Unbricking A 3D Printer The Hard Way: By Writing A Bootloader

There’s a sinking feeling when a firmware upgrade to a piece of equipment goes wrong. We’ve all likely had this happen and  bricked a device or two. If we are lucky we can simply reapply the upgrade or revert to a previous version, and if we’re unlucky we have to dive into a serial debug port to save the device from the junk pile. But what happens when both those routes fail? If you are [Arko], you reverse-engineer the device and write your own bootloader for it.

The offending bricked object was a Monoprice MP Mini Delta 3D printer to which he was foolhardy enough to apply new firmware after seeing a friend’s machine taking it without issue. Finding the relevant debug interface on its main PCB he applied the firmware upgrade again, only to realise that in doing so he had overwritten its bootloader. The machine seemed doomed, but he wasn’t ready to give up.

What follows in his write-up is a detailed examination of the boot mechanism and memory map of an ARM Cortex M0 processor as found in the Monoprice’s STM32F070CB. We learn about vector tables for mapping important addresses of interrupts and execution points, and the mechanics of a bootloader in setting up the application it launches. This section is well worth a read on its own, even for those with no interest in bricked 3D printers.

In the end he had a working bootloader to which he appended the application firmware, but sadly when he powered up the printer there was still no joy. The problem was traced to the serial connection between the ARM doing the printer’s business and the ESP8266 running its display. After a brainstorm suggestion with a friend, a piece of code was found which would set the relevant registers to allow it to run at the correct speed.

So after a lot of work that resulted in this fascinating write-up, there was a working 3D printer. He suggests that mere mortals try asking Monoprice for a replacement model if it happens to their printers, but we’re extremely glad he persevered. Without it we would never have had this fascinating write-up, and would be the poorer without the learning experience.

This isn’t the first time we’ve brought you 3D printer bootloader trickery.

Creality CR10-S Upgrade Shows The Effect Of Bad Power

The Creality CR10-S is a printer that has become quite popular, and is not an uncommon sight in a hackspace or makerspace. Some models have a slight defect, a smoothing capacitor is of insufficient size, resulting in reduced print quality. [Jozerworx] has replaced the capacitor, and posted a full guide as to how the task can be performed.

Hackaday readers will have among their number many for whom replacing a surface mount electrolytic is no bother at all, indeed we’d expect most 3D printer owners to be able to perform the task. Maybe that the post has such an extensive FAQ and seems to be aimed at newbies to soldering points to 3D printing having moved to a wider market. But it has to be remembered that the value in this piece is not in the work, but in the characterisation. At the end he posts graphs showing the effect of the modification on the temperature of the extruder, and on the temperature noise brought about by the poor capacitor choice. A reduction from a +/- 3 Celcius variation to one of around +- 0.1 Celcius may not seem like much, but it seems it has a significant effect on the reliability of the printer.

So this isn’t the most elite of hacks, on a printer heading for a wider marketplace. But it serves to illustrate that bad quality power regulation can have some surprising effects. It seems every new printer comes with a list of community-developed mods to make it usable, perhaps one day we’ll find a printer that’s at peak performance out-of-the-box.

Casting Metal Parts And Silicone Molds From 3D Prints

The invention of the relatively affordable 3D printer for home use has helped bring methods used to produce parts for prototypes, samples, and even manufacturing, closer to designers. This tutorial on how to cast metal parts from 3D printed silicone molds is a perfect example of how useful a 3D printer can be when you are looking to make a custom and durable metal part at home.

After 3D printing a mold design using an Ultimaker 2 [Matt Borgatti] casts the mold using Smooth-On Mold Star 15 that can withstand heat up to 450 °F (232 °C), which he points out is ideal for the low-temp metal casting alloy tin-bismuth comprised of 58% Bismuth and 42% Tin with a melting point of 281 °F.

You may have heard of molds created from 3D printed parts before, but what makes this tutorial great is that the author, [Matt Borgatti], really sets you up to be successful. He offers up plenty of insights including mold-making techniques and terminology like why you would need a well and runners designed as part of your mold when casting with metal.

You can either reproduce his designs or use the tutorial to create your own which makes it a good start for beginners as well as another method to file away for people who already have experience 3D printing molds. This post is also really a twofer. Not only do you get detailed instructions for the method but [Matt Borgatti] uses his casted metal part for a flat-pack camera arm he designed to document projects with which you can also build using his files found on Thingiverse.

To create molds for precision parts and to learn more about using a 3D printer as a tool in the casting process, check out this method for creating higher resolution molds with a resin printer.

