Question about making parts using 3D printing

GarryW · **Joined:** Wed May 01, 2019 12:09 pm **Posts:** 19

Col. Rohr wrote:

Okay let me ask it this way can we use 3d printing to make the molds for say the turret rings for PBY nose gun and other parts that mold have been lost over the years. The one thing I was told by the guys who own the PBY in Sanford Maine was that they can basically make everything for the nose turret except the nose ring.

I know the blueprints exist for the construction of the nose turret both for a -5 and -6 which had two different types of nose turrets,

From the hobbyist side, this is quite common place. Using a 3D printed model to create a mold is used extensively when you need something that is stronger than plastic filament. I see no reason why this wouldn't scale. Basically the same process that was used "back in the day" except utilizing technology rather than a die modeler.

kennsmithf2g · **Posted:** Tue Oct 22, 2019 5:42 pm

There is at least one company that uses robotic welders to "print" rather large parts. Post processing machining is used for the final shape.

airnutz · **Posted:** Wed Oct 23, 2019 7:26 am

It occurred to me this morning that I've seen some rather large rings formed from a ring roller on an industrial scale. If we're talking about the ring the turret or cupola rides on that's smaller, say 2" thick around 30-36" diameter which is relatively small to what's possible and pretty low tech. I dunno, whut do the engineers think?

bdk · **Joined:** Sun May 02, 2004 1:16 am **Posts:** 11324

airnutz wrote:

It occurred to me this morning that I've seen some rather large rings formed from a ring roller on an industrial scale. If we're talking about the ring the turret or cupola rides on that's smaller, say 2" thick around 30-36" diameter which is relatively small to what's possible and pretty low tech. I dunno, whut do the engineers think?

Normally a straight extrusion is formed into a circle and welded at the joint. A lot of engine and engine nacelle parts are made this way both out of steel and aluminum.

bdk · **Joined:** Sun May 02, 2004 1:16 am **Posts:** 11324

kennsmithf2g wrote:

There is at least one company that uses robotic welders to "print" rather large parts. Post processing machining is used for the final shape.

The technology for additive manufacturing is developing rapidly. Robotic welders have been around for decades and that is one of the key methods used, though welding has some inherent strength problems (inclusions, porosity, surface finish, etc.). The newer technologies use powdered metal and lasers rather than a conventional arc.

CAPFlyer · **Posted:** Wed Oct 23, 2019 3:29 pm

Remember here though that the majority of the "cost" of these things isn't the material or even the machine necessarily. It's time. Time on the machine, time for the computer, time for the person to run both, and most especially - time for the person(s) needed to take your design, turn it into a digital 3D model and then convert that to whatever code is needed for the 3D printer (and CNC router/lathe/machine if there's post printing finishing needed) before you even start making the physical item. While the software is getting pretty good to make this at least semi-automated, there is still usually a lot of clean-up needed by a skilled person to make it 100%, especially when you're taking about making something that needs a level of precision like the turret ring.

When you can amortize those up-front costs over several parts, the cost isn't great, but when you're just making one, or a few, then that cost makes it harder to justify the cost over more "traditional" methods.

chainfeed · **Joined:** Mon May 21, 2018 1:44 pm **Posts:** 49

Col. Rohr wrote:

CAPFlyer wrote:

Remember here though that the majority of the "cost" of these things isn't the material or even the machine necessarily. It's time. Time on the machine, time for the computer, time for the person to run both, and most especially - time for the person(s) needed to take your design, turn it into a digital 3D model and then convert that to whatever code is needed for the 3D printer (and CNC router/lathe/machine if there's post printing finishing needed) before you even start making the physical item. While the software is getting pretty good to make this at least semi-automated, there is still usually a lot of clean-up needed by a skilled person to make it 100%, especially when you're taking about making something that needs a level of precision like the turret ring.

When you can amortize those up-front costs over several parts, the cost isn't great, but when you're just making one, or a few, then that cost makes it harder to justify the cost over more "traditional" methods.

Very True, one reason why my old boss would go out to auctions and purchase old Mare Formers and Drop Hammers machines just for the spares, I think something like the turret ring for PBY could be done a good cost considering how many PBY out thee don't have the nose gun.

Speaking of 3d printing and CNC I wonder how far off are we from seeing CNC machines with 3d printing built-in.

Already been done! All the big players offer machine tools that have additive capabilities now.

https://www.youtube.com/watch?v=wOrUahat-K0

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