Don’t tell me about problems, give me solutions

By 08/08/2014 Kickstarter, News 4 Comments
print2colour_lighhouse

In most of our updates we talk about the difficult parts of the Robox project and we thought that it would be a refreshing change to talk about some of the great things we’ve achieved and why we still believe the Robox will be the best FFF 3D printer solution in the world.

Pause and Resume


The pause and resume feature is functional and allows a lot of control in the middle of a print, it can be triggered by the software, hardware or firmware. At any sniff of a problem the firmware can pause the print and let you know what’s up, the button in the centre of the reel can pause and park the filament on a quick press or auto eject the filament on a long press. This function will enable loads of cool things, there is the obvious changing of colour but alongside this is the possibility of placing parts into the print part way through such as captive nuts n’ bolts, wires and electronics, mechanisms and actuators; the possibilities are endless.
The video above shows a quick print at a 0.3mm layer height (300 microns), our draft setting, just to show how easy it is even in this early state. Coding in a “Pause at x layer” function will be a nice easy job for the software team now that the base code is in place.

Extruder Feedback

The feedback loop we added to our extruders gives us lots of extra functions, the main reason we added it was to give information to the printer that the filament was moving as expected, but the actual applications are much wider. We’ve invented a new type of extruder move which uses the feedback to detect when it’s fully loaded or un-parked and further to this we can control the power of these moves. Knots, snaps, tangles, tightly wound reels and end of filament on any of your favourite materials can be detected and resolved before they cause a problem. A day long print job doesn’t need to be scrapped just because the reel jammed or the filament ran out.

Gantry and Bed Levelling


The firmware can handle bed levelling in both directions perfectly, with no input from the user. The video above shows a fairly extreme example with the X axis on a crazy angle but it can deal with even worse than the example shown. In the X direction the firmware can independently control the two Z motors to level the gantry to the bed. In the Y direction the Z motors can be driven during a print to ensure that the bed level is the reference plane. This has led us to think about some other exciting possibilities – we could potentially map the topography of a build surface without any hardware changes, allowing printing on uneven surfaces – all very exciting! Watching the level gantry video, you can see the nozzle touching down in several places – it detects the surface and records all the data ready for printing. The start of each print has a quick XYZ test – another great feature that lets you concentrate on designing rather than printing.

Filament Recognition

This we’ve had up and running right from the start and it has become such a part of daily printing that we don’t even think about all the benefits any more. We change filament types willy-nilly and the software and firmware automatically sort out how to tweak the print settings. A couple of cool extra features that we added to the reels are filament and speed multipliers; these variables allow us to change the amount of material being extruded and the speed of the printer mid print. You can see the filament change colour within AutoMaker in the first video, this is more than just a graphic, it is reading the temperature and extrusion speed settings particular to this reel and recording the usage back to the reel so it can tell how much is left!

Auto-Filament Load and One-touch Eject

One of the reasons we can change the filament so easily and often is the awesome eject and load mechanism, entirely powered by the firmware and extruder feedback system. We are able to eject the filament without any delay on both the screen and reel button. The load is automatic too, just feed in the start of the filament and the extruder grabs it and does the rest. Again this is visible in the first video, just feed the material in and once detected the extruder will send it all the way to the head. Once loaded you can just press print!

User Manual

Please check out a draft version of the Robox user manual and other supporting documents here www.cel-robox.com/downloads/

3D Mockup

These are just a few of the things we’ve got working on Robox right now, every day we see new features and functions that we promised get added, it’s tough work but extremely rewarding.
We are just about on track to deliver the first of the full production Roboxes to the Kickstarter backers; we built in a little bit of contingency at the start but have used this up with a late change to the extruder’s gearbox. We found that if we used an acetal (POM) worm wheel against the steel worm gear we gain a significant efficiency percentage. We made the decision to stop production and reworked every ready-made Robox to include the new part. The extruder’s output power is now 150% what it once was with the same input power… that said we are now out of contingency so fingers crossed nothing unexpected comes up.
So all in all, we’re happy to say we’ve made some really positive changes to the Robox at the last minute, which might have meant a slight delay but also means a better product!
In other news, we’re also really excited to report that we are moving to larger premises, ready to stock the next few shipments of our Robox units, and to house the growing Robox team as we take on more staff in a bid to keep our new customers happy and speed up future development.

4 Comments

  • Profile photo of Dr. Woo Dr. Woo says:

    There seems to be a certain gradient in the transition areas between white and red of your light house example. Is this an optical illusion through transmitted light or is it cause by left-over material of the previous color in the heat chamber, which then mixes with the new color? If the latter is the case, it would be nice to have the option to automatically purge the nozzle near the Tip Wipe Blade, to ensure the nozzle contains only the new color/material before resuming the print, thus you get sharp transitions (when desired).

  • Profile photo of Olivier Olivier says:

    nice, nice, nice, nice, niiiiiiice

  • Paul says:

    Very nice, comprehensive update. A question about colour change – is a purge required after changing reels? Even with the needle valve system, there must be some molten plastic in the extruder. Also, shouldn’t a closed valve have prevented the stringing on top of the lighthouse?

  • Profile photo of Pete Pete says:

    Although we have been able to pause for quite a long time there has been very little time spent on what can be done during a pause. We will eventually have a system that pauses and cleans material from the nozzles before resuming it just needs programming time. There is an issue with timing, if the previous layer goes completely cold it is hard to stick the next layer to it, I got around this by adding perimeters (outside layers) which let the nozzle pass the area to be printed a few times.

Subscribe now to be kept up-to date with the latest Robox® news. Subscribe Now