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Jack772
01-08-2009, 05:18 PM
I just acquired 2 slitting saws. Both are 3.5 inches in diam, one is 1/8 and the other is 3/32 inches, HSS.
I have no idea how fast to run these. It's my first experience with saws. What are some typical uses?
Anybody have any ideas?
Thanks,
Jack

Dave P.
01-08-2009, 05:44 PM
Typical use is to take a "almost completed" part, snatch it from
a marginal set-up ( designed not to scratch it )
and sling it across the shop at a substantial velocity.
Typically destroying the part, bending the saw, the arbor it's mounted
in and whatever else it connects with on it's way to the garbage can.
Also may lead to foul language...
Dave P.

SGW
01-08-2009, 05:47 PM
Figure it out the same way as any other cutter. In your case, a 3.5" dia. cutter has a circumference of just about 11", or 0.92 feet. If you want 100 feet/minute cutting speed, that would be 100/0.92, or about 109 rpm. I probably run mine slower than recommended, but I tend to be cautious.

Uses? I'm building Edgar T. Westbury's "Unicorn" steam engine, and I just used a slitting saw to split the castings for the bearing blocks. I use them to take off pieces of material, instead of having to turn it all into chips. I've slotted screws.
Whatever.

Oh - when you use them, you'll hear that not all the teeth are cutting, and wonder if something is wrong. It's not. That's the nature of the beasts.

garyphansen
01-08-2009, 11:33 PM
I have used to gash gear teeth prior to hobbing. And like the above post said I never been able to get all the teeth to cut. Gary P. Hansen

Teenage_Machinist
01-09-2009, 12:40 AM
You will want a very on center arbor to get all teeth cutting..\


I suggest use of cutting oil (not coolant) on sides of non-sidecutting saws.

loose nut
01-09-2009, 11:26 AM
Make sure that you bring the cutter up to the work and start the cut slowly and after you have it started then you can increase the rate of travel, other wise its hard on the teeth and can grab the work (see Dave P.'s post for results of that)

hawgwrench
01-09-2009, 12:32 PM
I get alot more predictable result with smaller diameter....tend to run mine slower than max cause I'm a sissy and dont really care for the taste of metal....had several different brands too....the ones from Grizzly are better suited to cutting plywood...or carving your thanksgiving turkey....didnt last very long even with light cuts and slow speeds....

jkilroy
01-09-2009, 12:51 PM
"You will want a very on center arbor to get all teeth cutting..\"

I don't think there has ever been a slitting saw that cut equally on all teeth, its one of the laws of physics right? ;)

Calculate you desired chip load, in steel I'd suggest starting around .002. So if thats the chip load you want, and you have a 48 tooth cutter, not uncommon, you will need to feed .096 PER REVOLUTION to maintain that chip load.

Now, I'd start at 60fpm in steel, no faster until you get a feel for the setup. With a 3.5" cutter that is around 65 rpm. That means you are going to feed at 65 * .096 or ~6.25 inches a minute. That gives you an idea.

Now another tip, if you are going to cut deep, say .75 DOC, start by making a very light cut, like .125, then the following passes will be guided, to a degree, by the existing slot.

Do not even think about climb cutting.

Unless you are cutting cast iron, use LOTS of cutting lube.

Make sure your setups are secure, if anything gets out of whack, they WILL provoke much foul language.

Davek0974
01-09-2009, 03:06 PM
Typical use is to take a "almost completed" part, snatch it from
a marginal set-up ( designed not to scratch it )
and sling it across the shop at a substantial velocity.
Typically destroying the part, bending the saw, the arbor it's mounted
in and whatever else it connects with on it's way to the garbage can.
Also may lead to foul language...
Dave P.

LOL :)

I have done just that. Cutting the bronze bearing caps for a steam enginge. First one was fine second one grabbed half way, shattered the blade, bent the arbor and left a tooth embedded in the part which i could not get out.

I have greatly improved my success with flood coolant and lots of it, dont let the crap build up un the blade. I have also recently got some side & face cutting saws which seem much better.

Dave

HSS
01-09-2009, 03:14 PM
LOL :)

I have done just that. Cutting the bronze bearing caps for a steam enginge. First one was fine second one grabbed half way, shattered the blade, bent the arbor and left a tooth embedded in the part which i could not get out.

I have greatly improved my success with flood coolant and lots of it, dont let the crap build up un the blade. I have also recently got some side & face cutting saws which seem much better.

Dave


OHHHHH, he said "flood coolant":D

SGW
01-09-2009, 03:30 PM
Oh - be sure your mill is trammed properly, or the blade will bind.

Jack772
01-10-2009, 09:53 PM
I can't get it to work. It looks like it just scrapes the work. The blade looks like it has dulled. The mill, sieg x3, just slows down. The mill looks like it is not made for slitting.
Time to move on.
Thanks,
Jack

J Tiers
01-10-2009, 10:33 PM
I can't get it to work. It looks like it just scrapes the work. The blade looks like it has dulled. The mill, sieg x3, just slows down. The mill looks like it is not made for slitting.
Time to move on.
Thanks,
Jack

And how fast in RPM was it going?

