Author Topic: Vunderfoil  (Read 11350 times)

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #15 on: December 10, 2022, 11:48:20 PM »
Yeah, the biggest problem with Fusion 3D is that it's parametric to the core. It feels kind of free form when you are extruding rectangles into boxes, but to be adept at it you need to learn it from the parametric side before you start pulling and pushing stuff.

Tarquin, I understand what you're saying about sediment and salt density variations--if only because I converted my bead blaster into a vapor blaster. Add water to the bead blasting process and it's a whole different thing.

I am about as far away from Admin on the neurological fuckup spectrum as is feasible. Completely unmanaged ADHD. I'll probably have to pop some Concerta so we can work together. I have some left over from when I worked for a living. I wonder what the expiration date is on that stuff.

I am sure we can laminate over 3D-printed parts. I'm printing some polycarbonate parts right now with enough infill that they could be bagged pretty hard. The temperature is a concern as well, but if the ramp is right the CF would be set before the core gets wonky. Polycarbonate melts at about 180C but loses strength before that temp. I'll have to do some research to see what the curve looks like. The easy composite guy didn't have any problem with the huge mold he made, and as I recall that was PET, which is generally weaker and lower temp.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #16 on: December 10, 2022, 11:58:18 PM »
Looking at the foil sections we are all using for our sports, they are all either from the existing databases or very close derivatives (intentionally or not).  That doesn't mean the configuration is the same (the same section can be used to make very different, purpose-built wings), but I don't think you will find anything that strays far (if at all) from convention.

I think there's room for improvement in foil performance without getting too exotic. Most of the main wings I've looked at use washout to control how the foil stalls. You can get a similar result (stall at the root before the tips) by varying the foil cross-section from root to tip. And you can reduce both parasitic and lift-related drag at the wingtips--washout is draggy. The Dark Aero video I linked above talks about that approach briefly. They transition from a conventional asymmetric foil to a more symmetric cross-section at the wingtips. Something more to try. 
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #17 on: December 11, 2022, 12:09:56 AM »
Using my printer to make parts for my printer. It feels quite recursive until you notice the aluminum tape holding the fan in place. I think of this as my "old" printer though it's only a year old. If I printed this on the Bambu printer with the same material you would barely see the layer lines.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6443
    • View Profile
    • StandUpZone
    • Email
Re: Vunderfoil
« Reply #18 on: December 11, 2022, 12:11:35 AM »
Yeah, the biggest problem with Fusion 3D is that it's parametric to the core. It feels kind of free form when you are extruding rectangles into boxes, but to be adept at it you need to learn it from the parametric side before you start pulling and pushing stuff.

Tarquin, I understand what you're saying about sediment and salt density variations--if only because I converted my bead blaster into a vapor blaster. Add water to the bead blasting process and it's a whole different thing.

I am about as far away from Admin on the neurological fuckup spectrum as is feasible. Completely unmanaged ADHD. I'll probably have to pop some Concerta so we can work together. I have some left over from when I worked for a living. I wonder what the expiration date is on that stuff.

I am sure we can laminate over 3D-printed parts. I'm printing some polycarbonate parts right now with enough infill that they could be bagged pretty hard. The temperature is a concern as well, but if the ramp is right the CF would be set before the core gets wonky. Polycarbonate melts at about 180C but loses strength before that temp. I'll have to do some research to see what the curve looks like. The easy composite guy didn't have any problem with the huge mold he made, and as I recall that was PET, which is generally weaker and lower temp.

With Fusion, everything is easy, until you realize that the easy way distorts your section loops and you are left with pretty garbage.  That is why all of the foil instructional vids are using straight, non curved wings or wings of fused straight segments.  To get it right you need to be very careful with setup and order.  You need to get the planes done first and everything constrained before you begin. or the loft tools will throw errors.  These tools are very specific about the rails and guides that they will allow and we need all profiles and all guides to engage.  It took me 72 hours to get it, but we now have full control over leading and trailing edge independently, with infinite stage root to tip contouring and rotational control all while maintaining a perfect source .dat profile everywhere.  I am pretty stoked about that :)

tarquin

  • Sunset Status
  • ****
  • Posts: 370
    • View Profile
Re: Vunderfoil
« Reply #19 on: December 11, 2022, 12:16:37 AM »
I have no idea either. I just know at some point you should have designed a hydro foil and not down sized an aeroplane wing.
 Good luck and remember. You didn't make a mistake you learnt something. It's only a mistake if you stop trying and didn't learn something from it.

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6443
    • View Profile
    • StandUpZone
    • Email
Re: Vunderfoil
« Reply #20 on: December 11, 2022, 06:18:15 AM »
I agree that we don't want to be using airplane wings or downsized airplane wings and I would not have interest in doing that.  This one (maybe upsized to a front wing?) is based on a lightly cambered section, its thickness is at 10.25%.  This section is a morph between two sections, one of which is common in current watersport foils (reverse engineering makes that clear).  Essentially if you put a foil on one end and a banana on the other, in the middle, software will produce a foilnana.  You won't want to ride it or eat it, but...

