[ErnieD]

Hi,

I am having trouble setting Z 0. I reference all three axis, move to and set x0 and y0, move down until the cutter touches the top of the work set Z0, hit start and the Z axis moves up and not down. What am I doing wrong?

Thanks,

ErnieD

[300sniper]

are you using the offset screen to set your tool height (and xy offsets)? it doesn't sound like it to me and i think that is most likely your problem.

[ErnieD]

I have tried to set the tool height using the offset screen and I am having no luck. I must be doing something wrong.

[justgary]

ErnieD -

This seems like a silly question, but does your program actually say to move up? Most programs start by moving to a safe Z value first. If you set Z to some zero point and then leave it, it doesn't surprise me that the first move would be up.

I see two dangers in leaving the tool at Z=0 when you press start. First, the spindle may not have time to spin up before the tool engages the work; and second, if the program does not move to a safe Z first it might crash the tool on an X or Y move to the start position.

I generally set Z zero and then move the spindle up at least four inches to give it time to spin up. Also, I try to program work so that the highest point on the part is Z=0, and all cutting is done at negative Z values.

Can you post your program here so we can peek at it? Did you write it yourself, or use a CAM program?

Regards,

- Just Gary

[300sniper]

i'd also like to see your program.

can you explain how you were trying to set up your offset screen?

[ErnieD]

I have tried to set up the offset screen so many times that I am confused. I roughed out the profile that I want to cut last week and it worked fine. If someone would explain to me step by step how to set up the off set screen I would appreciate it very much. All I want to do is finish the profile and I am using the same code that worked before.

Thanks in advance,

ErnieD

[300sniper]

i'm starting to think you are calling up the wrong tool "t" or wrong height offset "h" in your g43 line, or have the wrong offset programed in your tool table. if the program was working before and you have been messing with the tool table, you may be calling up a tool that has had the height altered.

[R.DesJardin]

Are you clicking the Edit/Save Table Now button and then click the Apply button to save your settings? It sounds like you need to read through the manual and step by step set up your part and tool.

[justgary]

ErnieD -

You are feeding us information in very tiny bits, so it's hard to suggest a solution. If you post more, you'll get more.

The tool offset table assumes that you have a repeatable set of tooling so that you can replace each tool at the same height every time. TTS is such a set of tool holders. I'll assume you have TTS.

1. Measure the length of each tool in its holder and write down the value. If you have the full TTS set, use the special ring and the height gauge on the granite table. Otherwise, use a dial caliper or micrometer to carefully measure the length from the TTS ring to the tip of the tool. You can also use your mill and touch off each tool (but only set zero for tool #0). If you remove a tool from its holder, you must re-measure it and change the tool offset table when you replace it.

2. Choose one tool as the master tool. Tormach suggests the longest tool, but I use my 0.2" edge finder. Number all of the other tools.

3. Calculate the difference in length between each tool and the master tool (subtract the length of the numbered tool from the length of the master tool). Write the result down on the line for the numbered tool.

4. Start Mach 3.

5. Select tool #0.

6. On the offsets page, edit the tool offset table.

7. Enter 0 for tool #0. For each numbered tool, enter the difference calculated in step 3 for that tool in the row that has that tool number. Since you are dealing with Mach 3, you must always remember to press Enter after entering each value.

8. When you have finished editing the table, click Save and Exit (I'm typing this from memory, so they may have other names). A quick sanity check is to exit the tool editor and then re-open it to make sure it has the offsets you just typed in. If not, you did something wrong.

9. To use the tool table, set Z zero using the master tool (with tool #0 selected!). Next, select the desired tool number in Mach 3 and install that tool in the spindle. If you want your program to select the tool number for you and wait for you to change the tool, use "G43 Tx Hx", where x is the desired tool number. You must use both T and H or Mach 3 will not use the proper offset for the chosen tool.

I suggest trying just two tools (the master tool and tool #1) at first, and then add tools after you get the hang of it.

Regards,

- Just Gary

[philbur]

Why even bother with tool offsets and the tool table if you are running only one tool. I ran my machine for more than 6 months before I even looked at the tool offsets. Even after that I didn't use it that often.

If you touch-off the tool you are using then which way the tool moves when you "Start" is dictated by the G-code. So it depends on how you produced your G-code. It may be going to the change tool position, it may be going to the safe move height, it may even be going Home. Check your G-code.

Phil

PS: Like a naughty boy, if you want to know what he's upto you wait to see where he goes.

[benji2505]

i'm starting to think you are calling up the wrong tool "t" or wrong height offset "h" in your g43 line, or have the wrong offset programed in your tool table. if the program was working before and you have been messing with the tool table, you may be calling up a tool that has had the height altered.

Maybe he sets the tool height for the wrong offset: Sets the tool for G59 and calls G54 in the program. I would have to agree: one has to see the program before one can judge.