My (bad) carbide grinding setup

This topic has 8 replies, 6 voices, and was last updated 6 February 2020 at 07:50 by not done it yet.

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5 February 2020 at 00:41 #450747
dp2020
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@dp2020
I thought someone could get a kick out of my shoddy carbide grinding set up. I don't have any space to put a real grinder of any sort, so for grinding in my own scraper blades, this is what I came up with:

It's a 18mm diamond wheel in a chinese rotary tool, with a 3d printed 5 degree table attachment, running about 30k rpm — and to my suprise it actually works. Goes to show that a lot can be done with very little, if one accepts risk to life and limb
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5 February 2020 at 00:41 #19619
dp2020
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@dp2020
5 February 2020 at 01:40 #450748
Paul Lousick
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@paullousick59116
Better than nothing. If it works, use it.

Paul
5 February 2020 at 06:21 #450750
Pete Rimmer
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@peterimmer30576
If you have a lathe, you have a scraper grinder. Get yourself some 1500 grit flat lap discs 3 for a tenner from China. Remove the jaws from your chuck and stick the disc to the face of the chuck with double-sided tape. Don't use too much tape. Set the lathe for about 400rpm and you're off, just put a cloth over the ways or wipe them down after using.
5 February 2020 at 12:26 #450790
Howard Lewis
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@howardlewis46836
Where needs must and all that.

"C'est brusque, mais ca marche" as Peugot said (I think )

Would prefer to keep abrasives away from the machine tools, if possible, which is what your set up does.

Howard
5 February 2020 at 19:08 #450817
Pete Rimmer
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@peterimmer30576
Posted by Howard Lewis on 05/02/2020 12:26:40:

Where needs must and all that.

"C'est brusque, mais ca marche" as Peugot said (I think )

Would prefer to keep abrasives away from the machine tools, if possible, which is what your set up does.

Howard

Well I don't do it because I have a dedicated machine, but it's no more harmful than any of the many other sources of grit. Normal routine should be a wipe down and oil before use anyway.
6 February 2020 at 00:03 #450842
John Paton 1
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@johnpaton1
The back end of the lathe spindle is rarely used unless one uses a collet drawbar or hand crank for low speed.

that being so, and recognising low volumes of abrasive dust from diamond wheels, how about having a semi permanent grinding wheel set there, it would be a little bit away from the lathe bed? It would need a reasonably accurate expanding mandrel to mount it on and a decent catch on the change wheel cover to keep the rest in position.

On the other issue of abrasives and the lathe, does anyone know if all abrasive particles settle in the suds tank or does some of it get recycled in the coolant flow? The splash tray must attract lots of filth given its perpetually sticky state and on my lathe that gets rinsed over when using the coolant liberally.

( I might run some of the suds through a filter paper to see exactly what comes back up from the tank.)
6 February 2020 at 06:30 #450846
Pete Rimmer
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@peterimmer30576
You know what John, that's such a simple solution it's almost genius. It need not be as accurate as you think either – my grinder runs on a single bearing in a plastic housing. It shouldn't work by all right thinking but it does. You're hand-grinding a blade with very light pressure. All you'd need is a light disc with a loose sliding fit in the back of the spindle With a through-bolt and rubber plug & cap. load the disc on the bolt, poke it through, rubber plug and cap on the end, push it in the spindle hole and tighten.

Or you could get really basic and put a nut in the chuck and make a drawbar to hold a plate on the spindle end. That would work great too.
6 February 2020 at 07:50 #450849
not done it yet
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@notdoneityet
Not very semi-permanent. I open the rear door on my lathe very regularly to lubricate the gearing at the back end.😀

I don’t like abrasives near my machines, but finishing shafts to the last nth sometimes is a needs must situation. The bed is then covered in sticky (usually) paper that is then screwed up and discarded.

Dust from grinding can hang around in the atmosphere for some little while – not the large particles, of course – but still abrasive dust which settles somewhere eventually.
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