Thursday, October 3, 2013

Refurbishing an old ISEL X-/Y-/Z-Axis Machine

I bought from the company i'm working for an old 3-Axis Table made by ISEL.
The sold the tool because the Controller was incompatible to the new PC equipment.

I replaced the old linear motors by NEMA 23 stepper motors.

 


To drive the stepper motors i decided to order a cheap (china) TB6560 controller from ebay.

Here is a photo of the controller:



It has a kepad to move all axis manually and a coordinate display which can be calibrated to the steps/mm of the axis. This can be done for each axis seperately, which was good because my Z-axis has twice the steps/mm as the X- and Y-axis.

The controller is cheap but has some drawbacks, USB isn't working the onboard voltage regulators tend to overheat.

Modifications/Improvements of the CNC controller:


Voltage regulator overheatig

The controller has an aluminium housing why don't they use it as heatsink?
I drilled a 6.5mm hole in the housing whre the voltage regulators are placed. The regulators are placed on a very small metal block which has no thermal connection to the housing. I further drilled a hole into this block and cut a thread into it. Now it is possible to screw the haetsink of the two regulators to the aluminium housing.

 

USB is not working

so i have to use my LPT port... BUT my PC has no LPT port anymore. What to do now? I decided to do my own USB controller. It is based on a Atmel ATmega328 and it is running the famous GRBL firmware. This has several benefits. The first is, that i will have USB on the machine, the second is that GRBL is caring for the timings and the PC. So the timing between PC and milling machine becomes uncritical.

Empty PCB


The PCB fits into the widely available TEKO 10014 housing.

TEKO 10014 (Source: Teko Website)

Populated PCB



Next tasks add spindle and spindle.

If you are interested in more details or the PCB shown contact me.