Newbie looking at 6040 (China CNC) for polypropylene 15mm sheet

**Zeeflyboy** · 05-10-2017

I'm afraid I don't use the same motion controller as you, nor do I use Mach3 anymore... but it should be fairly straight forwards.

Hook it up to the same point that the normal probe goes to, but you just need to go to the ports and pins part to invert the signal mach is looking for as it's a normally closed circuit vs normally open. If you flip over to the diagnostics page of mach you should then be able to see the probe input trigger as you press on the probe tip.

It is definitely worth spending a couple of minutes dialing in the probe tip using a dial indicator before each use - the runout of the spindle/collets results in me getting anything up to around 0.1mm of runout all the way down at the tip which will affect any probing results. Within a couple of minutes of careful tweaking I can get that down to less than 0.01mm

As for probing on mach3 - I've never done it. I think there were some screen sets for mach3 that have probing built in, or you could write a small macro to do it (or use someone else's) but the info is out there if you have a look. Mach4 makes things quite simple with a dedicated probing section built in so I've never had to figure anything out in that regard.

**JOGARA** · 05-10-2017

Originally Posted by Zeeflyboy

I'm afraid I don't use the same motion controller as you, nor do I use Mach3 anymore... but it should be fairly straight forwards.

Hook it up to the same point that the normal probe goes to, but you just need to go to the ports and pins part to invert the signal mach is looking for as it's a normally closed circuit vs normally open. If you flip over to the diagnostics page of mach you should then be able to see the probe input trigger as you press on the probe tip.

It is definitely worth spending a couple of minutes dialing in the probe tip using a dial indicator before each use - the runout of the spindle/collets results in me getting anything up to around 0.1mm of runout all the way down at the tip which will affect any probing results. Within a couple of minutes of careful tweaking I can get that down to less than 0.01mm

As for probing on mach3 - I've never done it. I think there were some screen sets for mach3 that have probing built in, or you could write a small macro to do it (or use someone else's) but the info is out there if you have a look. Mach4 makes things quite simple with a dedicated probing section built in so I've never had to figure anything out in that regard.

Thanks for the info. The probe does look a tad off from stock. I forgot to get a dial indicator >.<

Trying out the ProbeIt plugin that creates a wizard to probe. It has tools like auto calibrate. Uses a known diameter though and I don't know if I got anything for that :/
Trying to think what I can get that is large enough but not going to break the bank...

**Zeeflyboy** · 05-10-2017

in reality you probably don't need to calibrate it.... if probing the inside of a hole for example, everything is relative so you will still find centre of the hole even if the measured dimensions were off.

Calibration is more of interest if you were measuring things for verification purposes.

**JOGARA** · 16-10-2017

0.03mm is the best I have gotten so far.
Finding it quite hard to get it any closer :/

Is there a way to get Mach3 to move a single step? 0.01mm is a couple steps on the stepper from the looks of it.
And how accurate is the mm readout in the interface? I would rather it move to the nearest 0.01mm rather than this...

**JOGARA** · 17-10-2017

So I just used the probe and by hand found the center of one of the button holes in my case.
Was then able to chamfer the edges.
Not bad, not great. Was a hair out on the Y. X was perfect.

I just added 0.025mm to the Y and it is near perfect.
So Zeeflyboy your method works... :p

The real test would be machining around my part top and bottom now with out much, if any step in the surface finish once flipped and had the same operation done.

I guess the best way to do the flip is to leave 0.0something on the bottom of my stock and then flip, then remove that last 0.0something and chamfer...?

**Snapper** · 18-10-2017

Originally Posted by JOGARA

So I just used the probe and by hand found the center of one of the button holes in my case.
Was then able to chamfer the edges.
Not bad, not great. Was a hair out on the Y. X was perfect.

I just added 0.025mm to the Y and it is near perfect.
So Zeeflyboy your method works... :p

The real test would be machining around my part top and bottom now with out much, if any step in the surface finish once flipped and had the same operation done.

I guess the best way to do the flip is to leave 0.0something on the bottom of my stock and then flip, then remove that last 0.0something and chamfer...?

How deep is your case to cut in one pass? I don't think you will ever get this machine to flip a part and cut from both sides without leaving a step, but you should be able to make it small enough to sand and polish out.

