This is a shot of my cnc control board with a capacitor burned out. Cheap Chinese stuff so I'm not surprised. It's off a 3018 machine but there are others that use the same board. Can someone help identify for replacement. The cap is across the barrel jack dc out at 24v switched by the relay to the right. Everything was running fine, tried out the spindle with a couple of cuts with no problems - until I installed limit switches. The control board has pins for 6 switches but I paired up each axis to save some time on soldering pesky little headers.
So I tried out the limit switches on the cnc with the homing command an to my amazement, first time round - worked like a charm.
Then went back to try out the spindle again but as soon as it was enabled it would trip a limit.
Now I have learned that unshielded cable on cnc acts like an antenna, so after installing some 47nF caps on the limit signals still got trips from the spindle just like before (maybe add some pull ups too). So I tried the methodical approach and removed one by one until no limits were connected.
TBH I should have known better and install a diode across the spindle but I was hoping(without checking) that it would be taken care of either within the spindle or on the control board. How wrong you can be....
Another thing I hadn't done is ground the spindle case and also the machine itself, I doubt this would have changed anything but looks like a must in such applications.
there is 105 printed underneath the cap so does that represent something?
Anyway thanks for reading.
So I tried out the limit switches on the cnc with the homing command an to my amazement, first time round - worked like a charm.
Then went back to try out the spindle again but as soon as it was enabled it would trip a limit.
Now I have learned that unshielded cable on cnc acts like an antenna, so after installing some 47nF caps on the limit signals still got trips from the spindle just like before (maybe add some pull ups too). So I tried the methodical approach and removed one by one until no limits were connected.
TBH I should have known better and install a diode across the spindle but I was hoping(without checking) that it would be taken care of either within the spindle or on the control board. How wrong you can be....
Another thing I hadn't done is ground the spindle case and also the machine itself, I doubt this would have changed anything but looks like a must in such applications.
there is 105 printed underneath the cap so does that represent something?
Anyway thanks for reading.