CR-10 Ultimate Y-chain MK2: Y-axis drag chain for bottom mounting by superkris

Last crawled date: 3 years, 1 month ago

CR-10 Ultimate Y-chain MK2
Version with advanced wire management
This is my solution for the Y-axis drag chain. It was design with these design idea's in mind:
Bottom mounted. No cable sticking out the back so it takes less space in a enclosure
Maximum durability. Chain must be mounted in the right way so it doesn't wear fast.
Compatible with most populair upgrades like leveling knobs and Y-stepper brackets
My 1st creation was MK1. This worked well. The simple design was effective, but i did not like the way the wires where routed. It would be very hard to remove the bed without cutting cables or a long disassembly time.
Trying to fix this made it necessary to change a lot of things in design and the way the system is mounted. I ended up with a whole new design that I called MK2. This design is very much superior in every way, and i recommend that you build MK2. It however requires a lot more parts so i published both so you can choose.
Attached drawings should give a clear image about the differences. You can find the MK1 design here: https://www.thingiverse.com/thing:2855282

PLEASE NOTE:
You will need to do some soldering. Extension cables will not work.
I recommend soldering new wires to the heatbed. You wil need a powerful soldering tool.
Higher feet are needed. I recommend these squash ball feet
This project will require you to drill a few small holes in your Y carriage.
Current version is only compatible with CR-10(S). May be compatible with Tevo Tornado
Making these mod's to your printer is at your own risk!
Parts list
For the MK2 design you will need to print these parts:
MK2 drag chain tray
MK2 duct cover
Chain clamp
MK2 S-Duct
MK2 S-Duct cover
MK2 Connector bracket (optional)
MK2 Connector clamp (optional)
MK2 Hole pattern card for drilling (optional)
You will also need these non printable materials
Drag chain (Please see appendix 1)
Suitable wire (Please see appendix 2)
4 pcs M5x8 bolts
4 pcs M5 V-slot nut (hammer nut)
14 pcs M3x8 bolts
5 pcs M3x12 bolts
5 pcs M3 nut
4 pcs M4x20 bolts
4 pcs M4 lock nuts (nylon)
Wire ties
Male + female XT60 connector
Any type if simple 2 pole male-female connector
Assembly instructions.
1) Start with printing and mounting some higher feet. The stock feed are approx 18mm. You will need at least 28mm (if not using cable tie), but more is better. I recommend these squash ball feet They measure approx 38mm and are great.2) Disassemble the heat bed and mark the center line on the Y carriage as illustrated in attached picture. It is very important the center line is placed accurately! If you are sure about the position, you can scratch the lines in the coating with a sharp object.3a) If you are using the suggested drag chain (see appendix 1), you can use the hole pattern card to drill the 5 holes. The instructions on how to position the hole pattern card can be found in the attached pictures.3b) If you are using a different type of drag chain, you can still use the hole pattern card to print the 3 holes for the mounting of the S-duct. Place the drag chain approx 1-2mm away from the S-duct.4) place 3 pcs of M3x12 screws into the 3 mounting holes of the S-duct. These will need to be screwed in as the holes are a little small. This is a design feature, not a error in tolerances. Screw the M3 screw all the way trough, so the full length is sticking out on the other side. Now place the S-duct underneath the Y-carriage. If you drilled the holes right, the M3 bolts should line up with the holes. Place the optional connector bracket on top of the Y-carriage and secure the parts with M3 nuts.5) If your using connectors for the power and thermistor wires continue to step 8, if not solder the new power wires tot the bed. Point them in the opposite direction of the original position. If you do not have any experience with this, i highly recommend you read appendix 3 about soldering below. Same goes for the appendix 2 about choosing the right wire.6) Extend the thermistor wires by cutting them just below the heat bed and attaching some new wires. Most 0,25mm2 or AW24 wire will be fine as long as its stranded. I recommend that you solder them, and used some heat shrink for insulation.7) Mount the heat bed back on the Y carriage in its original position.8) continue to step 10, if are NOT using the connectors. Solder the new wires (see appendix 2) to the male XT60 connector. Place it in the connector bracket and lock it with the connector clamp. Use 2 pcs M3x8 bolts to secure.9) Use any kind of small male-female connector that you like for the termistor wires. I used a 2.54mm pitch pin header for PCBs, and its female counterpart. Solder the new thermistor wires (any stranded AWG24 wire will do) to your connector and use a small cable tie to secure it to the connector bracket as shown in attached pictures. Use some heatshrink for insulation if needed. Other connectors i can suggest are a 3.5mm jack or a "DC plug".10) Route the wires trough the S-duct. The power wires must be next to each other and can not cross. Close the S-duct by attaching the S-duct cover with 7 pcs M3x8 bolts. Its best to lay the printer on its side. I recommend using some supports for this.11) Configure the drag chain. For the type i used (see appendix 1), i needed approx 20 links. The length can be changed at any later stage. Don't make it to short, or it will stress the chain. You only need the mounting bracket on the Y carriage. On the other end the last link is hold by a clamp.12) Mount the drag chain to the Y carriage using the M3x12 bolts and M3 nuts. Route the wires trough the dag chain. Lay them next to each other, and do not cross or twist them!13) Mount the MK2 drag chain tray below the frame using the M5 bolts and hammer nuts. The center of wire duct should be between the Z stepper, and the Z frame. You can play a little with the position as the tray is on the large side and you correct for position by adding or removing drag chain links.14) When you are sure about the position of the tray and the right length of the drag chain, you can use the drag