Drill Tip Comp and Drill Geometry

[Dave.L]

Greetings All,

 

It’s great to have drill tip compensation, however, the drill definition lacks a very important variable, the fact that most drills don’t come to a sharp point due to the drill geometry.

 

We produce very tight tolerance parts and parts where every feature requires inspection, probably like many of the forum members. In the last few months, I started using the chamfer tool type to define my spot drills so I could obtain the correct diameter of the spot (since the chamfer type has a variable for the tip flat). In many cases we have drill depths that are +/- .005 and since MC does not have a variable for the tip point we often need to make substantial length compensation in the control. I find that one drill to another (same tool, same manufacture) this value is consistent which is no surprise to me and I am sure no surprise to you guys.

 

It would sure be nice to have this variable in the drill definition.

[mayday]

shouldnt matter Dave, holding +-.005 is done at the machine. Drilling to an inch deep is -1.00 in code no matter what type of tool. measured in the machine correctly it will go -1.00

[Dave.L]

Mayday, I totally disagree. The depth of the point is not held, its the depth of the diameter. We measure the tool on a comparator now to get the tip info and then make the lg comp and the hole is dead nuts first part

[Programinator]

I find myself adjusting the spot drill depth at the machine a lot. It would be nice to be able to have the code come out perfect. I dont see how this is possible though with the variation in the tools being used. especially drills and spot drills and regrinds ect...Like you said you would have to use comparator for each tool.

[Dave.L]

If the variable was there, it would get you way closer than without it. The regrind is a good point but it would still be accurate if the grind was the same as the original (and it should be) for us, we dont use regrinds for many reasons so this would not be an issue.

[gcode]

You could use the chamfer tool definition for your drills. They have a field for a tip flat.

[Dave.L]

G, yes as I stated I use this for spot drills. I guess I could use it for drillls too but I dont know if other issues will arise. BTW, it makes searching for tools in the library a challenge.

[huskermcdoogle]

I am in full agreement here. It would make life much easier. It might be easier if the field was just tip height. So we could all run out and measure tip to full diameter length. All we would need for inputs would be tip angle and tip length.

 

 

Husker

[Kyle Waters]

maybe there is a way to get the "flat on tip" field accessible from the tool parameters?

[Allan]

How about using a variable @ the machine?

Then modify the post to output the depth + your variable, you check the drills on the comparator anyway. Part of the setup would be to input your variables for the drills.

 

Code would be like:

G81 X2.1234 Y3.1416 Z-[1. + #500]

 

Just a thought, I would not expect to see the drill definition changed any time soon.

 

Allan

[Dave.L]

There is no difference between using a macro variable and a simple tool length wear offset. The real point is, if you can properly define the tool then this will not be needed.

 

But, thanks for the suggestion. Marco varibles are very useful and we use them often

[Sbarner]

Doesn't the depth calculator have an input for flat on tip? I understand that having the variable in the tool definition is ideal, but I would think that you would be able to nail your tolerance with this, especially if you're measuring the flat with a comparator. My 2 cents...

[Dave.L]

quote:

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Doesn't the depth calculator have an input for flat on tip?

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Steve,

 

Thanks for the tip (no pun intended). I did not realize it was there.

 

However, it still sucks not to have this in the tool definition since you will need to look it up all the time.