Ronald L's CNC Machine Kit Build
Ronald's blackToe CNC Router is exhibited for the exceptional wiring work he has done and for a particular challenge he needed to overcome. First, a word about the challenge. Ronald's motors that he purchased contained shafts in a metric size and currently, my collars for the drive sprockets are sized for imperial shafts of 1/4" diameter. His shafts were a little too large and, upon my recommendation, he bored a larger hole. Unfortunately, the bore did not center properly and he is faced with a need to purchase collars for the motors shafts locally. When he overcomes this challenge, I will add more information.
The wiring work that he provided is truly exceptional. He even adapted PVC as conduit on the z-axis.
His words follow:
The torsion box was made with one difference to save time, the top of the box is in fact the table top. Put underneath some space for keeping MDF 4x2” sheets.
The angles on the rails were installed by using one of the bolts of the table. I used a grinder to reduce the material for the angle to fit nicely inside the bottom side of the rail I wanted to achieve one point in which the electrical cables from the machine were connected somehow from the gantry to the table. I thought about doing it on the air with some strings, but that was too much hassle. And the longer the cables, the longer the loss (although my drivers are very easy adjustable with a pot). The motors wiring on each of the gantry sides follow always the same connection pattern for ease of use.
All of the motors’ cables have pin crimp terminals that are used in conjunction with normal electrical block terminals for ease of use. These are screwed to the MDF of the machine, anywhere I found it best for avoiding issues. And especially for testing voltage, current, etc.. dead easy to do right on the motor and not on the other end where the motor drivers reside. My driver enclosure (including the power supply) is always closed on the floor and I never touch it in fact.
The cable used for the actual wiring as I’m using now bipolar drivers (BTW I just recommend to anyone on your site NOT to use unipolar ones, they are really really crap, these ones I’m using from Ocean Controls dudes are FAN-TAS-TIC for the price, they barely get hot (no resistor or similar) and the motors get just normal warm, whereas before they were working really hot) is 4 core normal white electrical PVC cable rated at 6A as the 3A one was out of stock, would have used the 3A one though. The 6A is a bit thicker, but works just fine and in fact better as there is less loss.
For the Z axis cable-canal in inverted U shape I’ve done something really simple. Went down to the local (fairly big) hardware store and got myself, 25mm electrical PVC tube, a couple of PVC inspection bends, I glued them together and installed them on right on the Z axis (4 screws) and they hang down to the back for perfect usage. What I have not fixed yet is to avoid the cables to band too much, I take it with much use the part where these are fixed to the block terminals might give up, but for now it works like a treat. Through the conduit I’m running the spindle power and the Z and Y axis motor 4-core cable. And that was it, dead easy. It takes some time to plan, but once done is done! Note: When installing the inverted U shape, sink down the Z axis to its lowest point, then fix the inverted U shape and leave 1” or 2” space between the chain and the tube, and viola! I’ve fastened the 3 cables together to minimize any issues. I thought at first to use some flexible conduit for this bit, but honestly this works as good.
For the other side of the gantry (the right side on the pictures) where you see the 3 grey flexible conduits going down, I have used the base of the side of the gantry to install a simple L shape aluminum angle in which I’ve fastened 3 straight plastic swivel glands. These serve to attach the 3 flexible conduits (20mm ones) in which I run 2 (motors) + 2 (motors) + 1 (router + limit switch -telephone type- cable). On the other end down in the middle of the table, I’ve simply attached the glands straight to the wood (3 screws per gland) and it’s really strong, so no issues when the table moves fast. There is a picture with the table all the way down to X0 and also another one on the other end. I’ve used cable fasteners to have all 3 conduits together to have it more tidy. This thing really works well and that’s about it, I’m done with cables, don’t have to touch these any more for as long as the table lives as it stands.