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

[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.