Re: OT: 3D printer, printing on flat metal for reinforcement?

You will usually also need to match coefficients of thermal expansion, or diurnal thermal variation will cause the bond to fail over time.

With hygroscopic plastics, humidity cycles can also cause bond failure.

Unless the plastic is actually a rubber, and is chemically bonded to the metal surface.

Joe Gwinn.

Joe Gwinn wrote in news: snipped-for-privacy@4ax.com:

I used to pot HV supplies and am familiar with these issues.

"Stycast" is a bad choice because when it shifts, it not only unseals joinery, it shears parts too!

The ONLY stuff NASA approved for HV potting media is called "CONAP". It is a very tough when cured polyuerethane media.

Once cured, there is no serviceability. ZERO. it attaches to surfaces so well it is really amazing stuff. Very tough too. I had a 1 inch thick, bottom of the bucket slab for years that I showed people. They could take their very sharp pocket knife out and jab it as hard as they can, and the stuff would grab and capture the blade tip within like a 1/4 inch depth every time. I think it could slow a bullet. Looks like frozen urine when cured. Don't know whay that color association popped into my head. iguess I should have said beer. Same stuff, just as yet unfinished proccessing. :-)

Anyway, yeah, a not so rigid "glue" like that CONAP between the two might do it. Good call.

Bill Sloman wrote in news: snipped-for-privacy@googlegroups.com:

Those machines are millions of dollars, dufus.

You know... (maybe) jet engine parts and the like.

John Doe wrote in news:rsbs40$prq$ snipped-for-privacy@dont-email.me:

ut the shear and other stresses placed upon that joint will NOT last. Even super glue would do a better job if you choise not only the wrong medium to join with, but it needs to be the right thickness. As in NOT pressed firmly together.

So it looks like used beer, but solid, The other day I was watching (video of) the clowns at "Demilition Ranch" shooting at some stuff like that.

Industrial 3D printed metal isn't all that good either.

The standard dodge is to use a 3D printer to make a wax image of what is to be made, and then use the lost-wax method to replace wax with real metal.

What this does not achieved is the strength of forged metal.

Joe Gwinn

Forging does rely on making the metal flow to orient it's dislocations in a way that suites the application. A 3D printer that could do that would be a remarkable beast.

Investment casting can't make parts with totally enclosed empty spaces, which 3-D printing can.

In principle, some forms of metal 3D printing could build up a structure with different alloys in different areas, but I've not seen anybody boasting about being able to do this.

Building in oriented single-crystal whiskers would be even more interesting, if it were practicable.

Nope. But I have read lots of articles from the metalworking world about the properties of additive manufacturing materials. 3D printing is good for some kinds of prototypes, but little else, so far.

The US Military is putting a lot of money into research on 3D printing, because it promises to reduce field support costs for repairing stuff in the field, far from home.

Joe Gwinn

No, and no plans to do so.

What special tool would this be? Cutters for 6061 are not difficult to make, but plastic isn't going to work for cutting aluminum either.

I do have a lathe, and they are perfect for such things. One can get small Chinese bench top lathes fairly cheaply, in the range for a 3D printer setup that can do metal for sure.

It sounds like what you need is a step drill; these are widely available and cheap.

Local hardware stores have an odd assortment of stuff, often of very low quality. But owning and operating machine tools or 3D printers will never be cheaper than buying.

A far better answer for random hardware is McMaster-Carr:

This is an industrial hardware store.

Joe Gwinn

You'll want hearing protection and goggles as well.

Joe Gwinn

Joe Gwinn wrote in news: snipped-for-privacy@4ax.com:

GE uses them to make jet engine parts.

I'd bet that you are underinformed.

The even 3D print Inconel.

We are not talking about what GE can do when money is no limit.

Inconel is chosen for its heat tolerance, while the original discussion was about replacing forged and hardened steel components.

And everybody is talking additive mannufacturing up. But few things have escaped tha lab.

But, please provide a link to what GE is doing. I'm sure it's interesting. I bet sintering and some machining is required.

Joe Gwinn

Yes, it's possible, but why not use fasteners to hold it more securely? You can drop a hexagonal pocket into the 3D printed part to hold a nut, for example, or print a countersunk hole for a SHCS or a flat-head screw. Best regards, Spehro Pefhany

Not for long, as the tempco mismatch will cause the plastic to pop off the metal.

Joe Gwinn

Joe Gwinn wrote in news: snipped-for-privacy@4ax.com:

components.

things

Not sintered but the internal structures is what they do it to attain, because those are hard if not impossible to 'machine' and inconnel isn't ever cast or sintered as far as I know, which isn't much in the metallurgic realm.

John Doe wrote in news:rua8i3$g6q$ snipped-for-privacy@dont-email.me:

And Like I stated, you need grooves or cleats to affix things like that to. Then there is stress analysis on those retaining elements that get examined for design integrity, and real world integrity.

Glue ain't it. Two flat surfaces peel apart with the introduction of shear forces.

Joe Gwinn wrote in news: snipped-for-privacy@4ax.com:

components.

things

Sheesh. 3D printing is the pinnacle.

snipped-for-privacy@decadence.org wrote in news:rus5dc$a3e$6 @gioia.aioe.org:

Here's another from a few years back. Looks pretty solid to me and the wording makes it sound as if to be bonded at the molecular level.

snipped-for-privacy@decadence.org wrote in news:ruudt4$1bgp$ snipped-for-privacy@gioia.aioe.org:

And another small form factor machine...