Building a CNC - Y-Axis - part 3

Yesterday, I started mounting the Y-axis ball bearing transmission to the arm.
First I had to deal with the transmission block vs stepper motor shaft difference of heights.

To address this situation I used an 0,80€ pencil rubber that I sliced to act as anti vibration pads beneath the linear transmission blocks. It's cheap and it does the job well. I'm hoping it will help me cope with the noise caused by the vibration of the steppers running, against the steel structure.

Next I made a steel plate that will act has the stepper mount plate, and weld it against the arm.

But when I mounting the arm in the CNC cage ...WTFFFF...
The ball bearing thread hits the linear rail of the Z carriage.
Fortunately I only made alignment welds. I had to cut them put the rails of the Y arm higher and re-weld them into place.

Has you can see there is now a very small gap between the Z-rail and the Y-thread, but I should suffice.

To be continued...

Building a CNC - Y-Axis - part 2

Here is an update of my CNC building.
Has I stated before I'm doing this in my lunch break. This resumes to 30 min. a day. It's starting to feel more like never ending story... :-P


The second arm (Y-axis) is in place and painted (don't mind the onions on the table....:-P)

CNC with X and Y axis arms mounted

If you remember part 5 of this build, you will notice that this arm is some parts short (the smaller 4x 10cm tubes). Initially I welded them, but if you remember by sketch these were not planed. Because of that if I make de Y-axis in the same manner I did the X-axis the bearing thread system + Stepper will not fit.
So I had to un-weld the hole thing. Even without these, the space to fit these components is very very tight. Let's see if I don't have to do any more changes.

This is the Z-axis linear guide bed mount (the start of it at least). This is actually the second one. I'm building this in the dark (it's all in my head. I've not sketched this or made any pre-measures). Because of the way the bearings and the metal sheet is welded the tube with the off-center holes is the one to be welded. Not the other way around. This is to avoid contact between the bearing and the metal sheet.

Z-axis linear guide bed mount build

It would be best if I just pre draw all in Sketchup to see if it fits. And I probably will. Other wise I will make a lot of mistakes in the way. We will see how it goes.

Fingers crossed...

SketchUp 3D to GCode plugin

Since the CNC build is very slow due to the lack of time to do any real iron working I've turned into an old quest that was still pending.

A year or so ago I started experimenting with the SketchUp API to have some fun and learn something new.
I've never programmed with Ruby before but my C and C# experience made it pretty easy to learn it in no time.
Then I came to an idea. Make a plugin to convert a SketchUp model directly to GCode.
I debated for a couple of months on the API classes to try to see how I would pull this off. Other things came and I put this project aside.
Early this week I decided to pick this up again. After some intense brainstorming to my self I came with an idea that seemed to work. And it did but the process do scan the model involved boolean operations on SketchUp solids (a hole bunch of them actually) and that is a performance killer.
When I increased resolution SketchUp would stall.

NOOOOO... I found a solution and it was too slow. But then the math concepts I learn in high school came to my head and BAZINGA...

Yeah baby...
What I'm showing here are the results of my SketchUp to GCode converter plugin.

This is in a pre-alpha stage right now, so I'm not going to go in to much detail about this, but I can tell you that it works... :-D

Here are a couple of examples (SketchUp model vs NCPlot- this displays the GCode)

SketchUp model	GCode plot
Example 1	Generated GCode - Dual pass mode
Example 2	Generated GCode - Single pass mode

With some small adaptations this can be used to produce plastic printing GCode too.
I'm developing some more features on this.

Stay tuned...