry over multiple days. After about a week each sample was put into a rig that tried to pull the two surfaces apart while measuring the force required to do so.

With e.g. two-part epoxy and super glue the parts would break rather than the glue layer, while with others the glue layer would give way first. All of these results are noted in the above graphic that has the force listed in Newton. The special notes and symbols stand for strong smell (‘Geruch’), the PETG itself breaking (‘Substrat gebrochen’) and high variability (‘hohe Streuung’) between the multiple samples tested per adhesive.

Interesting is that multiple superglues (‘Sekundenkleber’) show different results, while MMA (Methyl Methacrylate) and similar score the highest. The Bostik P580 is a polyurethane construction adhesive, usually used for gluing just about anything to anything in interior and exterior applications, so perhaps its high score isn’t so surprising. Trailing at the end are the wood glue in last place, with the UHU general adhesive also scoring rather poorly.

Clearly there are many options for gluing PETG parts, but some are definitely more sturdy than others.

Thanks to [Risu no Kairu] for the tip.

Continue reading “Comparing Adhesives For Gluing PETG Prints”

Supercon 2024: Joshua Wise Hacks The Bambu X1 Carbon

Bambu Labs have been in the news lately. Not because of the machines themselves, but because they are proposing a firmware change that many in our community find restricts their freedom to use their own devices.

What can be done? [Joshua Wise] gave a standout talk on the Design Lab stage at the 2024 Hackaday Superconference where he told the tale of his custom firmware for the Bambu X1 Carbon. He wasn’t alone here; the X1 Plus tale involves a community of hackers working on opening up the printer, but it’s also a tale that hasn’t ended yet. Bambu is striking back. Continue reading “Supercon 2024: Joshua Wise Hacks The Bambu X1 Carbon”

3D Print Stamps, And Ink Stuff To Your Heart’s Content With These Tips

Ink stamps can be fun to make and use, and 3D printers are uniquely positioned to create quality stamps of all kinds with just a little care. As with most things, the devil is in the details and the best results will require some extra work. Luckily, [Prusa] has a blog post that goes through how to 3D print the best stamps and includes concrete recommendations and tips to get the most out of the process.

Resin printers can create stamps too, just ensure a flexible material is used.

What makes a good 3D-printed stamp? It should be easy to use, transfer an image cleanly, and retain ink reasonably well. To hit these bases, printing the stamp face out of a flexible material is probably the most important, but a flat and smooth stamp surface is equally crucial. Satin-finish build plates will give a weathered look to the stamp, but textured build plates in general are no good.

As for the design, turning an image into a 3D object can be a bit challenging for novices, but there are tools that make that much easier now than it used to be. Some slicers allow importing .svg files (scalable vector graphics) with which to emboss or deboss objects, and online tools as well as free software like Inkscape will let folks covert images into .svg format.

Flexible filaments tend to be stringy so they should be dried before use, especially if the stamp design has a lot of separate elements that invite stringing. Any flex filament should do the job, but of course some specific filament brands perform better than others. Check out the full blog post for specific recommendations.

Pausing a print and inserting a pre-printed support piece (removed after the print completes) helps form big overhangs.

The remaining tricky element is that flexible filaments also tend to be poor at bridging, and if one is printing a stamp face-down on the build plate (to get that important, ultra-flat face) then the upper inside of the stamp may need some support for it to come out right. As [Prusa] suggests, this is a good place to use a manual, drop-in pre-printed support piece. Or if one has the ability to print in multiple materials, perhaps print the support structure in PLA since it is just about the only material that won’t completely weld itself to flex filaments. Of course, if one is designing the stamp entirely in CAD, then the best option would be to chamfer the stamp elements so supports aren’t necessary in the first place. Finally, don’t overlook the value of a physical design that makes handling easy and attractive.

Since 3D printing makes iteration so fast and easy, maybe it would be worth using this to revisit using rubber stamps to help create PCBs?

Software Lets You Paint Surface Patterns On 3D Prints

Just when you think you’ve learned all the latest 3D printing tricks, [TenTech] shows up with an update to their Fuzzyficator post-processing script. This time, the GPL v3 licensed program has gained early support for “paint-on” textures.

Fuzzyficator works as a plugin to OrcaSlicer, Bambu Studio, and PrusaSlicer. The process starts with an image that acts as a displacement map. Displacement map pixel colors represent how much each point on the print surface will be moved from its original position. Load the displacement map into Fuzzyficator, and you can paint the pattern on the surface right in the slicer.

This is just a proof of concept though, as [TenTech] is quick to point out. There are still some bugs to be worked out. Since the modifications are made to the G-code file rather than the model, the software has a hard time figuring out if the pattern should be pressed into the print, or lifted above the base surface. Rounded surfaces can cause the pattern to deform to fit the surface.

If you’d like to take the process into your own hands, we’ve previously shown how Blender can be used to add textures to your 3D prints.

Continue reading “Software Lets You Paint Surface Patterns On 3D Prints”