precision keeper cutting....

[Possum]

....

I do have the Harbor Freight tiny cut off saw, the problem is cutting precision lengths dependably. There's really no way to do it except maybe bolt the whole thing down and make an adjustable fence. The wet tile saw thing is the same deal, I have a plastic cheap tile saw but no good way to cut precise lengths. Worth looking into though, a wet diamond saw cuts perfectly with no heat.

I was serious about beating your keeper with a hammer, it will work harden it and you should hear brighter tones. Look at TTop keepers, they were punched real hard to make the holes, the whole thing is work hardened....

[David Schwab]

I do have the Harbor Freight tiny cut off saw, the problem is cutting precision lengths dependably. There's really no way to do it except maybe bolt the whole thing down and make an adjustable fence.

That's what I did. I have to cut batches of blades of several different lengths, so that was the only way to do it.

[Possum]

...

It did a fairly good job cutting and the clamp keeps the metal from getting hot enough to change the temper. Gonna try the cheap tile saw though, zero heat is better...

[David Schwab]

It did a fairly good job cutting and the clamp keeps the metal from getting hot enough to change the temper. Gonna try the cheap tile saw though, zero heat is better...

I think you are worrying about nothing. The blades I use are a bigger part of the pickup than a keeper, and I've cut them with hack saws, little cutoff wheels on Dremels, and the chop saw. Also belt sand or grind them and they do get hot. They don't sound any different. Not brighter, not darker. I do hear a difference with various steel alloys, but not from how I machine them.

Also, if work hardening makes the steel harder and brighter, wouldn't heating it make it softer?

I'd have to hear an A/B with the same keeper in normal vs. work hardened vs. heated to believe it will make a different that anyone but you will notice.

Here's a fairly easy test.. take the baseplate off a pickup and mount it upside down over the strings. Record the pickup. Now remove the keeper and whack it with a hammer, and put it back, and record it again with no other variables changing. Now try heating the keeper and repeat the recording. To make it easier, compromise the keeper by making the holes large enough to slip off the pole screws. Even if that isn't the best for tone, it will establish a control base tone to start with. Do all the abuse to the same keeper, not one of the same alloy.

[defaced]

Anything below the metals lower critical temperature (around 1300F (~700C) for low carbon steel) isn't going to affect the microstructure. Translation, if the color doesn't change, you're good with some margin for error.

[Bill M]

I use the wet tile saw because I already had it. I'm not saying its the best method to cut keepers, but it does work well for me. First thing I did was buy a good diamond blade for it and I've cut at least 250 + pieces with it and its still going strong. The saw I have has an adjustable fence and also a guide so I can guide the work piece in straight.

As for precision, I know once the fence is set all the pieces are the same length and thats good enough for me.

I just thought the tile saw was a good idea because it doesn't heat the metal up. Now if it is leaving traces of diamonds embeded in the steel, I don't know. I kinda like the Idea of that: DIAMOND TONE KEEPERS!

[ShannonH]

I kinda like the Idea of that: DIAMOND TONE KEEPERS!

It's your new ad copy. "Diamond Tone: Made With real diamonds!"

Note I didn't say "of real diamonds"

[David Schwab]

"Diamond Tone: for a sound that cuts glass!"

[David Schwab]

Keep in mind that the diamond abrasive will actually get dissolved into the iron if you use diamond to cut steel and you let the temp get too high.

It only has to be 392 F (200 Celsius). What happens is diamond will change its crystal structure to that of graphite at 392 F in the presence of a catalyst metal such as carbon steel and alloys with titanium, nickel and cobalt.

That will cause premature tool wear.

[Steve A.]

Wow- I think I just wandered into an advance physics class! Great stuff and I don't think that you would find anything like that elsewhere on the web.

One question: how would this discussion apply to the keepers in P-90's (or the lack thereof)?

Thanks!

Steve Ahola

P.S. I attached a PDF of this thread for your off-line archives.

[Bill M]

It only has to be 392 F (200 Celsius). What happens is diamond will change its crystal structure to that of graphite at 392 F in the presence of a catalyst metal such as carbon steel and alloys with titanium, nickel and cobalt.

That will cause premature tool wear.

Heck, if I have to change blades every few hundred keepers, thats no problem. As I stated, I've cut 250+ pieces already with the same blade. Apparently the steel, or the cutting blade isn't reaching the 392 F. Darn I was really set on having "Diamond Tone Keepers".

[David Schwab]

Heck, if I have to change blades every few hundred keepers, thats no problem. As I stated, I've cut 250+ pieces already with the same blade. Apparently the steel, or the cutting blade isn't reaching the 392 F. Darn I was really set on having "Diamond Tone Keepers".

I agree, but I was just pointing it out. It had been mentioned a few times, so I looked it up to find out the details.

I've already went through one ceramic cutoff wheel, so that's to be expected.

[Joe Gwinn]

Possum, I tried the abrasive cut off wheels. It worked fine, but it made the keepers very red hot at the ends. Not very good. So, now I use my $85.00 wet tile saw with a good diamond blade and it works like a charm.

If you try to run the diamond blade fast and/or dry while cutting any ferrous alloy, the diamond blade will be ruined in a flash.

[Bill M]

If you try to run the diamond blade fast and/or dry while cutting any ferrous alloy, the diamond blade will be ruined in a flash.

I'll have to make sure that I don't let the water tray run out when cutting.

[Spence]

Anyone have thoughts on how to cut keepers to length precisely? I've been cutting them on a bandsaw and grinding on a disc sander to length, but I don't like this method and too time consuming. Is there such a thing as a precision cut off saw?

I have hundreds of them for sale.