Hexagon Machining - Time Saving Methods

Thank you Elroy,

I just learned something new and it's opened up all sorts of possibilities.

Tony

Lacking the appropriate indexing fixture, I have actually cut a pretty accurate hex on a mill just by manually rotating the stock 120 degrees after each cut. The second and third cuts are critical, getting a good 120 degree alignment. Using something like a sine bar and some solid mathematics to get the depth of cut you need and to set the angle. Once you have the round stock cut to triangular stock, the last three cuts are opposite pre-existing flats...

Of course, building the fixture takes a lot longer than cutting the hex...

Is there a good reason for not buying extruded hex bar from the steel suppliers / steel mill?

The hex land on a round bar can be used to orient a second part or simply to provide a place to put a wrench or socket, for installation reasons.

For some reason I read the OP as wanting to turn the whole of the round bar into hex. Read it again and it's ambiguous.

Been through this here where a designer designed an adapter where (I think he intended) we were supposed to machine to hex then turn down a length to a smaller diameter round. There was no reason not to have hex all the way down. All I asked for was an adapter I could use a spanner on that had thread X to thread Y! It was respec'ed to use stock hex and just the threads machined...

Hexagon to be manufctered is at the end of rod of total length abt 120 mm . It is like a plug.

Hi sunhil2008,

We posted at the same time! Thanks for the clarification. I think the others have given you some useful tips.

Thats pretty close to 2-1/4 inch. Good chance you can find it as a stock size & just saw off wutever length you need.

Do you want something like this?

Cutters are available for suitable machines as mentioned in an earlier post.

I've seen somewhere a polygon lathe attachment but can't find it at the moment.

Hi NIGH

There are polygon turning machine ( PLC based ) which are highly productive but they are effective upto 30 mm dia. Thanx.

Have you tried to procure M.S Hex bright bar. They are readily available in Indian market.

As I stated earlier holding dia is 100 mm ( The part is to be made from rod of 105 mm

dia )

Can you gang mill on a vertical axis mill? If it was a horizontal mill you would use 2 cutters separated by the A.F. dimension of your hexagon. If you could do this on a vertical mill with the work piece horizontal you would only need to make 3 passes.

Dear ALL,

Thank you all for valluable advice. But still I want to know which will be good method for indexing ? It should be rapid. Please help. Thank you.

If you angle either the mill head or tip the vice to 30°, you can index off the last face milled.

Alternately you can machine a hexagon bush with a grub screw or 2 to put the bar in and use either gang mill or single cut and index on the bush.

As we don't know what the finished component looks like, it's a bit hard to advise. How about you upload a drawing

Tony

Polygon Box is the cheapest way to do the job ... might not be able to buy a box that big but you can make a simply one ... should well and truly pay for its self if you doing the numbers ... finish is usually pretty good ... tool is sharpened as a knife tool so that it peels the metal of the face not the diameter the difference in depth of cat ( radial ) does not affect the finish if you adjust the feeds so that the cut is not to heavy ... drop me a line if you want a sketch of a polygon box ... we also at times do shaped holes such as oval, square, hex in the lathe by rotary broaching. I find that now days people are not inclined to have a go at making tooling ... we make lots of special tooling for ourselves as half the time you cant buy what you need and the cost of adapting standard tooling some times works out dearer than making a piece of tooling. Batt

There are a couple of options

1st - you could start with Hex bar - potential 20% saving on machining time in comparssion to using round bar

2nd - you get a 4th axis cnc milling machine reducing your labour unit cost - reducing your time to set up - yet is limited to one unit per cycle

3rd - get a CNC lathe with milling attachment - reducing your time to set up - this option is also limited to one unit per cycle unless you get a twin spindle with two milling attachments

3rd - get someone in a 3rd world country to machine it from round bar and pay a low wage - be careful as lower the wage lower the quality - but you would have all the time on your hands.

4th - get a qualified tradesperson to do the job - this options offers a high degree of quality and less stress in comparison to the other options suggested.

5th - And the best option send us a copy of your product drawing and we will access the component and build you a special purpose machine.

Sunil 2000 units each month is a significant number of products for a single vertical manual machine.

I assume that you are a manager / owner of the business if the is the case we can reduce the machining time for you and your business if you have the order please contact us we would need to know the following information along with a drawing.

What is your budget - how much can you afford to spend?

What is the unit price you are seeking to achieve?

What is your hourly rate of work force?

What is your target cycle time and no of units produced per cycle?

When do you need to deliver the first batch of products?

Anthony@Alno

www.alnoproductservices.com.au

Anthony@alnoproductservices.com.au