In what material?

Dulled saws are nearly always from running way too fast. Does the Sieg even GO lower than 100 RPM? I looked up the HF ones, and most limit at 100 RPM, which would be about 90 SFM, fairly fast.

The mill "not being made for slitting" might be true speed-wise, but otherwise that wouldn't be correct. ANY mill will do all the milling jobs. The saw might be too big for it, though.

torker
01-10-2009, 11:42 PM
You will want a very on center arbor to get all teeth cutting..\


I suggest use of cutting oil (not coolant) on sides of non-sidecutting saws.
Would you care to share your wisdom...why we wouldn't use coolant????
This I want to hear...

Mark McGrath
01-11-2009, 05:36 AM
Any HSS tooling,milling,sawing,turning,in mild steel,start of with sfm of 50-70 fpm with coolant and at least 0.002" depth of cut per edge.It`s easy to work up the way.Start of too high and the cutter is finished instantly.
Mark.

GKman
01-11-2009, 08:55 AM
I go a couple of pounds of HSS slitting saws on eBay. Look expensive but won't cut pudding. Any idea what the rake angle and relief angle should be for cutting steel? Not making my living with them, but would like to cut a screw head once in a while.

For any of you claiming to be able to get one centered tell Guy Lautard. He can't. Maybe he'll put you in his next book.

SGW
01-11-2009, 09:01 AM
Speaking from experience....do you have the teeth pointing the right way?

Doc Nickel
01-11-2009, 09:03 AM
2-1/2" in diameter, 250 RPM, 7/16" DOC, 0.020" wide cutter, aluminum workpiece. Single pass, hand fed, every tooth was cutting (smooth sound, even when starting) and the motor didn't even know it was there.

Poor vise, but I'm working on that. :D

http://www.docsmachine.com/machineshop/tt01.jpg

This little horizontal is proving to be extremely handy.

Doc.

John Stevenson
01-11-2009, 09:11 AM
Doc,
Put the vise the other way, 90 degrees, so it pushing against the fixed jaw. that way it can't tip or throw the work.

Just a suggestion :rolleyes:

Doc Nickel
01-11-2009, 09:34 AM
Doc, Put the vise the other way, 90 degrees, so it pushing against the fixed jaw. that way it can't tip or throw the work.

-I did, later. :D

http://www.docsmachine.com/machineshop/stop04.jpg

The Nichols has an odd table; the first and third T-slots are smaller than the center slot. The middle slot is normal Bridgeport sized 5/8", the other two are 7/16" and rather shallow.

I'm still only just now getting this machine tooled up- hence the poor vise for the moment- and I had no T-nuts or bolts that fit the outer slots. The vise had no mounting tabs on the ends, only the sides, so it was difficult, at best, to mount it transverse.

Just a few days ago (same as the above photo) I made a couple of T-bolts specifically for this setup, from some old 3/4-ton lug bolts:

http://www.docsmachine.com/machineshop/tbolt1.jpg

So I'm getting there. But what I'd really like to do is get at least one, or better yet a pair, of the 4" or 5" import Kurt clone vises, and fit each with base keys- one parallel, one perpendicular- so that switching, depending on the work to be done, is only a few moments' work.

Plus I'll eventually carve up a small handful of appropriately-sized T-nuts, and start a collection of 3/8" and 7/16" studs, bolts, nuts and washers.

But for the moment, I need to finish the base/riser:

http://www.docsmachine.com/machineshop/010-02.jpg

Doc.

John Stevenson
01-11-2009, 09:55 AM
Just a few days ago (same as the above photo) I made a couple of T-bolts specifically for this setup, from some old 3/4-ton lug bolts:

http://www.docsmachine.com/machineshop/tbolt1.jpg


Doc.

Nice, my very first tailstock dieholder for 13/16" dies was made from a large truck wheel stud :D

After that I went round looking at all the parts in the stores not as this fits XX truck but what can I make out of that for my new lathe .

.

J Tiers
01-11-2009, 11:18 AM
Doc,
Put the vise the other way, 90 degrees, so it pushing against the fixed jaw. that way it can't tip or throw the work.



And so it can't close up the work on the saw, or more likely, lose its grip when the slit is cut and the work becomes more flexible due to the cut.....:eek:


A slitting saw that "can't cut pudding" is either as dull as ditchwater, or being used wrong somehow...... There has to be a sensible reason, because the darn things work rather well, so long as you don't try to cut too deep with a plain one.

Doc Nickel
01-11-2009, 06:47 PM
And so it can't close up the work on the saw, or more likely, lose its grip when the slit is cut and the work becomes more flexible due to the cut.

-Fortunately I learned that one way back in the hacksaw days. "Hey! Why won't this stupid saw cut anymore?!?" :D

That's why I'm thinking about getting two vises, and having each pre-set with the table keys. I do paying work in the shop, so time is money- sometimes I'll need the jaws parallel to the table, sometimes perpendicular. With a set of keyed vises, I can yank one and plunk the other down in moments.

Same reason I've collected seven arbors for this thing so far- it's faster to swap an assembled arbor than fiddle with spacers and nuts.

But I digress. :D

Doc.