routercnc_MK3

[njhussey]

Joined the red and orange together and got 54V AC across the black and yellow, so that is the correct series connection.


I cut the red and orange cables back to leave about 60mm showing, stripped and tinned then ends then soldered together. Heatshrink over the join, then another long heat shrink over the top to finish the series connection.

Crimped terminal ends on the black and yellow cables for the rectifier. Had a look at the datasheet and the terminal rotated 90 degrees to the other 3 is the DC + output. Diagonally opposite this is the DC - output. The other 2 are AC inputs.


Marked out the holes for the cap brackets, rectifier, toroid and corner bolts and started drilling a few out. Went with M4 tapped on the capacitor bolts. Getting there slowly . . .


The MCB hasn't tripped out yet on the few times I've turned it on (6A type D) but since I haven't connected the capacitors yet that probably doesn't mean much.

This was the way I joined my transformer from the technical description on the airlink website...

[routercnc]

Doh! I've cut the red and Orange back quite short and soldered them together. Can someone tell me if it matters this way around instead of Neil's picture ?
Thanks

[JAZZCNC]

Doh! I've cut the red and Orange back quite short and soldered them together. Can someone tell me if it matters this way around instead of Neil's picture ?
Thanks

Doesn't matter.!

[routercnc]

Dean you are a star thankyou!

And the wood was to make it easier to touch the end of cables with the multimeter - don't like zapping myself!

[routercnc]

Bit of an update.

Wired up the PSU caps last weekend and did a final check before switch on. so glad I did because I noticed that for some reason I'd connected the black cable to the positive side of the caps and red/white to the negative! I dread to think what would have happened if I'd switched on. I know electrolytics don't like that sort of thing and have seen small ones explode and unravel. These ones are much bigger! I always wear eye protection in the garage whatever I'm doing but it still would not have been pleasant.

So I switched the spade terminals over out of the rectifier so -ve went to -ve on the caps etc and switched on. Got 72V DC output so was happy with that. The type D 6A MCB did not trip so another good sign. I switched off and unplugged everything.

I then thought about re-soldering the cap cables so I wouldn't get confused with the wire colours if I needed to change anything in the future, but realised I had a problem. There was 70V DC stuck in the caps and the cables were therefore live. I tried discharging them by touching them on the power supply pins of one of the drivers but got a blue spark. I think this was because I couldn't really make a quick decent connection on the bare wire touching a small pin rather than anything untoward.

In the end I de-soldered one of the 10k resistors from the power module board (that held the capacitors) and managed to wedge/rest it across the pins of one of the caps. It took about 1 hour to discharge to 0V, probably not helped by the contact being quite light between the resistor and the capacitor.

This did get my thinking though about the voltage that the 12V DC relays would be switching across their terminals, and I wondered about the lifespan of the contacts. This coupled with the fact that if I e-stop the machine then there would be 70V DC floating around in the control box. So, the relays all came out and the drivers will be hardwired to the PSU. This solves both problems in one.

The PSU will be switched by a 25A SSR which is now on order. I looked for a contactor but they are all 24V and I only have 12V. I thought about changing to 24V but then would need to consider the LEDs, the pump, and cooling fans etc which are all 12V. So staying with 12V assuming SSR does the job. Here is the updated wiring drawing:

[ edit - spotted some copy/paste errors in the layout diagram above since posting so have corrected those ]

I've also just received a few more bits from Chalon components to form a second rail to house most of the DC side including power distribution, safety relays, etc. Here is an update of the control box layout:

[routercnc]

Did a bit more today.


Top left space is for 12V SMPS and VFD


I decided to use the DIN rail as the star earth point (instead of a small block I had in the corner of the cabinet) and am now using proper DIN earth terminals to connect up all the earths.


I've also added a lower DIN rail which is for DC, leaving the upper for mostly AC. I've also split out the main PSU positive into 3 feeds which will run down to the fuses on the new lower DIN rail and then into the drivers.
The old DC terminal blocks for 12V, 0V, and 12V 'switched' are gone and have been replaced by DIN rail terminal blocks (blue). I looked at all sorts of options here and went with these in the end. This type are actually meant for AC neutral so will be labelled clearly as 12V DC, 0V DC, and 12V switched.
The master relay and spindle inhibit relay are now on the DC DIN rail next to them.


The drivers have been moved down a bit and the trunking run around them. The BOB has plenty of space in case it starts mis-behaving and needs to be replaced.


The power supply has been wired up correctly (!) - still need to split out the black 0V cable into 3 feeds and tidy up the general wiring but otherwise PSU is nearly done. As reported previously it all works.


More terminal blocks are on order! All for now . . .

[GEOFFREY]

That looks very neat and professional. Well done. G.