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

**JOGARA** · 25-10-2017

I'll stick with the drill press then.
Wonder if these carbide bits will be better than my hss that I am currently using.
Sometimes the 1.2mm breaks so over 400 holes I am going to go through a few.

That or I do do it in the machine and use my soft jaws.
Might test repeatability tomorrow.

**Snapper** · 25-10-2017

I wouldn't use carbide bits on a drill press, particularly not that small. Your chuck likely has a fair bit of runout and carbide will snap in it like a digestive biscuit.

**JOGARA** · 26-10-2017

Originally Posted by Snapper

I wouldn't use carbide bits on a drill press, particularly not that small. Your chuck likely has a fair bit of runout and carbide will snap in it like a digestive biscuit.

Good point.

Not having much luck today.
1 HSS and 1 Carbide down so far and I have only been in the shop for a couple hours -_-

Gives me an excuse to buy some more bits.
Grabbed a 1.2mm for my M1.6 tapped holes (probably swap for 0.3mm as M1.6 holes are meant to be tapped at 1.25mm not 1.2mm).
Also got a 2.5mm for my M3 tapped holes and a spot drill.

**JOGARA** · 04-11-2017

Not sure what is going on here.

I have not used the machine in a few days, like 5-7 days.
When I go to home all the axis the Z does not stop when it hits the end stop.

Forgot how I fixed it last time it did this about 1.5 weeks ago.

Also, sometimes when I set my part offsets and then tell it to go to the part's zero, the Z will go about 5-10mm below the set Z. I then tell it to go to zero again and it lifts Z to the correct height.

[edit]
Why is it also normally open? Would have thought NC would be safer?

[edit2]
Gone into diagnostics and all but the Z axis limit switches are working.
The switch its self is working so guessing cable problem.

[edit]
Yea it is cable..

**Snapper** · 04-11-2017

I have the same thing with the go to zero command, always goes to Z-5, I just don't use it and use g0 x0 y0 if I ever need to go there for any reason. Keep meaning to look in to it but always forget.

**Snapper** · 14-11-2017

Are you measuring each piece of stock prior? There can be a lot of deviation on the extrusions, +inaccuracy from the bed and 0.3mm doesn't sound an unrealistic error at all. If you can use stock bottom as part zero and skim the top surface down slightly you will get far more repeatable results.

Also, if milling on a vice, have you trimmed/shimmed it? So that your jaws or soft jaws are square to your axis.

**JOGARA** · 14-11-2017

The stock is bang on 15mm.
The 0.3mm is across the length of my part.

I milled my soft jaws while in place so if anything it should be near enough perfect?

**Snapper** · 16-11-2017

Also another thing, have you checked your x and y axis are square? Because if they're not then you aren't cutting square shapes, you will be cutting trapezoids and that will show up badly with every flip. If you haven't aligned this yourself it will almost certainly be some way out, mine was massively out and took the best part of two days drilling, shimming, and hammering it all into shape.

**JOGARA** · 16-11-2017

[edit]

Just milled a part that worked before and it is correct.
Though I added 1mm body that I forgot to add to the setup so it milled 1mm lower in some parts than I wanted it to be.

It milled how the model is set up though so the depth I believe is correct. Will be able to fully check in a min.

I reinstate my comment on it being a Fusion360 thing not the machine or Mach3.

**Snapper** · 17-11-2017

If you think it's fusion, best thing to do is get on the autodesk forum and ask their techs. Their staff are generally quick and helpful at sorting things out, and there are some real fusion brains on there.