Inner slotting - rifling - mastercam 8

[Azi]

Hello everyone,

my friend would like to ask u about something.

Thing is, he is trying to do an inner slotting in a gun's barrel - rifling.

He made his own tool for that purpouse.

 

Now for the question - how should he proceed in programming this task?

How to import slotting tool?

And how to tell mastercam - do this helix groove inside.

- which toolpath should he chose?

 

 

Thank you for your advices

Best regards

Azi

[Guest]

He should buy a barrel blank and save the headache

 

 

Rifling isn't really a machining operation....there are special machines that create the rifling grooves.

 

http://www.firearmsid.com/a_bulletidrifling.htm

[Azi]

Well yes, you are right in that, but it should be doable on CNC lathe.

Considering fact - a tool will do only 0.1 mm depth of cut and rotation will be <0;90>°  on a 120mm length.

 

If it wasn't helix groove, it would be easy - just a rough toolpath with 0 spindle speed. 

And ofc defining a tool - cutting (3x) edges to be more specific - from IGS.  

[jlw™]

If he's bent on doing it, hand code it. This would be about as simple hand coding ad there is. Not to mention iges is not going to give good results. I would draw the geo if I wanted to do this.

[Azi]

Here are some images of what it looks like:

http://www.imgup.cz/image/WiR

http://www.imgup.cz/image/Wif

http://www.imgup.cz/image/Wi2

http://www.imgup.cz/image/WiT

 

How exactly would you draw a geometry of that tool? - an advice or any pdf describing it would be appreciated

And about the hand coding - on the machine or in mastercam? - Iam kinda failing with comming up with an idea how to tell mastercam tool No. 1 G01 from z 0 to z -120 while do rotation of spindle 0.34*360° (0.34 was taken from solidworks - parametr of helix)

[Guest]

Moved to the main forum as this is most certainly not an educational user

[Teh Bear without Brains kinda idiot]

He may damage the bearings .

BR

[Azi]

Moved to the main forum as this is most certainly not an educational user

Actually it is educational user. This is for machining of some parts for colt 1911 - for a thesis.

[Azi]

My apollogies i forgot to mention that stock will be made of EN AW 6063-T66.

So i doubt there could come to a damaging of bearings.

[jlw™]

Hope you don't plan on firing it!!!!!!!!!!!

[Allan]

The hand coding suggestion is best.

 

Looks like the tool is the WIT file so it is ran directly on center?

If on center;

M what ever (to turn on C axis control)

G00 X0. Z.4 (position tool)

G01 Z0.

G01 Z-120.00 C90. F250. (broach hole) IDK feed rate will depend on conditions; better use oil.

G01 Z.0 C-90. F500. (retract from hole)

G00 Z20.

(look for pieces of broach in chip tray)

 

If that tool is not cutting on center; you are looking for a timed cut with the live tool and spindle running.

Mastercam does not have a specific toolpath for that.

It can be accomplished using a contour toolpath and a few post tweaks.

Your control will need to have a Synchronizing command look for hobbing or polygonal turning in the Manual.

The actual toolpath for the polygonal turning will be best hand coded.

[Guest]

My apollogies i forgot to mention that stock will be made of EN AW 6063-T66.

So i doubt there could come to a damaging of bearings.

 

Actually it is educational user. This is for machining of some parts for colt 1911 - for a thesis.

 

 

My apollogies i forgot to mention that stock will be made of EN AW 6063-T66.

So i doubt there could come to a damaging of bearings.

 

 

Hope you don't plan on firing it!!!!!!!!!!!

 

 

1911 barrel, out of aluminum......

 

I concur, I hope no one plans on actually test firing it.....

 

:rummaging around:

 

Where is my 1911 barrel?

[jlw™]

You might be able to use a synchronous tap cycle and set the pitch to the twist rate.

[jlw™]

I'd lube with butter cut or something similar.

[Azi]

Ofc nobody here, especially creator of this maquette, would never think about firing from it   

Thank you Allan, that is what i thought.  - G01 Z-120.00 C90. F

  - yesterday i came up with an idea to set F equal to time needed for doing 120mm (in 1 min) and spindle speed equal to the curvature of the helix (0.3 per minute)

I just didnt know, that i can write it in G code like u did.

 

Edit: Yes it will be in the center.

[jlw™]

Can you upload a picture of your cutting tool?

[Azi]

Can you upload a picture of your cutting tool?

few posts above u: http://www.imgup.cz/image/WiT

[jlw™]

Ah, missed that. I would try a tap cycle. It's going to be all or none, peck will not work. You'll either cut the rifling or destroy the tool and workpiece. You need to take measures to keep the workpiece from pushing thru the chuck.

 

So you have peaked my curiosity. Can you provide a link to a manufacturer on that tool?

 

Do you have multiple inserts that progressively cut deeper?

[Thee Rickster ™]

Ah, missed that. I would try a tap cycle. It's going to be all or none, peck will not work. You'll either cut the rifling or destroy the tool and workpiece. You need to take measures to keep the workpiece from pushing thru the chuck.

 

So you have peaked my curiosity. Can you provide a link to a manufacturer on that tool?

 

Do you have multiple inserts that progressively cut deeper?

I wouldnt think so, aren't the grooves only cut about .003" or .004" deep?

[Azi]

 jlw - the tool was custom made by my friend, and cutting part was grinded from RADECO 

[jlw™]

I wouldnt think so, aren't the grooves only cut about .003" or .004" deep?

 

 

Yeah, I've seen cut rifling and button rifling.  They both (that I've seen) have multiple "steps" just like a broach.

[Thee Rickster ™]

Yeah, I've seen cut rifling and button rifling.  They both (that I've seen) have multiple "steps" just like a broach.

cool to know, i guess that would reduce any binding

[jlw™]

cool to know, i guess that would reduce any binding

Pm me your email, I have a really awesome book on how the first 1911s were machined.