Hexagons

[Roger HulettParticipant @rogerhulett83124]

I shall be milling some small hexagons on a round brass stock using my little horizontal mill and Warco dividing head. Are there any pitfalls to be aware of or other advice ? Thankyou

[Roger HulettParticipant @rogerhulett83124]

Milling hexagons

[BazyleParticipant @bazyle]

Does chuck screw onto the dividing head. Beware direction of cutting force unscrewing it.

After setting up the dividing head fingers do a test run to make sure you aren't 6 holes out by the end of the job.

[Tim StevensParticipant @timstevens64731]

I find it helpful to set the mill so that it will leave the flats a little too high, and to start, mill two, opposite each other. Check the AF dimension with caliper or mike, and then adjust the setting by just enough to give the finished size you need. Then go round all six at that setting and your nuts will fit the spanner as you hoped.

PS just to avoid misunderstanding, AF means Across Flats. This method works perfectly with nuts in other systems as well as the 'Unified' or US sizes marked as AF spanners.

PPS it should also be possible to mill flats of several times the nut thickness at one go, and then part off to give the finished nuts, remembering to cut a V-groove before each parting so the nuts have a chamfer. Don't over-do the length, though, as you cannot use a steady at the free end to support the work.

Cheers, Tim

[I.M. OUTAHEREParticipant @i-m-outahere]

FWIW i would splash out on a hexagonal collet holder as it saves stuffing around with dividing heads , i use mine all the time !

[IanTParticipant @iant]

Don't over-do the length, though, as you cannot use a steady at the free end to support the work.

Well, if you want/need to machine slightly longer lengths per 'rotate' – you can use a machinist's jack which you can use to support the first three sides. Then you can either adjust the jack – or (more simply) leave it as is and use a shim (that's equal to half the difference between the diameter and AF measurements) for the remaining three sides.

Regards,

IanT

[pgk pgkParticipant @pgkpgk17461]

'I needed to do similar (albeit a larger size) and couldn't be bothered to set-up the rotary table for it.. simply held upright in a v-block in the mill vice, do the first 2 flats then used a gauge from the fixed face to adjust the part's rotation for the next 2 flats and repeat.

pgk

[Anonymous]

It looks like the Warco dividing heads have an indexing plate behind the chuck, so there's no need to twiddle with the dividing plates and fingers. In my experience using the "spin indexer" function on a dividing head is way quicker than hex collet holders, and you don't need to worry about setting depth of cut at each index. I can't see there'd be a problem with length of work sticking out,; why not just use the tailstock?

Andrew

[IanTParticipant @iant]

Certainly could use a tailstock for a lot of jobs Andrew – but it does depend on what kit you have available. A Hex collet block is a lot cheaper than a dividing head or even a spin indexer for instance.

It also depends on the size of nut material you are trying to make of course… This was about 1mm AF hex

Regards,

IanT

[I.M. OUTAHEREParticipant @i-m-outahere]

By the time i remove the vise , set up either a dividing head or spin indexer and set up for the first cut i would have finished the job 3 times over with an ER32 hex collet block even if i left the vise up on the table the collet block would still win the race ! The only set up is a stop on the vise ( same as the type JB described in another thread ) fit the appropriate collet to the holder , stick the materieal in the collet and tighten . I only have to set this in the vise against the stop , touch off then set depth of cut and rip into it . I used to do all of my hexagonal work with a dividing head using the quick index fitted to it but once i saw the hex collet block in action i never went back to the old way , they are worth their weight in gold as far as I’m concerned ! If i had to cut a hex on a piece of bar where the hex is going to be a long one then yes i would use the dividing head and tailstock . One issue is he is using a horizontal mill so getting the arbour to clear the top of a dividing head may be a problem , that is if the OP is using the over arm and bracket – or is he mounting the cutter straight into the hole for the arbour ? If the over arm is being used the lower profile of the collet block would be an advantage , just spin the vise around so the jaws are parallel to the Y axis and set the block up in the vise – too easy !

[Anonymous]

Posted by IanT on 25/10/2018 22:23:03:

Certainly could use a tailstock for a lot of jobs Andrew – but it does depend on what kit you have available. A Hex collet block is a lot cheaper than a dividing head or even a spin indexer for instance.

