Slitting saws

[Hitch]

Excuse the phone notepad sketch...

Ways to cut the 2mm grove, all I can think of is making a gash arbor, and tacking a sacrificial slitting saw on the end... use it to destruction then clean up shaft and tack a new one on...
Could I countersink the bore on a cutter and make a locking washer to retain it?

Taking out the middle section first with a normal cutter, then running a slitting saw through to cut the 2mm grove looks like an easy way to my untrained eyes.

Material potentially will be stainless, so a bit tough going.

 

[spaffmonkey]

Is this a item you need a number of them making? Have you looked up a local water jetting company?
We recently got asked to make a selection of different metal fittings for a lady that does upholstery for vintage Austin cars. We made a few samples for her which she was very happy with but they were very labour intensive and not very cost effective so I drew the 3 different parts up in AutoCAD and sent to the local laser cutters. It worked out at about 30% of the price we had quoted so she was very happy as we reduced here price.
Sorry for the long winded reply

 

[Guzrik]

There is a dimension missing; the width of the initial slot that limits shaft diameter for the second cutter.
Does the floor have to be flat?
Is this a one off or a series?
Maybe convert to a weld or brazed assembly?

 

[Stupoty]

It would have to be a cutter not a silting saw as there is no relief for the bottom of the blade clamp.

Stu

 

[Brad93]

EDM

However if this isn't a part for a billionaire then you'll probably want a dozen of the cutters shown by @Stupoty, the chatter of a full cut on both sides of the cutter is gonna ruin them pretty quick. You'll definitely need flood coolant to try and wash away the chips before the tooth engages the other side of the internal t slot.

Edit: just seen it's stainless too. Gonna be hard going.

What's your budget for this part and how many of them?

 

[Stupoty]

EDM

However if this isn't a part for a billionaire then you'll probably want a dozen of the cutters shown by @Stupoty, the chatter of a full cut on both sides of the cutter is gonna ruin them pretty quick. You'll definitely need flood coolant to try and wash away the chips before the tooth engages the other side of the internal t slot.

Edit: just seen it's stainless too. Gonna be hard going.

What's your budget for this part and how many of them?

I didn't notice it was stainless , I haven't tried a wood ruff type cutter in that tbh. they seem fairly good for a 2-4mm deep slot in mild steel though.

I would worry that welding a very slim slitting saw to an arbor might distort it a lot and also I don't know anything about welding HSS.

As you say the wire edm would be perfect for that shape.

Stu

 

[Hitch]

The gap through is about 16/17mm ish, not critical really.
Only want 2 or 3.

 

[oldbikedavey]

The gap through is about 16/17mm ish, not critical really.
Only want 2 or 3.

Woodruff cutter will likely do that, one side at a time.....

 

[Agroshield]

As the others have said, it is normal to have the centre of the T-slot slightly deeper (0.25mm would be enough).

Any Woodruffe or T-slot style cutter has to cut at 2mm wide and 6.5mm deep. It may be a challenge to find a cutter of that aspect ratio. See here for 2mm Woodruffe slot dimensions: (https://roymech.org/Useful_Tables/Keyways/woodruff_keyways.html).

If the centre of the slot is 16mm wide, a machine hacksaw blade with the set ground off the teeth so it cuts to 2mm wide and reduced in height locally would be worth a try.

Stand it on its end an use a 2mm end mill to remove some of the material. You should be able to plunge in 10mm from either end, only leaving a 10mm deep bit in the middle.

 

[oldbikedavey]

As the others have said, it is normal to have the centre of the T-slot slightly deeper (0.25mm would be enough).

Any Woodruffe or T-slot style cutter has to cut at 2mm wide and 6.5mm deep. It may be a challenge to find a cutter of that aspect ratio. See here for 2mm Woodruffe slot dimensions: (https://roymech.org/Useful_Tables/Keyways/woodruff_keyways.html).

If the centre of the slot is 16mm wide, a machine hacksaw blade with the set ground off the teeth so it cuts to 2mm wide and reduced in height locally would be worth a try.

Stand it on its end an use a 2mm end mill to remove some of the material. You should be able to plunge in 10mm from either end, only leaving a 10mm deep bit in the middle.

Get a thicker one of larger diameter, and grind it back ?

 

[Guzrik]

Stand it on its end an use a 2mm end mill to remove some of the material. You should be able to plunge in 10mm from either end, only leaving a 10mm deep bit in the middle.

I like this, why not use a normal drill and drill as much material away as you can, to save the mill in the later step.
But then again, time vs money.

 

[Agroshield]

I like this, why not use a normal drill...

A drill is a good idea.

In suggesting an endmill, my thinking was that it would be stiffer than a twist drill and thus less likely to deflect. Carbide as a material is stiffer than steel and a 3 flute endmill will have a larger diameter core than a 2 flute twist drill. My guess of 10mm plunge depth is 5 x diameter, which is not too bad an ambition. It might be possible to go the full 7.5 x diameter with care. The endmill would also let you drill out the web in between nearly-touching holes. Plunging it in means there are no side loads on it so reduces the chance of breaking it.

The part could also be fabricated and bolted together.

 

[dave h 2]

End mills do not plunge as they do not cut in the centre, you need a slot drill, clue is in the names and one blade is longer than the other.