Slitting Saw Arbor

[Domagoj]

When I bought my milling machine, I also got a box of assorted tools, fixtures and whatnots. Among them was a slitting saw arbor that made me really happy since it appeared to be brand new, as if it has never been used. No actual saw blades, but a brand name $100 arbor itself is a goody worth noticing, so I got myself some blades and was happy to be able to finally saw anything that came my way (I don't have a bandsaw, yet). Unfortunately, I've been unable to find a way to use the arbor that didn't involve turning the entire milling head 90°. This is the arbor in question:


From the blade (which in this picture is mounted as low as it goes) to the bottom of the threaded core is about 50mm, which means that unless I tilt the milling head I would have to have the material sticking out more than 50mm above the vise, which would not only introduce some nasty vibrations, but is often impossible due to the fact that sometimes there is not enough material anyway.
I could tilt the head, but somehow the idea of tramming it every time doesn't appeal to me, so I'm looking at either buying a new arbor that will be much lower profile, or to get enlightened and schooled (I could be missing something obvious here...). Perhaps that's the reason previous owner never got to use it either?

Of course, there are $20-$40 arbors on ebay, such as this one, but somehow they don't instil much confidence.

I've looked around and this type of thing is similar to what I had in mind, namely short distance from saw to the end of the arbor:
https://spirittool.com/tool-arbors/
Of course, I expect this one to be more expensive, but I'm worried that if I buy the ebay thing, I'll still end up eventually buying something like the latter one.

Any advice?

[Mcgyver]

don't let tramming the mill stop you, it should be done regularly in any event (they do move) however I've not found it necessary to tip the head with that type of cutter.   Just come in from the side, with the cutter beside the vise instead of overtop. 

Of course its part dependent, can you post a sketch/drawing of what you are trying to make?

[Jasonb]

Small parts can be held at one side of the vice so that the arbor can go below the level of the vice, Larger items can be clamped to an angle plate so no jaws to get in the way, round stock held horizontally.

Having said that I mostly use an arbor with a CSK screw rather than the nutted variety

[Domagoj]

I was just trying to cut up some flat stock, and doing multiple ones I opted against using a hacksaw, trying to save some elbow grease.

Dimensions are 40x20 mm.
In this particular case, coming in from the side would be tricky since the saw I have is 100 mm in diameter, the arbor nut is 38 mm, so I'd be about 9 mm short of going all the way through. To go all the way through, I would have to clamp the flat stock on the edges. The stock is hot rolled and has uneven rounded edges, so clamping would be questionable, meaning milling the long sides first. A lot of work just for some simple cuts.
If I had a decent metal cutting bandsaw with a vise, it would have been a job done in 5 minutes.

The solution I finally got to was an angle grinder and milling the cuts clean and to a uniform size.
Yes, I could have used a narrower strip, but this was at hand.

[mklotz]

Make one like this...

https://www.homemadetools.net/forum/low-profile-slitting-saw-arbor-26210

[Jo]

That is not a slitting saw Arbor  That is the sort of arbor that I would use when cutting gears to mount the gear cutter on. You will probably find that its diameter is the same as ID gear cutters or other horizontal cutters and yes if you must a slitting saw   

For slitting saws you can get away with something much shorter. This is the sort of things you should be looking for:

You will note it does not have a key. The last thing you want with a slitting saw is a key, if it jams 

Jo

[TerryWerm]

I had an incident 20 years back where I was using a slitting saw on one of those inexpensive keyless stub arbors. Worked great until the saw jammed in the work which occurred very easily I might add. This resulted in the hex drive flat head screw getting so tight that there is no getting it apart anymore. Stripped the hex right out of the head while trying too. Result: saw and arbor are now one piece, permanently.

Ever since then I've always used a keyed type, and have never had anything jam either.  Now that I've got a horizontal mill as well as my vertical, I seldom use a stub arbor anymore.

So, if a stub arbor is the only way you can go, the choices are use the keyed type and ruin saw, part, or both IF and when it jams,

- or -

the saw possibly becomes a permanent item on the arbor when said jam occurs. This isn't so bad either as the arbors are cheap enough anyway.

Pick your poison I guess.

[Jasonb]

The down side to the one Jo illustrates is that the blade is only about 10mm below the end of the spindle so what you save on missing the vice you loose by the work hitting the spindle or are limited to thin work. I have also often heard it said that the multi size type are not that accurate, the one I used to have was not brilliant.

This is similar to what I tend to use but without a key.

https://www.chronos.ltd.uk/product/3-mt-stub-slitting-saw-arborssta3/

An R8 version here https://www.abmtools.com/product/straight-stub-milling-arbors/

[Domagoj]

You folks make some interesting points. Thank you for input, I'll have to sleep on this.

[Jasonb]

Found a better photo of the one I have that is similar to yours cutting work at the side of the vice. Ganging several saws on one of these arbors is quite a common method for cutting cylinder cooling fins so not sure why Jo is against using them for saws?

Yours does look to have a lot of excess thread exposed, maybe some of the spacers have been lost over time, if there is enough unthreaded shank available an extra spacer could be made up to move the blade nearer the end. This would allow the existing narrow spacer to go above the blade and the new one would in effect be a thick washer between nut and blade so would not matter if it were a tiny bit off thickness wise.

[Vixen]

Here is another example of the use of multiple slitting saws to cut cylinder head fins.

There are seven slitting saws, each of 36 thou thickness with 25 thou spacers mounted on the home made arbour, without keys. Spindle speed was kept to below 200 RPM and plenty of coolant fluid is required to flush out the chips. Chip control is very important.

The gang of slitting saws were plunged slowly to full depth and the cylinder head slowly rotated on the rotary table. That way you are always cutting into solid metal, leaving the delicate fins behind. You can see one cut was made to the full depth of the gang of slitting saws.

All slitting saws make a characteristic " zzick, zzick, zzick" sound when the touch the metal. Listen carefully at that sound and to the speed of the spindle, it becomes more constant as more teeth engage. Feed the saws in gently and continuously listening to the sound of the cut to control your rate of advance. Remember to use plenty of coolant to flush away the chips to prevent seizure.









Be brave, it can be done, with care

Mike

[Mcgyver]

Mike, beautiful work!

I was just trying to cut up some flat stock, and doing multiple ones I opted against using a hacksaw, trying to save some elbow grease.

Just opinion not an absolute, but its really not the best tool for that....I would encourage up to look at even the smallest bandsaw or keep hack sawing. 

The slitting saw mostly gets used as per all the photos above: for making slits.  Its usually a somewhat slow and risky operation...the deeper the cut the more you have to old your tongue just so.  (The context for all these statements are that we're dealing with fairly thin saw.  Its less so with thicker cutter.)

The reason is they are terribly flimsy and delicate and the cutter ends up slightly eccentric, partially as there has to be some clearance between the blade and arbor.  This means the saw mostly just cuts on a few teeth, and likely different teeth each time you mount it.   With a regular milling cutter, the cutting force loads the system and you all is good, however with a thin saw you have to be so light with the feed that you never get to load the system so it keeps cutting on a couple of teeth.  All this means you have to feed quite slowly or you risk jamming/snapping a blade.

PS, I'd also get rid the key if using a saw as thin as shown in your first photo.

[john mills]

using thin saws on arbors i don't use key through the cutter but do when I can use a key in the collar or spacer
to make sure it is driven if you have any larger dia flanges that is good too.this is were a horizontal mill
is usefull.but when you have a vertical mill these are the arbors you have to use ,keep the cutters as close to the bearings as you can and the part as close to the middle of the vice as possible as the vice won't hold well with the part is to one side special if the vice has any wear.