Does anyone have a Korloy 32mm indexable parting blade?

[MuzzerParticipant @muzzer]

[MuzzerParticipant @muzzer]

I've ordered one and probably won't see it for a week or two. In the meantime I'm making up a toolholder for it to suit my Bantam QCTP.

I'm wondering what the height of the blade is. And before you say 32mm, I'm pretty certain it's less than that. The 32mm seems to refer to the maximum height dimension of the rhombic space the blade fits into. However, as both sides of the long faces of the blade (the 150mm long ones) are chamfered at 15 degrees, the resulting height of the blade will be closer to 31mm I suspect.

They say it is compatible with industry std 32mm blade holders so perhaps a different make may also have the same dims.

This snip from the Korloy brochure illustrates my point. "H3" is 32mm, so what is the height of the blade? When I model it in CAD it comes out just over 31mm.

Any real world measurements would be very helpful so I get it right in the absence of the real blade. Thanks.

Muzz

[blowlampParticipant @blowlamp]

 

If they state the peak to peak dimension as 32mm, then that is what I would use to make a holding block as it remains constant regardless of the width of blade chosen.

You could also make you own blades like I did.

The one shown below will fit into a standard 26mm block too.

Martin.

Edited By blowlamp on 17/11/2013 10:02:55

Edited By blowlamp on 17/11/2013 10:05:41

[MuzzerParticipant @muzzer]

CAD model for Bantam-specific blade holder coming along. Basic section defined and extruded. Model of blade ready for assembly. WIP…..

Planning to use an end mill for the 15 degree lower lip.

[Anonymous]

Odd that you asked the question, I've just had one of these blades delivered; must be a happy coincidence!

The blade measures 31.33mm apex to apex.

Regards,

Andrew

[blowlampParticipant @blowlamp]

Oh, I see on your original picture where I've got it wrong.

Korloy are measuring the 15 degree angles from the upper and lower left corners of a 32mm high blank.

We really need the gauge of the parting blade you're going to use, but the peak to peak dimension of a 2mm blade I get at 31.464mm and 31.196mm for a 3mm wide blade.

Sorry for the confusion.

Martin.

[Sub MandrelParticipant @submandrel]

Surely it's intended that the holder is machined with a slot to match the blank as if it didn't have the extra chamfers and was 32mm high? This means that the holder will work even if there are variations in the depth of the chamfer and gets rid of the need for a precision machining operation.

Neil

[MuzzerParticipant @muzzer]

Andrew – thanks, very timely! That seems about right for the 2.4mm blade.

Martin – no probs. They make several thicknesses of blade for the different insert sizes and the same block dimension is used for all of them as far as I can tell. The thickest is about 5.3mm, so it would measure about 29.2 height. For a 2.4mm like mine, the theoretical height would be 31.38 without any deburring – pretty close to what Andrew measured. That's T x sin(15) where T is the thickness. May not sound much, but the clamp would struggle if I got it wrong by 0.6mm.

The other outcome of the modelling will be a block that works for a 2.4mm thick blade. The clamp is for thicknesses up to 5.3mm. I will make mine for only the 2.4mm blade and will thus avoid the "jaws" at the top and bottom sticking out by 3mm more than they need. Here's what I have so far: The insert feature is only approximate – I have no measurements to go on but it doesn't matter anyway apart from getting the cutting edge height roughly right, which I believe I have(!) – it's a Dickson type adjustable toolpost.

Merry

[MuzzerParticipant @muzzer]

I've now finessed the dimensions and constraints so that the clamp bar contacts the holder and the blade correctly and created the drawings I'll need to make it. Hope I haven't missed anything off the drawings….

This is one view of the trickiest part, dimensioned to suit my Bantam and its Dickson QCTP:

Now for the tricky part….

Edited By Muzzer on 20/11/2013 07:40:10

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