Slitting saw usage ?

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- Howard Beel
  
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posted
5 years ago

Tue, Sep 19, 2017 10:57 PM

This video shows a slitting saw mounted in a
boring head. Is there a special reason for doing
this? The cutting is simular to that of a shaper rather
than that of a saw cutting continously.

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Best Regards
Tom.

- J
- Joseph Gwinn
  
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posted
5 years ago

Wed, Sep 20, 2017 2:09 PM

On Sep 19, 2017, Howard Beel wrote (in article ):

Bad idea. And the saw slips for lack of a antirotation key. Probably cobbled together.
And the saw blade is badly fouled with adhering chips - looks like aluminum, even though the billet is dark colored. Slitting needs to be done wet.
Joe Gwinn

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- Jon Elson
  
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posted
5 years ago

Wed, Sep 20, 2017 6:38 PM

Yeah, that's amazing. As in, BAD! I always use a slitting saw with flood coolant. I have several arbors that can be used with them. The bigger ones do have a keyway, the smaller ones don't, but don't seem to slip with reasonable depth of cut and feedrate.
Jon

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- Howard Beel
  
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posted
5 years ago

Wed, Sep 20, 2017 7:55 PM

I have found that most slitting saws have some runout and usually need a touch up when mounted in the arbor. For some reason there always seem to be a few teeth that are higher than the rest. Some of the blades i indicated were 15 thou out of round and i sent them back to the vendor. After mounting the saw in the mill i indicate it and mark the high teeth then use a dumore tool post grinder to knock down the high teeth. I like the peterson expanding flush mount arbors and robbjack arbors.

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Best Regards Tom.

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- Jon Elson
  
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posted
5 years ago

Wed, Sep 20, 2017 9:09 PM

Yes, I can certainly hear the runout as a zing-zing-zing as the spindle rotates. It doesn't seem to hurt the operation or affect surface finish much in the groove. So, I just live with it.
My guess is these things are punched out of blanks, rather than machined and sharpened on an arbor.
Jon

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- Howard Beel
  
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posted
5 years ago

Thu, Sep 21, 2017 3:24 AM

It would be intresting to how the saws are made. Since they are made of HSS i don't think they are stampings. Maybe the hardened blanks are stacked and ground on a specialized cnc grinder, grind a bunch of the same size saws all at once?
Best Regards Tom.

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- Jim Wilkins
  
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posted
5 years ago

Thu, Sep 21, 2017 10:42 AM

I turned and milled the shank end of a 3/8" HSS drill bit into a 1/4" hex with retention groove to snap and lock into an extension shaft. It cut easily with HSS tooling. -jsw

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- Howard Beel
  
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posted
5 years ago

Thu, Sep 21, 2017 6:15 PM

All the HSS drills i have run into have soft shanks. Only the flutes are HSS. My collection of big drills were originaly 4 and 5 MT that i purchase cheap because there is no hobby market for them. Generaly you can buy them at industrial auctions for scrap prices. Just turn down the shanks to size you need. I use a collet chuck to hold them so the shanks don't mungged up.
Best Regards Tom.

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- David Billington
  
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posted
5 years ago

Thu, Sep 21, 2017 9:40 PM

Every slitting saw I have ever used seems to have some degree of runout and is noticeable in the noise of the cutting. Most I use are top quality as well and came from a local engineering company involved in high volume production when it was demolished for housing and I got a lifetimes supply of the things for no money, actually my neighbour sold some at the local model engineering club at the first bring and buy day and brought back more than I paid for the lot and I still have a draw full. I usually run without a key as it was running with a key using a large slitting saw, 8" IIRC, that it jammed and took out the main spindle key in the BP when running with a 90 degree head. I don't run them with flood coolant but do keep them well oiled.

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- Jim Wilkins
  
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posted
5 years ago

Thu, Sep 21, 2017 9:57 PM

I understood that the drills are HSS all over, but the shank remains annealed for better grip.

