Denford Microrouter V4

[andy_con]

restarted mach and they are now working.

the machine is working, still need a smooth a few things out but its working

[lucan07]

Its coming together that first cuts always the best

[andy_con]

another issue I have is when left on standby the stepper motors get very hot, to hot to touch. I took them down from 3.2amps to 2.8amps, they still get way to hot it just takes longer for them to heat up now

[lucan07]

Many drivers have sw4 on for half voltage I believe this is for standby mode only to solve that problem, but if they are touchable they are probably not to hot they are designed to run hot.

[andy_con]

If I leave my triac on over night the motors are stone cold the next day.

If I machine for an hour and half the motors are still stone cold, so just seems odd on the microrouter

[lucan07]

Likely the way the standby is accomplished, e.g. a PC can be sleeping completely monitoring a 3.3v micro current or running lots uf stuff in background and just turning screen & disks off.

[m_c]

Likely the way the standby is accomplished, e.g. a PC can be sleeping completely monitoring a 3.3v micro current or running lots uf stuff in background and just turning screen & disks off.

Lucan, that post just shows you've got little clue what you're talking about.

Denford are generally very conservative with their tuning. I've ran my little Novamill pretty much non-stop for 4 hours, and the motors only get warm. I suspect the conservative tuning, combined with being mounted to a relatively large lump of iron, means that they're not generating as much heat to begin with, and what heat is produced, is dissipated into a far larger lump of metal than a router.

I'm not aware of Denford using drivers that had reduced standby current, so I doubt that's why they remain as cool.

Why your router is running as hot, could be down to a few factors. Are you running a higher voltage supply? Are you running at a higher current setting than the original drivers?
Without going into specifics, a higher voltage essentially means the driver can force more current into the stepper motor when running at higher speeds (this is where your motor inductance figure comes into play), so the motor is producing more power and more heat.
A higher current setting will cause the motors to produce more power, and heat, while stationary and at speeds up to where the motor induction and driver power supply become the limiting factor as to how much current the driver can force through the motor.

So if you've increase either of those, then that's likely why things are running as hot.
From memory, I think it's acceptable to run steppers up to 80deg C, provided they're not getting that hot quickly i.e. it's fine as long as they take a couple of hours to get that hot. The big thing is that the iron core doesn't overheat to the point it demagnetises, as at that point the motor is only good for the scrap heap.