Quite so, but the OP says he has a Warco dividiing head, and they seem to come with tailstocks.

Andrew

[JasonBModerator @jasonb]

XD, you don't even need a vice stop, back of the nut against the vice jaw will act as a stop.

Having said that I much prefer the spin indexer, with a collet block you do need to make sure it is sitting down firmly in the vice, as I often work a part on the end of a 2ft length of bar there is a tendency for the overhanging weight to want to tilt the block

Horizontal mill can be used with a collet or collet chuck in the spindle and use the edge or end of a end mill so no overarm or large diameter cutter to get in the way. It's just a vertical mill on it's side.

[I.M. OUTAHEREParticipant @i-m-outahere]

Depends on what sort of kit the OP has for his mill , he may or may not have the collet holder for the spindle .

If the OP is limited to using the overarm and arbour he may have to do the job with the workpiece in the vertical position – depending on how long the piece is of course !

Another thing to consider is the amount of Y axis travel especially if using a collet chuck ( ER type ) in the spindle regardless of what he is using to hold the workpiece he may run out of Y axis travel and the only way to find out is to set it up and see . A cutter held directly in a collet that fits in the spindle ( mt collet ) will shorten things up though .

[John ReeseParticipant @johnreese12848]

Posted by Andrew Johnston on 25/10/2018 22:05:09:

It looks like the Warco dividing heads have an indexing plate behind the chuck, so there's no need to twiddle with the dividing plates and fingers. In my experience using the "spin indexer" function on a dividing head is way quicker than hex collet holders, and you don't need to worry about setting depth of cut at each index. I can't see there'd be a problem with length of work sticking out,; why not just use the tailstock?

Andrew

YES!

[John ReeseParticipant @johnreese12848]

I have at least 5 different ways of indexing things. Andrew's suggestion is a great solution, but I would probably fall back on my oldest indexer, made by Kalamazoo. I modified it by machining the sides of the casting about 1/2" above the bottom so it sits nicely in the vise with stepped jaws. On my size 00 index head it is a bit of a bother to disconnect the worm to use it as Andrew suggests.

Here is my link to the Kalamazoo

Kalamazoo Industries 5C collet indexing fixture

[Ian S CParticipant @iansc]

Depending on the accuracy required, the quickest way is in the lathe with a 3 jaw chuck and a filing res and file, and use the chuck jaws to index the work.

Ian S C

ps; you might need to make the filing rest, but it will come in handy in the future.

[Nick WheelerParticipant @nickwheeler]

Posted by Ian S C on 27/10/2018 12:20:39:

Depending on the accuracy required, the quickest way is in the lathe with a 3 jaw chuck and a filing res and file, and use the chuck jaws to index the work.

Won't that depend on how much material will need to be removed to create the hex?

[not done it yetParticipant @notdoneityet]

OP does not give much away.

Small, to me, is 10-12mm.

Are these hexagons going to be discrete parts eventually?

How many hexagons on each bar, the distance between and do they need to be lined up?

Possibly find the OP really needs to source brass hex instead of using round….

[Mick B1Participant @mickb1]

I used a 60 degree wedge, with the flat side of the flange against the fixed vice jaw, when I did the hex on these castellated flange nuts. The 60 deg set square from a kids' geometry set would probably have done as well.

[Ian S CParticipant @iansc]

I'v used the filing rest to put a hex on a 3/4" AF nut and bolt set (four off ea). Use as big a file as you can get, job done quicker than setting up the mill, rotary table and all. Made the bolts with extra material on the head, after filing the hex, the extra parted off and drilled and tapped as the nut.

Ian S C

[IanTParticipant @iant]

A bit off-topic – and I've probably mentioned this before but a few years back I needed to replace the regulator rod on one of my engines. Ian's post about filing reminded me that I used this dodge to quickly do the small 'square' on the end that locates the handle – not having a filing rest (still don't actually).

I used a collet block to grip (note brass 'adaptor' used to size collet to rod – only had two 5C collets!) the rod – and a 'roller' (scrap round piece) about the same diameter as the collet centre height to guide the file. All done in a few minutes – count a few strokes, rotate, do again, rotate etc – test for fit. For a single small nut – just use a hex block – or it's equivalent (see my earlier post for an example).

Regards,

IanT

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