[wavewizards]

Hi everyone and I am going to start with a apology I am always willing to learn but there is only so much you can learn by reading.
I have bought a milling machine emco that a guy has started to convert but has given up so I jumped on it as it was very cheap.
Now I stripped the machine and replacing the old ball screw with anti backlash type and moving the z axis motor as this was not placed in the right place.
This I am ok with this the problem comes with the electrics involved
Now I have purchessed the following

1 nema 34
2. Nema 24
3 ma860h drivers
1 36v 11 amp power supply
1 c11g bob

Now I hope these drivers are ok I have done the calculations on the motors and got ones with he right nm/in.
Now my first problem comes with power.
Now the combined amp for the motors is 11.2amps max now I no they will only use 75% so I believe that side is ok but the voltage for the motors combined is 11.3 volts but I have 36volts. Do I need to look for a different power supply.with less power?
Also I have had a issue that I tryied to run before I could walk and think I have screwed up some how because after test wiring the motors on the table one driver has a red light on as soon as you turn it on I guess I have screwd that driver and will need to buy a replacement. Unsure how as the wiring seemed to be correct.
Sorry for the hand full of question but I am new here and just want to learn and get this right as wife is going to kill me if I keep spending money on it.
I will post some pics of the machine how I picked it up and thanks for help in advance.this was per strip and throw away far to small motors.
Attachment 182307Attachment 182308Attachment 182309

[LeeWay]

Your motors can take about 75 to 80 Volts. That is okay with your drives. You will need to source a larger power supply to get the most out of the motors. That is if they are all rated the same voltage. I know they probably aren't. What is each motor rated voltage?

[wavewizards]

Thanks for reply
Nema 34. Rated voltage is 5.7volts
X2 nema 23 rated voltage is 2.8 volts each

[LeeWay]

So I am thinking it is a little over 50 VDC for the smaller motors. A 50 Volt supply would be what you want. Closest I know of from memory is about a 48 VDC. Lots of those around. There is a formula that is often used here to gauge what voltage a motor can use. It has to do with the inductance. What is the inductance on the 23's? I was just using the 20 times voltage, but using the inductance will get you closer to what it can actually use. It may be that you can use a higher voltage supply. Your Nema 34 will thank you for that.

You could always use two supplies as well, but that gets bulky and expensive.

[wavewizards]

I have 4 power supply's in total bought them as a joblot is there any way I could just two of the the power supply's I have are.

X1. 36volts 11amp
X3. 24volts 10amps

If so how would I set them up would I chain them or use to power certain motors?
My worrys were that running 2 power supply's would give me to many amps!

[LeeWay]

I'm no expert when it comes to electrical stuff, but if it were batteries, then you could hook them in series and get double the voltage. Power supplies won't work that way. You may be able to connect the output from like supplies and get double the Amps, but the volts would stay the same. Hopefully someone will straighten us out on that.

I wouldn't even bother with the smaller supplies.
I would run the all off the 36 VDC. That is where you will see the best performance out of your motors with the supplies you have. You could always Ebay those supplies to fund the proper sized one.

It will be a rare circumstance that you ever have all three motors maxed out at the same time, so 11 amps will probably work fine.

[Dr.Fiero]

My worrys were that running 2 power supply's would give me to many amps!

I'll only comment on this, but.... You can't have too many amps for a given load.

Voltage can be too high, but the resistance of a given load (be it a light bulb, or a computer) determines the current flow.

Hook a 1000 amp 6 volt power supply or battery up to a 6v lamp. It'll light up just as its supposed to. Hook a 12v lamp up to the same supply and it'll glow half as bright.
(Yes this is over simplifying ... Just making a point)

[Al_The_Man]

A couple of things to keep in mind, NEMA size is not an indication of torque sizing.
Also, depending on your controller, steppers in principle run at their constant rated current, even when stationary (unlike servo's) unless the drives provide otherwise, this as also the reason they reach their rated temperature even when sitting at zero rpm.
The reason for the higher voltage than the motor rated, is the drive attempts to maintain the rated Current as the inductive reactance value (Ohms) increases with rpm.
Al.

[LeeWay]

I know that Gecko drives can regulate the amount of amps it will take, so you can regulate them for particular motors.

The details about your particular drives are not known to me, but maybe someone can tell you or point you in the right direction for info on those.

[wavewizards]

Hi thanks for reply yes I no that the nema size does not state torque I have worked the weight and speed I want it to move and got the correct torque motors thanks for replying.

[wavewizards]

Ok so I have found this power supply slightly higher on amps but a lot higher on volts would this be more suited to my needs


Specifications:

Wattage 600 Watts Fan Cooled

Input Voltage 240V AC

Output Voltage 48V DC

Output Current 12 Amps

[LeeWay]

I would say that is a good choice.
I have two of those that size. One on my router and the other on my Plasma cutter. All Nema 23's. I use 80 VDC supplies for all my Nema 34's, but they are all pretty large.