Retrofitting an old PEAR industrial CNC

I’ve been using this old PEAR CNC machine for many years now.

It was one of the first computer-controlled industrial CNC machines to be made available on the market and, in spite of its age, it’s still a valid tool for some kinds of mechanical prototype production.

Sadly, last winter the motion controller decided to lose all the parameters memorized in the RAM for the umpteenth time, and considering how much it would cost to have the controller repaired by the manufacturer, I decided it was time to renovate and upgrade the whole machine with our new cnc4fun elctronic boards.

New controller board by nc4fun
The new controller board with command panel boards
The original CNC circuitry
Early phases of disassembling

The original DC motors were quite old (almost 30 years) and not compatible with the new controller, so I decided to replace them with new brushless ones, which are  also much better in terms of performance.

I made new mounting flanges and some 3D-printed  cable adapters to fit the new motors to the existing motor compartments.

One of the old motors
Old mounting flange
One of the new motors
A 3D-printed adapter
New mounting flange
A new motor ready for mounting

First tests on the motors

3D printing of an adapter

I only had a basic schematic diagram of the original CNC machine, which was not very detailed: due to this, I had to do an accurate “scavenger hunt” of the connection in order to understand how to rewire the machine with the new electronic boards and motors.

Part of the original cabling
Part of the original cabling

The original motion controller and the original drives were mounted inside two separate chassis. I replaced the two old chassis with my own simplified one, which supports all the new electronics.

Original boards and chassis
Original boards and chassis
Chassis for the new boards
New boards and chassis

After all these mechanical and dimensional adaptations, the time has finally come to install and rewire all the new hardware to the CNC.

Cabling the new electronics
Cabling the new electronics
New finished cabling
The electrical cabinet is now tidier

The cnc4fun boards also include a new powerful user control panel, which is housed in a UV-printed custom-made laser cut box.

Testing the cnc4fun user control panel
cnc4fun control pendant
The finished control panel
Testing the control station

Testing the control interface

Testing the control interface

The PEAR CNC retrofit and upgrade is complete with the addition of a new zeroing sensor!

Zeroing sensor
New axis-limit switch

Testing the zeroing sensor

Testing the tool measure sensor and procedure

The CNC retrofitting is now complete!
DIY tool carrier!
I also added brushes to prevent chips from entering the cnc

Testing the movements

Mist command

Testing the movements

Testing the tool changer

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