pulling hair out with boring

[Sbarner]

Greetings all,

 

One thing that upsets me the most in lathe is boring operations. There seems to be no end to the combination of lead in/out, overlap, shorten end of contour, depth of cut, etc. to prevent the damn thing from crashing.

 

I wish we had a feature to tell the boring tool to start on a given diameter. For instance, in the part I'm making now, I'm "drilling" a hole with an endmill. At first I was leaving .005 on the bottom face. The boring op still saw that as stock to be cut...even though stock to leave in Z was .01". Adjust the endmill so that it leaves only .002" on the bottom face...same thing. Here's the deal. I know the boring bar is smaller than the hole by .100. I KNOW that this operation can work. Why must Mastercam lathe make me ? Why do I have to mess around with Adjust stock to make this work? [/rant]

[Allan]

The defaults for the lead out is usually the issue, when boring. I usually make a small lead out move like .01 and set the angle to about -5 deg.

 

You have the option now to tell it where to start the bore from. That point is the end of the contour in the X dimension so if you have a .5" boring bar and you drill to say .562" you should chain a line in -Z as deep as your bore then in -X down to .562". The bore will start at .562 + the depth of cut.

[Jeremy Grigsby]

Yeah. To get a boring bar to only cut the diameter, i usually just choose a finish pass, and modify the lead out to be a short move. I only chain a line at the diameter i want to cut, nothing else. If you chain a bottom of bore, the boring bar it going to try to cut that.

[Jeremy Grigsby]

edited because of double post...

[Todd Mann from Fastech]

On your toolpath parameters page turn on the referance piont and set the approach at say like .1 smaller than your roughed in diameter and .1 in Z and then make the retrack the same.

[kazmir44]

 

Are you talking about a rough or a finish toolpath?

[Josh T™]

Do you have "Extend Countour to Stock" checked?

[Sbarner]

I put a file on the FTP. In the lathe folder, it's called "Cam Follower". Feel free to look if you want.

 

quote:

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Are you talking about a rough or a finish toolpath?

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The part where I'm having a problem is on the roughing pass. There is a .25" hole through the center, and a .75" dia x .65 dp bore. I use a 1/2" endmill to drill to .648" dp, and then just chain the bore geometry. The finish pass works fine.

 

quote:

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Do you have "Extend Countour to Stock" checked?

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No.

 

quote:

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You have the option now to tell it where to start the bore from. That point is the end of the contour in the X dimension so if you have a .5" boring bar and you drill to say .562" you should chain a line in -Z as deep as your bore then in -X down to .562". The bore will start at .562 + the depth of cut.

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This is probably what I'll do. Thanks for the advice.

[Sbarner]

Ok. I'm dumb. I could've sworn that I had shorten contour set to .125. It was only set at .100. Problem solved. Huzzah! Thanks all. Time for some java...