Continue reading “Casting Metal Parts And Silicone Molds From 3D Prints”

Repairs You Can Print: Fixing Pegboard Clips That Break Too Easily

Right now, we’re running the Repairs You Can Print Contest, where one lucky student and one lucky organization will win the fancy-schmancy Prusa i3 MK3, with the neato multi-extrusion upgrade. [Budiul] is a student, so he figured he would repair something with a 3D printer. Lucky for him, the pegboard in his workshop was completely terrible, or at least the pegboard hooks were. These hooks were made out of PVC, and after time, more and more hooks broke. The solution? Print his own, and make them stronger in the process.

[Budiul] started his fix by taking the remaining, unbroken hooks on his pegboard wall organizer and measuring the relevant dimensions. These were modeled in Creo 4.0, printed out, and tested to fit. After many errors and failed models, he finally got a 3D printable version of his plastic pegboard hooks.

Of course, replacing PVC pegboard hooks with ABS hooks really isn’t that great of a solution. To fix this problem of plastic pegboard hooks for good, he printed the hooks in halves, with a channel running down the middle. This channel was filled with some steel wire and acetone welded together. The result is a fantastically strong pegboard hook that will hold up to the rigors of holding up some tools.

While printing out pegboard hooks might not seem like the greatest use of time, there are a few things going for this hack. Firstly, these aren’t the pegboard hooks made out of steel rod we all know and love; this is some sort of weird proprietary system that uses plastic molded hooks. If they’re made out of plastic anyway, you might as well print them. Secondly, being able to print your own pegboard hooks is a severely underrated capability. If you’ve ever tried to organize a workbench, you’ll know that you’ll never be able to find the right hook for the right spot. There is, apparently, a mystical superposition of pegboard hooks somewhere in the universe.

This is a great hack, and a great entry for the Repairs You Can Print contest. You can check out a video of the hack below.

Continue reading “Repairs You Can Print: Fixing Pegboard Clips That Break Too Easily”

Water Cooling A 3D Printer

It may seem like a paradox, but one of the most important things you have to do to a 3D printer’s hot end is to keep it cool. That seems funny, because the idea is to heat up plastic, but you really only want to heat it up just before it extrudes. If you heat it up too early, you’ll get jams. That’s why nearly all hot ends have some sort of fan cooling. However, lately we have seen announcements and crowd-funding campaigns that make it look like water cooling will be more popular than ever this year. Don’t want to buy a new hot end? [Dui ni shuo de dui] will show you how to easily convert an E3D-style hot end to water cooling with a quick reversible hack.

That popular style of hot end has a heat sink with circular fins. The mod puts two O-rings on the fins and uses them to seal a piece of silicone tubing. The tubing has holes for fittings and then it is nothing to pump water through the fittings and around the heat sink. The whole thing cost about $14 (exclusive of the hot end) and you could probably get by for less if you wanted to.

Continue reading “Water Cooling A 3D Printer”

Repairs You Can Print: Model Coal Car Fix

Model railways are a deep and rewarding hobby, and the mechanisms involved can be both surprisingly intricate and delightful. A great example that may surprise the unfamiliar is that of model train carriages, such as coal cars, that are capable of both receiving and dumping a load at various points on a model layout. This adds realism and, if we’re honest, just plain old fun.

When [Phil]’s father received his Lincoln coal car from eBay, it was unfortunately damaged, and incapable of dumping properly. Instead of throwing it away, a replacement part was developed and 3D printed. The part was iterated on until the coal hopper could dump and retract smoothly.

This is the perfect example of a tidy repair executed through 3D printing. The broken part was extremely detailed and would be difficult and expensive to repair or fabricate through other measures. However, through the power of 3D printing, all that’s required is a 3D modelling job and a few hours to print it.

It’s a great entry into our Repairs You Can Print challenge, and covers the fundamentals of modelling and iterative design well. Got a neat repair you’ve done yourself? Document it on Hackaday.io and enter yourself!

3D Print A 3D Printer Frame

It is over a decade since the RepRap project was begun, originally to deliver 3D printers that could replicate themselves, in other words ones that could print the parts required to make a new printer identical to themselves. And we’re used to seeing printers of multiple different designs still constructed to some extent on this principle.

The problem with these printers from a purist replicating perspective though is that there are always frame parts that must be made using other materials rather than through the 3D printer. Their frames have been variously threaded rod, lasercut sheet, or aluminium extrusion, leaving only the fittings to be printed. Thus [Chip Jones]’ Thingiverse post of an entirely 3D printed printer frame using a 3D printed copy of aluminium extrusion raises the interesting prospect of a printer with a much greater self-replicating capability. It uses the parts from an Anet A8 clone of a Prusa i3, upon which it will be interesting to see whether the 3D printed frame lends the required rigidity.

There is a question as to whether an inexpensive clone printer makes for the most promising collection of mechanical parts upon which to start, but we look forward to seeing this frame and its further derivatives in the wild. Meanwhile this is not the most self-replicating printer we’ve featured, that one we covered in 2015.

Thanks [MarkF] for the tip.