Problem that I would like a solution for

[northwest]

I know this is opening a can of worms but here we go. Material is 304 stainless 50mm x 50mm box 3mm wall, 6m lengths x 6off. We need to put a 12mm slot up one side and welcome suggestions as to how to tackle this.
Welded a couple of brackets on one anticipating it will try to spread but I appreciate this may close the door on a few options. My pal originally thought 1mm slitting disk but we are going to need a few to do 6m lengths especially 6off and it will take forever. I was thinking the plasma? anyhow, suggestions welcome:




I did think a keyway cutter on the little mill? Going to be bloody tedious that.

 

[Anguz]

rekon it will bow like a banana whatever you do

 

[Guzrik]

Buy open box rail?

 

[Agroshield]

Maybe one of these and weld some droppers onto the base so it guides itself:

https://www.screwfix.com/p/erbauer-ewc1500-125mm-1500w-electric-wall-chaser-220-240v/247FX

See if you can find 0.8mm disks as they are 20% thinner than 1mm ones.

Turning 12mm wide x 3mm thick x 6m long into chips using a toothed cutter is going to be slower than sawing 2 x 0.8mm x 3mm x 6m slots.

Could stainless Unistrut be made to work as an alternative?

41mm Plain Channel - A4 Stainless x 6 Metre

41mm Plain Channel Stainless Steel A316 Grade (Unistrut Compatible) Order online or call us today Next Day Delivery - UK mainland

directchannel.uk.com

 

[Maker]

Why a keyway cutter over a regular end mill?

 

[hotponyshoes]

As mentioned, if the slot is full length, it will warp all over the place.
But plasma will do it quickly enough.
You'll get a load of sugaring on the inside with plasma, you could purge it which will help a bit.

 

[BrokenBiker]

thats not going to be fit for any use if its a full slot from end to end with nothing left to hold the ends together...id wager it bows considerably anyway in the middle given the length of slot...

is there nothing available already that would do the job instead of scrapping some expensive box section?

 

[Guzrik]

Turning 12mm wide x 3mm thick x 6m long into chips using a toothed cutter is going to be slower than sawing 2 x 0.8mm x 3mm x 6m slots

Two small (50x 0.8mm or so) sawblades on one horizontal shaft in the mill.
Clamp some blocks on the bed and push the box through.

 

[iNf]

Metal cutting circular saw?

 

[gaz1]

50x25 and 50x50 angle iron is what id have used and welded it and spot welded it down its length or slit welded down its length

your slit welding the angle iron to weld to the 50x25 box section

 

[Nomad]

I often make use of "creative" solutions but it's crazy to do 36m (6 off x 6m) freehand. I'm not saying it's impossible or don't do it just saying...

For a shorter job I'd be thinking of using a slitting blade in an angle grinder but for that length (and for a 12mm cut) it's not practical.

My best "alternative" thought would be a metal cutting blade in a circular saw (Rage or similar) with a guide rail.
Use either a 12mm wide blade (if such a thing exists) or ...
2 passes but that's 72m (2 x 36m) of cutting (mark a centerline + 5mm either side. 2 x 1mm cuts + 10mm center strip = 12mm slot).

Plan B would be offer beer tokens to anyone nearby with a milling machine

Hope you get sorted, keep us updated

 

[qwakers]

Stainless will blunt tct in short order.

 

[Hitch]

What is it for?

Curtain tracking?

No off the peg solutions...? what kind of accuracy is needed?

 

[Turbo]

Make a guide jig and use plasma.

But as others have said you expensive s/s box section will be scrap if you cut a full length slot.

 

[northwest]

Two small (50x 0.8mm or so) sawblades on one horizontal shaft in the mill.
Clamp some blocks on the bed and push the box through.

I like this idea, or a permutation of it. I will give it a couple more coats of thinking.

 

[Erie Fred]

Buy open box rail?

Stainless Steel Unistrut | Types 304 & 316 - Unistrut Store

Discover stainless steel Unistrut with superior corrosion resistance and durability. Ideal for harsh environments and long-lasting structural support.

unistrutstore.com

However it's not 50mm sq. rather 1 5/8" sq.

 

[Agroshield]

I like this idea, or a permutation of it. I will give it a couple more coats of thinking.

Please do so. I did not comment above as I hoped the plans in the flaw were too obvious to anyone who has ever used a slitting saw in a milling machine.

You know how fussy they are on rotational speed, feed, and coolant in free cutting steel, let alone stainless. They also cut very slowly. Thin ones like to shatter at the drop of a hat. Ganging up two thicker ones needs some power. They like ridgidity. 3mm wall box section will sing and vibrate. As the srip being cut off gets longer, it will sag and add to the tune.

You are not going to hand feed a slitting saw 6m using the handle on the leadscrew, so it needs power feed. Trying to push the material into the saw (as you would do on a wood-cutting table saw) is problematic. If you conventional cut, the blade is trying to lift the material off the table. Because it is above the thing being cut, if you want the cutter to press the material onto the table, you necessarily have to climb cut.

What is the X-travel of your milling machine? How many multiples (stock re-set and wind back the table) of that in 6m? If the cut spreads as it progresses, no problem, but if it pinches, that will be death to the saw.

---

With respect to the tube laser, all the ones I have seen work like a swiss lathe, where the stock slides in and out of the chuck (i.e. the stock moves along the X-axis but the cutting head stays fixed). How would that machine make two 6m long parallel cuts?

To me, it would need to cut one side for maybe 300mm, suck the stock back into the chuck, cut 300mm on the other side and then repeat. How would it work at the end of the cut as it has nothig to grip upon? It would seem to need stock longer than the 6m length. Maybe someone could provide details on how the specifics of what you require are suited to this machine.

A conventional laer that had a 6m travel has potential. It could be wise to make the cuts like the perforations in toilet paper and then remove the webs/tabs manually afterwards. If the stock moves after the first cut, the second cut will not be parallel or in the correct place.

 

[zzr1200]

AND..........

Now the real question that should be asked.........

Why does it need a slot in it and what for????

 

[frank horton]

seen slotted galve tube that size.....used for roller shutter doors.....
It may be avail in ST/ST but dread the cost....