Just to give an idea of the machines repeatability I zeroed in on the reamed hole mentioned above, moved my coordinate system over to the vice, milled out a part that was ~1hr machining time, came back to the reamed hole and it was 0.045mm out in Y and 0.02mm out in X.

You should be able to get the results you're after without probing everything. If this is something you're going to be making multiples of it would be well worth your time in making a proper jig.

**JOGARA** · 18-10-2017

Originally Posted by Snapper

How deep is your case to cut in one pass? I don't think you will ever get this machine to flip a part and cut from both sides without leaving a step, but you should be able to make it small enough to sand and polish out.

Just to give an idea of the machines repeatability I zeroed in on the reamed hole mentioned above, moved my coordinate system over to the vice, milled out a part that was ~1hr machining time, came back to the reamed hole and it was 0.045mm out in Y and 0.02mm out in X.

You should be able to get the results you're after without probing everything. If this is something you're going to be making multiples of it would be well worth your time in making a proper jig.

I have worked out that I don't need to do the flip on the outside.
I will just use the super glue method to stick my stock onto some sacrificial that I can reuse.
Adds a bit of work removing the glue but it has worked since day 1.

Flipping the part and milling the rest would have meant not spending time on that but it works, don't fix it.

At the moment I can make 2 cases at once. I'd rather not go beyond that as it is more setup and I just need to start making these things now.
Can't spend any more time trying to make it better for batch production...

I have got it to around 3 hours total per pair of cases (not including the rear of the case, though a pair of those are 30 mins.
I can probably get it down 10 mins just with less cautious lead in and lead out distances.
Most of the time is spent with my 6mm roughing bit. That takes out 95% of the material and totals nearly 2 hours of 3.
I have found that I can cut 2mm depth quite well at 75% of the feed it is currently doing (currently 1mm DOC) with my 6mm rougher, so putting adjusting that will result in less time too. Not much but another 10 mins off.

In total I a have 100 of 2 different case designs to make. At this rate I can make around 6 every day.
But for vast majority of that time I will be working on other things (tumblring, PCBs, Anodising, Finishing etc) while keeping an ear on it so it is not that bad.

**Snapper** · 18-10-2017

Just looked back through the thread for pics. I have a suggestion.

First, it looks like your buying custom cut plates? If so, order them cut to size, they always come cut slightly oversize, so rather than milling all that away from the edges, you would just be trimming a mm or so off each side saving you in both material costs and machining time.

Second, you could make a fixture plate for accurate location after flipping. Carry on machining out the guts inside on your vice, in the pic below the three holes circled you could drill out .1mm undersize, hand ream them to size, then use dowel pins in these holes to locate into the fixture plate. These dowels will also pretty much hold the part in X and Y, with a bolt through one of the big square holes and a large washer just to keep everything dead still. Then you can profile round the edge and chamfer or radius your top edges. When it comes to do the square hole which you have a bolt through, just have a pause in your toolpath and move the bolt over to a different hole. This would then also give you the ability to pull a case off and put a new one on without having to rezero, you could also run a toolpath on all your cases in a row, saving you the need to keep changing tools. If you have more than a couple of these cases to make, it would be well worth the price of a 10mm slab of ali and the hour or so it takes to draw up, machine and fix in place. And also far preferable to dealing with super glue.

(Ok it won't let me upload a pic for some reason, but there's only three holes I can see so you should get the idea)

**JOGARA** · 23-10-2017

So I finally got that grounding issue message. Guessing I just ground the spindle with the box of the controller?

**JOGARA** · 12-11-2017

Having some trouble with Fusion and I have no idea what is going wrong.

For some reason my heights are all over the place and is taking away too much stock on the Z.

Here is part of my case, in RED is what it is meant to be, and in BLUE is what I am getting (using my cheap caliper but it is pretty close to accurate).

I am using 3D adaptive clearing for the inside of the case, I set the bottom of the operation on the face of my part at the bottom. This is 2.5mm above the bottom of the stock (I have just switched to +2.5mm bottom stock instead of face selection). I then have another 3D adaptive to clear out the holes at the bottom of the case (I do this because I leave stock and then clean it up using a 3mm carbide).

Both operations are the same, just different heights and stock to leave.

(All my heights are .0mm or .5mm I don't have any heights that are .1mm other than telling it to go 0.2mm lower than the stock bottom for clearance reasons later in the setup)

Any ideas?