Comments sought on new build: A CNC Router for RC Gliders and Planes

[njhussey]

Today I was checking the wiring and powering up the relay to make sure that it bought the power on and that the door safety switch worked etc. and on measuring the voltage found that our single phase power supply is 242V which I think will mean that my PSU (25V+25V) will be putting out too high a voltage, or at least be too near the 80V limit of the AM882s for comfort....will dig out my calculations and have a look tomorrow :(

[JAZZCNC]

Today I was checking the wiring and powering up the relay to make sure that it bought the power on and that the door safety switch worked etc. and on measuring the voltage found that our single phase power supply is 242V which I think will mean that my PSU (25V+25V) will be putting out too high a voltage, or at least be too near the 80V limit of the AM882s for comfort....will dig out my calculations and have a look tomorrow :(

Neil chances are your mains power will most likely fluctuate up and down depending on time of day and demand around. My varies wildly upto 257v.!! . . . The drives will handle some over voltage without damage if just a slightly up but obviously not good running all the time above Max.!

[njhussey]

It's down to 236V today, powered it up and geting a nice 71V at the drives. The drives drain it down to next to nothing in about 20 seconds (not timed but it's a short time) I'll still at a later date put a 240V relay in and put a resistor across it to drain it quicker in case someone goes in the panel within that time.

Now on to the various safety circuits....time for some head spinning!!

[JAZZCNC]

I'll still at a later date put a 240V relay in and put a resistor across it to drain it quicker in case someone goes in the panel within that time.

Yes I would do this anyway neil because if your not isolating the drives enable signal then the motors will remain powered until caps drained and this will cause them to run on slightly before fully drained.

[njhussey]

The door isolator turns off all power so it's just for drainging the caps in case someone puts their hand on something.....although I've got hot glue over the soldered terminals on the caps so you shouldn't be able to shock yourself...

[JAZZCNC]

The door isolator turns off all power so it's just for drainging the caps in case someone puts their hand on something.....although I've got hot glue over the soldered terminals on the caps so you shouldn't be able to shoch yourself...

Ok understand that side but still same applies has when you E-stop the machine will run on.!

[njhussey]

I'm having the Estops (and AM882 alarms) go through a relay (and Pilz??) which will kill the power, the limits I was going to wire through a relay and to the enable of the drives.....