Well, I’ve been making a lot of items, but not posting, so I thought it was time. I’ve been doing a lot of decorative items such as this one - Asian Crane Door Holder which started as wood, then acrylic and then thin Delrin. It needed to glide better and still be tough enough for sleepy heads who forget to slide it before opening. The better design might cover the latch pull.
Yes, it’s commonly used in place of metal in many applications - the gears in small kitchen appliances or power tools, for example. It’s also the DuPont brand name for the material - acetal (Polyoxymethylene POM) resin.
I just can’t tell you how inspiring that Multi-tool is! Great design, a very good presentation on your web page.
I can see lifting the concept with different sized wrenches/tools for other hobbies. Nothing new about muti-tools but making it light and rustproof by making it from Delrin is inspired.
I was immediately thinking the same. But then I thought more about it and those already exist and are only $7 at Walmart. I mean, I have a nicer $25 one on my bike, but still… not sure one could 'forge allen wrenches and put them together as nicely as even the $7 tool.
Delrin (Acetal homopolymer) is far more rugged and a bit “slippery”. However, it’s hard to weld or adhere to things. As @eflyguy said, it is often used to create gears and such due to it’s strength and yet it’s easy to mill.
Here is what a plastics supplier said about it:
Acetal Homopolymer (Delrin) & Acetal Copolymers
Two primary versions of acetal are available, those are homopolymer and copolymer. Chemically they are roughly 90% identical, however each acetal variety offers its own unique benefits. In addition filled versions of acetal are available to help meet specific application requirements. Our plastics experts are here to answer your questions, contact us today.
Benefits of Acetal Homopolymer (includes Delrin):
Rigid
Thermoforms easily
Can be used in a wide variety of applications
Impact resistant
Good chemical resistant
Low moisture absorption
Stiffer than acetal copolymers, with higher flexural modulus at ambient temperature and in elevated temperature applications
Higher impact strengths, at both ambient temperature and low temperatures
Roughly 10-15% higher tensile strength than copolymers
Higher continuous use temperature than copolymers (95°C vs. 90°C)
Benefits of Copolymer
More flexible and pliable than homopolymer
Resistant to cracking at lower temperatures
No moisture absorption
FDA compliant
Can be welded
Can be bonded
Greater dimensional stability than acetal homopolymer, due to lower crystallinity
Better chemical resistance with high pH solutions (bases)
Lower centerline porosity (see below) in extrusions
Other trade names for Acetal include: Celcon®, Delrin®, Ensital®, Pomalux®, Polyacetal®, POM (PolyOxyMethylene) Sustarin®, Tecaform®, Ultraform®, Unital®, and ZL 900.
General Feature of Acetal Plastic Shapes
Excellent for general purpose parts in wet environments
Machines to tight tolerances
Homopolymer and Copolymer versions available to fit different applications
Filled versions available including PTFE and lubricants*
Available in FDA and USDA compliant grades
I used acrylic originally, but that took too much fiddling. I now use China Markers (wax marker). Rub it into the engrave/score and then easy to rub off the surface.
@bmcgrain@Tom_A The one thing that I would caution is that while Delrin IS strong, it’s not steel. So if you have a very tight nut, it may not be able to handle it. I had to adjust the design quite a bit to avoid flexing of the wrenches under strain. Still, for our application, it works for 90% of the need, so for rigging and de-rigging for regattas and adjustments during a race, the SailZing Multi-tool does the job well.
My next challenge is designing a new fitting for the Tack connection to the mast. The current design by the builder has a design flaw. I’m not totally sure if it can handle the strain there, but the odds are not horrible.
Sounds like a great application. My original design had a clip on it, which might be useful in that situation. Clip it to your pocket. My sailor friends didn’t go for it. My thought was that you can clip it to your tool bag in the boat for easy access.
