Cutting a tapered bore on a lathe

[Thoob]

Hi. I was wondering if its possible to keep an even depth of cut while cutting a taper. Right now mastercam cuts in steps on x only. Is it possible to get it to cut evenly throughout the bore? I'm asking this because there is a taper in the bore already and I need to cut a keyway while its in the chuck. I am locking the spindle and approaching the part like a broach. What I want to do is cut .002 depth at a time until i get to .200 while cutting along the taper in x and z. Hope I explained this good enough.

[Pilot Plant Supervisor]

On the lathe rough properties tab, click on the "angle" button next to the rough direction/angle.

[Thoob]

Awesome, thats it. Thanks Pilot.

[crazy^millman]

Another way to approach is use finish and set number of passes with step over. I use to do this for roughing casting shapes where there was always irregular shapes. With a taper you need to figure out the angle. With a finish pass then multi pass and setting the distance you are done without having to figure it out and angle. Also if it goes taper to straight then it will all be tapered and not follow the complete bore the same.

 

HTH

[Thoob]

Another way to approach is use finish and set number of passes with step over. I use to do this for roughing casting shapes where there was always irregular shapes. With a taper you need to figure out the angle. With a finish pass then multi pass and setting the distance you are done without having to figure it out and angle. Also if it goes taper to straight then it will all be tapered and not follow the complete bore the same.

 

HTH

Never thought of doing it that way. Fortunately my taper does not go straight. Its just a taper and I know the angle already as I had to cut the tapered bore myself. Thanks for that tidbit.

[crazy^millman]

Glad to share my knowledge.

[JAMMAN]

Another way to approach is use finish and set number of passes with step over. I use to do this for roughing casting shapes where there was always irregular shapes. With a taper you need to figure out the angle. With a finish pass then multi pass and setting the distance you are done without having to figure it out and angle. Also if it goes taper to straight then it will all be tapered and not follow the complete bore the same.

 

HTH

 

This is the exact way I do it and it always works well, I like it better than the staircase approach.

 

The only time I feel rough is better is when you have an existing profile and are turning it in to something else, saves tons of time. We do that a lot where one profile becomes another. Tag both lines and MC figures it out, or at least it did in 9. I haven't tried that "exact thing" in X6 yet, but I bet it works the same.

[crazy^millman]

I haven't tried that "exact thing" in X6 yet, but I bet it works the same.

 

 

It does.

[Thoob]

Ok guys, here's another question. The broach tool I will be using to cut the keyway is .440 wide. Its on a 1" diam bar. How do I draw this in Mastercam to use a custom tool? Am I missing something here, and its easy to do or am I just crazy?

[GoetzInd]

Ok guys, here's another question. The broach tool I will be using to cut the keyway is .440 wide. Its on a 1" diam bar. How do I draw this in Mastercam to use a custom tool? Am I missing something here, and its easy to do or am I just crazy?

 

You're not crazy. MC lathe is extremely limited in verify 3d tools. It would be awesome if you could select solids as tools . Would make stuff like this a breeze.

 

Mike

[Thoob]

So how does one go about getting the tool to work? I have a 3d model of the tool I drew up. I attached it here. How would I program the keyway in Mastercam or basically how would I define this tool?

Broach Tool

[GoetzInd]

Draw it as a custom tool (2d) but it will not verify correctly since MC will revolve everything (your posted code will be good though).

 

Mike

[Thoob]

Draw it as a custom tool (2d) but it will not verify correctly since MC will revolve everything (your posted code will be good though).

 

Mike

I understand the custom 2d but what view would I be drawing it from?

[crazy^millman]

The best way is to take a lathe tool and save it to a level and just change it to be what you are after. Starting from scratch is the hard way IMHO.

[Thoob]

Ya but 1 the tool is already drawn and 2 what tool would I use to start? None of them would be able to be defined properly. The easiest way I see to do it is to just use a boring bar for verification?

[GoetzInd]

The easiest way I see to do it is to just use a boring bar for verification?

 

+1

[Thoob]

Ok thats what I did. Thanks for the replies fellas.