« Last Edit: December 11, 2022, 06:20:51 AM by Admin »

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #21 on: December 11, 2022, 08:33:12 AM »
I have sporadic experience with Fusion 3D (hmmm, that's more or less true with everything I do). I have to go back to basics every time I restart using it seriously. I've never done anything complex with it though I've been dinking around with it for years. But it (or some competitor) is a core requirement for doing anything useful with a 3D printer or laser cutter, and I do enough of that to maintain some level of attention.

You are absolutely right about things falling to shit if you don't get the 2d plane right. The most frustrating moments are when you turn something into 3D and it won't move, copy, rotate, or otherwise do 3d shit. It's ALWAYS because the constraints are wrong. I think you're a long way past my high water mark. So I've got a goal. Goals are good.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

finbox

  • Malibu Status
  • **
  • Posts: 54
    • View Profile
Re: Vunderfoil
« Reply #22 on: December 11, 2022, 09:17:07 AM »
Hi,
Have you been able to run a Computational Fluid Dynamics (CFD) program with the proposed foil shape? If you can compare it to a know front foil - this could help validate you design prior to making it real.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #23 on: December 11, 2022, 10:19:34 AM »
From my lightweight research it looks like we should be fine using polycarbonate for prepreg laminating. It maintains toughness up to 140C, which is surprising since it starts to melt at 155C. I suspect, but haven't been able to verify, that once it's been melted and formed the melting temperature might be higher. I generally print it at 260 to 280C with the bed heated to 90C--the Bambu labs printer can do that handily since the print head is all metal. I'm not sure why they do this, but the printer nozzles for the Bambu printer are not replaceable--you need to replace the entire head, transferring only the heating element and thermistor. It's probably a more accurate head than a screw-in nozzle would permit. The heads are relatively cheap ($15) and are available in a variety of nozzle sizes and materials. I bought one of each size and material (brass, hardened steel, etc.). Now that I'm screwing around with my Prusa printer again I've got to say, I love that Bambu Labs printer. It prints ABS like it's PLA. and PLA parts come out looking like they were injection molded. Printing ABS on the Prusa is nearly pointless except for very small parts. I use a filament dryer for everything and the ABS still pops and warps like wet filament.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

surfcowboy

  • Cortez Bank Status
  • *****
  • Posts: 4929
    • View Profile
Re: Vunderfoil
« Reply #24 on: December 11, 2022, 01:34:06 PM »
Admin, this is inspiring.

I'm working out a printer now myself. Let me know if you guys want me to take a bullet wet laminating one of these when you get some protos cooked up.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #25 on: December 11, 2022, 02:21:03 PM »
Cowboy, I don't know your application, but take a look at the Bambu Labs X-1 Carbon printer. You'll have to wait a while for it, but they're saying end of December now. That might slip. I got mine about a month before I left for Maui and I was blown away. So much so that I thought about shipping it here, but decided to ship my Prusa instead. If only because the Prusa can be disassembled into a small-ish box and the Bambu can't.

I've got a lot of printers, if I include ones I haven't used in a while it's probably eight or nine. I use mine a lot to make custom parts, replacement parts, molds, prototypes, etc. a lot of the stuff I used to make out of metal with milling, welding, sheet forming, riveting, etc. I now just print. There seem to be two kinds of people who buy 3D printers. Those that like the tech and print tchotchkes, and people who make parts. Well, there's a third kind too--those who get one, don't really have a use for it, and give it to me. Two of my printers came from them.

I would normally say if you need a build area bigger than 230x230x230mm then you need a different printer, but the slicer for the Bambu Labs handles splitting big stuff into chunks for assembly with startling ease and accuracy. Take a look here. some of the more critical comments were handled in subsequent software updates (which are frequent and painless).
https://forum.3dprintbeginner.com/t/bambu-lab-x1-carbon/479/26
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

jondrums

  • Peahi Status
  • *****
  • Posts: 894
    • View Profile
Re: Vunderfoil
« Reply #26 on: December 11, 2022, 06:33:57 PM »
The foil sections used on wings and tails these days are MOST CERTAINLY NOT standard NACA sections.  Not even close.  I extracted sections from several different wings I have owned and I know this for a fact.

The CFD program to use is XFOIL.  This is a really simple 2D CFD for foil sections.  You can get lift and drag vs. angle of attack for various reynolds numbers (speeds).  It takes a bit of skill to understand how to read these outputs, but put in some time reading up on it and you can figure it out.  There are a number of third party softwares available that use the open source XFOIL core and put a GUI on top.

