Slitting saw advice

[Sshire]

Getting the shop ready for the new machine arrivals in the next few weeks.
Thoughts for most used sizes of slitting saw blades for small engine builds. I know it's tough without any specific engine in mind but 3 or 4 to have on hand. I'm going to make the arbor. Also sources would be helpful. I've looked at the usual suspects (Enco, MSC, Travers, etc) and I'm more confused now than when I started.
Thanks so much
Stan

 

[mklotz]

Since they can be ganged (e.g., two 1/32 saws will make a 1/16 kerf), buy a variety of small aliquot sizes.

It's an interesting math problem... What's the smallest selection of saws that can be combined to make all the 1/32 sizes up to a max of, say, 3/16? (I'm deep in something else right now so it's left as an exercise for the reader.)

You might want to consider getting a carbide-tipped circular wood saw as described here...

http://www.homemodelenginemachinist.com/index.php?topic=1952.msg15740#msg15740

 

[awJCKDup]

Hi Stan. I have a set of small 6 Piece Rotary Saw Blade Kit from Harbor freight. The largest is probably about an inch and a quarter dia. they are HSS. I made my own arbor, and when I use them I run them very slow, with a very slow feed rate. They have served me very well so far. I think the smallest will cut a .030 slot. Oh, the best part is they are less than 5 dollars. Just my 2 cents.

John

 

[Sshire]

Marv and John
Thanks for the speedy replies.
I hadn't known that they can be ganged. That simplifies matters.
I may actually have the wood blade with all the woodworking tooling I've collected over the past 25+ years. Have to mount a search party.
The saw permutation problem is intriguing. I'll work on it.
I'm off to the local Harbor Freight in a few minutes to get those blades and I'm going to order at least a few 1/16th blades from MSC or Enco.
Thanks again.
Best
Stan

 

[Ned Ludd]

Hi Stan,
A word of warning when ganging thin slitting saws, they can spread! The voice of experience here, unfortunately, once I was putting a screwdriver/coin slot in some Pre-war dashboard mounted fuse holders and ganged two blades together to get the required width. Lo and behold I ended up with two slots as the blades spread. It only happened the once, but it is something to look out for.
Ned

 

[mklotz]

The saw permutation problem is intriguing. I'll work on it.

I thought about it in the shower this morning. I should learn to take my own advice - in additive combinations the binary system gives you maximum sizes for minimum pieces.

Consider saw blades in units of 1, 2 and 4 thirty-seconds, i.e., 1/32, 1/16, and 1/8. Then, by ganging, we have:

1 = 1
2 = 2
3 = 2 + 1
4 = 4
5 = 4 + 1
6 = 4 + 2
7 = 4 + 2 + 1

thus all the 1/32 increments from 1/32 to 7/32 with only three saws.

 

[Rayanth]

Hi Stan,
A word of warning when ganging thin slitting saws, they can spread! The voice of experience here, unfortunately, once I was putting a screwdriver/coin slot in some Pre-war dashboard mounted fuse holders and ganged two blades together to get the required width. Lo and behold I ended up with two slots as the blades spread. It only happened the once, but it is something to look out for.
Ned

This sounds like the result of either swarf working its way between the blades, a bent blade, or perhaps a not-quite-tight attachment to the arbor allowing one to work loose, causing the swarf condition.

- Ryan

 

[djc]

A word of warning when ganging thin slitting saws, they can spread!

As a lot of slitting saws are hollow ground to give clearance (and thus require no set on the teeth), this is perhaps to be expected. Squeeze the middles in, out pops the perimeter. You have to put a very thin shim between the two blades before tightening the arbour.

 

[Dave G]

One thing to keep in mind is the surface speed of the cutter. On some of the small mills the slowest speed is still too fast for the cutter dia. Try to purchase slitting saws that will fit your mill speeds, the larger the cutter dia, the lower the speed of such cutter. I keep a good selection of slitting saws on hand and use them quite often. Carbide slitting saws can be run at a higher RPM and may be a solution for mills with too high a speed range. It's best to check your surface speed requirements before ordering. Dave

 

[bezalel2000]

I thought about it in the shower this morning. I should learn to take my own advice - in additive combinations the binary system gives you maximum sizes for minimum pieces.

Ain't binary great you only need 8 sizes to cover every step from 1/32 to up to 8"

but IIRC 4 of them might be considered slab milling cutters.

Bez

 

[dgjessing]

Don't expect too much from those HF blades - I've got some and made an arbor for them. The arbor hole in the blades are not exactly in the center though, so all the work gets done by one or two teeth. You can manage to do small stuff with them, but, well, don't expect too much :