Square end on round stock – Milling?

[Roger TheShrubberParticipant @rogertheshrubber24386]

Hello good people!

 

After a bit of advice. I need a repeatable way of milling a square end on round (6mm dia) brass stock – 4mm wide across flats. I have a WM14B warco milling machine at my disposal. Quite new to milling…My question is how to achieve this whilst obtaining good work holding and indexing.

Thanks very much!

 

[bernard towersParticipant @bernardtowers37738]

Collet blocks, Indexer, Dividing head ,it depends on what gear you have but at that size collets would give good repeatability

[JasonBModerator @jasonb]

All the above plus these if you don’t have the items.

If the overall length is not too great then just hold vertically, locate ctr and mill the 4 sides. A stop will allow you to do multiples. Backlash and compensating for it does become an issue if you don’t have a DRO.

If there is plenty of length then simply clamping something square to the far end and using a square up against that will index your 4 sides.

Or just use the rear of the vice jaw to index 3 faces after milling the first.

 

[Peter Cook 6Participant @petercook6]

+1 for collet blocks, provided you can mill the squares close to the workholding method chosen.

If you can’t and there is a lot of stick out, it gets hard to get the precision. You could always take the incompetents way out as I did here and thread a bit of 4mm square stock into the end of the  6mm rod.

[VicParticipant @vic]

As mentioned, collet blocks are an easy way of doing this. I have several ER32 versions. Another method I use is with a Spin Indexer.

https://www.arceurotrade.co.uk/Catalogue/Collets/5C-Fixtures/Stevensons-5C-Indexing-Head-with-ER32-Nut-and-Adaptor

 

[DalboyParticipant @dalboy]

If it is a short piece by using a V block stand it upright and mill the square on the top. This will require you to find centre and off set for each side from centre.

[ZanParticipant @zan]

Dal boy no need to find the  centre, measure od subtract 4, divide by 2 and cut until u get that size ie  4 + cut size from above

Use the  feed dials after initial cut and  re measure.

Total cut should be just under 1mm

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, a Stevensons square collet block is an easy way of doing it. Just nip in a collet and hold the block in a vice, with the nut against the vice sides, mill each flat in turn, making sure the nut is against the vice each time, and there is no need to alter the quill, once you have it set for the depth.

Regards Nick.

[DC31kParticipant @dc31k]

Specifically for a square, a collet block or indeed anything at all clamped onto the stock is not required. In some respect, those options are icing on the cake.

Mill the first face by touching off on the top and adding 1mm depth of cut. Rotate 90 degrees and use a square against the just-milled face to align the second surface.

Anything at all clamped to the table the other end of the stock will provide length control.

For a hexagon, instead of using a square to align the just-milled face, a commercial hexagon nut can be used:

For a pentagon or any other regular polygon, cut one out of card and stick onto the stock (you do not need to stick it on concentric – think about why this is so). Align one side vertical (square to the table) to the table.

[old martParticipant @oldmart]

I do have a pair of er25 collet blocks which will hold up to 16mm diameter, but as the rotary table is normally sitting on the Tom Senior, that is more likely to get used. We also have er40 which has collets up to 30mm, and must find out whether collet blocks are made in that size. As members respond, even more clever ways of getting the job done are coming to light.

[JasonBModerator @jasonb]

My weapon of choice is the spin indexer though collet blocks can be better for some jobs say if you want to put a slot down the middle of the square once it has been formed.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi old mart, Banggood sell them ER40 Collet Blocks and so do Amazon ER 40 Collet Blocks

Regards Nick.

[BazyleParticipant @bazyle]

Perhaps the original poster wouldn’t have asked if he had a shed full of equipment and/or the desire to buy equipment for his friend’s mill as mentioned in the first post.
Instead of a collet block a small piece of square material preferably steel or aluminium but possibly a hard plastic or wood can be drilled 6mm and cross drilled for a locking screw. Use a bit of brass or plastic under the screw to avoid marking the job. You may need to buy a M4 tap for the screw but that is small, cheap, and has other uses for the rest of your life.

Just to add to the implausible and over the top methods fit two side and face cutters to your 1 1/4 arbor with 4mm of spacers between them and set up in your horizontal mill. Cutting two flats at once at precisely 180 degrees will speed the job. Run the job at night on cheap rate electricity so the load of the 5HP motor doesn’t add too much to the bill.
Otherwise to do it in the lathe just set up a square template in your Armag profiling head as they can do outside forms as well as holes.

