Materials
Here is a list of parts and the materials used (or not used) on a RepRap Mendel. The goal here is to brainstorm new materials that are better, cheaper, easier to work, or easier to acquire, as well as to explain why particular materials succeed or fail. This page can also be used to judge the most successful materials used by the community. eventually maybe we can add some code so that we can vote for particular materials. In the meantime, just edit this page to add info or examples for both failures and successes.
Contents
Goals for this page
- a)List all materials used and the reason for use
- b) List failed materials with reason/theory of failure
- c)List untested but promising materials and explain their potential.
Metals
Steel
Used to form the frame of Mendel and Eiffel, as well as for Bearings and Fasteners (bolts/nuts/washers)
- Galvanized cheaper than stainless
- Stainless No corrosion
- Carbon Steel cheapest, but rapidly corrodes unless painted or kept coated with oil.
Copper
The second-most-electrically-conductive metal, and so used in practically all category:electronics PCBs and wires.
Aluminum
Advantages: lighter than steel and much stronger than plastic. Disadvantages: heavier than plastic and weaker than steel.
Brass
Used for the nozzle, or "Hot End" of extruders. Not sure why brass is used?
quote from Team Open Air[1]:
The reason that people started off with copper and brass is because they are EXCELLENT conductors of heat, and we want the heat from the nichrome wire wrapped around the nozzle to be conducted inside to the plastic to melt it. However, with a thin, long cylinder it is very easy for the heat to move inward, even with an insulating material for the nozzle. But the copper and brass also carry it sideways a LONG ways, requiring a long rod of PTFE or other high temp plastic to isolate the heat of the nozzle from the Stepper Motor and any electronics.
Plastics
Thermoset
PEEK
High temperature plastic, easily machined, less thermal creep than PTFE.
PTFE
PTFE, also known as Teflon, is used in Extruder Hot Ends (Nozzles) and Bowden Extruders for its low friction.
Caution PTFE gives of very toxic fumes when over heated.
BakeLite
High temperature plastic found in most kitchen saucepan, frying pan handles. First tried by Grogyan on his JunkStruder, material suggested by friend. Machineable, low thermal creep. Available everywhere.
Thermoplastics
Thermoplastics are extrudeable. (Unlike Thermoset plastics.)
ABS
ABS: User:Nophead had some problems [2] with his Mendel X-axis carriage degrading from the heat coming off his extruder nozzle. suggests that low temp exposure will shorten the lifetime of extruded parts. reflective heat shield or fan might mitigate this issue, or a carriage design change that moves extruded parts away from the hot end.
PET
PLA
other melty materials
- water ice (IceRap) (it's technically not a plastic, but it melts when you heat it like all thermoplastics ...)
Wood
- For all pages tagged "wood", see category:wood
lumber
- WolfStrap -- lots of 18x45mm and 18x70mm softwood lumber (so-called 1x3 and 1x4 softwood lumber can be substituted)
- Wooden Mendel
- Trystan's Wooden Mendel
- Adesina - A Wooden Mendel RepStrap
Fiberboard
LDF (low-density fiberboard) also called particle board, or fiberboard MDF (medium-density fiberboard) HDF (high-density fiberboard) also called hardboard
Plywood
Glass
When used as a bed parts come off very flat, but a Heated Bed might be required. User:Mike Bushroe has successfully made Glass Nozzles. [3].
Kapton
High temp tape used mainly to attach heater element to the extruder. perhaps could be replaced with PTFE heat shrink wire rap?
Caution Kapton gives off noxious fumes from the adhesive, adhesive does drip onto barrel and nozzle, making it very icky. Available mostly everywhere.
Nichrome
Primary source for the heating mechanism of the extruder. Comes in two varieties, uninsulated (available mostly everywhere), insulated (fiberglass coated, difficult to acquire, if not impossible, locally).
Carbon Fiber
Carbon fiber rods and tubes in ~8mm diamater are available at mcmaster carr. They would be much lighter than steel and can be machined to similar tolerances. Steel will last longer, we must assume, but would CF Rods last long enough i.e. the life of the machine? They are cheaper as well. if true 8mm can be found in high tollernace, it would be a good experiment to try replacing the non-threaded rods with CF rod or tubing.
McMaster Carr also has Hith temp CF, which might be useful in an extruder. presumably would not transmit heat like metals, but be easier to work than glass or ceramic, yet sturdier than PTFE.
Materials by Part
Frame Materials
- Main page: frame material
Frame Issues
Any? Not Printable?
Extruder Materials
- Main page: Category:Extruders
Extruder Issues
The design ethos of the extruder should be focused on using the fewest materials and skills to construct a extruder that works consistently with multiple materials. The extruder, being the heart of the machine, can end up being a complex part. However, it seems that the part is becoming more complex in order to solve an issue with the X carriage, not the extruder.
PEEK and PTFE are being used in order to protect the extruded carriage parts from the hot end. Would it be easier to construct an X carriage that doesn't melt? For example, perhaps an all metal or plaster cast carriage, or using wood to mount the extruder but having thermoplastic parts for the x-rail bearing mounts.
The standard X carriage, with the extruder hot end directly underneath, puts the carriage directly in the hot plume of the extruder. Mounting the hot end to the side of the carriage is better but can reduce build area slightly, but could be minimized by mounting the x axis rails one-above-the-other instead of side-by-side.
bed materials
- Main page: bed material
External Links
More on Glass, Ceramics, and Carbon from McMaster-Carr. Mechanical and Physical Properties of various materials. VERY USEFUL(PDF is copyrighted, so just a link).
