Diamond coated hacksaw blade - need source

Anyone know where to buy a diamond-coated hacksaw or coping saw blade? (USA only) I need something to cut a stuck bearing inner race off of a small motor shaft and I'm sure it's hardened steel. I looked on google and only found Australian listings. A bearing puller is no good since it's right against the commutator and impossible to get anything behind it.

Reply to
WKW
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Can you dremel tool though it?

Wes

Reply to
Wes

Dremel cutoff wheel?

Reply to
David Lesher

One decent method is to cut it with a 1/8 cut-off wheel in a die grinder. Cut about 90% thru in 2 places, and if the heat hasn't loosened it, a chisel in line with the shaft will split it. Just mask off the electrics from the sparks.

Reply to
Stupendous Man

I do not know of a source for the blades but I do not think that is the easiest way to remove the race.

A small bearing splitter would probably hold on the groove enough to pull it. Sometimes a copper tubing flaring tool will clamp tightly enough to do something like that, especially if you fill the groove with a suitable wire. You can also just grind it thru in one or 2 places, being careful to not grind into the shaft. Sometimes a hard hammer blow will crack and loosen it. Arc welding on such a race will generally loosen it.

Don Young

Reply to
Don Young

Hmm ... do you have a Dremel or something similar? Use one (or several to get the job finished) of the brown abrasive discs to cut two grooves into the inner race parallel to the shaft axis and 180 degrees apart. They don't have to go all the way down to the shaft -- just perhaps 3/4 of the way.

Then put a cold chisel in the start of the groove and hit it with a solid hammer (wear safety glasses, because the parts will probably fly.

The grooves probably won't go all the way to the commutator, but they should not need to -- you will have started a stress concentration zone, and once you hit it with the hammer you will supply the stress and induce failure in the bearing race.

Good Luck, DoN.

Reply to
DoN. Nichols

I used a cut off disk in a dremel to get a groove on two sides, then inserted a screw driver blade and popped it apart. Gerry :-)} London, Canada

Reply to
Gerald Miller

Not diamond, but round hacksaw blades encrusted with carbide are easy to find. Ought to cut hardened steel, since it will cut a Coke bottle.

Reply to
Leo Lichtman

Yup, Remington rod saws, used to be a staple at the former local True Value. Dremel cutting disks are cheaper, though.

Stan

Reply to
stans4

snipped-for-privacy@prolynx.com wrote in news:76b1dbe1-2290-436b-afd1-9743b05f01f3 @f40g2000pri.googlegroups.com:

Thanks for all those tips. I had no trouble at all finding those carbide grit edge hacksaw blades and rods on the web. I just bought 12 blades for $12 on eBay. (Under $1.50 each with shipping) I have a Sears dremel type tool also, but I haven't been able to find the discs I had. And those things break so easily I'm going to try the hacksaw first.

Wade

Reply to
WKW

Here are the reinforced cut off wheels I use. I buy them from my local Menards store. It doesn't pay to buy the ones without the fiberglass reinforcement, they break like glass.

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Reply to
Up North

These are a lot cheaper

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Reply to
Up North

FWIW, if you soak those non-reinforced disks in a few drops of thin CA glue (hobby super glue) and let them dry thoroughly, they hold together much better.

Best -- Terry

Reply to
Terry

"Terry" wrote: FWIW, if you soak those non-reinforced disks in a few drops of thin CA

^^^^^^^^^^^^^^^^^^^^^^ Thanks, Terry. That sounds like a great idea. BTW, would CA glue also strengthen the reinforced disks?

Reply to
Leo Lichtman

It might not be a big issue with such small cutting disks as the ones being discussed, but doesn't CA glue give off nasty fumes when it's heated?

Reply to
Wild_Bill

The suggestions to use the tiny abrasive disks with a high speed rotary tool or Dremel are a good solution.

The fragility of these thin (not reinforced) is an issue, but I rarely have one break while using them. I like the reinforced disks where it's not as easy to have a firm grip on the tool near the nosepiece, but the thin disks perform very well if the user doesn't try to steer them, let the disk grab in the cut or let the direction of the rotation feed (pull) the disk.

I can almost guarantee a high disk failure rate (that the fragile cutting disks will fail) if the workpiece is held in one hand and the grinder/tool is held in the other hand. But when the workpiece is held securely in a stationary vise/holder and the tool is held securely, the fragile disks perform very well and are a cost effective solution to making small cuts.

When the cutting direction is opposite the direction that the disk would travel if allowed to, the disks' fragility isn't a big problem.

BTW, there are diamond dust coated steel disks in the same size range as the small, thin cutoff disks that aren't fragile, and will cut/notch/grind various hard materials. An expensive diamond abrasive wheel shouldn't be used at high speeds on steel, but a $.80-.90 disk doesn't usually fall into that category (for most of us, anyway).

I got a blister pack from HF that included an arbor with a 1/8" shank and 4 or 5 diamond disks that only cost $4-$5 with an order of other stuff. I don't use them frequently, but I think I'm still using the first one removed from the pack.

These small power tools aren't impressive to look at, but when I encounter a fuctup fastener in a close location (where a torch or an air chisel aren't appropriate - junkyard work), the small tool is extremely worthwhile.

I've got a few old rotary tools that were made in the 1930-40s (0-1/8" and also 1/4" shank models) that still perform nearly as well as when they were new, and still perform the tasks that they were intended to.

Reply to
Wild_Bill

Probably would, but I've never had one of those break. They just wear down.

Reply to
Terry

Hadn't noticed it myself... though it sure gives off some eyes-n-nose-burny stuff as it cures. Cutting-disk treatment is best done outside or in a well-ventilated place.

Best -- Terry

Reply to
Terry

Dad had one - it was round and a spiral. Grit was in the lands of the spiral. I have no idea where to buy one now - but I'd look into jewelry suppliers.

Martin

WKW wrote:

Reply to
Martin H. Eastburn

there's a stained glass wire saw that uses blades like what you're looking for.

saw:

blades:

regards, charlie

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Reply to
charlie

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