Free Cable Drag Chain & Comb Generator
Free cable drag chain and cable comb generator. Size it to your cables, travel and bend radius, with end brackets and lids. Order it printed in NZ.
What It Does
A moving axis needs its cables carried, and a catalogue drag chain is only available in the sizes somebody else chose. This tool builds the chain around your bundle instead: give it the clear space the cables need, the travel of the axis and the bend radius the cables can stand, and it produces the link, the lid, both end brackets and the number of links the travel calls for. It runs live in your browser and nothing is uploaded to design a part. Designing is free; we print the kit and courier it anywhere in New Zealand.
Sizing It Round The Cables
Start from the bundle, not the chain. Measure the cables laid side by side, add a little for the sleeving and for the fact that a bundle is never quite flat, and that is the inner width and height. A chain that is too tight chafes the insulation on every stroke, and one that is far too big whips about and knocks. Wall thickness follows: under 1.6 mm the plastic round the pin bore is fragile, and 2 to 3 mm is the useful band for everything but the largest chains.
Bend Radius, Pitch And Swing
The bend radius is set by the cables, and it is the one number in the design you do not get to argue with. Every cable has a minimum bend radius, and a drag chain that bends tighter than it will shorten the cable's life dramatically. Pitch is the distance between pin centres: a shorter pitch gives a smoother curve and more parts to make, a longer one is quicker to print and turns the loop into a polygon. The two together decide the swing angle each link is allowed, and the tool works that out and stops the links before they can fold flat the wrong way.
Links, Lids, Pins And Brackets
A snap-in lid lets you drop the cables in from above and close the chain afterwards, which is worth a great deal when a connector is already fitted on one end. A fixed top bar is stronger and quicker but means threading. Wide links with a fixed bar bridge a long way across the top, so the lid is usually the better print above about 20 mm inner width. Pins can be barbed to snap in and stay, or plain for a chain you expect to take apart. Both end brackets come with the design, drilled for the screw size you pick.
Cable Comb Mode
The same tool makes cable combs: a spine with a row of teeth that grips cables at a set pitch and holds a loom flat and tidy. Set the slot count, the cable diameter and the pitch between slots, and choose whether the cables snap in past a narrowed neck or thread through closed holes. Neck interference of about 0.6 mm holds a cable without fighting you; much more than 40 percent of the cable diameter and the teeth snap on insertion instead.
Materials
PETG is the sensible default for a chain: tough, mildly flexible, and it does not go brittle. Pins under 3 mm shear easily in PLA, so either go up in pin diameter or move to PETG or polycarbonate. Nylon is worth it on a chain that runs constantly, where wear at the pin is what eventually ends its life.