Logo
Builders' Plan Gallery  |  Hip Pocket Web Site  |  Contact Forum Admin  |  Contact Global Moderator
January 21, 2020, 11:46:45 AM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with email, password and session length
 
Home Help Search Login Register
Pages: [1] 2 3 4 5 6 7 8 9   Go Down
Print
Author Topic: VP Hubs - for the techies among us  (Read 19681 times)
0 Members and 1 Guest are viewing this topic.
Olbill
Titanium Member
*******

Kudos: 68
Online Online

United States United States

Posts: 2,556

Topic starter


Ignore
« on: August 09, 2009, 03:40:08 PM »

These pictures are all from 2004 and 2005 but represent several of the common and uncommon VP hubs in use.
From left to right:
Dezso Orsovai
Ivan Tregers
Lutz Schramm
Peter Kuttler
Kornechuk
Ron Green
Attached files Thumbnail(s):
VP Hubs - for the techies among us
VP Hubs - for the techies among us
VP Hubs - for the techies among us
VP Hubs - for the techies among us
VP Hubs - for the techies among us
VP Hubs - for the techies among us
« Last Edit: August 09, 2009, 03:51:21 PM by Olbill » Logged
Olbill
Titanium Member
*******

Kudos: 68
Online Online

United States United States

Posts: 2,556

Topic starter


Ignore
« Reply #1 on: August 09, 2009, 03:50:25 PM »

More hubs.

Ukranian double spring hub (cm - not inches!)
Kevlar wound hub
Kevlar wound hub for 35cm
Tissue tube hub
Keller hub
Nick Aikman hub
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Logged
MrTurtle
Guest

« Reply #2 on: August 09, 2009, 09:10:39 PM »

Steve Brown
?
Tom Sova
John Kagan
Doug Schaefer
Richmond's VD

Photos by Zaluska
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Logged
FlyF1D
Bronze Member
***

Kudos: 4
Offline Offline

United States United States

Posts: 23



Ignore
« Reply #3 on: August 10, 2009, 12:39:53 AM »

Tom Sova's 35cm hub (that's not a bagel, it's a Cheerio!)

Ray Harlan’s “inverted” VP features pass-through actuator arms and a boron reinforced hub
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Logged
Sundance12
Model Airplane Builder
Global Moderator
Platinum Member
*****

Kudos: 72
Offline Offline

Canada Canada

Posts: 1,066


MAAC #25680, VE4BDF (amateur radio callsign)

WWW
« Reply #4 on: August 10, 2009, 11:04:07 AM »

Awsome examples of mechanics, thanks for posting those images, just amazing.

Sundance12
Logged

Resources and tools for scratch builders and plans builders.
www.northof49tech.com
Olbill
Titanium Member
*******

Kudos: 68
Online Online

United States United States

Posts: 2,556

Topic starter


Ignore
« Reply #5 on: August 10, 2009, 01:09:05 PM »

Here's one of my F1M VP. This is much heavier than the ones pictured before and is not suitable for F1D but it works very well - 2 World Records (one pending) and 2 wins at USIC. I have the greatest respect for people who can build a beautiful piece of functioning machinery at such a small size and weight. For the cavemen builders among us this picture shows that such a high level of cragtsmanship isn't totally necessary to make something that works.

Also here's an article I did a few years ago for building VP hubs suitable for Penny Plane and F1M. The hub pictured below is the next hub I built after doing the article. It's basically the same design but just built lighter.

http://www.indoornews.com/modules/articles/article.php?id=3

Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Logged
mkirda
Gold Member
*****

Kudos: 16
Offline Offline

United States United States

Posts: 679

WWW

Ignore
« Reply #6 on: July 20, 2012, 09:43:26 AM »

Just wondering if there was anything similar out there for VD mechanisms...

