Finished assembling the machine again (shrouds for belt housing, soundproof cover for power drawbar etc) and then connected up the sensors in a vaguely final sort of way. I had thought of fitting a snazzy connector to the cover plate but that was rather scuppered by the lack of any obvious candidates. So instead I opted for a chocolate block connector and a plastic cable gland. I know, it's a bit shit really but it'll have to do. For the cable I just used some CAT 5 cable - unshielded twisted pairs. I grounded one of each of the twisted pairs used in the signal lines to sort of try to improve the noise immunity so hopefully it'll be OK.
Once it was all put back together, it didn't look so bad:
And then I routed the signal cable back into the head through an existing hole, where it can be picked up by the existing screened cable back to the controller. I've got about 8 spare lines in there:
Gear selector solenoids:
Connected up the regulator, solenoids and air lines for the high / low gear range selector mechanism. There is one air line to drive the (rotary) solenoid to the "high gear" position and another solenoid to drive it back to the "low gear" position. It all works now using a bench power supply, although I have yet to wire it in to the CNC controller - this will require messing about inside the control cabinet.
Bolted it in place:
Then connected up the hoses:
The other solenoid is for the power drawbar - it brings the impact driver down to engage the drive coupling. It was already in place and connected up.
This is where the air lines connect up to the rotary solenoid (which is mostly hidden behind the switch box). There's a sort of cam with a notch on it on the end of the shaft to trigger the microswitches at each end of travel. These are already wired back to the controller box, so will be fairly quick and easy to connect up the last step to the CNC controller:
To control the 24VDC solenoids from the controller, I'll have to order some DC (FET based) SSRs from Farnell. These should do the trick. The datasheet is here. Of course, the fixing holes are on different centres to those I'd previously drilled and tapped for the AC (triac based) SSRs I bought for the coolant pump, lube pump etc - 47mm vs 22mm - so I'll have to blast some more holes in the chassis plate which is a PITA.
While thinking about the wiring for the gear change solenoids, I thought I'd sus out the autolube pump. It's a Bijur TM-5 autolube pump. My particular model is a D2990. The model number denotes the discharge cycle time which in this case is every 32 minutes (for 50Hz supply). The discharge volume (of oil) is adjusted if necessary by changing the length of the piston stroke. I assume it is preset to the correct level for the machine - I haven't changed it.
I'd assumed that the pump was "dumb" and had to be triggered every so many hours of machine operation by the controller. Instead, it appears that there is a small synchronous ("clock") motor that operates continuously and when the correct interval has passed, a piston movement happens. It's probably a spring and a ramp if you know what I mean. The different models have different cycle times ie presumably have differently geared motors. It's not quite rocket science.
The Newkye controller has "lapsed time" and "pump duration" parameters (or similar terminology), which determines the time between lube events and the time the pump is powered. This confused me but with the Bijur pump on this machine the bottom line is that I don't need to control the timing with the CNC controller - it's already taken care of inside the pump. That simplifies the wiring at least.
So now I just need to connect up the pump so that it is powered when the machine is "running". However, if it is simply powered from the main switch and I leave the machine idling for ages (overnight?), it would lube every 32 minutes and I'd come back to an empty reservoir and a load of oil oozing out from all over the machine. Instead, I'll power it from the coolant pump which will generally only be enabled during actual machining. That's simple enough, as the 240V power to the coolant pump already goes to the rear of the machine, right next to the lube pump. It could have been planned....
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