But before you do this, consider just taking a moment to extract the foil section from a foil you really like and copying that - this picture should show you how to do it:

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6443
    • View Profile
    • StandUpZone
    • Email
Re: Vunderfoil
« Reply #27 on: December 11, 2022, 11:13:41 PM »
The foil sections used on wings and tails these days are MOST CERTAINLY NOT standard NACA sections.  Not even close.  I extracted sections from several different wings I have owned and I know this for a fact.

The CFD program to use is XFOIL.  This is a really simple 2D CFD for foil sections.  You can get lift and drag vs. angle of attack for various reynolds numbers (speeds).  It takes a bit of skill to understand how to read these outputs, but put in some time reading up on it and you can figure it out.  There are a number of third party softwares available that use the open source XFOIL core and put a GUI on top.

But before you do this, consider just taking a moment to extract the foil section from a foil you really like and copying that - this picture should show you how to do it:

The Xfoil data already is given for the thousands of sections that are present at the online databases.  My comment was that what is being used by foil makers is already there, whether intentional or not, and that you can confirm this for yourself by reverse engineering (as in your image).  Once you have your section dimensions you can search the databases by these dimensions and the sites will produce all foils of these dimensions. Scan through those and you will find your section.  You can then download and overlay your measured section in software.  That is really interesting to see where else these foil sections are in use.

http://airfoiltools.com/search/airfoils
https://m-selig.ae.illinois.edu/ads/coord_database.html

The provided info, in combination with knowing what is already in use for our sports, is super helpful in selecting a start point section for home builder designs such as ours. 

That is primarily for sections though and some provided testing for straight wings produced form these sections.    Tarquin and finbox (thanks for the push guys!) are suggesting running analysis based on our produced wing export files and I want to do that.  If you guys know of something accessible please let me know. This will be most valuable when we can export a finished system (both wings, fuse, mast, hardware) and test as a whole but the individual components will be interesting as well. 
« Last Edit: December 11, 2022, 11:18:13 PM by Admin »

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6443
    • View Profile
    • StandUpZone
    • Email
Re: Vunderfoil
« Reply #28 on: December 12, 2022, 12:15:39 AM »
Where do I send my "sponsor me" video to?

We will build some pass-around wings for sure.  Once we get some rolling and have some designs with merit, consider yourself signed up.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25859
    • View Profile
Re: Vunderfoil
« Reply #29 on: December 12, 2022, 08:35:40 AM »
I think current foil manufacturers are missing an obvious bet. They sponsor kids with supernatural talents to showcase their expensive gear, that no kid could possibly buy without willing investment from Dad and/or Mom. The target audience is geezers and sub-geezers, and the marketing message should be simple: "Our wings are so great that even Bill can do this". Cut to a video clip of me wobbling through a jibe, blowing a tack, and straining to get to my feet during a knee start. Marketing magic. You're welcome.

Then again I'm not sure of Admin's ambitions but the thought of doing this commercially makes me gag. It will be great fun, and perhaps it can stave off the inevitable decline of my cognitive ability. Wait, what was I writing about??
« Last Edit: December 12, 2022, 08:40:52 AM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

 


* Recent Posts

post Re: GPT 5, Sam Altman, What's coming
[Random]
PonoBill
March 17, 2024, 05:30:44 PM
post Re: 2024 North Mode Pro wings:
[Classifieds]
cnski
March 17, 2024, 05:09:04 PM
post Re: HOT Chicks on Stand Up Paddle Boards!
[SUP General]
burchas
March 17, 2024, 08:50:00 AM
post Re: HOT Chicks on Stand Up Paddle Boards!
[SUP General]
Night Wing
March 16, 2024, 07:02:05 PM
post Re: HOT Chicks on Stand Up Paddle Boards!
[SUP General]
blueplanetsurf
March 16, 2024, 03:28:57 PM
post Re: GPT 5, Sam Altman, What's coming
[Random]
LaPerouseBay
March 14, 2024, 12:38:42 PM
post Re: GPT 5, Sam Altman, What's coming
[Random]
LaPerouseBay
March 13, 2024, 07:59:28 PM
post Re: FS - Ocean Rodeo Glide A-Series Wings (3m/ 4m / 5m), USA
[Classifieds]
StellaBlu
March 12, 2024, 07:27:21 AM
post FS - Kalama Barracuda
[Classifieds]
VB_Foil
March 11, 2024, 05:43:58 PM
post Re: Vision Pro
[Random]
Bean
March 11, 2024, 03:46:42 PM
post Re: Vision Pro
[Random]
PonoBill
March 09, 2024, 11:06:32 AM
post Happy International Women's Day, lady zoners!
[General Discussion]
LaPerouseBay
March 08, 2024, 07:28:47 PM
post Re: Vision Pro
[Random]
Admin
March 08, 2024, 04:45:53 AM
post Re: Vision Pro
[Random]
PonoBill
March 06, 2024, 11:00:24 PM
post Re: Vision Pro
[Random]
Admin
March 06, 2024, 10:15:55 AM
SimplePortal 2.3.7 © 2008-2024, SimplePortal