Regards.
Mike Kirda
Logged

Olbill
Titanium Member
*******

Kudos: 68
Online Online

United States United States

Posts: 2,556

Topic starter


Ignore
« Reply #7 on: July 20, 2012, 10:41:29 AM »

Mike
The case for VD's looks pretty strong for efficiency gains over VP's and I'm not one to discourage people from going for whatever advantage they see. That being said I know 3 top F1D fliers and a few other assorted brave individuals who have invested a lot of energy in VD's. As far as I know the current situation is unchanged from several years ago - Jim Richmond is the only person successfully using VD's in competition. Here's a really grainy jpeg of an old INAV drawing of Jim's mechanism.
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Logged
Dave Andreski
Titanium Member
*******

Kudos: 82
Offline Offline

United States United States

Posts: 3,052




Ignore
« Reply #8 on: July 20, 2012, 11:15:37 AM »

Not sure if this will help but here goes...
From Model Builder, Sept., '85.
Dave Andreski
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Logged

Aspire to inspire before you expire.
jakepF1D
Gold Member
*****

Kudos: 8
Offline Offline

United States United States

Posts: 450


1996 World Champs



Ignore
« Reply #9 on: July 20, 2012, 04:25:54 PM »

INAV 121 has an article by Jim Richmond with detailed drawings and pictures.  If you can't find it I'll figure out a way to post it here.

I would also echo what Bill said which is that while VD might be theoretically better, most people that try it go back to VP.  The only other person I know of that had some success was Rich Doig, and even he had a lot of problems with it.  I watched him spend hours trying to get his prop to work at the '96 world champs.
Logged
mkirda
Gold Member
*****

Kudos: 16
Offline Offline

United States United States

Posts: 679

WWW

Ignore
« Reply #10 on: July 20, 2012, 04:44:21 PM »

INAV 121 has an article by Jim Richmond with detailed drawings and pictures.  If you can't find it I'll figure out a way to post it here.

I would also echo what Bill said which is that while VD might be theoretically better, most people that try it go back to VP.  The only other person I know of that had some success was Rich Doig, and even he had a lot of problems with it.  I watched him spend hours trying to get his prop to work at the '96 world champs.

Hi Jake.
I have a Lulu reprint copy, thanks. If someone has a copy of Slobodan Midic's figures from INAV 123 that is legible, I'd appreciate a copy.
The Lulu reprint is illegible.
I also couldn't figure out the 7 degree angle - like where that was supposed to be in relation to the propeller center line.
Reading the reprint, I just found it interesting and wanted to understand it.
It wasn't until I held one of Brett's VP props that it clicked for me and I really understood the pictures.
I'm kind of at the same place with these VD mechanisms.

Regards.
Mike Kirda
Logged

jakepF1D
Gold Member
*****

Kudos: 8
Offline Offline

United States United States

Posts: 450


1996 World Champs



Ignore
« Reply #11 on: July 20, 2012, 04:53:20 PM »

Speaking of Brett's VP prop, does anyone have pictures of his carbon prop?  I assume the 42 minute flight was done with it, but I haven't seen pictures. 
Logged
green-man
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 289


One of my F1D VP propeller hubs - weight 104 mg.



Ignore
« Reply #12 on: July 22, 2012, 02:23:01 AM »

Here's a pic of Brett's model by Nick Ray, 'borrowed' from Facebook.

The type of carbon used is important - you can't just use any old stuff.

Also, 2 pics of Lutz's carbon prop from the 2010 F1D Belgrade Champs.
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
Re: VP Hubs - for the techies among us
« Last Edit: July 22, 2012, 02:42:23 AM by green-man » Logged
jakepF1D
Gold Member
*****

Kudos: 8
Offline Offline

United States United States

Posts: 450


1996 World Champs



Ignore
« Reply #13 on: July 23, 2012, 12:59:22 PM »

Thanks for the pics.  I'm still working to get my regular VP props working well so these are a little bit off for me.  That said, I think this will probably be the next big thing in F1D.  What is different about the carbon he's using?
Logged
green-man
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 289


One of my F1D VP propeller hubs - weight 104 mg.



Ignore
« Reply #14 on: July 23, 2012, 01:23:31 PM »

It has to be ultra-high modulus carbon which is stiffer than normal Wink.
Logged
mkirda
Gold Member
*****

Kudos: 16
Offline Offline

United States United States

Posts: 679

WWW

Ignore
« Reply #15 on: July 23, 2012, 03:05:18 PM »

It has to be ultra-high modulus carbon which is stiffer than normal Wink.

So where can one source this extra stiff carbon?
I am a long ways off from playing with carbon for outlines, but it seems to me the most difficult part of this hobby is often sourcing the proper materials.
I'd buy some just so I could play with it later...

