mach3 wont reset keeps saying external emg stop requested

[dazp1976]

Why so many.? . . . You are just melting down the other electrics and heating the planet with all that wasted electricity.!

Regards a larger PSU for Geoff then he's only controlling a few relays and the BOB, He'll be lucky if pulling 1A total so he's still got 2.5A spare with 40W 3.5A PSU.

Geoff go with Clive's suggestion the 36W will be fine.

They only use what they need.
60v for the Nema 34's.
36v for the Nema 23's. (Although I now know they could probarbly go on the 60v fine).
24v for BoB spindle, estop, limits.
5v for the BoB pul/dir etc and SSR relays.

It's been added to over time and I'm still learning. In reality I could ditch the 36v as suggested above and also ditch the 5v by using a step down module from the 24v for the needed 5v. Only recently realised they existed lol. I'll wait until they fail and re-jig it all later on. That's why I got the larger than needed 24v supply for when this change occurs.

[Geoff57]

thanks everyone for your help and advice great forum ordered a psu today i will let you know how i get on
when it arrives and i have installed it in, the current situation we are all in it may be a while before i receive it
thanks again stay save thanks Geoff

[Kitwn]

My controller has -3.3V, -5.0V, -12V, +3.3V, +5.0V, +12V, +24V and +36V supplies available so I win!!


There seems to be some misunderstanding in the last few posts about the significance of current/power rating of supplies. To clarify...

If you install a 12V supply rated at120W then the unit CAN deliver a current up to 10 Amps but in practice will deliver the current required by the load. If that is only 1A, the supply will deliver 1A. This is a power of 12 Watts. The power drawn from the 240V mains will be 12W divided by the efficiency of the supply. Switch mode supplies like the ones in the photographs typically have an efficiency around 85% so you will draw 12/0.85 Watts from the mains, about 14W. That gives 2W of waste heat.

If you decide to install a 12V supply rated at 240W instead, the maximum current it can supply rises to 20A. ALL the following results, including electricity used and waste heat stay the same. The only changes are that the supply will be physically bigger and cost more.

[JAZZCNC]

If you decide to install a 12V supply rated at 240W instead, the maximum current it can supply rises to 20A. ALL the following results, including electricity used and waste heat stay the same. The only changes are that the supply will be physically bigger and cost more.

There is NO misunderstanding Kit we know this very well, the point was why use an oversized PSU that costs more money when not coming close to using the maximum output of the original.?
Regards your and DazP # of PSU's, which was the other point of my objection, you are still producing heat and burning electricity that isn't required. Heat is the enemy of electronics so anything that lowers it can only be good.!

. . . . Next you will all be telling people Bigger steppers are better.!

[cropwell]

. . . . Next you will all be telling people Bigger steppers are better.!

I have got a couple of Nema 17 steppers fron a 3D printer extruder bar, will these be OK if I build that steel tubed gantry mill?

[JAZZCNC]

I have got a couple of Nema 17 steppers fron a 3D printer extruder bar, will these be OK if I build that steel tubed gantry mill?

Depends on the tube wall thickness.? Anything below 0.3mm and you'll be fine...

[dazp1976]

There is NO misunderstanding Kit we know this very well, the point was why use an oversized PSU that costs more money when not coming close to using the maximum output of the original.?
Regards your and DazP # of PSU's, which was the other point of my objection, you are still producing heat and burning electricity that isn't required. Heat is the enemy of electronics so anything that lowers it can only be good.!

. . . . Next you will all be telling people Bigger steppers are better.!

Nooooooo. Bigger steppers are crap! unless you supply them with a very large voltage. Especially those 1700oz things with 8mh inductance from China. Seen a few make that mistake.

As for the PSU I don't see many of them that have failed unless they're running close to or over capacity. If the machine has car type relays in use and/or a few of them, then they may suck life out of it. If this is the case you're either replacing all the relays or going with a bigger supply (what's cheaper). (At least I only went 38w more! lol) Trace your wires and check what's in use.

[cropwell]

My point about automotive relays is that they draw a lot of current, some of them nearly 1 amp. That may damage the electronics that feed the coil. I am not concerned about PSU capacities, more than the BoB. In this case I do not know where the relay is fed from.

In fact I have spotted two of the little buggers in the photos, there may be more.