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

[Snapper]

I have the same machine. A couple of things. I have recently done a batch run like what you're wanting to do. I did it by marking my vice with a bit of white electrical tape and eyeballing the edge of the stock up to it, drilled all the holes with the same drill bit (smallest hole size, the larger holes I opened it manually with a cordless whilst the next part was on the machine) on the vice then moved them over to a fixture plate for profiling, located by two dowels after reaming two of the holes by hand, then ran the profile paths, chamfer, flip, chamfer.

If you are touching the home switches at any point, don't. They are lousy and will introduce anywhere between 0.04 to 0.32 error on each axis. The machine itself isn't so awfully bad at repeatability, there is a bit of backlash in mine but it ran the ops on all 6 of the parts I made without any major visual error. I chucked up my dti between each tool change and rezeroed off the reamed hole on my bed I use as a reference just to be sure but it was probably a waste of time.

To step jog, press tab on your keyboard in mach3 and you can change between continuous jog mode and step jog, and also change the step value. Spinning a dti in a reamed hole to find zero I use 0.01mm step and I'm normally back out the hole and putting a tool in within a minute.

Tool changing is the enemy. My z setter is nuts for some reason and will never give close to the same result twice so I've been z setting with a feeler gauge for awhile, takes a little longer but it's absolutely on point. Cleaning the spindle taper, spindle threads and collet nut between each tool change is also a real bastard (I've just ordered a second collet nut so I have one clean with the tool mounted ready to screw in). And also spend far too much time making sure I have the mist nozzles pointing in the right place.

[Zeeflyboy]

Tool changing is the enemy. My z setter is nuts for some reason and will never give close to the same result twice so I've been z setting with a feeler gauge for awhile, takes a little longer but it's absolutely on point. Cleaning the spindle taper, spindle threads and collet nut between each tool change is also a real bastard

I do something very similar these days - I have a reel of 0.01mm shim steel and I jog the tool up to just short of the z-zero surface, then jog in 0.01mm increments while sliding the shim material back and forth. Once it grabs you know you are 0.01mm above the surface and it works rather well for me.

Interesting point about cleaning between changes... Until relatively recently I never paid much heed to this and the amount of gunk that I managed to clean out of my spindle bore was eye opening. more than halved my runout by cleaning it out.... now every tool change I use compressed air to clean out the collets and bore, and usually a piece of oiled kitchen towel to wipe out the bore before then re-inserting the new collet if changing collet size.

[Snapper]

I do something very similar these days - I have a reel of 0.01mm shim steel and I jog the tool up to just short of the z-zero surface, then jog in 0.01mm increments while sliding the shim material back and forth. Once it grabs you know you are 0.01mm above the surface and it works rather well for me.

Interesting point about cleaning between changes... Until relatively recently I never paid much heed to this and the amount of gunk that I managed to clean out of my spindle bore was eye opening. more than halved my runout by cleaning it out.... now every tool change I use compressed air to clean out the collets and bore, and usually a piece of oiled kitchen towel to wipe out the bore before then re-inserting the new collet if changing collet size.

I use a thicker 0.55mm gauge purely because it's more solid so easier to keep straight and flat. I eyeball down then step jog back up until it fits under.

Yeah cleaning everything is absolutely paramount to getting a nice cut. Specially with alu, chips get in the slots in the collet and cause absolute carnage. I use isopropyl alocohol on paper towel. It's quite amazing just how much black comes off everything, even after a relatively short op. I have a piece which got scrapped anyway because I didn't realign the flip properly, but each side done using the same tool in the same collet in the same nut and the difference in surface finish between the two sides is incredible. The difference being when I first inserted the tool for the first side I forgot to clean everything up first. I will dig it out the scrap box tomorrow and upload a pic as it's a great example.

[Snapper]

Here's two pics from different angles. Again this was the same tool in the same collet in the same nut running the same g-code file. Only difference being on the top half (first op) I forgot to clean everything when changing the tool. For the lower half I took the tool out and cleaned everything up.

Quite a difference!!

[JOGARA]

Thanks for all the info.
I have been using the tool bit to touch off for a while and get okay results. Was hoping the probe would be better and faster.

I have 2 holes in my soft jaws to use as touch off points. I might try and use that method instead of touching off the edges.
The ProbeIt thing is acting up though with the auto probing. Probes something then fucks off somewhere....


Trying to use this bit to make my Fillets. https://www.shop-apt.co.uk/corner-ro...ide-45hrc.html
I am not 100% on the Fusion tool library and can't find examples for this sort of tool.


NOTE, Diameter is set to 1.3mm and shaft to 8mm. This image is old.

I got it to work though it was either too close to the part on the XY or too high on the Z. Not used it in over 2 months.
Any ideas?



I'v been cleaning mine out too. Not noticed any difference though I have not been looking.
For me it gets clogged up in the collet so when removing the tool I blast it.


[edit]
Think I got it working now. Though speeds and feeds are probably wrong.
Lots of chatter.