Belts per knife?

[Nathan the Machinist]

I can't recall the last time I ground on a steel that was under HRC 60 or less than 2% vanadium...

 

[Natlek]

I'd have to do some math to figure that out. I still run the single speed grinder I built when I first started out. A new variable speed machine is next on my new tool list.
Its not slow but its not real fast.
Maybe they work better on a faster grinder, but I found them to cut horribly compared to the Norton (and even the vsm) belts. If I'd never used anything else I'm sure they'd seem great, just like how Norton blaze seemed great until I tried anything else

@Geoff , I understand what you say and I agree with it. I'm the one who needs to try other brand belt and then to make judge . But , by reading the posts in this topic, it is just unbelievable for me that belts last that much short time ...............If this were to happen to me, I would come back to my file jig ......ASAP My friend from USA is coming for a new year on a visit ...I will tell to him to buy for me some belts to try ...especially for a new grinder that I work on .And in this topic is mentioned every good one belts I must try

 

[Ken H>]

I run on 30 m/s and on 50 m/s

That's pretty fast, but ceramics do require high speed. 30 meters = about 98 ft, and times 60 to get feet per minute like we normally use would put it almost at 6,000 SFPM - "IF" I did my math right. That's a good speed for 36 to 60 grit ceramic belt. Now, 50m/s, that's 164 ft/sec, times 60 for around 9800 SFPM.... Now, THAT would throw some sparks!

 

[Natlek]

That's pretty fast, but ceramics do require high speed. 30 meters = about 98 ft, and times 60 to get feet per minute like we normally use would put it almost at 6,000 SFPM - "IF" I did my math right. That's a good speed for 36 to 60 grit ceramic belt. Now, 50m/s, that's 164 ft/sec, times 60 for around 9800 SFPM.... Now, THAT would throw some sparks!

Your math is right . That's way I work on new grinder .On this one with two wheel , sparks travel full three circle around belt , not pleasant that much to grind I found somewhere data that this kind of belt can run over 80 m/s .... ?
This is tracking arm for my new grinder , 2cm. thick steel , it take less then 5 second to grind end where are bearings in half circle ...........

 

[Brock Cutlery]

So this and an older thread made me do some testing on belts I was ready to throw out.
I put an old 40 Cubitron on my 14 inch wheel, and it cut really well. I was tapering a 3.5mm down to 1.5 at the tip (yep, no surface grinder).
It cut like a champ and removed a lot of steel. I knew this already, but forgot about it until this thread.
I also did some testing by just pushing hard for a bit to 'fracture' the media. Seemed to work really well on a couple of belts, not so much on a couple of others.
I figure I must have already pushed them past their prime. So I did get quit a bit of extra life out of some belts that are a bit expensive.
Thanks for all the great advice!

 

[BearPawBlacksmithing]

Wow! Id be more worried about putting a hole in my jeans tbh!


I go with the stock removal method, so for large ~1/4" thick blades i would go through 2 entire 50 grit 72" hermes ceramic belts and they would each get me an extra smaller blade done. After that is a 120 grit belt.

I push my belts to the absolute limit. I might start forging the bevels from now on... good quality belts here in Australia aren't exactly cheap!

AUSTRALIA!!! Haven't they banned anything over 2'' there???

 

[Jesse WW]

AUSTRALIA!!! Haven't they banned anything over 2'' there???

Heh, its worse than that friend; you're not allowed to carry around any form of blade in a public place unless you're a tradesmen with a multi-tool. Being caught with a knife is something like a $1000 on the spot fine and doubles on public transport. Police can search you anytime, anywhere, without any kind of excuse.

Here in the state of Victoria (known throughout Australia as the nanny-state (other states are a lot more relaxed regarding knife/sword laws)) you literally require a permit to own a sword or a dagger, and even then there is no real legal definition of what constitutes a "sword" or a "dagger" so its really left up-to the interpretation/how much common-sense the officer at the time has. Not only that but a sword permit requires you to store your swords in a locked cabinet/safe.

I guess you can say its actually the worst place a knife-maker can live. Whats worse is that all these laws have failed to even put a dent in decreasing knife related crime/violence. Its truly pathetic.

 

[timos-]

I was able to profile and 50% rough grind the following:
2 180mm XHP santoku
1 250mm nitrov chef
2 180mm w2 pettys
1 250mm w2 chef
1 small nitro v parer
1 240mm nitro v suji, with only the following:
1 already worn yellow 3m 684 belt and one new 977 belt (both 40 grit)

Not bad but I still expect to use around 6 belts per knife on average to finish them.

 

[Natlek]

That's pretty fast, but ceramics do require high speed. 30 meters = about 98 ft, and times 60 to get feet per minute like we normally use would put it almost at 6,000 SFPM - "IF" I did my math right. That's a good speed for 36 to 60 grit ceramic belt. Now, 50m/s, that's 164 ft/sec, times 60 for around 9800 SFPM.... Now, THAT would throw some sparks!

I love sparks

 

[Ken H>]

WOW!!!! That's some sparks!!! Just be sure your hand doesn't slip and hit the belt!!! I've done that at 4,000 SFPM, and took a knuckle down in a hurry!

 

[SamaraVolk]

I don't have permission to move a thread out of Custom... someone will though.

Don't get mad but I can rough grind 10-12 knives on a single 36 grit ceramic. It is all about pressure and direction. I can just as easily ruin a belt with one knife. If you are getting sprayed in the face with bits of abrasive when you start out, your angle of approach is off. At times you need to apply significant pressure to fracture the abrasive and get new life. I also tend to ignore the "direction" on belts but not sure if that does anything to extend life. Get a stone wheel dressing tool... the ones with the rolling "spurs". They bring back belts from the dead. I have never had a belt break but I'm sure I just jinxed myself by saying that.

Thanks for the tip on the dressing tool. I'll check it out

 

[Natlek]

I'm curious. How many belts and what type do you guys go through to grind a bevel? I've been going through 2 40 grit ceramics on annealed 1/4" 1095 steel. I'm not talking polishing, just to get to the desired edge thickness.

This Quote is from one belt manufacturer . . . .

1. Ceramic belts are probably a waste of money on some grinders that have neither the speed nor power and the belts will glaze and go blunt very quickly.
   
   
2. As amazing as good quality ceramic belts are, they are not at all recommended for soft material. They glaze and clog up, quickly ruining an expensive belt.

And here is another HSS steel /M35/ knife I grind on same belt ................