V9.1 Incremental Drill Depths?

[J Coulston]

I am running V9.1, it is not calculating incremental drill depths properly. Here are my settings

 

Clearance: 0.225 Abs

Retract: 0.05 Inc

Top of stock: 0.125 abs

Depth: 0.05 abs

No Tip Comp.

 

N8 G43 H1 Z.225 M08 T18

N9 G98 G81 Z.05 R.175 F10.

 

 

Clearance: 0.225 Abs

Retract: 0.05 Inc

Top of stock: 0.125 abs

Depth: -0.075 inc

No tip comp

 

N8 G43 H1 Z.225 M08

N9 G98 G81 Z-.075 R.175 F10.

 

This is not correct it should still be Z0.05. On backplot the tool moves as follows.

 

Z 0.225

Z 0.175

Z 0.025 where is this move coming from?

Z –0.075

 

No matter what incremental depth I use the tool always feeds to 0.025 than adds the incremental depth.

 

What am I missing?

 

Thanks John

[Rick Damiani]

What is your feed plane set to?

Where is the drill point you are selecting?

Does that point have a depth assigned to it?

Can you post the file someplace so we can have a look-see?

[Jack Mitchell]

John,

 

quote:

---

Clearance: 0.225 Abs

Retract: 0.05 Inc

Top of stock: 0.125 abs

Depth: -0.075 inc

No tip comp

---

Could you please just step back for a moment and appreciate another approach, this is not to say that you or I are incorrect in what it is that we are trying to accomplish.

 

Clearance: .1 Abs

Retract: .1 Inc

Top of Stock: 0 Abs

Depth: .1 Inc

Use tip comp

 

I guess it goes with the way we are taught or the way that we learn, try this approach as a suggestion.

 

 

Regards, Jack

[Ralph@Faustson]

John,

You may be missing somthing here..

If you "pick" a point at X0 Y0 Z0 then the incremental Z-.075 from that point would be Z-.075, the increment that you enter on the drill parameter page is from the point you pick.. not the absolute Z top of stock that you enter in previous box. Likewise if you "pick" a point at X0 Y0 Z.125 then you would have Z.05 as absolute drill depth as you desire.

[J Coulston]

Duh sometimes you just can’t see. The points where picked up from Z0.

 

Thanks for your help.

 

John

[Brian G Scullion]

After recently going on a mastercam training course .I was instructed that as a general rule either work in incremental or absolute but try to avoid mixing these up . So says the cad/cam guy.

 

( this may or may not help you all situations are different.)

[P_Scott]

John,

 

What are the Backplot Display settings in Mcam? If you are Displaying an Interpolation for Step Mode, this may be where the .025" value is coming from. I tried a simple drill cycle using all the same values you tried on my V9.1 and it Backplots and displays all the values correctly (z.175 next z-.075). With Interpolate on, the Backplot will produce numbers that are based on the Interpolation distance value. Check your Backplot Display settings to make sure Interpolate isn't on. The true test of what the toolpath is doing will always be in the actual G-code, not in Backplot. HTH

 

As far as mixing the Abs and Incr. values in the operation goes, you just have to be aware of what each value represents. Incremental is useful for drilling same-size holes at different start depths. HTH

 

[ 04-09-2003, 03:06 PM: Message edited by: Peter Scott ]

[Rick Damiani]

quote:

---

After recently going on a mastercam training course .I was instructed that as a general rule either work in incremental or absolute but try to avoid mixing these up . So says the cad/cam guy.

---

Some general rules are useful. Some aren't useful at all. Following this general rule will keep you from taking advantage of some very nice features that can simplify your toolpaths, reduce your cycle times, and minimize the opportunities for error.

 

What you should do is use absolute or incremental when they are appropriate, as your geometry allows.