Vario BF 20 mill DC motor to 3 phase motor conversion

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HMEM Supporting Member
Jul 1, 2012
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Hello friends.
Maybe somebody finds this thread interesting.
So I have bought this mill brand new 2.5 years ago.
Before 3 weeks during milling process I heard loud bang in the electronic
box and my dear mill machine was death.
I have found electronic board burned and interrupted DC motor winding.
Some owners of this mill claim on internet forums that
they burned 3 motors what I consider as too expensive
so i have decided to go for SIEMENS 450 W 3 phase brushless motor.
Conversion was really easy to do //4 new holes to the motor hub,
and motor shaft diameter cut from 12 mm to 10 mm for first
gear wheel // .
I decided for speed controller VIBO E550 standard with 1 phase input 230 V and detachable key board // very practical thing //.
This controller offers a lot of parameters to set up but for me is important
only soft start/stop function and torque adjustment plus internal cooling fan.
Controller has in built 24V DC source that can be connected to the orginal RPM meter.
All hardware is accommodate in plastic box HAMMOND RL 6685
Pictures show more.


Nice! Most of the mainline Chinese motors are known to be crap, barely capable of running at rated levels. Many users have the same issues with imported machines here in the USA.

So how is the 450 watt motor working out for you? Being Siemens I'm hoping that is 450 watts actual output power. The suspicion is that you will be getting better performance.
Thank you guys
Wizard 69
Genuine China motor is labelled as 800W DC
Common 750W AC motors have quite big body for BF 20 mill.
So I have decided to buy 450 W motor //especially built into small
350 W motor casing // I found that only Siemens offers this special type of motor. But price is 100% higher than price of normal motor //80EUR//
Anyway I am not deep chips maker but it seems to me that mill now has the same power as it had with DC motor.
Maybe wide range of digital torque from controller does good job.

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