E-chain, short for energy chain is also know as cable carriers, cable track, and drag chain. E-chain is a wire, cable, and hose management system for guiding and supporting these lines to moving components while providing abrasions resistance. E-chain is commonly seen on 3D printers, CNC lasers, and milling machines to guide the wires that must run to the tool heads.
I downloaded an e-chain STL for use in a project, and after printing it I realized it had some issues like it would go past flat so the unsupported side was folding over and dragging on itself, and it had a curl perpendicular to the bend direction.
After looking closely I realized that the design was exactly that of injection molded versions. To promote cleaner and easier printing with fusion deposition model (FDM) type machines there were some overhangs to be removed and the supports could easily be designed to use less plastic that is to be discarded than the slicer software would put in. Lastly there are many sizes of wires used on CNC machines so the design was copied to multiple sizes and options.
One general note on selecting e-chain, for proper function the inside measurement need to exceed the wire size by roughly 15%.
Part number scheme for e-chain:
ECH-XX-YY-ZZZ-MOD
XX: inside height of chain in millimeters
YY: inside width of chain in millimeters
ZZZ: Bend radius of chain in millimeters. Bend radius is specified along the center of the chain, or along the pins.
Inside dimensions given because specification must typically fit the cables going through it.
MOD: Optional modifier, see options below.
blank: standard e-chain link.
W: Links of the chain are a sparse web to reduce the printer material used by roughly 15%. It is also less protective of the wiring as there are more holes through to the wire.
N: Can be added onto the other modifiers. Version of chain without the predrawn supports in case the supports do not work with other 3D printers so you can use your own. This modifier can be added after W and C, as other do not require supports, example ECH-XX-YY-ZZZ-CN. This modifier comes with the predrawn supports version as a backup in case of problems with predrawn supports.
BP: Mounting base with pin.
BH: Mounting base with hole.
FP: Flange mount with pin
FH: Flange mount with hole.
Printing Notes:
1. Use needle nose pliers to remove the supports inside the chain links.
* break one leg then the rest of the supports should remove clean and easily.
2. Avoid printing near the corners of the bed. The thin lines tend to peal up due to lower temperature in the corners.
3. There is an intended orientation of printing. The supports and overhangs have been designed in one direction to give the best printing results.
4. Use of the scale function to get wider links for greater number of cables is not recommended due to support optimization at given size.
5. Do not use scale function to get taller links than designed because the pins will become ovals and not rotate. Please pick the correct size for your application.
Assembly Notes:
1.Use the slope on the pin for the mating linkโs side walls to bend around the pin until seating inside the hole.
2. E-chain will be stiff at first, there is significant break in during early stages of usage.
3. Installing wires in chain is easiest by taping one end of the cable bundle together then inserting into the chain laying flat on a hard surface.
4. For long chains it is recommended to make multiple sections of the chain, insert the wires through all sections of the chain, then put the chain sections together. It will make getting the wire through the entire chain easier.
5. Screws holes in bases are sized for #6 or M3 flat head screws.
Design Notes:
1. This chain has been designed and tested with optimization for FDM type 3D printing in mind. Overhangs have been minimized, and tolerances have been set around FDM 3D printer capabilities.
2. Selection of e-chain size is based on cable bend radius, diameter of cables, and number of cables. Please keep this in mind when selecting the size of e-chain for your application.
3. Not all wires tolerate repeated bending, and reduced lifespan may result. It is recommended to pick wire types that are rated for repeated bending when installing inside e-chain.
4. The designed height and width are over sized because the dimensions change during assembly. If you measure the CAD model and find they are larger than nominal this is intentional.