Cutting a long slot.

[NeoTech]

So i need to cut a long slot, about 20cm long, and about 40mm deep, and about 6mm wide.. So tried this with a mill.. that did end in thee broken mills.
I dont have a side-milling cutter for doing this, not in 68 diameter, 6mm wide and with a 22mm center hole anyway..

So im thinking, can this be done on a shaper? the slot is not going all the way trough, so it will stop "dead" in the end of the slot.. but its open in one end. (its for a integral knife frame)

[PeterE]

Just a thought, but why not start the slot by chain drilling? That way the need for milling is very much limited to the final finish which also should spare the milling cutter quite much. The depth will not be a problem either.

/Peter

[Jonny]

Assume this is in steel?

Do these things about twice a week but usually 8 to 10.2mm slots up to 48mm deep. Keep an eye and ear open for any change of note, things can happen quick.
For 6mm I would start off with a 5mm as far as it can go then change over to a 6mm, it will give a better finish and avoid the torqueing off. Constantly clear out debris and look at the cutter often , see if its deflecting and all should be fine with coolant.
There wont be many 40mm flute x 6 dia cutters available, don't skimp carbide of reputable brand.

No advice on shaper but will have to constantly clear out the slot same as above. Air line.

[Manxmodder]

If using a shaper the stop point needs a hole driling so the tool has somewhere to break the chip into.
If not then the swarf starts to impact and pack at the termination point of the cut.
Also what Jonny said,the cut needs frequent clearing of swarf and some cutting fluid should used.
Another option would be to use a slitting saw indexed across several passes to bring the slot to finished width.
...OZ.

[trapper]

Yes agree with everbody.The  ideal way clamp it to table stub arbor in the nose of machine  a mill where you could take head off and work off column,use a "chipping saw"or "stagger tooth"saw bobs your uncle,The shaper method would work like has been said you want a hole to run your tool into at end of stroke to stop a build up,the depth your going to with such a small diameter tool is unsuitable for a shanked tool will snap-

[trapper]

Just thinking you can pick used saws cheap on ebay try and get a 3/16th wide side and face cutter or a chipping saw they are stagger toothed cut better than a sliitting saw,as the name suggests the plain saws are really to be used for splitting things-yes I know they can do a deep slot but thats not what they were intended for,so go for one of the others much more suitable for deep slots-a 3/16 is a common size should easily get one of those normally with a inch bore so you may have to turn a stub arbor to hold it-you will have to open your slot out .039ins to get your width but you can bump the feed up to do this.A 6ins diameter tool will give you about inch clearance

[NeoTech]

I shall try both the drilling a **** ton of holes. and if that isnt working trying the making a hole for the shaper..

As stated finding the tools required was a hassle thats why i thought of using the shaper and a parting tool. ;)

[Jo]

I don't know what it is for but could you silver solder a couple of bits of steel together with spacers to form the slot?

Jo

[NeoTech]

Ah well its for an integral folding knife, a large one. Basicly the handle frame is a one piece, that you mill out and then fit all the pins and lock inside, and the blade is then "closing it up". in this case i will have about 0.35mm on each side of the blade to spare. Its a custom order and i thought i had ths down.. but apparently not.

[hanermo]

If you are trying to be practical .. just go down down the road to someone with a commercial mill, who can use rigid carbide effectively.
Should not be any problem on a modern tool, and take maybe 20 mins.

Agree on saws, and drilling.
Lets us know how it turns out.

[NeoTech]

Ok, going down the road and as a commercial company for help.. Where i dont know anyone.
I would most likely. and i'm 99% sure that i would get a "no, we dont have time".. even if the machine is  unused, just standing in a corner.
Why..? Welcome to sweden.. At least around here.

[petertheterrible]

Why not use a surface grinder with a cut-off disc or fly cut it from the side.  If no surface grinder is available, a hand-held angle grinder can be used if you are careful and don't mind coloration.  Finnish the job by milling and with luck no-one will no that you cheated and didn't mill from the start.  This cheat is intended for the home shop where end-mills are precious and not for production as the foreman will probably go ape for the angle grinder idea.