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Author Topic: Mach 4 Thread Milling  (Read 218 times)

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Mach 4 Thread Milling
« on: July 11, 2025, 03:18:09 PM »
Is there a Wizard for Mach 4 for thread milling? If no wizard, what is a good way to generate the g-code for milling an internal thread on a mill using a single form threadmill?
Re: Mach 4 Thread Milling
« Reply #1 on: July 11, 2025, 08:07:08 PM »
Hi,
I use Fusion and it has a perfectly good threading toolpath feature.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
Re: Mach 4 Thread Milling
« Reply #2 on: July 11, 2025, 08:35:25 PM »
Hi,
I work with automotive instruments and on occasion require very small screws. The smallest I done successfully is a  13BA thread, which has a major diameter of 1.2mm
and a thread pitch of 0.25mm or 102 TPI!!

I was lucky and got off EBay five new Kyocera 98M11-0250LFA1 threadmills for $15USD. They are 1.1mm dimeter with a 0.25mm clearance, two flute. I could and did the external
thread of the screws above at 1.2mm major diameter. I made them in 316 stainless with a 3mm thread length. They were for a classic Jaguar tachometer from the fifties.
The smallest I could do an internal thread with these ultra tiny endmills is 1.4mm, but still pretty damned small!

The trick is to use a large number of very shallow passes otherwise the tool flexure beats you when it does not break the tool outright. That in turn requires that your machine can
do circular interpolation with micron type repeatable circularity. My machine made these screws and measuring with a micrometer found a ovality of about 0.02mm, which I thought was
pretty fair.

Craig
'I enjoy sex at 73.....I live at 71 so its not too far to walk.'
Re: Mach 4 Thread Milling
« Reply #3 on: July 12, 2025, 08:17:58 AM »
I downloaded a program from  https://www.chestnutpens.co.uk/misc/home.html some time ago which works very well.  However currently Norton is blocking access to the site as there is a certificate problem.  The site owner modified his internal threading code so it could cut down from the top to allow the use of a standard tap (with all but one of the cutting edges ground off).