Bio Dynamic 500 Mixer

Our mixing machine for BD 500 burnt out its motor last year.

BD 500 Mixer

We had a spare few motors just lying around. Some were well used items retrieved from a defunct dairy and one was the motor on our 1920's reconstituted milking machine. The milking machine has remained idle for nearly 20 years since we stopped breeding. It has a very good motor bought especially for the job and expensive.

Well it was time to bite the bullet and get the mixer functioning for next week.

At first I examined the old dairy motors to see if any were strong enough for this job. There was one that looked reasonable but the support brackets were badly rusted. An hour or two later the casing brackets were replaced with those from another motor. But the testing showed the motor was still not as good as preferred.

The non functioning motor

Some cut and shunt spares

And so it was a trip down to our hayshed where we had set up the milking machine and the newer motor was removed.

The biggest problem is the wiring. Not as simple as two wires. There are 5 wires to connect. One of which is Earth. That leaves 4. The complication is because the mixer turns one way creating a vortex and then stops and turns the other creating chaos.

Examining the connections

I was thinking that it would be as simple as lining up the wires on the old motor with the wires on the new. But not so. The new motor has a completely different setup. Well at least it looks completely different. I know from vague memories a theory that the basic operation is the same and that it just looks different.

The replacement motor

There was a small hope that the internet may supply some answers. Lots of forums on motors and reversing etc. but nothing that gave me any viable solution.

I set up a test bed near the mixer with electrical power and ran a series of tests. It was easy to make the motor go one way or the other but how to make it change direction using the mixer?

After lots of playing and thinking I eventually tried a test that worked. Who needs Sudoku or Crossword Puzzles. After installing the motor and testing the forward and backward operation I called it quits. Will test the mixer under full load next week. Oh and I also gave all the bearings a grease.