Cutting threads on neck inserts

[david]

Hi to all,

 

Our company is inquiring about a 5 axis Okuma mill to cut threads on neck inserts for blow molds. I was wondering if anyone uses this process and how complicated the programing end of it might be. Any advise would be very much appreciated.

 

David

 

Mcam X3 Mill 3 w/solids

[htm01]

we cut threads in a 3 axis mill,you can do a helix but i like to just mill a circle and add the z move in editor.

[david]

Thanks for the reply htm01. I forgot to mention that the profile of the cutter is the same as the finished thread. With that in mind the centerline of the cutter must be perpendicular with the helix of the thread at all times. We currently cut these on a modified manual mill with a special spindle cocked at whatever the helix of the thread is and use a rotary to go up and down in Z whatever the pitch might be.

[Bill R]

I cut threads, in neck inserts for extrusion blow molds for years, with a three axis Haas VF-4. The threads always in tolerance. I never had the need for tilting the cutter. Are you working on injection blow or something?

[htm01]

yeah we used to do them in a bridgeport with a threading table but without the tilt it only cuts slightly wider,used to use cutters the were thinner but been doing this for 30 years and haven't been rejected yet, doing blow molds holding +/- .001 on the threads.

[Bill Sp]

I do it often to cut luer threads on mold inserts. I do it on an Integrex and using Mazatrol.

[david]

How difficult is programming a 5 axis to keep a cutter perpendicular to the helix, or to produce a part with bores at various angles from a given plane. I currently run a Okuma horizontal with a B axis( index of 1 degree increment only). At times it is nessecary to program from center of rotation and I have that down pat. Would programing a 5 axis be the same concept?

[Bill Sp]

I program the same way,using the center of rotation of the B axis to keep it perpendicular. Bores at different angles is all done with Mazatrol by defining a new planes.