Caulking Gun Becomes Useful Press Tool For Fuel Line Fittings

May 11, 2022 by Lewin Day 29 Comments

The simple caulking gun is really useful when you’re working on some bathroom repairs or squirting construction adhesives about the place. However, with a few simple mods, it can become a great help in the mechanic’s workshop too.

It’s a great tool for cleanly pushing fittings into nylon fuel line.

This build consists of a series of 3D-printed parts that can readily be adapted to a garden-variety caulking gun. First up are a pair of fuel line clamps which are fastened together with nuts and bolts, The nylon fuel line is inserted between these, and the bolts are tightened up to hold the line firmly in place at the end of the caulking gun. The fitting to be installed into the line is then placed on the caulking gun’s plunger. It’s then a simple matter of pulling the trigger on the caulking gun to slowly press the fitting into the nylon line.

It’s a great hack which creates a useful linear press with just a few cents of PETG filament. If you find yourself doing a one-off fuel line job on a modern car, this could be just the tool you need. Parts are available on Thingiverse for those eager to print their own. The design is made for 3/8ths inch line, but could readily be modified or recreated to suit other diameters.

3D-printed tools can be useful in all kinds of ways, even in heavy-duty applications like press tooling. It often doesn’t have the same longevity of traditional metal tooling, but for small one-off jobs, the price saving is often more important than the hardiness of the tooling itself. If you’ve whipped up some great 3D-printed tools of your own, don’t hesitate to drop us a line!

3D Print Finishing By Spraying Glazing Putty

May 10, 2022 by Dave Rowntree 19 Comments

Finishing off 3D prints is a labour-intensive process, and getting a good looking, smooth surface suitable for painting takes a lot of time and plenty of practice. Deeper printing layer lines or minor surface defects can be smoother over with a variety of materials, from putties to resins, but the deeper the defect, the thicker the filler and that takes it toll on the surface details – smoothing those out and making fine details less distinct. [Darkwing dad] has another solution that looks pretty easy to achieve, by mixing acetone with glazing putty it can be airbrushed over the print surface in one go. After a little experimentation with the ratio of putty to acetone, a wide open nozzle and a low pressure, it was found that a nice even spray could be achieved. Importantly it dries in just a few minutes, enabling multiple coats to be applied in a short space of time.

Once sufficient thickness has been applied, the coating can easily sanded to get a smooth result with the worst of the gaps filled, and the layer lines nicely hidden. The final part of the filling process is more typical, with a few coats of filler primer applied straight from a rattle can, followed by a light sand and you’re good for painting.

We’ve covered smoothing 3D prints practically as long as we’ve been covering 3D printing itself, and there are multiple ways to do this, depending on the filament material, your budget and you tolerance for noxious fumes. Here’s a guide for smoothing using UV curable resins, using a special smoothable filament with IPA, and finally if this is just too fancy, smelly or expensive, just whip out the old butane torch and smooth those prints with good old fashioned fire.

Continue reading “3D Print Finishing By Spraying Glazing Putty” →

A Crazy Wave Automaton

May 8, 2022 by Anne Ogborn 9 Comments

[Henk Rijckhaert] recently participated in a “secret Santa” gift exchange. In a secret Santa, everyone’s name goes in a hat, and each person must pick a name without looking. Each gives a gift to the person whose name they drew.

Henk needed a gift for Amy, a friend who loves the water and water sports as well as maker-y things. So he built her a wave automaton — a sea wave and fishies, and documented the build in this video.

The build is mostly plywood and 3D printed parts. We have to think reprising it in a nice wood and brass would make a lovely project for a hobby wood and metalworker.

The bulk of the project is 30 plywood boards stacked up with spacers. Each board is mounted with a 3D printed stepped bushing on one end that rides in a horizontal slot. On the other end is a 3D printed eccentric riding in an oversized (about 5cm) hole. So the board moves in a circle at one end and back and forth at the other for a very nice simulation of an ocean wave. Continue reading “A Crazy Wave Automaton” →

Super Tough Resin Is Literally As Tough As Nails

May 6, 2022 by Dave Rowntree 29 Comments

Resin printing still seems to polarize opinions amongst hacker types, with some considering such machines a good tool for the right tasks, and some just plain rejecting them outright. There are many arguments for and against, but like fused deposition modeling (FDM) machines, resin printers are improving in leaps and bounds — and so is the liquid resin itself. Nowadays low-odor resins are common, colors and finishes are varied, and now thanks to some dedicated development work, the brittleness that often characterizes such prints it being addressed. [Mayer Makes] has designed a super tough “engineering resin” that he demonstrates is so tough, you can print a nail and hammer it into a block of wood! (Video, embedded below, if you don’t believe it.)

