Electronics for New Machine + Chinese Spindle + VFD

[mturneruk]

Thanks Chaps.

Jazz I have home switches. Prox sensors.
UCCNC is very similar to Mach, just without so many bells and whistles.

In the past I have been plunging into my workpiece at Job 0,0 to make a point so if I lost position for what ever reason, i could manually by eye line up again.
Not very accurate and not very satisfactory.

Just reading the UCCNC manual and yes there is a way to save offsets, something I haven't ever really understood.
In fact its a single button press to "Offset Current Position". I will test, but I assume this saves the current position as a job Zero point relative to the machine co-ordinates.

One thing I was very happy with is that after two hours of running, the machine went back to the zero point and it looked exactly right.
The machine co-ordinates were also exactly as they were when I started. So accuracy is looking good.

I will at some point put a homing switch on my A axis as well to ensure my gantry is square.

One thing I have just decided is that there is no business in 3d machining wooden stuff. It takes so long!
I have been making a complex mirror frame and it has taken me all week. Each side of the frame took 3 hours machining.
Something tells me that 3d machining is also very hard on the machine as all 4 motors are working flat out for long periods.

Back to the drawing board on the business front.
Do either of you guys know of people making stuff and making it pay ?
I guess you have to find a niche.

Thanks
Martin

[JAZZCNC]

Just reading the UCCNC manual and yes there is a way to save offsets, something I haven't ever really understood.
In fact its a single button press to "Offset Current Position". I will test, but I assume this saves the current position as a job Zero point relative to the machine co-ordinates.

Yes I know that's why I said it. I do have UCCNC but don't use it. Mainly because there boards are USB not because the software isn't any good. It's Ok software but a little basic for me.

OFFSET's are easy really.! You just have to get your head around the fact you have 2 Coordinate systems. MACHINE & WORK.
WORK coordinates are variable and you can define ZERO anywhere on your machine bed.
MACHINE coordinates are FIXED and never change. Only way they can change is you move the HOME Switch.

WORK ZERO or correctly termed WORK OFFSET is just an OFFSET distance from the FIXED Machine ZERO Position. Save this OFFSET distance and you can always accurately get back into position by Homing the Machine and then sending to WORK ZERO.

Now where it can get a little Tricky is the Fact you can have Multiple WORK OFFSETS each having it's own unique ZERO Position. This is done using Special OFFSET G-codes G54, G55, G56 etc upto the limit of the controller.
By default you are proably using G54 so never really are aware of the fact and by default your CAM software will be using G54 offset.

But lets say you wanted to cut 3 different jobs in 3 differant materials using same tool. First place each material on the bed and define Zero and save the offset for that material using one of the WORK OFFSET's codes.
Then what you can do is produce individual G-code for each part. Then copy & paste into one Large file. At the start of each Job you enter the OFFSET code you have setup in advance. ie job #1=G54 #2=G55 #3=G56

Now when the code runs after first job it goes to next WORK OFFSET and starts again from the new Zero.

Try it using the MDI. First go to OFFSETs and enter different values in G54 and G55. Make sure machine is away from any of the coordinates you typed. Now Enter G54 G0 X0Y0 and it should go to that posiiton and DRO's will display ZERO's. Now type G55 G0X0 Y0 and it go to that position and the DRO's will read Zero's.!

Do either of you guys know of people making stuff and making it pay ?
I guess you have to find a niche.

Yes I know many but Can't tell you what they do because of client confidentiality.!!. . . . . Well I could but then I'd have to Elimnate you.!! . .
Your right thou most are Niche markets and they earn well from them.!

[mturneruk]

Got it. Thanks Jazz.

X and Y are cool. For me now it's just the Z that changes after each tool change.
Have you got an automatic tool change system - Is that another ball game ?
Where would i start with that ?



I am (EDIT:: reasonably) pleased with this, but it took me a whole week to design and make. Hence the 1/2 million lines of gcode and 9 Hrs + machining.
Onto the next idea...
Do you think i could make these out of moulds using the CNC to make a plug?

Cheers
Martin

[JAZZCNC]

Have you got an automatic tool change system - Is that another ball game ?
Where would i start with that ?

You start by taking out a Mortage and or selling the Wife. Then yes it's all new ball game. Not massively difficult but expensive and will require some coding or Macro writing. This is one of the reasons why UCCNC is restrictive because you can't easily take full control for things like ATC.

I am pleased with this, but it took me a whole week to make. 9 Hrs + machining.

Looks very nice but 9hrs is nothing for 3D work. I've got people who makes things that take 12-18hrs minimum with Millions lines of code and are only 200x100 rectangles. I cut 6ft sq mural made in 4 pieces for school wall that each piece took 22hrs and ran continous.

As you get more experienced you'll be surprsied how much you can fetch Cycle times down. If your doing 3D jobs it's worth Re-tuning your motors biased towards acceleration rather than velocity. It will bring cycle times down considerably.

[mturneruk]

I was increasing my acceleration and velocity as I went along. Bit at a time.
What i noticed was that the Z axis was the limiting factor, so i increased it, and then obviously my job completed faster, but I felt sorry for my machine. Everything was very warm. Spindle, steppers etc.
Not boiling though, but very warm.

Also I only have one 3mm ball nose bit and i didn't want to break it. I roughed with a 6mm ball 2.5mm stepover, 5mm DOC and then finished with a 3mm ball with a step over of 0.75mm.
Forgetting the design I did, what is the optimum tool size / Stepover for this kind of thing?

Something tells me it's better to design something that allows you to use a bigger tool.

[mturneruk]

One other thing was that the amount of clean up I had to do was a significant pain in the ass. I wondered if running the spindle faster or slower might reduce that. I tried a range of speeds, but settled on about 15000 as it sounded nice.

[mturneruk]

PS. Can't sell the wife, she looks after the kids while i'm CNC'ing.