Web Goblin cnc has begun

[Web Goblin]

It makes more sense looking at the cad screen.
Like I say it might just be me. All the machine I have worked on always have the x axis as the rail and they all home , the ones that do home anyway, at the bottom left and some of them home at both sides left and right in they have two carraiges. I am getting used to it, I just have to remember thats it not a profiling machine:confused:

Ian

[Web Goblin]

Jazzcnc,
I dont know about Mach but USBCNC can be configured for turning.

Ian

[Web Goblin]

I decided that I wanted to see the display on my inverter so that I could get a basic idea of the spindle speed.
I removed the front cover from the inverter and found that the display box could be removed. As the photo below shows tha display box is connected by a 10 way ribbon cable.


I made and fitted a new cable, 10 way flat ribbon ran inside some shielding then covered in heatshrink.



Cut out the box lid and fitted the display unit.




Fitted the speed control pot and an emergency stop button and connected everything up.


Power on and test.

All seems ok.

Regards

Ian

[JAZZCNC]

I like to see my VFD screen but not for speed.?

I have it set to show current being drawn this shows me the load on spindle this way I can see when the tool is getting worn. Also good for gage to show material hardness, esp usefull with shity ALi that has soft or hard spots.! . . Also tells me If I'm being greedy on the DOC.!

[Jonathan]

Everything Jazz just said... I almost invariably leave mine reading current. Especially on the lathe as there it's actually possible to hit the current limit, though I don't cut that fast often :naughty:
I mounted my VFD on the ceiling above the lathe so it's easy to read and accessible which is handy when thread-cutting.

How long is the ribbon cable? Good to see that the signals made it that far.

[Web Goblin]

I might well change the display to current later on. At the moment I am still taking it easy with depth of cut and feed speeds till I get used to what I can get away with.
Jazz, I know what you mean about Ali. You can hear the change in the tone of the cutter when you get a change in the material. We also get it alot when cutting mild steel on the laser at work. The cut quality will be really good then it will go crap for a while when we hit a bit of crap steel. Sometimes it can be right down one edge of a plate. Makes the operators think the beam alignment has gone out.
Jonathan, the ribbon cable is around 2.5mts in length at the moment. This might get shortened a bit when I decide where I am going to mount the box.

[andrewbond]

Hi,

I know I'm a bit late coming back with this but..

Just curious, did you use a brake resistor on your high power drives?

Andrew

[Jonathan]

Just curious, did you use a brake resistor on your high power drives?

Brake resistor allows the VFD to stop the motor faster ... increases the deceleration.
Sounds good at first, but really since the spindle stops in about a second without one, and my lathe will stop on the VFD in 2.5s without a brake resistor I really don't see the point. You're just stressing the motor more by putting a much bigger force on it during deceleration. Or if it's on a lathe the gears/keyways in between will wear faster.
The only exception to this is for an emergency stop where you want the spindle/motor to stop as fast as possible.

[Web Goblin]

Andrew,
no brake resistor. I just let the spindle slow down as normal.

Ian

[andrewbond]

I meant the resistor terminal on the stepper driver?

Andrew