Slotting/slitting saws and the lack of concentrically

[starr256]

Slowing things down lowered the dB level, but the noise persists. Using a stethoscope and a diagnostic diagram I am thinking it is the bull gears. Not much I can do about it now. I do like the idea of mating an arbor for each bigger saw and then grinding them as a single unit. Now I have to research this idea of using the mill with a rotary table to do the grinding. One more distraction to delay work on the original project. Typical.

 

[WobblyHand]

Slowing the saw speed is to preserve the cutting tool and to achieve the correct SFM for the material being cut. If you had a carbide blade you could run it about three times faster than HSS.

As far as distractions or job diversions, that happens to everyone. Think you are right to track down the root cause of the noise issues. That stuff rarely cures itself.

 

[David2011]

As far as distractions or job diversions, that happens to everyone. Think you are right to track down the root cause of the noise issues. That stuff rarely cures itself.

Still getting used to a new lathe and still using the old one occasionally which doesn’t help at all, my mind wandered while making a cut that took about a minute. When it came time to disengage none of the controls were where my muscle memory said they should be. Instant panic so I shut the motor off. I love the carriage mounted motor control rod and lever. I’ll make it a point to continue to think about what I’m doing.

 

[WobblyHand]

Still getting used to a new lathe and still using the old one occasionally which doesn’t help at all, my mind wandered while making a cut that took about a minute. When it came time to disengage none of the controls were where my muscle memory said they should be. Instant panic so I shut the motor off. I love the carriage mounted motor control rod and lever. I’ll make it a point to continue to think about what I’m doing.

Glad you saved the situation. Brain f@rts or things like that are real. Been caught on occasion. Have to maintain situational awareness when using our machines or it can get bad fast. Focus, finish and move on to the next step.

 

[durableoreo]

slotting saw blades (6 x 0.312 and 5x0.125)

This reminds me of plain milling cutters. My slitting saws are on the scale of a few 32nds. So I wonder if the noise is caused by a large load. You might be cutting on a single tooth, too. I suppose the combination could result in a fairly violent tool engagement and gear noise.

I recommend cutting oil in one of those 2-oz luer-lock squeeze bottles. I drip it directly on the saw, near where it enters the cut. If it's flinging off a 3" blade, it's faster than I typically run. Can't say for a 6" blade, though.

I have occasionally considered if I should make a dedicated hub for each saw. I wouldn't want to have a full R8 tool holder for each saw. However, a hub for each saw seems good. That would require a matching taper in an R8 shank. Seems like it would solve some of the runout issues AND serve as a diversion during all that free time! Maybe an MT1 for 3" cutters. Or Jarno #3...

This type of work might fall in the category of working hard to be lazy. I should probably just indicate in my 1/32 saw, which is what I use the most often.

 

[RaisedByWolves]

A high precision arbour and quality slitting saw will always have a tiny runout. In over 40 years and seeing almost a hundred shops, I've never encountered a guy who could claim no runout on his slitting saw. The regrind idea is SUPER promising, and is attractive to me!!! Great idea @Huub Buis !!

I kind of look at it as a feature, not a flaw.

Think of it like this, if you’re only cutting with part of the blade, the rest of it is still sharp.

When it gets dull just spin it 180 on the arbor and …..new blade!


Besides, even with a say R8 mandrel to eliminate the collet, you’re still going to have some runout.

 

[epanzella]

I have multiple arbors and slitting saws. They all cut decent but none are free from the yang yang yang of eccentricity.

 

[David2011]

When I first started using my homebuilt slitting saw arbor I was really disappointed in the concentricity. Thought I had done a better job than that. I was using it on a Jet-16 round column mill. When I got an Index 645 it wasn't noticeably different. After I sent the quill and spindle back to Wells-Index for bearings and a regrind the saw still has a hair of runout but instead of cutting for about 1/4 of a turn it's cutting about 3/4 of a turn. Last night I cut some screw slots in 416 stainless. With a 4" saw running at 300 rpm and a slow feed it was so nice to use. W-I said the runout before regrinding was .0015". Huge difference!