Author Topic: Longer Fuselage for Stability and Pump  (Read 4654 times)

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6300
    • View Profile
    • StandUpZone
    • Email
Re: Longer Fuselage for Stability and Pump
« Reply #30 on: January 10, 2023, 01:25:24 AM »
https://www.seabreeze.com.au/forums/Wing-Foiling/Wind-Wings/Axis-RadicallyShort--77mm-advanced-fuselage-prototype?page=1

https://youtu.be/cYIIVNXmvTc

This is the problem I have mentioned above.  He introduces a new fuse length, a super draggy connection, a mount intersecting the tail of the wing, and a new (adjusted but not equal) mast position at the board mount.  This is why you have to question everything in foil knowledge.  The bullet points are so often simply misattributions.
« Last Edit: January 10, 2023, 01:34:07 AM by Admin »

EastCoastFoiler

  • Waikiki Status
  • *
  • Posts: 48
    • View Profile
Re: Longer Fuselage for Stability and Pump
« Reply #31 on: January 10, 2023, 02:59:46 AM »
EastCoastFoiler - do you think that your setups are inherently more pitch stable than one which has more stab lift with mast further back. I understand that in a static state the two setups (forward with less stab lift, and back with more stab lift) achieve the same centre of lift, but I don't know if they behave the same once in use?

I currently positive shim my setup (799 and 899 with 325P on CS ADV fuse) for more pitch stability, and I enjoy the way it rides that way but would be interested to see if I can remove the shim but still keep the pitch stability and possibly increase glide too! Should add this is for winging but the physics will be similar...

@Solent Foiler as you move the mast forward the whole setup becomes less stable.  Thatís the limit to this efficiency gain.  That along with the track placement limits of your board.  It is, however, something you can adapt to.  Shim for less lift and love the foil forward till itís uncomfortable but not unrideable.  Give it a few sessions and it will feel fine.  What was previously unrideable is now uncomfortable, repeat.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25744
    • View Profile
Re: Longer Fuselage for Stability and Pump
« Reply #32 on: January 10, 2023, 08:26:47 AM »
This looks even more like what we are building. The thought process for required strength of the fuselage is the same--we don't need much if all we are supporting is the stabilizer and resisting the torque it applies.

https://www.youtube.com/watch?v=ycN_mw2ahJ0
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.

Dontsink

  • Sunset Status
  • ****
  • Posts: 312
    • View Profile
    • Email
Re: Longer Fuselage for Stability and Pump
« Reply #33 on: January 10, 2023, 10:43:57 AM »
My nerdy side says putting the mast smack on top of the central part of the wing should have all sorts of nefarious consequences in drag ,increased stall speed etc.
This central bit of the wing is always creating lift at any speed fast or slow, any interference should matter.
But the guy in the vids (James A. Goulet) says it works fine and his V3 version is quite refined and well made.I tend to believe people that are selling nothing :).

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6300
    • View Profile
    • StandUpZone
    • Email
Re: Longer Fuselage for Stability and Pump
« Reply #34 on: January 10, 2023, 01:40:21 PM »
This looks even more like what we are building. The thought process for required strength of the fuselage is the same--we don't need much if all we are supporting is the stabilizer and resisting the torque it applies.

https://www.youtube.com/watch?v=ycN_mw2ahJ0

Good direction but this is more of the half attached approach.  Frankenfoiling extra fuse parts to fuse wells on existing foils is always going to compromise.  The designs I have ben posting fully and directly incorporate the mast head into a solid carbon block which is integrated part of the carbon wing.  There is no mast head exposed to create form drag and interference drag and no joining of legacy structures.  There is no mast extending aft of the fuse.  That is a missed opportunity.  There is no abrupt end to the collar at the fuse joint.  That step-down is again unnecessary drag and should be seamless.  Same is true on the tail end.  Top mount, particularly this style is essentially a dam.

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6300
    • View Profile
    • StandUpZone
    • Email
Re: Longer Fuselage for Stability and Pump
« Reply #35 on: January 10, 2023, 01:49:16 PM »
My nerdy side says putting the mast smack on top of the central part of the wing should have all sorts of nefarious consequences in drag ,increased stall speed etc.
This central bit of the wing is always creating lift at any speed fast or slow, any interference should matter.
But the guy in the vids (James A. Goulet) says it works fine and his V3 version is quite refined and well made.I tend to believe people that are selling nothing :).

