Upgrading 3020 CNC Router Cables & Connectors - Part 2

The track for the Z-axis was just a tad wider than the existing track, so I was able to use the same mounting brackets and tray. I am using the same cable and track as I did for the lower chain in the previous post. The only difference is this chain is a little narrower (since it only has to pass two cables). 0.41" x 0.79" instead of  0.41" x 1.18". I also only purchased 2 feet.
http://www.mcmaster.com/#55835k34/=q4lpi9 
See Part 1 of the cable upgrade for more links on the cables & chains.

All of the bends were tight with the cable, but don't strain the steppers, or impede movement.

There is a slight problem with the power cable for the spindle motor. Since it moves up and down, there needs to be a certain amount of slack in the wires. I had to add (after this photo was taken) about 3-4" of wire to give it the necessary range of movement. Technically there should also be some kind of cable chain to serve the motor, but on a CNC this small, it's hard to find anywhere to mount it that doesn't interfere.

All axes hooked up the the control box with the next connectors and shielded cables.

Limit switches are probably going to be my next project.

Upgrading 3020 CNC Router Cables & Connectors - Part 1

Why?
- EMF/EMI
The spindle is controlled using PWM and a high voltage. This can induce currents in the other wires locates close by.
- Low Quality Wire
CNCs see thousands...millions of repetitive motions. The wires will break at some point no matter how good. It's well known with these units that they ship with low grade wire that can have breaks after only a few hours of machine operation. I'm going to upgrade to wire/cable that is specifically designed for use in a CNC machine.

Cable Selection:
McMasterCarr - http://www.mcmaster.com/#catalog/119/802/=m38xy7
Manufacturer - http://www.igus.eu/iPro/iPro_01_0013_0021_GBen.htm?c=DE&l=en
Description:

• The bodybuilder of the wire world, this cable never gets tired of flexing. It has stranded copper conductors and is often used in cable chain and track for robotics, CNC machines, and material handling equipment. It has one green/yellow ground wire, unless noted. CE approved. Maximum continuous length is 100 ft. Note: The total number of conductors includes the ground wire.
• Shielded cable eliminates electromagnetic interference (EMI).
• 300-VAC Cable
• Has black insulated conductors with white sequential numbers.
• Shielded cable has tinned copper braided shielding.
• Standard—Good for general use; cable withstands periodic exposure to most oils and fluids. It has PVC-insulated conductors surrounded by a PVC jacket. Temperature range is 23° to 158° F. Passes FT1 vertical flame test. UL recognized and CSA certified.
• Oil Resistant—Handles continuous exposure to oil and fluid. It has TPE-insulated conductors surrounded by a polyurethane jacket. Temperature range is -31° to +176° F. Passes FT1 vertical flame test. UL and C-UL recognized.
• Heavy Duty—Made to last over 17 million high-speed cycles. It's oil, abrasion, and chemical resistant and has TPE-E (thermoplastic elastomer) insulated conductors surrounded by a polyurethane jacket. Temperature range is -40° to +194° F.

Required Cable Lengths: (approximate)
X-Axis -
Y-Axis - 26" or 65mm
Z-Axis -
Spindle Motor -

Total Length Required:

Cable Track:
McMasterCarr - http://www.mcmaster.com/#catalog/119/1531/=phqkmp
Manufacturer - http://www.igus.eu/iPro/iPro_01_0002_0002_GBen.htm?ArtNr=06.30.028.0&c=DE&l=en&aeartNr=060.30.12PZ
Description

• When space is tight, you need low-profile carriers. Snap-together links make length adjustment quick and easy. Join lengths by hand; use a screwdriver for dis-assembly. All are black glass-filled nylon. Operating temperature is -40° to 266° F. Compatible with this style of Igus carriers.
• Feed-through carriers require the cable and hose to be threaded through the entire length.
• Mounting brackets are made of black glass-filled nylon and have a built-in plate for strain relief. Fasteners for mounting the brackets to the surface are not included.

The lower, main track, requires capacity for 3x cables (X-axis, Z-axis, & spindle) while the upper track requires capacity for 2x cables (Z-axis & spindle). Depending on your spindle's current draw, you may find it necessary to double up on the wires you use (2x 18AWG for positive and 2x 18AWG for negative).

Length Lower Track:
Length Upper Track:

Connectors:

These obviously match the new panel I made in a previous post. They are decent quality and are definitely over kill for this setup. Best of all, they are metal, so I can ground them. I connected the shield of the wire to the connector itself so the entire cable's shield is grounded. I have not yet found optimal connectors for the stepper motor end of the cables.

Installation:

2" Wide x 1/8" Thick piece of flat stock cut to length. Drilled and tapped for M3 screws.

You could use a piece of angle bracket from a local hardware store. I used a piece of scrap aluminum from a power supply frame that I cut to size. I drilled and tapped the side arm of the CNC.

The tightest configurations looks to strain the cables.

So I gave it some more length even though it will not exactly be compact. Now the cables are nice and flat. Also there is less strain on the chain.

Final complete assembly of the primary cable chain. X, Z, & Spindle cables are run through it.

I will do another post (Part #2) on installing the secondary cable chain for the Z and Spindle cables.

Replacement Rear CNC Panel for CNC Controller

The original panel is made out of very thin sheet metal that bend easily and is not very rigid. The use of space is not very optimal either.

The panel was machined with the router into1/8" thick Delrin (Acetal Resin) plastic. I bought a 4" x 12" piece for a mere $6.69 from McMaster-Carr (P/N 8739K15). I will probably be doing the front panel over in the same material.

I used a TiCN-Coated Carbide End Mill, Two Flute, 1/8" Mill Diameter, 1/8" Shank Diameter which I got from the same place for $13.47 (P/N 2416A17) to do all the cutting. It was amazingly sharp and was able to cut at very high feed rates.

 

I added an additional for a future axis, limit switches, or other i/o. "Military" grade connectors are more like military style, but they are much better quality than the original connectors. I paid $33.11 for all 5 connectors shipped from China. One key thing is that the panel side connectors have female pins so that if the unit is turned on, without servos & motors connected, the chance of shock is lower.

I had to relocate the PSU slightly to accommodate everything. Nothing major, just drilling new holes.

I may consider posting the AutoCAD drawing of the panel so that others can make it along with the G-code. Let me know if there's demand out there by posting comments.

Unpacking the 3020 CNC

I received my CNC and took a few pictures of how well it was packaged. Take a look!

 The box was not that impressive at all from the outside, but it was deceptively well packed as I found out.

 The foam was cut perfectly to fit every nook & cranny of the box to prevent any movement of the machine during shipping.

 Even the servos were very well packed in a thick foam case made specifically for them.

 Here is the CNC router on it's new base, a craftsman tool bench.

Purchased Chinese 3020 CNC Router

I purchased a generic 30mm x 20mm CNC bench top router for manufacturing PCBs at home. Below are the stock images of the machine which were included on the FleaBay listing. I will be taking pictures of unboxing and setup and posting them once I receive the machine. Then of course I'll follow up with software configuration and my first routing tests.