mass finishing? 3

0.015"??? As in, fifteen thousandths of an inch? Nope. Not likely. You can soften edges by brushing, etching, etc. Mass finishing gets dicey on long stick-like parts. Running the laser out of focus will only lead to worse edge conditions.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

I was afraid of that answer. might be able to get away with less than .015;

a rope rubs against this edge under tension. when I leave the edges unfinished, it abraids in quick order. I have been hand finishing with a coarse diamond file, and that is working well. the resulting edge is a bit rough , which works, but I will need better finish in production.

All that to say: maybe even .005 would suffice.

I am testing the bead blast process now, expecting to see results in a week or two.

Does the rope thread through the ID? Brushing can work for both ID and OD, it might be worth checking out. Search abrasive filament brush.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

Just dug this old contact out of my files. I believe they're still in business. Tubes are their specialty. I am not associated in any way with this company.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

yes, the rope threads through the tube, then around a small clevis pin "pulley" and out the slot. Abrasive filament brush may be just the right thing for hand re-work on the tubes that I've got. thanks! It's embarrassing- such a simple detail, and I've been looking (on and off) for over a year for a better option than files, dremmel-grinding or debur tools..

I had considered piercing at one point, but did not get anywhere as I was not thinking in large enough volumes. I will check in with these guys, as my volumes are looking bigger, thus more realistic for punching.

cheers

Good luck. Important details that are make-or-break on a project should not be embarrassing, no matter how seemingly "simple" they are. We've all been there.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

You might look at something like Extrude Hone. It can round all hole/slot edges in the tube wall in a single operation. And unlike a manual process it will give a consistent result of the edge round profile. Not sure about any set-up or tooling costs involved, or what the per-piece cost would be for your part quantities.

pictures?

round or square tubing?

Is rope life truly acceptable with the edges broken?

Are you deburring just the edges on the outer surface, or some of the inner edges too?

CNC machining in place of laser cutting could add chamfers or even radiuses as part of the hole and slot creation.

How many of these "laser cut holes and slots" have a rope running through them? If it's only one or two it would be much easier to set up a machine to deburr them in a controlled manner than try to develop a mass finishing operation. You could easily use up your entire 500 piece production run just trying to get a mass finishing operation to work. Extrude Hone could work well, particularly if you can set it up to only do one or two "holes and slots". Trying to get it to simultaneous remove equal amounts of material on a lot of holes probably would not work.

You could try electro polish, it will remove material all over but it will remove material from the corners faster. However, it's not going to take .015" off. It's also not that cheap.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

Tmoose,
round, seamless 1" tube
I have not seen any abrasion with even "crappily" deburred edges, both inside and out. I think some of the rope damage is due to the "serations" that result from the laser pulsing. So it may be more than the edges.

the inside edge seems the most important.

Tbuelna,
This is a relatively low precision consumer product, so extrude hone looks to be a bit out of my price target, but may apply to my day job- we do a lot of polishing, though simple geometry. thanks

dgallup,
2 slots and 1 hole need to be processed. I was hoping for the "just drop these in the tank of acid for 5 minutes before anodizing" response. If setups are required, I imagine bead blasting will be the "cost effective" solution. I've been quoted over $1 per (even at a decent volume), which is more that I will ideally pay. but cheaper than my assembler doing hand rework on the parts.
And equal ammounts of material removal is not required here- just softening of those sharp edges. I probly should quantify my radius requirement better/ I have a feeling that .005" may be fine. I am using super abrasion resistant rope.

cheers

Could you use a separate plastic grommet that snaps in place? This could vary between custom injection mold to cut extruded stock that is placed only on the straight sections or all around. It depends where the rope is rubbing and with how much force. A brush on or spray on coating might be worth looking into as well that could be applied only to the edge. Some of these options may be cheap enough for your needs.

good idea about a molded or extruded part. It could be possible on the slot- the rubbing is on the straight edge. but i've just discovered the small hole that passes the rope (opposite the slot in the picture, so not directly shown) also is having some cutting action. yay Beta testing!

Any reason not to mill them? Then a followup pass with a chamfer tool on the outside and a dovetail on the inside. I would expect the part would not require any deburring and the cut faces would be smooth.

OTOH I wonder if this is the sort of task you could use a Baxter on with a bead blast cabinet.

I agree with hendersdc's idea to use a plastic grommet. Make it snap-fit and/or adhesive bonded to the tube. If you can make a CAD model of the custom grommet, it is very cheap and quick to have small quantities made using 3D plastic printers.

thanks for the help! I'm looking into punching for fabrication- that should help immensely with production costs providing we can find the right option for breaking the edges.

this is a volume production (my designs are usually machined, so this is where my expertise is). I hope to minimize part count, while also minimizing cost.

Machining these tubes is more costly than this product can support (I am hoping to get the cost down to less than $5 each at a volume of around 500 pieces).