As we start to key up CEL and Robox for dual material printing we have introduced a lot of new concepts. Most of our users will have seen some of these multi-material features creeping into AutoMaker over the most recent few releases. Today we’ve added another new feature with AutoMaker 2.01.02 Download here.
We think that one of the most useful features of multi-material printing is the ability to use one material for your part and the other as support structure. This means with the correct choice of material, support can be greatly improved. One of the Materials we been testing is PolyMaker’s PolySupport, we’ve found it to print well in a wide range of temperatures and have consistent structural and functional properties. PolySupport is designed to be a support material for PLA and we found that although its a PLA based material it delaminates easily from PLA and other materials making it very easy to remove. It has elastic and flexible properties which mean its a joy to peel from your model, infinitely easier than using any other Peel-able support material we’ve tested, in-fact its so good we’ve added a this new support gap option.
To further improve the support that an easily peel-able material can give your part we can remove the gap between the top and bottom surface, this gap was necessary when you needed to break-away support structures of the same material. We semi-automated this option, when AutoMaker sees that you are using a different material for support than the one chosen for your parts it will automatically deselect this option.
I hear some of you say “Why peel-able, why not focus on dissolvable support?”, well, we thought the same when we started to print with multiple materials but quickly discovered that dissolvable material solutions are messy, take a long time and are often difficult to process and store. Peel-able support can often be removed in a few minutes, where dissolvable support material can take hours if not days to disappear and often require some peeling as well. One thing you might have read about on the internet is the use of limonene to dissolve HIPS away from ABS prints, this is not a reality, after only a few tests we found that limonene does dissolve HIPS, but it also damages the ABS beyond usefulness. The other thing is that unless you LOVE the smell of oranges you quickly grow tired of all your parts, the office, your finger and pretty much everything you own having that pungent smell. Don’t misunderstand me, dissolvable materials will have their place, but for a large majority of support applications we feel easy peel-able is the way forward right now.
We’ve also exposed some of the controls around the generation of support structure to you so that you can tune your profiles to get more perfect parts.
- Autoupdate now uses port 80 rather than port 8001
- Added Support Gap function
- This controls the vertical distance between the support material and model material which affects how easily support material can be removed
- Disabled automatically if support material is different to model material (useful when using specialised peel-off support material)
- Horizontal (Support XY Distance) and vertical (Support Z Distance) offsets are configured in the Print Profiles page
- If Support Gap is enabled the system will introduce a vertical gap between support and model material
- If Support Gap is disabled there will be no gap between support and model material
- Improved filament saver function for dual material printing (automatic heater control during prints)
- Grouped advanced mode controls onto an Advanced Mode menu on the Preferences page
- Automatic selection of correct head type on profile page
- Modified status display to make use of Material 1 and Material 2 clearer
When AutoMaker updates are available your system will usually find and offer an update automatically. If you are behind a firewall or some other system which prevents this, please visit www.cel-robox.com/downloads/ and download the most recent AutoMaker package.
AutoMaker sometimes needs to update the firmware on your printer. Please allow the firmware to update as requested by AutoMaker. If you do not allow the firmware update to take place, AutoMaker may not be able to communicate with your printer.
IMPORTANT NOTE: a firmware update will power cycle your printer so ensure no operations such as a print or calibration are running at the time of the firmware update.
SLA (Stereolithography ) is often compared to the FFF (Fused Filament Fabrication) / FDM (Fused Deposition Modelling) process of 3D printing and always shows very impressive results. The detail level is far superior for SLA but there are a lot of complications to the process. Due to the huge numbers of dentists, dental labs and orthodontists contacting us recently I thought I would share some of what I have learned.
The most common comparison is the strength of the parts created from resin vs those created with fused filament which always comes out on top. Next are the many resin handling issues which make filament printers much easier and safer to use.
It is easy to discount FFF/FDM completely by just looking at pictures of the excellent smoothness of an SLA print vs an FDM print. The SLA process can create a smoother and more detailed surface finish and and can create a fully solid, partially transparent part which is difficult to achieve on FFF /FDM machines without post processing. This makes it harder for those of us demonstrating fused filament fabrication printers to keep a viewers attention.
To someone viewing the printed results of 2 models side by side it would be hard to choose the FFF / FDM print if visual quality or surface detail was the goal. In a comparison of useability which requires strength, the FFF /FDM print is far more likely to come out on top particularly due to the huge selection of material types available. The SLA materials tend to be closely linked to specific printers, it is unlikely a 3rd party resin will be allowed or compatible. This limits the SLA user to the resins developed by that manufacturer. In a comparison of workflow the SLA process is quite scary, warning labels and notes on resin handling and cleanup dominate but the consumption of core components of the SLA printer along with litres at a time of IPA (Isopropyl alcohol) and the expensive resin is certainly worth exploring before any decision is made to exclude filament printing. The accuracy of the two methods should theoretically be the same but I have yet to see an SLA print which has been perfectly dimensionally accurate while my Robox is within 0.01mm in all axes without my input all day every day. Cost comparisons are far further apart than the price of the printers would suggest. SLA resin cost is high, plastic filament cost is low. This expensive resin is wasted with every print, plastic filament is only extruded as required. This cost in particular is not shown in “part cost comparisons”, nor is the very wasteful rinsing in IPA to remove excess resin following a print or the cost of the consumable resin carrying and curing parts, or the disposal and storage as well as low shelf life for expensive SLA resins. Oh and the space required for SLA printing is rarely mentioned, you really need a spare room and some strict policies to control the spread of sticky resin the smell and the harm to the environment.
