Buttress Thread - OD Turning application - Questions

[ThickChips]

Hi,

I am tasked with turning a OD Buttress thread (ANSI 45/7°)

Insert:  https://tinyurl.com/56km9dsf

I was hoping to get a few questions answered before I scrap the first part lol.

I guess the first question is, can I 'trick' mastercam and use a regular threading toolpath by inputting correct angle (45) and pitch etc? 

Or must I draw a custom tool and do some custom threading toolpath.... 

 

 

Thanks a lot

[AHarrison1]

You should have a Buttress thread insert option when creating a new thread tool.

[crazy^millman]

I have always used the correct tool with the correct defined process and all was good. I have done Zero degree lead ones they were a pain to do. You can download the model from the NOVO app with the correct holder. Then build the 3D tool and go from there.

Here is what I download from there https://www.dropbox.com/s/vozcl6r0pkpsb61/Tool%2051.STP?dl=0

[AHarrison1]

In thread operation choose select from table then drop down to buttress

[Corey Hampshire]

This probably doesn't help you since you want to do it in Mastercam, but I just used the canned cycles on the machine to thread my parts. G76 threading cycle (fanuc) and called it a day. Acme, Metric, Pipe, Butress, Standard....all G76. This was back in the X5/X6 days, when things didn't play nicely. I haven't tried to thread in Mastercam for some time. I'm sure it's better now. 

[ThickChips]

Hi,

Thanks all. The tips have been wonderful. I didn't realize MCAM had a buttress insert already in there.

 

The problem I am facing is that the insert they offer is the INCORRECT buttress form. There are 2 buttress thread directions depending on what direction the thread must resist load and mcam offers no way to flip the insert?. Here is the tool I have setup:

 

This needs flipped so that the 45° is LEADING not trailing.

 

 

[crazy^millman]

7 minutes ago, ThickChips said:

Hi,

Thanks all. The tips have been wonderful. I didn't realize MCAM had a buttress insert already in there.

 

The problem I am facing is that the insert they offer is the INCORRECT buttress form. There are 2 buttress thread directions depending on what direction the thread must resist load and mcam offers no way to flip the insert?. Here is the tool I have setup:

 

This needs flipped so that the 45° is LEADING not trailing.

 

 

Save the tool to a level through the lathe tool manager. Flip the insert then use that level to define the tool.

The other option is to use 3D tools.

[AHarrison1]

The direction of the insert i don't think is important as far as actual machining is concerned.

The problems I generally come up with is gauge point of the insert which for threading inserts is the tip.

Nine times out of ten  I have to alter the z depth of the threading op, especially up against a shoulder.

[ThickChips]

Hi all,

I was able to get a working program. I didn't bother to try and make a custom tool. I just left the insert direction as the stock buttress and posted. No issues.

The other tip that was helpful was using 'Select from table...' for establishing the thread toolpath parameters. However, often Buttress threads are used on large diameter components, which mcam does not support. Even the Machinery's handbook doesn't list values above 6.00 IIRC. However, this helped set up the included angle and start angle etc. 

 

Thanks a lot!