This particular resin is destined for mixing, given its natural cured shade is a kind of greenish-grey, but it does have a neat trick of presenting a definite yellowish hue when not fully cured, which is very helpful. This is particularly useful when removing support structures as you can use the color change during the curing process to judge the right moment to snap off the thicker sections, minimizing the risk of damaging the print. The resulting printed part is also tough enough to withstand subsequent traditional post-processing, such as milling, giving greater final finishing tolerances. Try doing that with an FDM print.

One of the neat things about resin chemistry is that you can simply mix them in their liquid form to tune the resin properties yourself and they can also be colored with specially formulated dyes without affecting the other properties too much, so this new super-tough resin gives prototypers yet another tool in their resin armory.

Thinking of taking the plunge and giving resin printing a try? Checkout our handy guide which may give you a leg up! If that doesn’t swing it for you, you could always use resin to help smooth out your FDM prints. It’ll probably still smell funny, mind.

Continue reading “Super Tough Resin Is Literally As Tough As Nails” →

Maze Bolt Toy By Lost PLA Casting

May 5, 2022 by Anne Ogborn 8 Comments

Maze bolts, a bolt which has a maze along its shaft traversed by a pin on its nut, are great fun. Here’s a really beautiful metal version by [Robinson Foundry], made by a process more makers should know about – lost PLA casting.

His basic method is to 3D print in PLA, and then use more or less the same process as lost wax casting.

He 3D printed the part, along with the sprues and risers that go along with casting, in PLA, then dipped the parts in slurry ten (10) times. He heated in a kiln to 500°F (260°C), the PLA melted and ran out or burned away. With the PLA gone, after repairing a few cracks, he raised the temperature to 1500°F (815°C) and vitrified the slurry into a ceramic. He now had molds.

The nut is bronze. The bolt is aluminum. He poured the metal with the molds hot, held in heated sand, so the metal can flow into all the small details. The rest of the project is just cleanup, but we learned that you can vary the finish produced by glass bead blasting just by varying the air pressure.

A great demo of a useful technique and a fun toy at the end.

We covered a great technique for doing lost PLA casting using a microwave.

Continue reading “Maze Bolt Toy By Lost PLA Casting” →

partially finished print, with the embedded animation

Flip Book Animations On The Inside Of 3D Prints

May 4, 2022 by Anne Ogborn 5 Comments

We’ve all seen 3D printed zoetropes, and drawn flip book animations in the corner of notebooks. The shifting, fluid shape of the layers forming on a 3D printer is satisfying. And we all know the joy of hidden, nested objects.

Hackaday alumnus [Caleb Kraft] has a few art pieces that all reflect all these. He’s been making animations by recording a 3D printer. The interesting bit is that his print is made of two objects. An outer one with normal infill that gives a solid form, and a layer cake like inner one with solid infill. It’s documented in this video on YouTube.

There are lots of things to get right. The outer object needs to print without supports. The thickness of the “layer cake” layers determines the frame rate. I had to wonder how he triggered the shutter when the head wasn’t in the way.

His first, experimental, piece is the classic ‘bouncing ball’ animation, inside a ball, and his mature piece is Eadward Muybridge’s “The Horse, In Motion” inside a movie camera.

We’ve covered [Caleb Kraft] before, of course. His Moon On A Budget piece is wonderful. And we’ve covered a number of 3D printer animations. and 3D zoetropes. We particularly were drawn to this one.

Thanks [jmc] for the tip!

Continue reading “Flip Book Animations On The Inside Of 3D Prints” →

Wearable Electronics Takes The 3D Printing Route

May 3, 2022 by Jenny List 6 Comments

There was a time when a cheap 3D printer was almost certain to mean an awful kit of parts, usually a so-called “Prusa i3”, which was of course as far away in quality from the machines supplied by [Josef Průša] himself as it’s possible to get. But as Chinese manufacturers such as Creality have brought machines with some quality and relaibility into the budget space these abominations have largely been crowded out. There are still cheap 3D printers to be found though, and it’s one of these that [3D Printing Professor] has mounted on his wrist (Nitter) for the ultimate in portable manufacturing.

The Easythreed K7 is a novel take on a 3D printer that positions the device more as a child’s toy than a desktop manufacturing solution. It’s somewhat limited in its capabilities by its tiny size but by all accounts it’s a usable machine, and at around $100 USD it’s about the cheapest 3D printer for sale on the likes of AliExpress. The wearable mount is probably best described as a forearm mount rather than a wrist mount, but has provision for a battery pack and a small roll of filament. And this contraption is claimed to work, but we maybe would think before committing to a day-long print with it.

This may be the smallest wearable 3D printer we’ve shown you so far, but it’s not the first. That achievement goes to Shenzhen maker [Naomi Wu], who strapped one on her back way back in 2017.

Thanks [J. Peterson] for the tip!