In the chart below I’ve listed some positives and negatives of each method along with typical usage and costs. Blue indicates the best in my opinion for each row. I obviously support filament printers in this, perhaps your comments can sway my opinion?
My conclusion is this:
SLA is not a threat to FFF / FDM printing, if anything the 2 methods can work side by side as their benefits do not overlap. Personally I would not let the resin (or the smell of it) near my home or my family but if I had a dedicated space within a business and the training and staff to run this then I would consider SLA as an addition to several far lower priced FFF /FDM printers. I could print many iterations of a design on the filament printers and perhaps a surface model on the SLA machine once the design was final, actually it might be best to just outsource that part…
SLA should remain in the hands of professional labs or dedicated service providers, FFF /FDM is for everyone. In fact with the low cost of filament printers, every designer should have one on their desk.
It has been a little while since we last updated you on where we are with the dual material head, but I hope we can be forgiven for the lack of communication – especially as the real reason for this is that the entire CEL team have had their heads down testing the latest prototypes for faults, fact finding, and future proofing.
But we feel an update now is timely, as we are getting so close to being able to launch the new head to market; we really are almost at the end of what feels like a very long development journey.
Software is the biggest challenge as there really isn’t a good dual material system on the market to use as a template and both the slice engines we currently use aren’t able to deal with dual material prints in a consistent manner. This means we essentially had to start from scratch creating innovative software for this particular hardware development.
Before we get deep into the dual material system progress it’s worth mentioning what we’ve done to the software in preparation for this momentous task.
For the release of AutoMaker 1.02 we spent a good amount of time restructuring and developing the post processor. We gained a much better understanding of where and how to open and close the needle valves, how to integrate the material the needle ejected into the model and how this is going to affect dual material printing.
For the upcoming version of AutoMaker we’ve actually recoded the post processor from scratch, our new level of understanding was restricted by our previous work. This updated thinking has gone into the current version of AutoMaker and is the backbone of dual-material capable AutoMaker version 2.
Right back to dual material and where we are now….
There are a lot of new requirements needed to take a multitude of models and turn them into a multi material print. We wanted the ability to take a 3D model, break it into individual parts and allow the user to easily select which part was going to be assigned to which material.
Because most models which require multiple materials will need two or more separate parts, we wanted to add Group/Ungroup and model splitting. The Group/Ungroup and model splitting all have to be combined with the original transform functions so that we keep the parts’ relative position.
After we started to look closely at the model files AutoMaker was expected to handle we found a very high percentage had imperfections – not normally a problem as the slice engines do some simple repair work – but a bigger problem if you’re trying to bisect the data and then add back in the missing vertexes, polylines and faces. We’ve not fully finished this aspect of the software and currently only warn users of the imperfection in the models that may cause problems later.
We now have a software tool that allows us to perform all of the above functions and it’s helping us finish the development of all the hardware.
The development of the software will continue up to and beyond the date you receive your new hardware, but for the first version of AutoMaker which is capable of doing dual material prints we have tried to keep the functionality to a minimum so that we can ensure stability.
After a few false starts we’ve now got working dual material heads and an innovative second reel holder complete with reader. We are also taking a very close look at the management of the Bowden tubes and cables between the x-carriage and chassis.
We were worried that the differing flexibility in filaments would affect the homing accuracy and thus distort the mapping of the bed giving poor first layers. We’ve made a fancy new cable chain to take the data and power cable and slightly constrained the Bowden tubes which now both reference the X-rails rather than the carriage.. (sorry if this is too geeky), basically we have more stuff to help improve probing and tidiness.
Another thing that only the people in the know would notice is that we have added a USB socket into the build chamber. It’s been there from the beginning – hidden away in the centre of the reel – but we’ve never got round to exposing it. We thought as we were designing a new PCB for the dual reel holder we would add the missing plug so you can start playing with it too.
The needle valve system has been extremely important in the quality of printing that Robox can achieve when talking about single material prints, removing all the stringing from one island to the next. When you use this innovative system with a dual material head it starts to become even more impressive.
All the dual material prints we’ve seen from other manufacturers have to include some sort of wipe tower, ooze screen, long cool down / heat up period, or purge sequence. None of this is necessary if your print head can stop the flow of material at its nozzle tip like the Robox can. Our very first print from the new system was one of the best we’ve seen. So now we’ve worked out how the system works, we’ve got working samples, and we are producing great print results.
The final step is to ensure that all materials will flow through the new hardware smoothly, tidy-up the interface and test, test, test… I can’t tell you how big a chunk of work this last section is. We need to try every single combination of user input and output and not just once, on one machine. This needs hundreds of times on many printers by many different people to ensure that all the logic we’ve put into the software and hardware doesn’t crumble when given to a user who hasn’t been involved in the development. With this in mind we’re now at the stage where we’re asking some of our customers who have placed pre-orders to beta test the first batch of hardware from the final production line.
So all in all, we’re really, really close. If it sounds like we’re no further forward than last time – bearing in mind we finished our last update by saying we were “testing, testing, testing” – please be assured we are. But after testing comes tweaking, and then more testing!
So the final date is……???
We can’t say for sure, at the moment things are looking great and we hope to be able to launch the dual material head end of November, as per our last post. If not then, early December. But to reiterate the sentiments we made last time, we will only release the head if we’re confident it’s going to produce excellent results for everyone.
THANK YOU once again for your unwavering support, stick with us, as in just a couple of months the Robox 3D printer will make its mark as something completely different from anything else out there on the market – and we want you there with us to enjoy the ride.
Oh you want a picture of a dual material print? Well….here is a sample of what we have to come.