Author Topic: How to cut a 1/2 round slot.  (Read 372 times)

Offline Arnak

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How to cut a 1/2 round slot.
« on: December 12, 2018, 03:35:27 PM »
Hi,

I would like to cut a slot for a bearing in a piece of 1/2 round aluminium as per the attached pic.

The problem is that I cannot find a slotting cutter with a small diameter shank. :doh:

I can only think of a standard 16mm T slot cutter with a ground down shank, to say just under 6mm to fit into the 6mm dia 1/2 round slot that runs up to the bearing location.

The 50mm dia rod will be cut in half lengthways then pinned back together and re-turned back to round.

The 6mm hole is then drilled, the 2 halves separated and the 16mm x 8mm deep slot formed.

Bearing thickness is 6mm.

Once the slots in both halves of the rod have been machined the bearing is inserted and the halves pinned back together.

Any ideas on how to cut the slot, please?

Martin

Online efrench

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Re: How to cut a 1/2 round slot.
« Reply #1 on: December 12, 2018, 03:56:31 PM »
Boring head on mill could work, but wouldn't it just be an interrupted cut on a lathe?  A groove tool should work.

Offline Jo

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Re: How to cut a 1/2 round slot.
« Reply #2 on: December 12, 2018, 04:13:05 PM »
Ali is easy to cut: Find yourself a piece of 16mm dia Silver steel machine it to provide a 16mm diameter 6mm thick end with a 5.5mm ish shaft (Leave the rest of the shaft a size to hold in a collet chuck). Give it a centre drill hole and then mill yourself some, say 8, teeth round the cutter surface using support in the centre hole. File to give them a bit of relief (look at your other milling cutter edges to see what I mean  :thumbup: )

Harden in the normal manner...

Cut the 3mm (6mm diameter) half groove using the side of an end mill. When you use the cutter lubricate it to stop the chips sticking, cut on a slow speed, don't go in too fast and remember to clear the chips.

Jo

P.S. Make sure you get your teeth the right way round on the cutter.
So many engines to build and yet so little time.

Offline Arnak

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Re: How to cut a 1/2 round slot.
« Reply #3 on: December 12, 2018, 08:09:44 PM »
Hi Guys,

Thanks for the advice. :D

The 6mm groove is no problem as that can be drilled first after the rod has been re-rounded after being cut in half then joined back together.

Then I will need the cutter...

I will try the 16mm silver steel and make a cutter as suggested.

I can then use it in the mill with a collet chuck. :headbang:

Martin