Skipped M998 during tool change

[am64]

i have been using my new 1100 for few weeks without any issue. But today when I ran a new project it started just fine until the first tool cycle was complete. My code calls for M998 go to tool change position but the z axis stayed at the last cutting position and I herd some odd motor sound for few seconds and every thing stopped. Mach3 asked for the 2nd but I could not place the 2nd tool since I had no z hight. I manually raised the z axis few inches so I could place the 2nd tool. when pressed start cycle, the z axis moved rapidly and crashed into my workpiece. I checked the code line by line and did not see anything unusual. Am I missing anything or doing something wrong?

[philbur]

Rerun the code cutting air and see what happens.

Phil

PS: If you manually move position to load a tool you cannot just restart the machine and expect the code to know you have moved position. However this does not explain the failure to go to the tool change position in the first place. It might explain the plunge into your work piece on restart though, if the programmed tool change position was actually higher than you manually positioned it. What did you set the tool change position at.

PPS: Describe the noise from the motor, in as much detail as possible, when it failed to go to the tool change position.

Phil

[crawley]

PS: If you manually move position to load a tool you cannot just restart the machine and expect the code to know you have moved position. \

This is only correct in G91. In G90 absolute mode you can move manually and the program will know exactly where to go back to. I do it all the time to get longer drills in or to move the spindle out of the way to vacuum the table. It's never screwed up once.

[Steve Seebold]

i have been using my new 1100 for few weeks without any issue. But today when I ran a new project it started just fine until the first tool cycle was complete. My code calls for M998 go to tool change position but the z axis stayed at the last cutting position and I herd some odd motor sound for few seconds and every thing stopped. Mach3 asked for the 2nd but I could not place the 2nd tool since I had no z hight. I manually raised the z axis few inches so I could place the 2nd tool. when pressed start cycle, the z axis moved rapidly and crashed into my workpiece. I checked the code line by line and did not see anything unusual. Am I missing anything or doing something wrong?

DID YOU HOME ALL AXIS' BEFORE YOU RAN YOUR FIRST TOOL?

[kevinro]

i have been using my new 1100 for few weeks without any issue. But today when I ran a new project it started just fine until the first tool cycle was complete. My code calls for M998 go to tool change position but the z axis stayed at the last cutting position and I herd some odd motor sound for few seconds and every thing stopped. Mach3 asked for the 2nd but I could not place the 2nd tool since I had no z hight. I manually raised the z axis few inches so I could place the 2nd tool. when pressed start cycle, the z axis moved rapidly and crashed into my workpiece. I checked the code line by line and did not see anything unusual. Am I missing anything or doing something wrong?

Be sure you started out with a Ref All (Ref XYZ). More specifically, if any of the axis displays on the DRO have a red box next to them, you need to reference the machine. If you don't, then MACH3 will not do a tool change operation since it doesn't know where the spindle is relative to the limit switches.

[am64]

Yes I did Ref ALL before running. I did contact Tormach today and they are aware of this issue / Mach3 bug. Every thing works great until the program needs to change the tool. The spindle stops, the M998 is called, but the stepper motor (z-axis) stalls. I know I should have not raised the z manually for a tool change but like a fool I did. The motor noise when stalled was like grinding noise for few second never heard of it before. Tormach told me to turn off the tool path view and run it without any tools and see if this problem repeats. I just started another run and will see if it repeates. I will update.

[VaderSpade]

Yes I did Ref ALL before running. I did contact Tormach today and they are aware of this issue / Mach3 bug. Every thing works great until the program needs to change the tool. The spindle stops, the M998 is called, but the stepper motor (z-axis) stalls. I know I should have not raised the z manually for a tool change but like a fool I did. The motor noise when stalled was like grinding noise for few second never heard of it before. Tormach told me to turn off the tool path view and run it without any tools and see if this problem repeats. I just started another run and will see if it repeates. I will update.

Moving the Z manually made no difference, you had already lost the steps, and your zero.
Starting the machine again without re-zeroing was the foolish thing. BUT how are you supposed to know???

If Tormach knows about this bug and others (and we know they do) how come they haven't contacted owners before their machines crash????

Do they expect owners to find some obscure post on the internet???

When someone loses a finger someone will need to answer!

[am64]

Update. I ran the program with ToolPath View off as instructed by Tormach. This time I did not encounter the problem. Z-axis moved to tool change positon as porgrammed. I am going to run it one more time with Tool Path view On and see if the problem repeats.

[VaderSpade]

Use caution my problem was hit or miss with no clear pattern. I had several crashes with the tool path display turned off, although that did help.

[crawley]

maybe of interest to you: rather than calling for the machine to return to a home/tool change position, I always call a G91 G0 Z4 move when I want a tool change that simply raises the tool 4 inches to give me clearance to swap tools. Obviously depending on what is coming out and going in it is sometimes more or less than 4, but if the home position call is what is giving you fits I would just never write that code. I've got over 5000 hours on my machine and I've never once called for a M998 or any other home position. I trust my 1100 enough to run lights out, it hasn't made a mistake ever as far as I know. I on the other hand make mistakes all the time.

[shred]

Same here. I don't know why everybody likes M998. A G91 to a couple inches from top of travel and it works well.

[mactec54]

I don't know why everyone is still trying to still use this M998 when it apears to be a problem with Mach

You don't even need it, to do a tool change