More upgrades on the BF20 CNC!

CNC, Other Projects / Sunday, November 1st, 2020

It passed quite some time from the day I upgraded the spindle of my cnc.
The day I installed the brushless motor with about the double of the original RPM I already knew that the original ball bearings wouldn’t last so much.

Well some months ago those ball bearings finally “gave up”.
I heard some bad noises coming out of the head while the motor was spinning but the cnc wasn’t milling anything and I immediately knew what I had to do.

I disassembled the motor and the I pulled out the original ball bearings from the structure of the milling machine.

I didn’t have the right extractor so I build myself one with a M10 threaded bar and a couple of scrap pieces I had around the lab.

After disassembling the two bigger ball bearings I had to remove the conical roller bearings on the quill. It was quite hard but with some other handmade tools I finally pulled them out.

And here they are in all their beauty after a good clean with gasoline. Even if they are not good anymore for the cnc I think they could be useful for other projects so… I’ll keep them.

So now that I had practically stripped down all the parts of the milling machine head I decided to give the machine a new life with a new paint job.

I started by cleaning and degreasing the head and then I grouted the small holes that I didn’t need with 2 components car body filler. I gave it a good sanding and then I masked all the parts that I had to protect from paint.

Then I repeated the same process on the white parts on the z axis column that I wanted to paint.

After three coats of paint this was the result. I decided to used hammered grey paint to give a more industrial look to the machine.

The new ball bearings that I had ordered had finally arrived and so I could start reassembling the head onto the column.

Inserting them was a bit easier than pulling out the old ones, but it gave me cold sweat anyway because there was always the risk of destroying a good new ball bearing if the wrong procedure was used. Anyway I used the same method with the M10 threaded bar to insert the ball bearings into their seats.

The quill roller bearings need a bit of lubrication before assembling them. So I used some lithium bearing grease.

And here it is the machine all in one piece.

Here you can see that the cnc spindle runout error was reduced to pratically zero.

A couple weeks after this upgrade I decided to finalize the enclosure of the milling machine.

In the previous years I had used plexyglass panels to keep water splashes from wetting all my lab.
But due to their fragility I decided to go with something a bit more reliable, so I took the measures of the tank and designed on the cad some panels.

Then I made them out of laser cut Aisi 304 stainless steel.

Since I had to lasercut some parts I decided to make a new front plate for my cnc to give it a good new look.

The installation of the panels was quite easy, I decided to drill the holes for the screws directly on the panels when I installed them so I wouldn’t incur into misalignment issues.

The harder part was to increase the length of the motors and sensor cables and organize them well.

I decided to use a derivation box and some cable glands to make an accessible point were I directed all the sensor cables.
There I soldered the common cables of the sensors (like ground etc).
and got out with only a “big” cable that contained 8 individual wires.

Some good old duct tape was a great way to fix the cables to the back of the machine panels 😛

Then I reconnected all the new wires to the cnc controller and the job was done.

Here’s the final result:

I hope you’ve enjoyed this article, if you have any questions just ask.
See you next time!

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