Designing nose cones

[Quasar]

What thickness would you want to make the nose cone when designing for BT60 and smaller sizes? Thanks.

[K'Tesh]

That totally depends on the material you are using...

Vacuform? Injection mold? Blow mold? Carbon fiber? Fiberglass? 3D printing? Pine? Balsa?

[astronwolf]

That totally depends on the material you are using...

Vacuform? Injection mold? Blow mold? Carbon fiber? Fiberglass? 3D printing? Balsa?
This is the 3D printing subforum.... :rolleyes:

[K'Tesh]

This is the 3D printing subforum.... :rolleyes:
Sorry my bad... I checked in with "Today's Posts". Didn't see the subforum

[Jerry Irvine]

I would guess over 1/16". On 4" I prefer over 3/32". There is a minimum reasonable for the process itself that doesn't apply, for example, to fiberglass. Blow molding for example would be 1mm to 1.5mm.

[teflonrocketry1]

It depends on the body tube diameter and the relative diameters of the shoulder and nosecone. I like to 3D print with at least 2 layers of overlap between the nosecone body and shoulder. For smaller cones about BT-30 and below that amounts to 3 layers at 0.4mm width; for larger diameters above about BT 30, 4 layers seems to work good. It is best to do a layer by layer view in your slicing software and look for the amount of overlap. A single layer of overlap will be weak at the transition point unless you are doing a post treatment like isopropyl alcohol for PLA and acetone for ABS; but even then the one layer of thickness will still be the weak point. For cones wider than BT-60, I use 5 or more layers as indicated by the amount of overlap shown in the slicing software. This becomes a problem as body tubes get thicker and the difference in cone and shoulder diameter becomes greater. There are some tricks you can use to get sufficient overlap between the cone body and shoulder to get the structural integrity required.

[vcp]

What thickness would you want to make the nose cone when designing for BT60 and smaller sizes? Thanks.

That's going to totally depend on what you're trying to do. All of my NARAM-60 models , including the 45mm dia egglofter, https://www.thingiverse.com/thing:3056609 , were printed single-wall vase mode for light weight, and they turned out to be very durable (in ABS). The only finish was sanding out the layer striations completely, which thinned them even more.

So consider single wall a practical minimum, it's hard to go less, and add from there.

[Quasar]

Thanks for the responses, but most of what you guys said went right over my head. I'm a complete NOOB and know almost nothing about 3D printing. I'm using Autodesk Fusion 360 to design the shape I want, but I don't know how thick to make it. It's for a BT-55 tube. If anyone can point me toward some good learning resources, I'd greatly appreciate it. Thanks.

[vcp]

That's ok Mike, we all gotta start somewhere. First question, do you have a 3D printer? Or, are you planning to use one at school or a library or something (where you'll probably be limited to PLA plastic). If you have your own, is it limited to PLA (or PLA types) or can you print in ABS or PETG or something else?

The only reason I could do single-wall (that's just one noodle of extruded plastic, or about 0.5mm thick) is that I was printing in ABS which is much less brittle than PLA. Thin-walled ABS prints become very flexible.

Vase mode, that I mentioned, is a printing method for single wall prints, in which there is no discrete 'step' when transitioning layers as the print progresses upward. The extrusion is a continuous single wrap around the shape you specify.

Do you know how the slicer software prepares your design for printing? In many cases, there is no need to specify wall thickness in your CAD program - you can just do a solid shape, and then specify the wall thickness in the slicer. Do you know what slicer software you'll be using?

Resources, hmmm. For 3D printing in general, or specifically rocketry related? For rocketry, we'd probably need to find some threads on one of the forums.

[Quasar]

That's ok Mike, we all gotta start somewhere. First question, do you have a 3D printer? Or, are you planning to use one at school or a library or something (where you'll probably be limited to PLA plastic). If you have your own, is it limited to PLA (or PLA types) or can you print in ABS or PETG or something else?

The only reason I could do single-wall (that's just one noodle of extruded plastic, or about 0.5mm thick) is that I was printing in ABS which is much less brittle than PLA. Thin-walled ABS prints become very flexible.

Vase mode, that I mentioned, is a printing method for single wall prints, in which there is no discrete 'step' when transitioning layers as the print progresses upward. The extrusion is a continuous single wrap around the shape you specify.

Do you know how the slicer software prepares your design for printing? In many cases, there is no need to specify wall thickness in your CAD program - you can just do a solid shape, and then specify the wall thickness in the slicer. Do you know what slicer software you'll be using?

Resources, hmmm. For 3D printing in general, or specifically rocketry related? For rocketry, we'd probably need to find some threads on one of the forums.

Thanks for the thoughtful response, vcp. I don't have a printer, yet, but there is one where I work. However, I'm not sure if I can talk the guy that uses it into letting me do a personal project with it. If I remember correctly, it's a MakerBot brand printer. When I do get my own, I'll get one that can use ABS.

If I can use the one at work, I'll find out what software the operator uses. I really don't think he uses it much, as I've been working there for over two years and I've never seen him making anything.

As far as what I'd use a 3D printer for, yes, I would do some rocket parts, but I'd probably use it more for other things.

Thanks again.

[vcp]

... If I remember correctly, it's a MakerBot ... I really don't think he uses it much, ...

After being one of the founders of the industry, MakerBot had a spell that earned them an extremely poor reputation for quality. It could be that he doesn't use it because it doesn't work worth a ****. (ps. I own an early MakerBot that works quite nicely.)

[teflonrocketry1]

Are you familiar with RockSim software used for the flight simulation of model rockets? If you are, that software makes it easy to draw model rocket parts and export the files into the 3D printers slicing software https://www.apogeerockets.com/education/downloads/Newsletter476.pdf

The article also reviews the workflow for 3D printing and gives tips on where to learn about 3D printing and 3D printers from YouTube channels like "Makers Muse" and "Todays 3D Print".

I is best to first learn how to draw the 3D parts, since free 3D print services are easy to come by at places like local libraries and schools; and there are for pay 3D print services like Shapeways. A good 3 D printer can cost less than $200, but you have to be mechanically inclined and willing to learn and put up with the nuances of the printer you purchase.

[Quasar]

Hi, Bruce. Yes, I'm somewhat familiar with RockSim, but since I'm learning Fusion 360, I'd like to stick with that for the design phase. I read your article and found it very informative. However, I'm confused about something. You state, "At 3 layer thickness, the fin can and launch lug won’t fit over a BT-20 body tube nicely and the pin or bottom of the nose cone doesn’t fit into the bottom of the nose cone if the nose cone is printed with 3 (or more) surface layers thickness.". I thought that whatever you design, that's what gets printed. For example, if I want the nose cone wall to be 2 mm, 5 mm, 10 mm, or a completely solid cone, can I not do that? Thanks.

[Quasar]

Here's what I have so far.

https://i.postimg.cc/fyvhNSg1/NCSection.jpg

https://i.postimg.cc/gJ8WgTyz/NCRender.jpg

https://i.postimg.cc/DfQhsRy5/NCMesh.jpg

https://i.postimg.cc/tJbHwNDh/NCPrint.jpg