Hello everyone im new to this forum and would like to share my recent plasma table build. Im using a HF start plasma CUT70H and i have seen alot of people having problems getting this systems to run smoothly due to high RF/HF noise from the plasma.
But i have sucessfully built a system running this with no interferance problems at all. Basicly im using cheap chinese components and a normal consumer PC.
So this is basicly to help anyone having issues with cheap HF plasma systems. It is possible to get it to work! Just needs some planning when setting up the system.
Components:
- CW5045 x 4 Drivers
- 270oz 23hs8430 nema23 Motors x 4
- Simple 5 axis breakout board (Parallel)
- Openbuilds OX 1000 x 750 mm table
- Trafimet A141 Torch
- Compact THC 150
- Homemade water bed
- Mach3
- SheetCAM
- Draftsight (CAD)
First when i ran the system after assembly hell broke loose... I had all sorts of random problems, Computer BSOD, Motors moving around without input, Keyboard/mouse stopped working, Mach3 randomly stopped middle of cut etc etc..
What i did first was to drive a earth rod as close to the machine as i could, this was just a regular steel pipe that i drove about 1m into the ground with a slagehammer in my case it's about 3 meters from the machine then i bolted a 15mm3 cable to that and screwed it on a copper bar on the machine, then basicly earthed everything to that copper bar with separate earth cables for each component of the machine. What i earthed was:
- Gantry
- Torch carriage ( Z axis )
- Machine bed
- Water bed
- Computer chassis
- Plasma cutter chassis
After this it was noticibly better but still had signal issues, So i used shielded cables for the Stepper motors, Switches and grounded them in the machine ( Only on one side do not ground the end at control box! ), Also shielded cables to the THC, Parallel cable.. well basicly all cables should be shielded and grounded at one end. But still had strange issues with the Stepper drivers making the motors move by thier own when the HF came on, so i clamped Ferrites on all cables and also wond all stepper cables and signal cables 2 turns ferrite core rings this eliminated the signal issues wich made the motors move randomly. Also power cables to computer and SMPS to drivers where wond in ferrite cores (Around 3-4 turns) After this the system has no interferance issues at all! all it took was basicly some earth cables and some ferrite rings and some cable management not an expensive fix if you ask me. (the plasma source and driver electronics and PC is now max 1.5m apart and works flawlessly)
Hope this can help someone thats building a similar system.
Best regards.