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"mica", not "mice".
The MT2 tailstock on my lathe and B&S 7 spindle on my mill limit drill bit size to around 3/4" for heavy cuts, 1" by going slowly. I cut larger holes by boring or with a hole saw. -jsw

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- David Billington
  
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posted
5 years ago

Thu, Sep 21, 2017 10:28 PM

I find annular cutters, rotabroaches, work great in my lathe and mill and make light work of cutting the bulk of the material out, far better than holes saws. In the mill I just chuck them in a 3/4" collet, in the lathe I use a modified 2MT to 3MT adapter bored to 3/4" and fitted with 2 grub screws at 90 degrees.

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- Jim Wilkins
  
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posted
5 years ago

Thu, Sep 21, 2017 11:17 PM

Thanks, I'll watch for a used set. -jsw

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- Howard Beel
  
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posted
5 years ago

Thu, Sep 21, 2017 11:39 PM

If you take a taper shank drill and test the shank with a spectrascope you will see it is not HSS. I know this for a fact. Back in the 1970's i was in the bussines of buying and selling alloys. Back then M2,M3 HSS would fetch around $3.00 per pound. We always cut the shank off taper shank drills to maximize profits.
The largest drill i have is 2.75". Don't use hole saws anymore, switched over to annular cutters. For boring i like the kennametal twin bore tooling, no more tapering concerns and they use cheap carbide inserts. For big holes a treapaning tool is the way i go.
Best Regards Tom.

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- Howard Beel
  
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posted
5 years ago

Thu, Sep 21, 2017 11:50 PM

Agreed annular cutters also require less HP to do the job putting less strain on your machine. They don't have the problem of chip packing that hole saws have.
Best Regards Tom.

- E
- Ed Huntress
  
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posted
5 years ago

Fri, Sep 22, 2017 12:03 AM

Yes, and they're a lot less prone to shatter when they're deflected sideways.

Note how long it takes to anneal HSS -- 2 to 8 hours.You can't do it with a torch.

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- Jim Wilkins
  
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posted
5 years ago

Fri, Sep 22, 2017 1:34 AM

Annular cutters are on my shopping list now. However the large round holes I mostly cut are for analog panel meters in thin aluminum or plastic for which not grabbing is more important than cutting speed.
I've been putting cheap analog meters on my solar panel downleads after losing a nice digital Wattmeter to possibly static electricity. -jsw

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- Howard Beel
  
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posted
5 years ago

Fri, Sep 22, 2017 2:02 AM

You will be happy with annular cutters. For thin materials and plastics start with a sloooow feed. I have found that thier cutting action is agressive much more so than a hole saw. Run them slow to start with, fine tune as you go along.
Best Regards Tom.
I

- L
- Larry Jaques
  
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posted
5 years ago

Fri, Sep 22, 2017 9:21 PM

Annulars are wicked, aggressive looking tools. I ordered some hole saws on Ebay and they accidentally sent a set of diamond core bits in a different size set. Got a full refund and kept the diamonds. Ended up buying a single deep hole saw locally, and it cut the metal door easily.

Bummer. Aren't your panel frames, ground wires, and control panel face grounded? Which meter, Watt Meter (blue al), DROK, or Bayite?

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- Jim Wilkins
  
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posted
5 years ago

Sat, Sep 23, 2017 12:10 PM

It's a stand-alone system at 24V or less, which is allowed to be ungrounded. There is a ground rod for the generator when connected. The panels can be patched in parallel for 12V or series for 24V so one has to float. The lightning arrestors trip at 70-85V.

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"Be sure to make that connection (between negative and equipment grounding) in one place only."
This is the meter that failed by reading high. I can't prove static caused it.

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- Larry Jaques
  
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posted
5 years ago

Sat, Sep 23, 2017 1:27 PM

Isn't static electricity usually measured in the kV?

I get the ground loop thing, but since they're not electrically connected, I'm going to ground my frames and rails from a separate ground right next to their end of the roof, for the unlikely instance of lightning. The redwood would be the most likely strike point, with the power poles coming a close second, and the house/panels 3rd. SWAG I'm glad I don't live in your Lightning Alley.

Perhaps they should rename it BangBad? (mindless Blue State humor) PeaceFair looks a mite like a Bayite, enough that both could have come from the same factory. Perhaps I'll treat my Bayites a bit more cautiously from now on, since I hadn't been thinking about static damage.
Gotta get those panels UP!