I love GeraldO's design, but wanted my cable chain up as high as possible and out of the way. With just chain links, it hung down quite a bit, and looked a little weird. (See the last picture.)
As GeraldO says - The strain on the X-axis cables of the CTC/Flashforge/Replicator printers has been documented to cause the endstop cable and/or the X Stepper motor cable to break and potentially cause a fatal short, often destroying the mightyboard controller.
I have not experienced this, as I became aware of this design flaw soon after buying my printer, and took precautions to prevent this failure. His design works great, but I wanted to re-mix it a bit to suit my taste and put the cable chain as high as possible in the printer.
I re-mixed the bracket to span a little more than 1/2 the distance of the chain, that way it can be mounted up high and out of the way to still allow for good access to the print bed from the right side opening. I also designed it with openings to capture two standard M3 Nylock nuts. The other parts are exactly the same parts that GeraldO designed.
In my re-mix, I only needed 12 links, so you may want to just print a dozen (or perhaps 2 or 3 more) instead of the full 'plate' of 24. I also changed the Cable Chain Arm mounting hardware to use M3 bolts and nuts.
This upgrade includes his original bracket which mounts to the stepper X-axis stepper motor and houses/protects both the stepper motor cable and the end stop cable in a cable chain. (Again, these are just duplicated from his original design.)
4 M3-14 bolts (Two to mount the arm, 2 to mount the bracket to the X motor)
2 M3 Nylock nuts to mount the arm
2 M3 washers (Optional, but recommended for bolts that mount the cable chain arm)
It's best to print this in ABS, especially if you're going to be enclosing your printer to print ABS well. Other plastics will soften.
Post printing clean-up
I had to clean up the faces of the links quite a bit in order to get them to bend smoothly. I used a small file and repeatedly put the links together to test the movement, then dis-connected them to file them more... Rinse & Repeat until they move freely. ;-)
Power down the printer, disconnect your power supply and USB cable (precautionary, we don't want any shorts!)
Disconnect the x-axis endstop and stepper motor cables and remove them from the axis carriage. Remove the two M3x5 bolts which hold the stepper motor in place (See image with green circles over the bolts)
Depending on whether or not you have performed the XL upgrade, your cables may not be routed through the back right corner of your Replicator. For this mod to work, the stepper and endstop cables should be coming out of the machine from the back right corner of the bot.
For the CTC Dual, you'll have to remove the bottom cover to re-route the cables. There's just one screw at the bottom of the right side of the printer, then the cover slides towards the center of the printer and lifts out of place from the front a little bit, then slide it forward to come out of the slots on the back panel of the printer.
Feed both cables though your copy of ctc_cable_chain_arm and begin assembling your cable chain by feeding the cable through, and snapping the links together one at a time. I assembled the chain first and fed the wires through later. This was a bit of a mistake as pushing the wires through after it was assembled was a real PITA! (My re-mix only uses 12 links on my CTC)
Pull your Y-axis all of the way to the front of the bot and continue to assemble the chain until the end comes up to the bottom of the stepper motor. There should be enough slack such that when the carriage moves to the extremes, the cable chain should never be pulled tight.
Mark the spot on the inside of the frame where the holes are for the ctc_cable_chain_arm part are. I made the vertical face of the bracket flush with the edge of the window but it is an entirely aesthetic choice. Put it where you wish! The provided holes are 3mm round for use with M3 screws.
Drill the holes through the frame using a 3mm drill bit (or whichever size your bolts are).
OPTIONAL Now that your cable chain has been properly sized you may want to "break it in" by moving it around for a while. Depending on how tight the links fit this may not be an issue however, mine were extremely tight and required an hour or two of flexing before they moved freely. [I (Jeff) filed the links down first to make them smooth before installing them in the printer. ;-) ] Having the chain flex freely will reduce the additional strain on the carriage's motion! If you've done this, reassemble the cable chain.
Feed the endstop and stepper motor cables all the way through the channel in the bottom of cable_chain_end_stepper and snap it onto the end of your cable chain.
Push your copy of cable_chain_end_stepper onto the bottom of the X-axis stepper carriage, it should fit snugly. The slots should line up with the slots on the carriage for the stepper motor screws. Sometimes the fit is tighter so you may need to push up a little harder to make it all line up.
Take the washers from the M3x5 bolts you removed from the stepper mount and put them onto your M3x14 bolts. Screw in the M3x14 bolts into the stepper's holes to secure the bracket (and the stepper).
Use your other 2 M3x14 bolts bolts to secure the other end of the cable chain (the long arm) to the frame of your printer. The heads of the bolts and washers should be on the outside as I've integrated M3 nut captures on the cable arm.
Now that everything is secured you should take the time to check the range of motion of your carriage. Move it from extreme to extreme in the Y-axis direction and check to see if anything is pulling or resisting its motion. 12 links should be perfect, but if the cable gets too tight, you'll need to add a link or two (or more if you mounted the arm lower than I did). If the cable feels sticky or resists motion you may want to remove it and flex it for a while to loosen it up.
Once the cable looks and feels right, you can now connect the wires back to the endstop and stepper. Route the wires through the channel on the side of the carriage. Connect the endstop cable by passing it through the hole in the carriage. Connect the stepper motor by routing it around and down to the stepper motor connector.
You're done! Enjoy your new, fancy looking cable chain!