645 is currently being used by CNC shops around the world to support quick turn prototypes for Pre-Pilot and Pilot runs as well as some limited production runs. As global supply compresses and just-in-time becomes just-a-little-late, more and more CNC shops are jumping in to fill quick turn needs.
645 is machinable with similar settings and cutting speeds as used in Cast Nylon blocks.
Thermal properties are slightly higher than Nylon 6,6 and Nylon 6,12.
Threaded Brass Inserts work well when installed with a soldering iron set to 250C.
Do NOT use water-based solvents as 645 will take on some of the solvents and become discolored. - Permanently!
To adhere other parts to 645, they must also be made of 645 and bonded with "ComPlete Nylon Glue", heat gun, or soldering iron.
The pliability of 645 follows the same size and density rules that apply to injection molded nylon for 100% fill parts.
For more pliability, you can reduce fill to something less than 100%
For less pliability in a smaller part, you can decrease the line diameter in the slicing SW. This will cause the printer to extrude more material than usual, thus filling all gaps, resulting in a less pliable part. For overall reduction in tensile, turn any fans that blow onto the part "ON".....Note, these should otherwise always be "OFF".
What are the major differences to me if I print in 645?
There is almost no de-lamination. The bonding of thread-to-thread at the correct temperature is very impressive. Of course, even injection molded parts are subject to splitting at right angle transitions, but compared to ABS and PLA we know you will be impressed. 645 gives off no odor as compared to ABS. Residual odors come from the humidity (water) that boils or steams off during printing.
What makes 645 different from standard nylon?
645 uses a modification to the standard material chain resulting in a new co-polymer to dramatically enhance bonding. To accomplish this, both the new co-polymer and manufacturing methods are unique to 645. The resistance to chemical degradation was also a top priority for 645 as the ability to 3D Print molds as well as operate in harsh environments was at the top of the list of material performance requirements. The final requirement for 645 was surface finish.
What setting will I need to change in my slicing software?
Most testers found they only needed to make sure their idler tension was tight so the material didn't slip. Otherwise, it's install and print! Users with direct drive 1.75mm extruders found that a small increase in retraction distance helped to eliminate trailing threads.
How do I get prints to stick to my platform?
The best bonding is to coat clean glass with PVA (Elmers Glue All) and heat the glass to 45-50C. This creates a significant "tack" that should hold all prints in place.
Are there fumes and odors?
Taulman polyamide materials give off almost no odor as compared to ABS. Most residual odors come from the humidity (water) that boils or steams off during printing and 645 had no measurable HCN.
Will 645 foul my nozzle if I leave the heater on?
Nope! We have left our heaters on for over 8 hours after a print with no issues at all. We also commonly move back and forth from ABS to 645 with no issues at all. We just purge about 50mm and start printing.
Is there any chemical that I should not use with 645?
Yes, any strong acids or Chlorine's/Bromine's can be a problem. They will break down the bonding of threads and weaken the printed part.
What will be the biggest differences in my part from being printed in ABS and then 645?
1. Strength - Some testers have reported 80%-100% fill is as strong as injection molded parts.
2. Weight - 645 is lighter than ABS and PLA.
3. Pliability - A major advantage with 645 is the pliability that some of us have desired for a long time. Pliability means that multi-part assemblies are more likely to work as designed with minimal filing, cutting, and sanding. Springs can be completely compressed and return to a printed state.
4. Slippery Surface - 645 can eliminate collars, U-joints, washers, separate raceways, and ball joints by using the material's slippery properties. Ball bearings that require no lubrication are easily printed. And most important, threaded holes that won't delaminate under pressure.
Nylon 645 SDS