Author Topic: CNC Adventure  (Read 2780 times)

Daggers

  • Guest
Re: CNC Adventure
« Reply #15 on: November 27, 2020, 07:44:46 PM »
I hope this information helps any one who like me knows little about the cnc process.
I have spent the last couple of days looking at software both for the cnc machine and also software for preparing  and sending the manufacturing data.
First the machine.
Two pieces of software are required, the firmware that controls the movement of the machine and is specific to the model of the machine, this was preloaded. The second is the software that interprets the code that represents item being machined (gerber). The machine comes with a disc containing an executable file for the download of gerber and also does contain the firmware should it be needed to be reloaded. Other software was contained on the disc for controlling the item requiring machining but i did not use these programs.
After looking at various control programs I settled on a freeware program GrblGru. This takes a 2D dxf input which can then be manipulated into a 2.5D model. It also has the advantage of having a full 3D model of my machine that can be used for simulation.
The machining can then be simulated on screen, including a full 3D rendered image of the final machining. Then the software can control the actual machining in real time.
My first attempts, produced today, are shown below.
The next post will contain some of the problems encountered on the way.
P.S the extra lines on the image are all my own work.

Daggers

  • Guest
Re: CNC Adventure
« Reply #16 on: November 28, 2020, 02:31:42 PM »

Just a couple of notes following on from previous post, the material being used for the tests is a soft twin layer engraving plastic and a 3mm engraving D bit. Cheap ebay purchases which i will use until confident on the process, then move to alloy/milling cutters.
The main problem i encountered was a sudden drop of data to the machine. This resulted in either halting the machining or just missing lines to be engraved.
Looking on the net it seems that engraving motor noise corrupting the signals to the steppers can be a problem.
So i rotated the board 180deg on the back of the machine, this enabled me to route the motor wire away from all stepper wires. The length of the motor wire was three times the length required, therefore this will be shortened. The rerouted wire seems to have solved the problem, we will see.
The depth of cut, for me, has been the most difficult to gauge, as you can see from the image on the previous post. The control software(GrblGru) allows you to set a total depth and incremental depths/passes. I tended to go too deep at first causing the cutter to dig in. After some further tests I have started to get some decent results.
The grbl version supplied on the board has been updated to the latest version. This was downloaded from the web and loaded using a program supplied on the machine CD(xloader). This update is required by some third party software.
Now moving on to some slightly more complicated dxf files.
GrblGru screen image shown below.
Great fun, keep safe.