Lathe bore past back stock bndry

[FP1]

Problem with simple ID bore through. I have a steel burn-out ring 8"OD, 5.5" ID, 1.75" thick. Using lathe rough bore operation. Just want to bore it out to 6" ID. Stock set up is 8"OD 5.5" ID, 1.5"thick, with left margin set to .250.

 

I want the bore bar to go an extra .100 past the back of the stock. I have "use stock as outer boundary" selected. I have tried Lead-out extend .350. I have tried add line .350 x 180 deg. I have even tried adding a line in my geometry. With all 3 methods only the last boring pass will obey the extra length, the others will not go past the back stock boundary. Any ideas how to get around this?

[Philcott]

Have you tried without "use stock as outer boundary" selected? You have the stock set to 1.5" thick and this might be what is stopping the bar from going all the way through.

 

One other thing. I don't understand why you have the left margin set to .25".

 

Phil

[Philcott]

Also, with "use stock as outer boundary" selected you might try fooling with the adjust boundary option. I don't usually use this but it has come in handy from time to time.

 

Phil

[FP1]

If I set it to "disable stock boundary" it only takes one roughing pass. I need at least 3 passes. Next I changed my stock to 1.75" thick and removed the left boundary. Got the same results, the first two roughing passes will only go back to the stock boundary, only the last rough pass will go the extra .100.

 

I tried fooling with the "adjust stock", it will let me shorten the back boundary but it won't let you lengthen it beyond the stock setup values.

[Philcott]

FP,

 

Without seeing the file I won't be able be of much more help. If you can put the file on the FTP site I'll have a look tomorrow. It's probably something easy.

 

What version are you running?

 

Phil

[FP1]

Not sure how to post it to FTP and it is such a simple file prolly not worth the FTP space. It is just a steel ring. Just want to rough bore it out from 5.5" up to a 6" ID. I need all the roughing passes to go .100 past the back stock boundary. Yeah I could lie about the stock boundary but wondering if this is just the way it works.

[crazy^millman]

Well you are telling Mastercam there is 1.5 of stock and if you want to machine 1.75 of stock you need ot tell it that. If you have it set-up as 1.5 of extra stock past 0 and .25 as material on the front and then want to go .100 past that then you need to tell Mastercam it has 1.85 of stock. It will do everything you tell it and if you tell it there is only 1.75 of stock however you define it it will cut 1.75 of stock. Now there are way to cheat certain things, but without a file I can spin you in circles real quick.

[Reece L Gibson]

On the lead in a nd lead out, use the "add line".

Give it your .350 and use 180 as a vector

[FP1]

I uploaded the file to the ftp site. file name is borethru.mcx

linky

1st and 2nd rough pass go to Z-1.781

3rd (last) pass goes to Z-1.881

I think mastercam only applies the extend or add line (lead out) to the very last pass. What do you think?

[Guest]

simply lie to it and tell it your stock is 2" long or even 1.85 works

[gcode]

Mastercam lathe should have a setting

to force roughing paths past the boundry

of a part, but it doesn't

As stated earier, the simplest work around is to

lie and make the stock .100 thicker, than is really is.

[FP1]

quote:

---

Mastercam lathe should have a setting

to force roughing paths past the boundry

of a part, but it doesn't

As stated earier, the simplest work around is to

lie and make the stock .100 thicker, than is really is.

---

gcode, this is the conclusion I came up with also. Just wanted to know if I was missing something. Thanks for looking/responding.

[heavychevy2155]

Just go to lead in/out and on the lead out tab, check the extend box and put .1 in the amout box and hit the extend button.

[Philcott]

FP1,

 

I looked at your file and this is what I came up with.

 

I turned off the "Add line" in lead out, Cheated a bit by telling the stock setup that the length was 1.85, used adjust stock and clicked on the middle option (horizontal blue line), regenerated and I had the path you wanted.

 

So there you go. As far as I am concerned there should be a way to tell the roughing passes to machine beyond the stock so we wouldn't have to lie to the program about the width of the stock. Maybe send in a request to add this as a lathe feature addition.

 

Phil

[FP1]

quote:

---

So there you go. As far as I am concerned there should be a way to tell the roughing passes to machine beyond the stock so we wouldn't have to lie to the program about the width of the stock. Maybe send in a request to add this as a lathe feature addition.

---

The quote above is exactly what I was thinking when I started this thread. I needed to see if anyone else saw it the same way before I send in the suggestion.

[Reece L Gibson]

I looked over the file, if you use the "Canned Rough", use the stock for outer boundary, and add a line with the 180 deg vector and .35 for length it will produce the desired results. Have you sent this file into Mastercam QC?

 

I noticed on your file on the FTP, it only goes the extra distance on the last past.