chain clamb and the M4 nuts and bolts, to lock the last link of the drag chain in place. Make sure the drag chain is centered and sits straight in the tray. Make sure you can move the bed without the drag chain touching any of the sides of the tray.15) Hold the wires in place so they remain uncrossed inside the drag chain. They should have plenty of room to move free within the drag chain. In the round part of the drag chain, they should not be pressed to the bottom or top of the chain. When in the right position use a cable tie to secure the wires to the tray.16) Attach the "aviation" plug at the new desired wire length. Use some braided sleeve if you want too. Attached you can find a picture of the plug if you forgot the positions. Mount the MK2 duct cover with 5 pcs of M3x8 bolts17) Solder 2 pcs of wire to the heat bed. Point them in the opposite direction of the original position. If you do not have any experience with this, i highly recommend you read appendix 3 about soldering below.18) Check for the right wire length to the male plug mounted in the connector bracket. Make sure the cable is long enough. It should run a little bit in a S shape instead of straight. Attach the female XT60 plug19) Do the same for the themistor wire so the wire can relax in a nice position.
Additional information.
Appendix 1: Drag chain type
This drag chain will need to do a lot of traveling. For this purpose i don't feel a printed drag chain is the best solution. FDM printers like the CR-10 are not accurate enough, and materials like PLA are not wear resistant enough. Best thing is to just buy this drag chain. Universal drag chains are cheap and can be found at may cheap market places like Aliexpress and Ebay.
In the attached pictures you can find all dimensions of the used drag chain. If you cant find this specific drag chain, you can look for a similar type. This type is commonly known as a 10x20 type drag chain. 10x20 is the internal dimension in mm.
Other dimensions are:
Radius: The radius to the center of the chain. In my case approx 25-26mm
Outer width: 25.7 mm, I recommend staying within 26mm to give the chain some room.
Outer thickness: Approx 12,5mm but this is mostly related to the chain height
The height is determined by the the radius and the outer thickness and can easily be calculated with: 2 x radius + thickness.
The max height for my design is 68mm
The max width is 28mm (26mm recommended)
With this knowledge you should be able to select a chain that fits. I however recommend that you buy the exact same chain as i did. Its $ 4,- and will always fit. It wil also fit the mounting holes i used in my design. Other drag chains may not.
The Aliexpress seller is SingaSong. The current link for the item is: https://nl.aliexpress.com/item/Free-Shipping-10-x-20mm-10-20mm-L1000mm-Cable-Drag-Chain-Wire-Carrier-with-end-connectors/32733132867.html
At some point i may add a printed chain to if people keep requesting it. I'm sure many existing can easily be adapted. Have you done this, pleas sent you you pictures and STL's so i can add them to this upload.
Appendix 2: Wire type
I can write a lot about this, but i'll try to stay with the basics. Your 3D printer will probably not run 24/7 for the coming 20 years. Therefore the wire does not need to be up to code, but you do need to buy a wire that is up to the task.
USING THE WRONG WIRE CAN RESULT INTO FIRE HAZARDS and can have a negative impact on the amount of heat the bed can generate.
I measured my bed at approx 0,8-0,9 ohm. At 12V the current will be approx 15A. This is in line with other specs I found online. At this "high" current level a noticeable amount of current will be dissipated in the wires meaning they will warm up. The core temperature is related to the amount of wires and the surrounding temperature. When printing ABS at a high bed temperature while in a enclosure the surrounding temperature can be quite high.
A 2,5mm2 (or AWG14) wire is rated at approx 15-20A at 30 deg C depending on regulations. The actual current the wire can carry depends on the type of insulation and ambient temperature. A 70deg C rated PVC cable at 55deg C wil be rated as low as 10A instead of 21A. A big difference. The 2,5mm2 wire now seems to thin to carry he 15A of current! On the other hand, a 6mm2 wire (AWG10) wil be very big and not very flexible enough for drag chain use.
So lets accept the wires might get a little hot, and the insulation can age fast. I think the practical maximum size is:
Metric: 2,5mm2 or 4mm2
US: AWG14 or AWG12
The used type of insulation is also very important. It needs to be flexible, and withstand high temperatures. Some types are:
PVC 70C (most common): Not great, Its flexible enough, but temperature is to low
PVC 90C: Better temperature, but usually less flexible so not great either
Silicone: Great for temperature and flexibility.
Rubber: Decent temperature and high flexibility.
Wire styles that i would recommend are SiF, SiFF and LifY. I dont know about AWM styles, but the original heat bed wire is AWM 3135. This is a silicone type and should be very suitable.
Appendix 3: Soldering on the heat bed.
The aluminium heat bed is designed to spread the heat generated by printed circuit on the back. Aluminium will conduct the heat very well so it will be hard to get enough heat onto the pads. I have a high quality 80W iron and was barely able to get enough heat in.
If you are a novice in soldering or do not have the right equipment, ask somebody else to help. De-solder the original wires first. Do not just rip them of, you could easily damage the solder pads.
Some general guidelines
Use a 80 or 100W soldering tool, and set it to the maximum heat it can candle
If available use a short and thick soldering tip to transfer the heat better
Solder with lead has a lower melting point. This may help
To little solder tin will make it hard to transfer the heat to the pads.
Take all the time you need. Don't try to rush it.
Help me improve these designs!
Please post your feedback about my designs. If you have any questions. i'll be happy to answer them, but please do read the description first.
I would love to see your makes of this!