Taulman3D Alloy 910 - First impressions count!

posted 24 Aug 2015, 10:00 by Colin Bell

One of the materials from Taulman3D that I've been waiting for an excuse to try is their Alloy 910 line.
This material is a new for 2015 co-polymer alloy, which they boast an incredible tensile strength (8100PSI) and high durability, which is in line with all of their current range of nylon co-polymers. Being a big fan of the 645 nylon for parts which require these types of features, I've been looking for ways to 'tame the beast' - 645 is an amazing material to produce parts with, quite literally second to none in terms of strength, heat tolerance and durability, but it can be challenging to print with consistently, with warping being the key issue for my set-up.

As it happened, today I got commissioned to create some simple kitchen S-Hooks (for hanging pots and utensils from a rack), and <gasp> I've run out of 645 again. Seriously, the rate I get through this stuff is crazy, I've got through four reels of it in less than two months! Lurking in my nylon drawer was a sample pack of Alloy 910 which I had yet to try, so I decided to give it a bash on the S-Hooks.

According to the data sheet, Allloy 910 should print using the same settings that I currently use with Nylon 618, so I loaded those up - the table below shows Taulman3D's recommended settings:

Print temp = 245C - 250C
Nozzle = any size
Print speed = equivalent to ABS
Retraction = 1mm/.1mm nozzle or for a .5mm nozzle = 5mm
Print bed = Hot = Glass heated to 45C with coat of PVA
Cold = BuildTak with coat of PVA

The machine I wanted to use for this job is my Printrbot Simple Metal, which is currently configured with a heated bed covered with PEI. Normally for nylon, I would clip a Tufnol board over the top of the PEI, however I decided not to for some reason, and this proved to be a great decision, as it turned out not to be required. Alloy 910's adhesion to PEI is pretty good off the bat, however I found that due to clumping (more on that later) the part had a tendency to be caught by the nozzle and lifted off the bed, mid print.

In order to combat this, I did three things. Firstly I added a light coat of Gluestick on top of the PEI (and really it needs to be a very light coating as the Alloy 910 adheres extremely well to it. Additionally, I added a 2mm Z-lift on layer changes so that the nozzle cleared any end clumping. Finally, I set the bed temperature to 50c.

The S-Hooks I was creating needed to be strong and relatively smooth, so I sliced them for 100% infill and a 0.05mm layer height.  I printed them relatively slowly, at 20mm/s and kept retraction at my normal Nylon 618 settings of 3mm at 30mm/s.

The print process using this material at the settings I mentioned above were pretty typical of printing nylon, with a couple of exceptions. As I said, bed adhesion was no issue at all, and there was zero warp or shrinkage with this material, even in a draughty room with the air-con running - this is definitely a major plus for the Alloy 910, as most of my previously mentioned nylon material challenges are cause by warping and shrinkage in one way or another. This particular model runs the layers end to end with a very small surface area touching the bed, so was a good test of this.

Of course, nylon being nylon, some stringing is inevitable, especially between parts. Using my standard nylon retraction settings of 3mm/30mms, I still got a good amount of cobwebs between the objects on the bed. This proved extremely easy to remove though, just running a razor blade over the surface. One of the issues with cobwebbing like this is that some of it tends to get wiped up and collected on the nozzle of the hot-end, and then gets dragged over the print. Then the cobwebs clump into a charred black lump which gets deposited either at the start or end of the layer, usually in the same place each time. A Z-lift of 2mm stopped the part getting caught on the hot-end, so the print was safe, however it did leave said black lumps. In future, should retraction fine tuning not cure this (Taulman3D are recommending and additional 1mm on my current settings), I think it should be pretty easy to compensate by adding a small amount of removable support material to the sliced print job - once complete, the black lumps would come off with the support material, leaving the model intact. For the parts shown here though, I simply sliced the charred 0.5mm section off the model (after some effort, this stuff is very resilient to blades) with a razor blade. Being 100% infill, this worked well in this case.

As I said previously, Alloy910 sticks very well to PEI, and with a layer of glue stick on top of that made the part rock solid on the bed. Removal was fairly straightforward though - I just sprayed some tap water onto the parts and waited a couple of minutes for the glue to dissolve - the parts popped off the PEI after that without much issue.

After a quick clean up with a razor blade, I found the surface of the parts to be very smooth, although not as 'slippery' as with some other nylon types - 645 for example feels almost like PTFE to the touch, and 618 is almost as glossy when printed at the right temperatures. As I was printing in a 0.05mm layer height, I didn't expect much ridging, but what was there was almost completely invisible to the eye, and indeed to touch. The printed colour is a kind of pale milky white - I'll be dying these parts though, so will post on how that goes - normally I dye the line prior to printing, so this will be a new experience for me.

The parts themselves are very strong as you would expect - I tried to test to destruction on one of the parts, and found that the Alloy 910 is extremely flexible and has what I would consider to be a perfect layer bonding. I have no doubt that Taulman3D's tensile strength boasts are fully justified. It is possible to deform the part, for example, I stretched the S-Hook out into a straight line and twisted and pulled as hard as I could for some time - this didn't even really dent the model where the pliers were gripping them, and no amount of pulling would cause de-lamination. Once I let go though, the part didn't immediately spring back to its original shape, more of an elongated version. With a bit more pulling and twisting though, I was able to get it basically back into the original shape and it held that once I was done. After that bit of torture, I hung a 2.5kg pot from the s-hook and it held it without issues, only starting to deform when I upped the weight hanging from it to over 7kg. Even at 7kg I think I could have added more weight, but I decided that the hooks would be fit for purpose and stopped there. Bearing in mind the size of the small S-Hook (65mm) this is incredible.

In conclusion, I think I will place my next nylon order for Alloy 910 rather than 645 - I need to do some further testing with bridging, support and complex structures, test for machining properties like being able to drill and tap threads into it, but for now it looks like it could be a perfect replacement for 645. The ability to print on PEI and get no warp, curl or shrinkage and get all the other benefits of a strong nylon line is just too good for me not to play further with it....depending on how it handles supports and rafts, it might even be a replacement for ABS and PLA!