Close

Future plans for Oasis

A project log for Oasis 3DP

A powder and inkjet 3D printer based on HP45 inkjet technology

Yvo de HaasYvo de Haas 11/05/2018 at 06:440 Comments

I have spent the past few months working hard to get Oasis ready before the deadline of the Hackaday Prize. While I am of course a bit sad that I did not win, I knew that I was going against some great projects. Congratulations to all the winners.

My goal for the past few months has been to get Oasis 'working'. Printing, as good as I can in the time I have. Now that I no longer have any deadlines, I will dial the amount of work I put in Oasis a bit back. This does not mean that I will stop it, not at all. 3DP has been really interesting to me for the past few years, and I still want to make it better, but I need to catch up with other things too, something that I made little time for the past few months.

While it may take a while, these are the things I hope work on with Oasis for the coming time (not in order):

Materials

So far I have been printing with original Zcorp materials. This is not really going to work well on a cheap(ish) and open source DIY powder printer. Zcorp powder and binder is REALLY expensive. I have had my eyes on several recipes since Plan B year ago. I compiled the most notable ones here. Now that I have a machine that is workable, I will finally test some of these recipes.

My main focus will be ceramics, then gypsum. Other material options such as sand and maybe metal will be for an unplanned future.

Depowdering

Cleaning parts is difficult. For Plan B I built a box with gloves and an air pump to clean the parts. While this works surprisingly well. I want to make a better tool using better parts. This will be a negative pressure chamber with better recovery of the powder. I also want more pressure for the cleaning air. Lastly, I hope I can make it somewhat portable.

Firmware

Firmware works, sort of. Both the decoding of printing lines and the printing happens in  the main loop. Because of this, I cannot print much faster than 50mm/s right now, while the absolute max should be around 400mm/s. I do not hope to get the maximum speed without FPGA's but I do hope I can reach around 200mm/s without much fuss.

To get to this speed I hope to offload all of the inkjetting code to interrupts and DMA. If I manage that, I will instantly lose the biggest bottleneck in the code. Set up inkjetting for one burst using interrupts, and letting it trigger through DMA. I might need to update the controller side of the PCB to make it work, but that is a small price to pay for higher speeds in my opinion.

I also want to add features such as virtual speed and hardware trigger so it can print without an encoder, making it more usable to other people as well.

Software

Python I had to learn from scratch. If I would write it again now, I would do a lot of it completely different. And so I probably will. Too many points to mention, but I will make it faster, more stable, more usable, and to fix a problem I still have, make it output Plan B code as well.

Another thing I want to do in software is make it usable without 3DP. I have yet to think of a way to make a universal inkjet driver for use in other projects, but it is something that I would be really interested in.

Selling parts

I have been getting requests for assembled printhead drivers. I ran the numbers for an assembled driver, and I get to the $150-200 range. Right now, with all the software and firmware in a meh state, I really am not comfortable selling it at those prices. I will take effort to make the price go down by redesigning it, and improve the software so it will work for more people and I actually feel comfortable selling it at higher prices.

Color printing

I want to find a way to print in full color. There are several options. One is to add a CMY head. HP has ones that are compatible with the HP45 connector. It is narrower however, limiting print speed. I can also make a driver for 5x HP45 printhead. More expensive, but a lot faster. What I decide on will be for later, but I do want to get full color available at some point.

A new printer

Oasis is a prototype machine. An easy to alter proof of concept. If people want to get easy access to 3DP printing, an easier to build design will be needed. While I will keep Oasis the prototype, at some point when I have fixed ALL the other things, I will design a better, easier to build and assemble printer. This is not going to be next year, but I do plan on it.

Until then any questions you have can always be asked. 

Discussions