CATERPILLAR 390D LME 1:8

[Timberjack3000]

Hello everyone



today I'll introduce you to my new drive system. After the conversion to brushless motors was quite disappointing, I decided to use brushed motors again. In terms of power, my first drive (brushed motors from Servonaut) was very good. Even the steep ramp up to the workbench wasn't a problem.

Now I have brushed motors from Dunker again. Namely the GR63x55 in the 12V version. I built a planetary gear in I = 3 directly on the motor. This is from ZD and runs really very easily and precisely with a very high degree of efficiency. After the planetary gear there is a worm gear with I = 7. On the one hand there is the 90 ° deflection and on the other hand it is self-locking. This means that I can simply park the excavator in any inclined position. After the worm gear, there is a 1: 2 reduction by means of spur gears. Then the wave goes "outside". Then you go to the Turas by means of a large link chain and I: 2.8. Thus the overall ratio is I = 117.6. Thanks to the enormously powerful Dunker motor with a nominal speed of 3000 rpm, the speed is now also suitable.

But what was the biggest point for me for this renewed conversion is the sensitivity of the drive under load. This was not possible with the brushless motors. And it is extremely important to be able to drive off very sensitively, especially on a steep ramp. The controller from Beier Electronics fits perfectly with these 12V brushed motors from Dunker. Approx. 35 to 40A are drawn under high load. The regulator can briefly up to 60A. Another nice side effect is that the controller hardly heats up and does not make any annoying noises like the brushless controller.

What was certainly very unfavorable for controlling the brushless motors is the electrical rotary feedthrough. Due to the long supply lines and the additional contact point at the rotary feedthrough, the controller cannot accurately determine the correct position of the motor and thus cannot optimally control the rotary field. This is completely irrelevant with the brushed motors.

So much for the background. Of course, I also made a new video. Have fun watching.


https://youtu.be/F8R2Vs81bI8