Replacing Nylon Filament with BASF’s Ultrafuse

When considering all the properties of a “tough” 3D printer filament, I consider Nylon to be at the top of the list. I admit, I attempted to use Taulman3D’s Nylon 645 to print most high-wear components of my robots over the past few years including gears. However, looking back I now really regret my choice to use Nylon. Watching this video, from Maker’s Muse, I learned about BASF’s Ultrafuse PLA PRO1 as a possible alternative for gear printing, and I thought I’d try it for myself.

What’s wrong with Nylon?

I’m an experienced 3D printer with thousands of hours of print time under my belt, but I have never worked with a more challenging filament than Nylon. Here are some of the challenges:

• Humidity absorbance – Nylon filament will suck water right out of the air. Attempting to print directly will result in “spitting” and very poor results. To avoid this issue, a filament dryer is needed. Also, keeping the Nylon in a humidity-controlled bag/box is necessary, but never seems enough. I had to throw away a half-used spool because of the water absorption.
• Temperature – After much experimenting, I’ve found that 255 degrees C is about right, much higher than other filaments.
• Cost- a 450g spool costs $34, much higher than other filaments ($0.075/gram)
• Warping – I’ve struggled with heat bed adhesion and seen quite a bit of warping of parts despite my use of glue, adjusting the heat bed temp, and other tricks. I think I’ve thrown away more parts than I kept because of this.
• Speed- The 3D printing process needed to be slowed in order to get good results. Trial and error resulted in the addition of a 3mm retraction setting on the nozzle while printing which takes extra time.

The Last Straw

Most recently, I had a gear failure for my Mouse Droid. Of all the issues, this was one I did not expect from Nylon. The whole reason I picked Nylon because of its toughness, so very frustrated to see this happen.

It appears, due to a single bad layer, that the teeth completely separated from the base of this bevel gear. The result was a free-spinning gear that did not transfer to the axle inside the differential gear box to move the Mouse Droid. I’m not sure how this happened, but suspect it was caused by heat buildup after driving it hard for about an hour.

Additionally, this gear box has always caused ‘clicking’ noises when moving which led me to believe that the gears were slipping when too much torque was applied. After taking some measurements, I found that there was a bit of shrinkage in the parts which likely caused an imperfect fit for the gears. Also, the irregular layers of the Nylon may have caused some issues – I saw similar on other prints. Finally, Nylon is a slippery material, and this property may have been working against me with these bevel gears.

BASF Ultrafuse PLA PRO 1

I’ve been using eSun’s PLA+ for most of my prints recently because of how easy it is to print with, coupled with it’s excellent properties. I was thinking of using it to print the gears until I saw the Maker’s Muse video. While eSun’s PLA+ performed better than most, the BASF Ultrafuse PLA PRO1 was surprisingly better in every category tested. His results were encouraging, so I thought I’d give it a try for myself.

• Humidity – I accidentally broke the seal on the box and let the filament sit in the open air for over a week before trying to print. It worked without issue, without the need for a firmament dryer.
• Temperature – Manufacturer recommends 200-220 degrees C, which is the same as other PLA. I chose to run mine toward the hot side, so printed at 215 degrees C and got good results.
• Cost – It’s not cheap, but cheaper than Nylon. After shopping around, I found a 750g spool cost about $40 USD ($0.053/g). For comparison, a 1kg spool of eSun PLA+ costs $25 USD ($0.025/g).
• Speed – Similar to PLA, you can print this at high speeds

Although I only needed to replace one broken gear, I decided to reprint all 4 in the gear box. I chose to print with 100% infill and 0.1 mm layer height for high detail. The print required about 1.5 hours.

The end result was very good. Compared to the Nylon, there was no shrinkage. Each tooth looked crisp and clean, and I found zero imperfections. I applied a generous layer of synthetic grease to reduce heat, and re-assembled the gear box.

To my relief, the Mouse Droid had regained full functionality with the new gears. As a bonus, the ‘clicking’ sound was gone so, no gear slippage (so far).

Conclusions

I know there are many, many options available for 3D Printing filament that would work well with high-wear parts like gears. I’ve read some articles about interesting properties of “alloy” filaments supplemented with carbon fiber and glass. I’ve also considered more traditional alternatives such as ABS, PTEG, and others. However, the results I get from augmented PLA continue to impress me and I’ve yet to find a filament type that is easier to work with and cost effective. So, I’m excited to give the BASF PLA a try and hopefully use it in place of Nylon for all future prints.