Filament Idea

[Conrad Hoffman]

Not sure if anybody else has thought of this but I'm posting it here to make it public, short circuiting any patent thoughts.

If you were to mix an abrasive with 3d printing filament, you could print custom polishing and grinding tools. Things that you could use in a Moto-tool or by hand. I'm thinking of maybe 600 or 800 grit silicon carbide for finer work, though any abrasive up to diamond could be used. If it worked like a grinding wheel the filament material should break down slowly, exposing more grit. You could print a curved surface for coarse working optics. Other curved surfaces for polishing irregular objects. Tools for a rotary tool would obviously be round. The fine abrasive probably wouldn't wear nozzles too much, as they hold up to carbon fiber. You could also print high friction surfaces where sliding was undesirable.

I'm using the spaghetti theory here- throw ideas against the wall and see if anything sticks!

[aeberbach]

At what RPM does the printed disc fly apart? I don't think the rotary tool idea is a very safe one. Unless you can get a very high ratio of abrasive to binder I don't think hand use would work either.

[Kean]

I believe ruby tipped nozzles are generally recommended for printing potentially abrasive or difficult materials (carbon fiber, wood or metal filled).  Brass nozzles apparently don't last long, so the alternative is hardened steel but ruby is superior.

This could be tested with carbon fiber material, but I suspect lack of abrasive material and structural integrity will be issues.

I pretty much only print ABS, so I have no first hand experience, and outsource as much production 3D printing as possible.

[jpanhalt]

There are soft matrex abrasives available such as Cratex and many other brands.  Virtually any abrasive wheel, hard or soft,  can be reshaped for a particular purpose.  Dressing tools are available for doing that.  Excerpt for hand finishing (e.g., some Cratex products), most abrasive wheels run at a fairly high rpm and can create a lot of heat..

I don't see where the presumed convenience of a DIY printed abrasive would outweigh the risk and inconvenience. 

[janoc]

That's a completely impractical idea - both because of the inherent danger of the tool flying apart while in use and also because the nozzles would need to be extremely hard - or you would destroy them after one or two prints. With normal brass nozzles it is completely enough to print stuff like "wood" filament to destroy them because the brass is soft. Even hardened steel nozzles get damaged/worn out with carbon reinforced filaments pretty quickly (and have a lot worse thermal properties than brass). And you want to print silicon carbides? 

If you want custom shaped tooling for whatever reason, just 3D print a mold and cast the carbide + binding agent (glue) in it. But I  really don't see where one would need something that special that it would warranty such hassle, given that abrasive tools and disks are readily and cheaply available in pretty much every shape, form and grit imaginable.

[jduncan]

Apparently 3M disagrees with you: https://www.3m.com/3M/en_US/metalworking-us/applications/precision-grinding/technology/superabrasives/precision-structured-wheels/

[Conrad Hoffman]

Well, at least I'm not completely crazy!

[sleemanj]

The thing with 3d printer filament, the core defintion of it, is that it melts when it gets hot.

The thing with grinding attachments, an unfortunate side-effect of them, is that they also get hot.

Making your grinding attachment out of a thermoplastic, doesn't sound like an eminently good idea to me.

[Conrad Hoffman]

Right now I'm using 3D printed grinding/polishing tools with decent success. The only downside is I have to apply the abrasive manually. I know it's the internet, but you guys need to think of things from the viewpoint of possibilities, rather than all the reasons a thing can't work. A lot of things I try don't work, but the percentage that do has allowed me to make a living over the years.

[janoc]

Apparently 3M disagrees with you: https://www.3m.com/3M/en_US/metalworking-us/applications/precision-grinding/technology/superabrasives/precision-structured-wheels/

And you think that is intended to be printed on a typical hobbyist machine?  Of even using a thermoplastic filament?

"Customized for you. Printed by 3M."

[janoc]

Right now I'm using 3D printed grinding/polishing tools with decent success. The only downside is I have to apply the abrasive manually. I know it's the internet, but you guys need to think of things from the viewpoint of possibilities, rather than all the reasons a thing can't work. A lot of things I try don't work, but the percentage that do has allowed me to make a living over the years.

A ton of things are technically possible to do. That doesn't mean it is actually practical to do them. Most often for economical reasons and nothing to do with technology.

Labeling people who point that out "naysayers" is just totally missing the point.

[jduncan]

I think it's a flaw in the nerd mindset. They prefer to latch onto the first obvious difficulty as a way to appear smart rather than brainstorm productively.

[jduncan]

But I really don't see where one would need something that special that it would warranty such hassle, given that abrasive tools and disks are readily and cheaply available in pretty much every shape, form and grit imaginable.

The point is your lack of imagination limits you - the idea is at least good enough that it got a 3M executive a nice resume bullet.

Seems like the folks at Virtual Foundry might have pondered this as well: https://shop.thevirtualfoundry.com/collections/filamet/products/silicon-carbide-filamet

[thm_w]

Apparently 3M disagrees with you: https://www.3m.com/3M/en_US/metalworking-us/applications/precision-grinding/technology/superabrasives/precision-structured-wheels/

They show a heated 3D printhead, but, surely they'd use SLS process not FDM?

The point is your lack of imagination limits you - the idea is at least good enough that it got a 3M executive a nice resume bullet.

Seems like the folks at Virtual Foundry might have pondered this as well: https://shop.thevirtualfoundry.com/collections/filamet/products/silicon-carbide-filamet

Yeah this is relevant, cool.
But, says to be sintered in argon at 2,100C. Which is a bit of extra effort.

https://spectrumfilaments.com/en/filament/silicon-carbide/

[Conrad Hoffman]

Yeah, I know there are also other ceramics that can be printed, but they need that high temperature sintering process, well beyond what my small kiln can do. Fortunately, they offer a sintering service. You just have to contend with the shipping delay.