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Thread: Wet sharpener with CBN -no water
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18th November 2019, 10:47 AM #1Senior Member
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Wet sharpener with CBN -no water
Hello all,
I need to upgrade my sharpening system.
Am thinking of getting a wet system and replacing the wheel with CBN wheel and not use water.
My existing wet grinder is useless because the shaft got rusty and swelled so much the wheel does not run true, so much so it's useless.
The idea of a sharpener which can accept many jigs is appealing.
Anyone here tried a CBN on such a machine?
Do these machines have enough grunt to run heavier CBN wheels.
The other option is a slow bench grinder on which I can use CBN wheels.
cheers
conwood
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18th November 2019 10:47 AM # ADSGoogle Adsense Advertisement
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18th November 2019, 10:55 AM #2
Hi Conwood
Don’t waste your money. The ultra slow, wet grinders will work with a suitable (180 grit) CBN wheel, but they grind very slowly. Wet grinders were designed this way to avoid overheating the steel.
For the same money - or less - as a new wheel and new shaft, you could get a 6” CBN wheel (again 180 grit) on a full speed machine, which will have a similar surface speed to a half-speed 8” wheel. I use the latter, but 8” half-speed machines are difficult to access. If you can find one, then grab it. That is my preferred set up. I have both 80- and 180 grit wheels. The 180 grit gets used 95% of the time.
Regards from Perth
DerekVisit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.
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18th November 2019, 11:07 AM #3Senior Member
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thank you for the informative reply Derek.
So you are suggesting I go with a full speed 8 inch machine and run a 6 inch CBN?
If that is the case then I would need to get jigs for bench shisels and turning chisels, which is not a problem.
cheers
conwood
ps- just looked at your website which I shall look at in depth.
Lots of info on there for which I thank you
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18th November 2019, 07:59 PM #4
Hi Conwood
I am not sure if the diameter of the arbor/spindle for the 8" grinder is the same as for the 6" machine. I was thinking of a 6" machine for a 6" wheel. That is the cheaper option, plus it will have a slower surface speed than an 8" wheel (running full speed).
Regards from Perth
DerekVisit www.inthewoodshop.com for tutorials on constructing handtools, handtool reviews, and my trials and tribulations with furniture builds.
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19th November 2019, 11:34 AM #5Member
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I have 6 cbn set up with tarmac jigs works a treat,
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21st November 2019, 08:11 PM #6
[QUOTE=derekcohen;2163201]
Don’t waste your money. The ultra slow, wet grinders will work with a suitable (180 grit) CBN wheel, but they grind very slowly. Wet grinders were designed this way to avoid overheating the steel.
For the same money - or less - as a new wheel and new shaft, you could get a 6” CBN wheel (again 180 grit) on a full speed machine./QUOTE]
IME, overheating is not an issue with grinding HS steels.
The experience of others also supports this.
High carbon steel is a different matter.
Putting aside the savings that Derek points out in going with a 6" setup, unless you need to grind HC steels why grind slower than you need to?Stay sharp and stay safe!
Neil
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21st November 2019, 10:27 PM #7Taking a break
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22nd November 2019, 11:48 AM #8
Yes, depending on how/which red... Red heat - Wikipedia
In practice, you are not going to get anything approaching 'black red' on a CBN wheel with normal sized tools. Sintered CBN wheels abrade relatively cool compared to Alox wheels, thus far fewer sparks.
Yes, bluing is only cosmetic and typically only happens at lower temperatures between 300-400°C. Anything below 'very dark red' (abt. 600°C) is not going to de-temper the HSS steels we use, but just don't quench a HSS tool that has been heated up from grinding as that can create micro-fractures at the cutting edge that will weaken it.Stay sharp and stay safe!
Neil
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22nd November 2019, 12:23 PM #9Member
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Hi I just checked the Vicmarc site they have their own system now. It all depends on your budget.