Originally Posted by posix I don't know what I like better, burning my finger on the driver board or burning my finger on the motor. Which do you prefer?
P.S. it seems that once I switched to a chopper driver all that heat that used to be on linisteppers just transferred to motors themselves!  |
FINALLY! 
I'm very happy to see that someone else has finally compared the linistepper drivers to a chopper driver and shown what we have been saying all along is true: The heat comes out somewhere! Motors or drivers, you pick.
And, yes, it is easier to add heat sinks at the driver, and the motors will perform better, but also, the motors are generally more expensive to replace.
The reason why the motors are stalling and running slower on the chopper is that they are hot, and heat reduces the strength of the magnetic fields in the motor. Have you seen those science demonstrations where the flame heating the magnet causes it to loose its field? And over time, with enough heat, magnets permanently loose their field.
Heat isn't good for mechanics either. Running hot like that will certainly increase the rate of wear on the motors bearings and can possible speed the breakdown of the resin holding the motor windings together.
A chopper driver sales person would tell you that you need a bigger and/or different motor, and you probably do, but with a linear driver, you can use a smaller / older / cheaper motor and get the same or better performance.
For a larger application, the lini just couldn't manage it and bigger motors with a better chopper driver (more filtering of the output waveform) would be required. But in the Hobby CNC arena, given the size of machines we are driving and the loads we need to move, a cheap old unipolar motor and the low cost Linistepper kit (with GREAT BIG HEATSINKS) is a good solution.
Linistepper vs the Choppers:
02-24-2006, 03:44 PM
Linear Mode