In every instance the fuse ridge begins central wing.  That ridge intersection is where the drag will occur.  The mast rising above that is not going to change that.  There will be drag there but it will not be more than further back (conventional placement).
« Last Edit: January 10, 2023, 01:52:15 PM by Admin »

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25744
    • View Profile
Re: Longer Fuselage for Stability and Pump
« Reply #36 on: January 10, 2023, 02:58:38 PM »

Good direction but this is more of the half attached approach.  Frankenfoiling extra fuse parts to fuse wells on existing foils is always going to compromise.  The designs I have ben posting fully and directly incorporate the mast head into a solid carbon block which is integrated part of the carbon wing.  There is no mast head exposed to create form drag and interference drag and no joining of legacy structures.  There is no mast extending aft of the fuse.  That is a missed opportunity.  There is no abrupt end to the collar at the fuse joint.  That step-down is again unnecessary drag and should be seamless.  Same is true on the tail end.  Top mount, particularly this style is essentially a dam.

I'm more sympathetic to the half-attached (assed??) approach since it's what I routinely do. But I agree, there's a lot of opportunity to reduce drag left on the table here. But I think his efforts are more to see what works and how it feels than to make an optimized system. It's comforting to me to know that the fundamental elements of the designs we're working on have been demonstrated to work well.
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: 6300
    • View Profile
    • StandUpZone
    • Email
Re: Longer Fuselage for Stability and Pump
« Reply #37 on: January 10, 2023, 03:58:13 PM »

Good direction but this is more of the half attached approach.  Frankenfoiling extra fuse parts to fuse wells on existing foils is always going to compromise.  The designs I have ben posting fully and directly incorporate the mast head into a solid carbon block which is integrated part of the carbon wing.  There is no mast head exposed to create form drag and interference drag and no joining of legacy structures.  There is no mast extending aft of the fuse.  That is a missed opportunity.  There is no abrupt end to the collar at the fuse joint.  That step-down is again unnecessary drag and should be seamless.  Same is true on the tail end.  Top mount, particularly this style is essentially a dam.

I'm more sympathetic to the half-attached (assed??) approach since it's what I routinely do. But I agree, there's a lot of opportunity to reduce drag left on the table here. But I think his efforts are more to see what works and how it feels than to make an optimized system. It's comforting to me to know that the fundamental elements of the designs we're working on have been demonstrated to work well.

By half attached, I mean half of the mast head on the foil, half off (aft of the foil).  Mast fully fully encompassed allows a full carbon block to entirely support and surround the mast head.  That block can be carbon-rodded deep into the wing  avoiding torsional problems and all of the undesirable flex.  The mast is given too much leverage when only partially supported.

PonoBill

  • Cortez Bank Status
  • *****
  • Posts: 25744
    • View Profile
Re: Longer Fuselage for Stability and Pump
« Reply #38 on: January 10, 2023, 08:15:23 PM »
Ah, yes. now I understand what you mean. I printed a Frankenstein version of my shroud today with no part cooling since my replacement part didn't show up yet. My new Big Bambu did show up so I spent part of the afternoon getting that unboxed and set up. The result of paying no attention to the print meant the job got fairly hosed, but interestingly the mast fit into the slot beautifully.

This should solve a few printing issues. I labeled every packing support and widget so I can pack this up and ship it to Hood River in a few months. The packaging from Bambu is really good. Let the games begin.

« Last Edit: January 10, 2023, 08:16:55 PM 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.

Admin

  • Administrator
  • Cortez Bank Status
  • *****
  • Posts: 6300
    • View Profile
    • StandUpZone
    • Email
Re: Longer Fuselage for Stability and Pump
« Reply #39 on: January 10, 2023, 11:37:22 PM »
Ah, yes. now I understand what you mean. I printed a Frankenstein version of my shroud today with no part cooling since my replacement part didn't show up yet. My new Big Bambu did show up so I spent part of the afternoon getting that unboxed and set up. The result of paying no attention to the print meant the job got fairly hosed, but interestingly the mast fit into the slot beautifully.

This should solve a few printing issues. I labeled every packing support and widget so I can pack this up and ship it to Hood River in a few months. The packaging from Bambu is really good. Let the games begin.

Sweet.  She has arrived!

 


SimplePortal 2.3.7 © 2008-2023, SimplePortal