lathe problems with round inserts

[Ray H]

I'm having a heck of a time getting any tool with a round insert to perform properly. I am trying to finish the yellow radius. I have a chain (line, arc, line) left side comp. The tool keeps going behind the line and is displaying a purple line in backplot and not blue. I think Mastercam is having a fit trying to find the radius. I aslo experienced a similar issue on this part where the stock after the operation shows a hefty collision, however the code is good but after operation the stock shows the tool gouging out the backside of the line. in attached pics dogbone 2 shows good backplot cutting. dogbone 3 shows the stock afterwards with the stock gouged out. 

Any ideas will help greatly

 

[AMCNitro]

Change the compensation on the tool definition .

 

 

[Ray H]

the first option was picked and only the 4th option was available. the middle two are greyed out. Its a custom tool as well. I thought it had something to do with where I drew the toll tip radius. I moved it from zero zero to tangent to x+y+ quadrant. there was no change.

[AMCNitro]

Go to the tool definition page , hit Draw Tool and take a screenshot, then post it here

[pro grammer]

The nice thing about lathe is on your custom tool you can put your nose radius drive point anywhere.

[Colin Gilchrist]

Post up a Mastercam File, so someone can take a look.

The problem is likely with your Tool Definition. Could also be "direction". You said "yellow radius", but "left side". The side would totally depend on "chaining direction", so you are likely on the "wrong side of the chain, based on the chaining direction".

The "Draw Tool" function is your best friend in Lathe. This will show you how the tool is setup to function on your turret (yellow is "insert up", orange is "insert down"). You can "flip the handed-ness of the holder, by going to the holder tab. (This allows you to switch from Left-Hand to Right-Hand, or vise-versa).

The "compensation point" all depends on how you are touching off the tool on the machine. For true cutter compensation, (for example, to control the radius being cut), you would need to use the "center point" of the radius, and enter the "actual radius" in the Offset Register for that tool. Then you can enter a plus/minus value to the cutter comp, and physically change the diameter, face, and radius values together, by editing a single offset parameter value.