[HuubParticipant @huub]

I would dril (ream) a hole in a square block and add a locking screw. That will make it easy to repeatedly mill a square at the end of a 6 mm rod.

As an alternative you can bolt a 10 mm thick square plate at the end of the bar and use that square to align the bar after each face is milled.

A (CNC) rotary table would be nice to have for these kind of jobs.

Personally, the CNC lathe would be my first choice and the (CNC) mill and (CNC) rotary table would be my second choice.

[Roger TheShrubberParticipant @rogertheshrubber24386]

WoW Thank-you all for the guidance – many viable options I did not even consider; clearly a lot of experienced hands on here. I’ll report back with results when finished.

Be well.

Roger!

[IanTParticipant @iant]

And if/when the power goes down, you can always get yourself a hand shaper and do it quietly by candle light Roger

(and get some exercise too!)  🙂

IanT

[Nicholas FarrParticipant @nicholasfarr14254]

Hi IanT, I like that idea, and if you can get your shaper outside on a nice day, and it not being too hot, you can do it in good old fashioned daylight.

Regards Nick.

[BazyleParticipant @bazyle]

We forgot to mention a filing rest in your treadle lathe, indexing with a changewheel.

[Bazyle]

On Bazyle Said:

Just to add to the implausible and over the top methods fit two side and face cutters to your 1 1/4 arbor with 4mm of spacers between them and set up in your horizontal mill. Cutting two flats at once at precisely 180 degrees will speed the job. Run the job at night on cheap rate electricity so the load of the 5HP motor doesn’t add too much to the bill.

Sets of precision spacers for horizontal mills are rare; finding a metric set for an imperial arbor is probably impossible. I have recently acquired a set for a 1-1/4″ arbor, but of course they are imperial:

No need to run the mill at night, a 5hp motor won’t even notice the cut.

Julie

[Roger TheShrubberParticipant @rogertheshrubber24386]

This thread is a perfectly layered sandwich of helpfulness, subtle sarcasm, and dry engineering humour of which I thoroughly approve. I thereby award you all with a virtual shrubbery [second hand of course – the knights (whom formally said ‘ni’ turned their noses up.]

Going to try Bazyle & Huub’s low-cost solution!

RtS

[Bazyle]

On Bazyle Said:

We forgot to mention a filing rest in your treadle lathe, indexing with a changewheel.

Isn’t filing by hand to precise specifications the first thing one is supposed to learn? The OP didn’t mention what the part is for, but it’s small enough to be a quick job in the vice.

[Nick Wheeler]

On Nick Wheeler Said:

….The OP didn’t mention what the part is for, but it’s small enough to be a quick job in the vice.

Yes, but the OP said repeatable, so presumably more than one. In which case filing would become tedious.

Julie

[JasonBModerator @jasonb]

As The OP says he has a vertical mill might as well stick to methods that suit it’s use.

This is one of the methods I mentioned earlier if you don’t have much in the way of tooling. I’ve assumed a vice and a milling cutter are available but not much else.

Pack the work up on whatever you have so it stands just over 1mm above the top of teh vice jaw. Touch the cutter onto the top of the rod, note height then reposition cutter 1mm below the crest of the rod and take a cut.

Loosen vice, rotate stock 90deg so face just machined is against the fixed jaw and cut again. Repeat & Repeat again.

I saw this method in a book aimed at beginners😉

Add a length stop if you want or if the edge of the cutter is set flush with the end of the vice jaw as I did here then you can just push the shoulder from the first cut against the vice jaw.

Note if a shorter length of rod then stop the machine when repositioning the work.

[old martParticipant @oldmart]

Thanks, Nick, that will help finding different sizes of collet. As it happens, I had looked on ebay just after posting here and found a French seller with a pair of er40’s for £42 including postage and went for them. I now have everything er40, from MT3 holders,R8 holders and a 100mm dia plate which can fit the 1 3/4 X 8W and 1 1/2 X 8UN backplates of both lathes and collets from 3-30mm. I blame another volunteer, Roger who gave us the MT3/er40 and some collets for starting the ball rolling. Up till then, we had been happy with er25 size.

Just in case somebody does not know, if you put work in the very end of some types of vise, a similar thickness piece should be fitted in the opposite end of the jaws otherwise the moving jaw can rotate slightly. Jaws out of parallel do not hold work properly.

[Roger TheShrubberParticipant @rogertheshrubber24386]

Thanks very much for this Jason!

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