POLYGONAL TURNING

Very clever!!

https://www.youtube.com/watch?v=oCFfvmREacA

... a general YouTube search under "polygonal turning on the Lathe" will yield up more fascinating gems. Did you learn something today?

https://www.model-engineer.co.uk/forums/postings.asp?th=184337&p=1

Thats fairly interesting. I like the way that its geared to the head stock, and changing the ratio changes the number of flats. I saw an Okuma lathe that had a geared head that used what looked like a carbide 3 insert saw. It cut the hex on a stainless steel fitting, except the hex was at the back of the part and smaller than the front detail.

I am sure that the spindle could have sensor like the electronic leadscrew project an a suitable stepper, it could be done without the universal drive etc.

Thanks for the post and link.

I posted this a while ago.

Steve.

Has anyone made a setup for a Myford lathe to do polygonal turning?

I think I have seen a home-built hob-relieving attachment (maybe Charles Lessing). The principle would be the same.

Neil, I have seen a video, probably on YouTube, of a lathe with a very rapid X axis being used to cut polygons under the control of Linux CNC.

Martin C

Here is one 

Edited By Martin Connelly on 04/01/2023 08:32:36

About 45 years ago I briefly worked for a company making flow control valves, they had a couple of capstan lathes, cannot remember if they were Ward or Herberts but they had a polygon box attachment that mounted on the turret and allowed the machining of squares or hexagons. Does anyone remember these attachments or can they explain the workings of them?

I guess it is the next step up from a "backing off" lathe, that had the facility to machine gear cutters with a form tool and back off the clearance for the cutting edges as the blank was turned. A few manufacturers made them. Operated in a similar way with the toolpost moved in and out as the spindle rotated, timed through as set of gears.

Also quite a bit like some of the ornamental turning that was popular late 19th century. Those guys did some elaborate stuff. Tom Walshaw (Tubal Cain) did a book on the topic, amazing stuff.

Backing off a gear hob as it is turned in the lathe:

And, of course, one of our members does interesting things - likely these have been posted before:

Boring non-square holes:

https://forum.linuxcnc.org/10-advanced-configuration/38549-non-circular-boring-linuxcnc-fun?start=0

and, not sure if this person is here, turning non-square shapes:

Somewhere, I saw someone knurling with a single-bit tool and LinuxCNC.

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LinuxCNC is great! The best controller for home and business by far. Inexpensive, flexible.

Not for everybody, though. Some have great skills in areas, other great skills in other areas. Some fantastic designers/machinists can't get their heads around the flexibility of LinuxCNC. We all have our strengths, that comment is not meant to demean anyone.

While google on polygon turning, a company in India makes a unit that does polygon turning on manual lathes. The cutter head is run from the lathes headstock held in the chuck or other adapter. There is a drive shaft out the end of the cutter holder, and that connects to the spindle assembly mounted on the cross slide. The drive from the lathe spindle to the remote spindle runs at half the cutter speed. They have 1,2,3, teeth cutter bodies. They did not have any prices for their units. What I like about it, is that both are normal lathe rotation directions. It may just be something on my list to make one day.

Neil

**LINK** perhaps. Not specific to Linux, just a g code generator.

Wera Wuppertal designed these machines in the 1970's-1980's to make their hand tools using the lathe cutting tools geared to the headstock, they then went on to do the same principle using CNC control, the machines are used in car plants manufacturing gear box internals etc.

As a machine tool service engineer I worked on these machines and found them fascinating, to see a piece of round bar being turned into a triangle was interesting to watch.

Martin P

Wera Wuppertal designed these machines in the 1970's-1980's

If by "these machine" you mean polygonal turning attachments, they pre-date the '70s.

As an apprentice I was seconded to the Pegler Hattersley brass valve plant in Halifax around 1978/9 to assist their electricians to rewire the hot press shop after a fire. In the machine shop, the operating screws for gate valves were produced from brass bar on Wickman 6 spindle bar automatic lathes & the small square that the handwheel drives through was produced using a polygonal attachment. These were old machines in the late '70s, operated by cams & not PLC/CNC controlled. I have not been able to find when the Wickman machines started in producion, but guesstimate that the machines I saw were '50s production. They were well used enough to get worn to the point that they were completely refurbished by another Pegler subsidiary company that I also got seconded to for a couple of months.

The Pegler Halifax plant is long gone now (as is the Hattersley Heaton Brighouse plant were I was employed). It was a complete production facility for small brass valves, with an automated foundry, hot press shop, machine & assembly shops. The machine shop was internally know as "The Golden Mile" due to the asphalt floor being impregnated with brass chippings from the multiple bar auto lathes & rotary transfer machines that machined the valve body castings.

Nigel B.

What I meant was that they designed a system to machine all sided shapes on fully automated machines, I know the process was prior to that as Wickman multi spindle lathes had the option of a pecker device on one of the spindles to create a hexagon, I served my time at a Lucas CAV factory where diesel injectors were made and we had over 40 Wickmans some fitted with the Pecker.

Martin P

Have a 'Google' at this!