[itolond]

Hi Forums,

Running mach3 to a CNC Sherline mill (4 axis rotary indexer) CW for SW as CAM software- few questions around this:

The scripts to determine the centre of holes,surfaces etc..(all ok on this) however my question revolves around when you flip/move a 'partly' milled work (newbie).

I have a circular design with Three (3) lugs (w/M4 holes) that will be used to secure the finished product to a surface, the circular design has a number of features which can only be milled on one side (3 axis mill setup) and then the material needs to be flipped over. centre point / orientation established and then the next milling run can continue (being the last to finish the job).

Question- How do I orientate the piece and have Mach understand this?- I will need to use the probes and scripts to ensure accuracy (esp with circular pieces). but how does this all come together?

[RCaffin]

I am not sure I fully understand what you are asking, but let's try.

If you need to mill both top and bottom of a part, you will need to flip it over. For this to be done successfully, there are a few things you need to look after.
1) Sacrificial base plate must be used, and it must be skimmed flat and horizontal.
2) Use pins, NOT screws, to locate the part in both positions. Screws are too sloppy. The holes for the pins in both the base plate and the object need to be a nice fit.
3) In theory 2 pins are enough; in practice you should use at least 4. And they should be as far apart as possible.
4) The pins must come in pairs, oriented on-axis. That is, both pins in a pair must have the same Y position (or X, it you want to flip that way).
5) The pins LOCATE: you will also need clamps to hold down.

I use pins of 2.4 mm diameter: either short bit of 2.4 mm Ti welding wire or the shanks of 2.4 mm drill bits. The holes are also 2.4 mm, NOT 2.5 mm. That does mean some tight fits, which is intentional. But you could use any diameter you want.

Then you program accordingly, assuming a straight mirror.

Cheers
Roger

[itolond]

I am not sure I fully understand what you are asking, but let's try.

If you need to mill both top and bottom of a part, you will need to flip it over. For this to be done successfully, there are a few things you need to look after.
1) Sacrificial base plate must be used, and it must be skimmed flat and horizontal.
2) Use pins, NOT screws, to locate the part in both positions. Screws are too sloppy. The holes for the pins in both the base plate and the object need to be a nice fit.
3) In theory 2 pins are enough; in practice you should use at least 4. And they should be as far apart as possible.
4) The pins must come in pairs, oriented on-axis. That is, both pins in a pair must have the same Y position (or X, it you want to flip that way).
5) The pins LOCATE: you will also need clamps to hold down.

I use pins of 2.4 mm diameter: either short bit of 2.4 mm Ti welding wire or the shanks of 2.4 mm drill bits. The holes are also 2.4 mm, NOT 2.5 mm. That does mean some tight fits, which is intentional. But you could use any diameter you want.

Then you program accordingly, assuming a straight mirror.

Cheers
Roger

Hi Roger,

I sorta get what you are saying - does this assume the material is flipped perfectly on a axis?, as this would not be the case. or are you saying the locate pins are consistent and the material is simply flipped and the only adjustment would be material height?

[RCaffin]

Well, that's how I do it - ON axis. But that may be because it suits what I am doing.
If the pins are not perfectly on-axis then the geometry gets a bit complex. That's up to you.
Height - that is entirely up to you! You might have to carve the sacrificial base up a bit to suit.

Cheers
Roger