CB CNC Part 18 – Connecting CNC Machine to Controller Enclosure

In this video I will connect the CNC enclosure to the CNC machine itself.

Ok I think what I need to do next is re-solder the correct aviation sockets.

The first thing I’m going to do is re-wire the stepper motor panel sockets from the four pin ones I used to test the motors, to five pin aviation sockets. I have used cable that can be shielded from electromagnetic interference. The extra pin on the panel mounts will be soldered to br aided shielding on the cables, and then go to a ground terminal within the enclosure.

I made a jig to hold the socket while soldering, by drilling a hole roughly the same size in a piece of ply. Once I tinned the contacts I soldered these together.

I also have to rewire one of the 4-Pin JST Connector to an extra cable as I am using two stepper drivers for each of the motors of the Y axis. When I originally tested the motors I connected those two steppers together, because that controller only had a total of three drivers.

So I put the crimp things in there and the idea is you just push the wire in and squeeze it. I have about 4mm of wire exposed.

I’m not doing a great job filming this – but you have to press the crimp twice. The first time you hold the crimp terminal in the appropriate jaws of the pliers, push the wire in without knocking the crimp out of the jaws, and do an initial crimping. That should hold the wire and crimp together loosely so you can move them further into the jaws, to a raised section which re-crimped the connection so it is even tighter and can fit into the plastic plug.

Ok this is better, it’s gone all the way in.

This is something I just figured out while making a lot of mistakes. So an alterative to make the JST connected up yourself is to buy them pre-assembled.

So all you’ll have to do is solder onto the ends – maybe cut it down and solder here. Another alternative is to just simply to wire directly to the stepper drivers.

I am now going to install all the proximity sensors to their mounting holes on the plates. I have two pairs of proximity sensors wired in parallel for the x and y axis, and a single sensor for the z. I use a thin offcut of profile to line up the holes in the extrusion with the plates, drilled those out by hand. I’m going to hide some of the wiring by passing them through the aluminium profile. This was something I overlooked when designing and cutting the plates, but will make the finished CNC machine look a lot neater.

I’m just going to feed this through and make sure it comes out of the other side.

I’m also going to also shield the proximity sensor cables with separate copper braided sleeve which will go over the cable.

Ok I’ve been popping the sensors in their mount. I’ve also go this braided copper sleeve which is tinned – that’s why it’s this colour.  Which I’m going to put on the cables before I solder the extensions onto the panel mounts. And the reason I’m using this is to shield the wiring so I reduce interference causes me problems.

When I had the braiding the entire piece of aluminium will act like a faraday cage, shielding the wire.

I just need to connect the braid on these two to that one.

So from the proximity sensors, the brown goes to red, the blue goes to black, and the black goes to green and I’m not using the white cable because I only need three cores.

  • Brown/Red = Power
  • Blue/Black = Ground
  • Black/Green = Signal

I’m just going to wire the panel mount socket to the wire for the… this particular one, and if it works I will do the rest.

Ok so before I put the heatshrink on and screw it all together I’m going to just plug it in and check that it works.

So it’s really important to make sure all the proximity limit switches are plugged in, otherwise the controller will assume there is a break in the circuitry because they are connected and there won’t be any homing. So I’ve done these two which are the X and Y and I just  need to do work out the length and solder the Z. These are inductive so I need to put some metal maybe a screw or something in there. Unfortunately I didn’t put a mount here for the z axis so for now I’ll just cable tie that on.

Around the same time I tried to wire the pump and fan for the original water cooled spindle.

Let’s see what happens when I turn this on.

I had to give up because, for some reason the pump just wouldn’t work. I probably could have spent several days working out what had gone wrong but I decided to just buy an air cooled spindle instead.

That’s on, but I can’t hear that running.

Before you smash that dislike button thinking I’m just throwing money at the problem – first of all money is a valid and essential part to solving some of the more complicated problems in life. But I also blagged the water cooled spindle for free, so I’m not so much throwing money at the problem, but doing what I would have done had I not wasted my own time first. That and it’s not the 1990’s, and technology has moved on to the point that we don’t necessarily need water cooling, apart from in the nuclear industry – which means it’s safe to change my mind.

Ok I’ve decided watercooled spindles are too much of a ball ache so I’m gong to undo all of these now. I’ve ordered a replacement air cooled spindle.

I’m now going to change the water cooled spindle with the air cooled one.

Sometimes you just have to accept it’s ok to change your mind, about something. I got this spindle for free. I tried to use the water-cooling method but I can tell it’s going to cause me more problems than it’s worth and taking this out is going to make so much more space in the trunking, I think the machine will look a lot neater as well.

I bought a new air cooled spindle and I’m going to replace the watercooled one with this. It doesn’t look as good quality as the previous one, and the sockets a little bit different too so I’m going to have to re-wire this.

This one has a nice spin to it, while this stops a little more abruptly. The motors probably been left in the cold for too long and the grease and the bearings are a little thicker so when it’s been turned on for five to ten minutes, this should improve. The collets is also a little bit  bigger on this one, this is an ER16 while the other one only an ER11 so I got more options with what I can attach to  this.

The socket opening is a little smaller than the previous one, and I couldn’t get in to fit after I replaced the plastic covering with the black braid and added the headshrinker over the cable. This entire build has been a complicated patchwork of mistakes for me, but I’m close to the end now.

I’ll double check I’ve solder this correctly. 1 is brown, 2 is black, 3 is grey and 4 is green and yella.

The spindle works but I can’t actually control the RPM with software yet because I need to adjust some parameters in the GRBL config.h file – so what you’re seeing now is done by using toggle switch and potentiometer to change the speed directly via the VFD – if I turn the spindle on by writing M3 in the command line in bCNC, the RPM goes to max and the toggle bar in the software is unresponsive. I want to move the machine around to make sure everything works ok and that the steps are set correctly.

What the fuck happen there? Fucking hell, I had one switch in the wrong position so they were moving at different steps. Anyway here goes again.

So this is where you write congratulations in the comment section – I made it. Thanks for joining me on this journey – and especially to my handful of committed patreons whose subscriptions have kept me stocked up with coffee and biscuits while I endeavour – you guys are absolute stars.

The majority of the physical work is done and the machine and enclosure are connected. There’s still a few problems I need to solve including the emergency stop causing an overload message on the VFD, Controlling the RPM in software, Getting the surface scan feature to work on bCNC, and also three of the four steppers don’t seem to hold when the machine is idle.

I’m going to save those for a troubleshooting video – which is what I’ll work on next where I’ll look at the software and firmware in a little more detail. I am a little daunted at the idea of delving into the cove of firmware, but I don’t have a choice it’s where I must go. So thanks again for watching and I’ll hopefully upload a video soon.

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