Could someone recommend a setup please for G540?

[eddie3000]

I am a complete newbie, and I would like to here your opinions and recommendations for setting up my g540.
I received my gecko g540 a week ago or so, and I have 57BYGH78-401A motors. They are rated at 2.8A, so I put a 2k7ohm current limit resistor. The motors get too hot IMO, I have measured about 75ºC after a quarter of an hour period of constant operation. Would changing the resistor to 2K reduce the heat? Is it a good idea?
Keling sold me a 48V 7.8A power supply, they said it was perfect for the g540. I don't know, but isn't it a little tight?
Another doubt I have is regarding the use of the 4 inputs and two outputs. I want to have homing switches on all 4 axis. So I guess that already uses up four inputs. If I wanted to use limit swithes independent from the home switches, would it be a good idea to have work in serial together with the e-stop?
At the moment I don't have a proper spindle, I am using a normal hand mini-drill with manual speed control. The only thing I can think of is using one output to activate a relay to turn it on or off, but I can't think of anything to regulate the speed other than manually. Any ideas?
Is an extra parallel port worth it for extra ins and outs?
There are so many possibilities that I don't know what is best. I would like to hear your opinions on what setup is better or safer or cheaper or whatever. For your info, I am a hobbyist, not a pro, and I'm just doing this for fun. Thanks!

[rowbare]

Stepper motors tend to run hot, most are designed to run up to at least 90C.

They will run cooler if you reduce the current but you will also be derating your motor by about 30%. If you are over-powered you might get away with it but that only means that you should have chosen smaller motors to begin with.

What is the inductance of these motors? I can't find any information on them.

bob

[bobsch]

Did you put the current resistors at the G540 end of the cable? It makes a big difference in heat.