Raptor 2 / T REX 3 Cable Chain Update

introduction

It is very important to pay close attention when replacing the cable chain. Observe for any damage to wiring, wire sleeves or any other components

14 Step 1 — Disassembly 1a. 





 

Make sure all power cables to your 

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3D Printer are unplugged including wall plugs (A/C) and/or USB cables. 

All screws and fasteners are right 

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hand thread. That means righty tighty, lefty loosey. During this procedure, keep all screws and hardware for reassembly. 

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All work will be on the lower frame assembly so start by disassembling your Raptor 2 / T REX 3 machine and getting to the point in the picture. 

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This document was generated on 2020-12-04 01:25:50 AM (MST). 

Remove any filament that is installed. 

Unplug all connections between upper and lower frame, including the LED, DB15 cables to each print head and X and Z axis connections. Unplug and remove the display. 

Remove the chassis ground (if installed) then remove the control box. 

Remove the 8mm socket head screws (2) that hold the upper frame to the lower frame and push the bed all the way forward. 

Double check that no wires are attached and lift off the upper frame. 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 2 — Disassembly 1b. 





 

Disassemble the plug end 

To disassemble the power cable plug, you'll need a #1 phillips screwdriver. First, remove the 

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screw securing the blue cover and rubber strain relief. 

Next, remove the plastic strain relief bracket screw. 

Step 3 — Disassembly 1b. 





 

Loosen the screw terminals to remove both cable ends. They are not polarity specific (side does 

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not matter). The screws just need loosened, not removed. 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 4 — Disassembly 1b-1c. 





 

Remove the rubber strain relief collar. It will not fit through the chain. 

Remove A/C power cables from relay. 

Cut 3 zip ties 

Remove the printed relay cover 

Using a #1 phillips screwdriver, loosen the 2 connections 1/2 to 3/4 turn on the AC side of the 

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relay. 

Step 5 — Disassembly 1d. 



 



 

 

Remove the thermistor wires. 

To access the thermistor wires, you must first remove the daughterboard cover. Using a #1 

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phillips screwdriver, remove all 4 screws and pull the cover off. 

Remove the thermistor wires by loosening both sides of the blue phoenix connector with a small 

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flat blade screwdriver then pulling the wires out of the blue connectors. 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 6 — Disassembly 1e. 

 



 



 

 

To prepare the wiring to fit through the old cable chain, you must tape loose ends with electrical 

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tape. 

Fold over the relay connections and tape so it is smooth and as small in diameter as possible. Tape the power plug ends together 

Tape the thermistor wire ends together and to the orange sleeve. (shown in step 8) 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 7 — Disassembly 1f. 

 



 



 

 

To remove the cable chain, you must cut a few more cable ties and remove some screws.  Be careful not to cut into any wires or sleeving! 

Cut any cable ties securing wires to the cable chain. 

Remove the M3 socket head screw with a M2.5 hex wrench. 

Loosen the M3 socket head screw to align the T Nut with a M2.5 hex wrench. 

Remove the M3 socket head screw and T Nut and set aside. They will be installed on the new 

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chain soon. 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 8 — Disassembly 1g. 

 



 



 

 

Tape the end of the thermistor wires to the orange sleeve. This will make install easier later 

Pull the old chain off the machine. 

Hold the wires on the bed side. 

Start pulling the cable chain away from the bed. 

With the old chain fully removed, notice the taped end. This will make installing into the new 

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chain much easier. 

Be gentle! If the cables get stuck, pull the wire back through and inspect your taped areas. They 

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must be smooth and small to fit through the old chain then retry 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 9 — Reassembly 1a. 

 



 



 

 

The chain has to go on a specific way! You can call it the shorter end or male end but install the 

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side circled in green over the wires going towards the bed heater. 

Make sure your tape job on all wires that go through the chain is still intact and get your 

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replacement chain in hand. 

Feed the wires through the new cable chain. 

Insert the cables into the new chain with the correct chain end facing up. 

Make sure you have tape here, securing the thermistor wires to the orange sleeve. 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

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Raptor 2 / T REX 3 Cable Chain Update Guide ID: 128155 - Draft: 2020-01-14 

Step 10 — Reassembly 1b. 

 



 



 

 

Pull the cables all way through the chain until the chain is close to the Y Carriage plate. 

Leave a little length in the cables so they can be cable tied to the outside hole on the chain end. 

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The M3 socket head screw will go through the inside hole. Tighten it with the M2.5 hex wrench. If the chain does not clear the screw, you may have an earlier version machine and the screw is 

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in a different location. Go to: http://bit.ly/38haROn for help with this. 

Route the cables to the correct side. 

The orange sleeve bunch should go towards the relay side. 

The thermistor wires (some will be red bare wires, some will be in a white sleeve) will go 

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away from the relay. 

Pre-install the M3 socket head screw and T Nut to the inside hole as the outside hole can be 

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used to secure the wiring. 

After you have pulled the wires through completely, you can remove the electrical tape. 

 

 

Step 11 — Reassembly 1c. 

 



 



 

 

Resecure cables to the machine 

Make sure you secure the cable bundle on each end of the cable chain with a cable tie. Be sure to trim cable tie ends off flush so they are not sharp. 

Tighten up the frame side chain hold down with a M2.5 hex wrench. This side uses a T Nut and 

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you need to make sure the chain is tight to the frame before proceeding. 

This screw triggers the end stop. Make sure you position the chain so that it is clear of this screw. If the chain does not clear the screw, you may have an earlier version machine and the screw is in 

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a different location. Go to: http://bit.ly/38haROn for help with this. 

Reinstall bed heater connections to the relay. They are not polarity specific (side does not matter). Using a #1 phillips screwdriver, tighten the screw terminals. 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

 

Step 12 — Reassembly 1d. 

 



 



 

 

Reinstall thermistor wires 

A small pair of needle nose pliers may help with this step. 

Insert thermistor wires and tighten screw terminals. Be sure to gently pull on them to make sure 

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they are secure. 

Install printed daughterboard cover with 4 screws. 

Make sure cables are not pinched and push the cables back into the slot in the frame. 

Reinstall relay connections and hardware 

Install AC connection cover 

Cable tie power wires 

This document was generated on 2020-12-04 01:25:50 AM (MST). 

 

Step 13 — Cable Chain Installed 

 



 

 

Reference steps 1 and 2 to reassemble the bed heater power plug. 

Leave the power cable unplugged to test the thermistor. 

With everything hooked back up, you should be satisfied with your work! 

After double checking that all wire connections are tight, it is a good time to test that both the 

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thermistor work (in that order). You can plug in just the control box, display to test the thermistor. If the thermistor is not plugged in (or broken), bed temperature will read -14. 

If you have a normal ambient temperature reading on the display, you can plug the power cable in 

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and test that the bed heats by going to manually setting the bed temperature to a low value of 50. Some reasssembly has been left out to keep things smaller. Refer to earlier steps.