Regards.
Mike Kirda
Logged

jakepF1D
Gold Member
*****

Kudos: 8
Offline Offline

United States United States

Posts: 450


1996 World Champs



Ignore
« Reply #16 on: July 23, 2012, 03:37:44 PM »

I'd buy some just so I could play with it later...

This is exactly my thinking.  I've realized over the years that if I see something I like I should buy it now even if I don't plan to use it for a while.  So many things in the world of indoor have disappeared over the years.
Logged
green-man
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 289


One of my F1D VP propeller hubs - weight 104 mg.



Ignore
« Reply #17 on: July 23, 2012, 03:42:23 PM »

I don't know Mike. I think Brett has tried several different types so you could ask him.
Logged
jakepF1D
Gold Member
*****

Kudos: 8
Offline Offline

United States United States

Posts: 450


1996 World Champs



Ignore
« Reply #18 on: July 23, 2012, 03:52:52 PM »

I found some high modulus unidirectional fabric at the link below.  I'm guessing you could separate fibers to make your own tow for an outline, but I'm not sure if that's a good solution.  Perhaps someone can ask Brett what he's using.

http://www.cstsales.com/uni_carbon_fabric.html
Logged
green-man
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 289


One of my F1D VP propeller hubs - weight 104 mg.



Ignore
« Reply #19 on: July 23, 2012, 04:15:54 PM »

Taking strands out of what looks like a Russian unidirectional cloth is the way that Lutz started with carbon. Lutz sent me a sample and it's very easy to seperate the strands into usable pieces. But I think? that Lutz, Brett and Ivan are now using strands taken directly from carbon tow.
Logged
mkirda
Gold Member
*****

Kudos: 16
Offline Offline

United States United States

Posts: 679

WWW

Ignore
« Reply #20 on: July 23, 2012, 04:20:00 PM »

Hexcel IM8,9 or 10 look to have the proper modulus. It appears that they come only in 12K tow, so it would be relatively difficult to separate versus 1K.
I'm still looking...

Regards.
Mike Kirda
Logged

green-man
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 289


One of my F1D VP propeller hubs - weight 104 mg.



Ignore
« Reply #21 on: July 23, 2012, 05:11:17 PM »

From an email to me from Ivan: -

"Lutz used HM roving M46J( Mitsubishi, Toray yarn). I tried it but it is problem to separate a very fine strand of those roving which I need for insert to gap of the form. The gap is very delicate, it start from 0,4 square to 0,15 square mm.
For my cf outlines I used HM roving Tenax UMS 40 which is good for separated a fine strands. Next time I want to use stronger roving Mitsubishi Dialead K 63712, or Granoc CN60 which have very small elongation and the fibre is thicker than Tenax or Toray fibres.
I use only the resins for aeroplane : Ciba geigy ( Vantico) 5052XB which have excellent mechanical properties.

The complete weight of my propellers is from 260 to 270mg."

Nick.

Logged
jakepF1D
Gold Member
*****

Kudos: 8
Offline Offline

United States United States

Posts: 450


1996 World Champs



Ignore
« Reply #22 on: July 23, 2012, 05:32:42 PM »

Thanks for the info Nick.  I found a nice data sheet for the Mitsubishi Dialead K63712 material.  Now I need to figure out where I could buy something like this.
Logged
Tapio Linkosalo
Platinum Member
******

Kudos: 28
Offline Offline

Finland Finland

Posts: 1,189



Ignore
« Reply #23 on: July 24, 2012, 02:44:36 AM »

Have the guys mentioned,

- what kind of fiber/resin -ratio they aim for / have achieved? The best laminates should have 50 to 70% fibers, but for prop outlines at reasonable weight this may produce too thin outlines. Larger dimension would mean stiffer outline (this is why balsa is so good stuff in indoor construction). Also,

- did they get to the final dimensions by laminating, or did they have to sand the laminate down?

I tried to make some carbon outlines in a silicone mold a few years ago, but failed miserably. The result was heavy and flimsy. Also, I would have needed to sand the outline down to weight, and I did not like the idea, but would rather develop a molding tecnique that would produce final outlines right out of the mold. After that unsuccessfull attemp I decided to stick to balsa and try to solve my other F1D building problems first... :-)

... talking of VP's, I attach a pic of my latest VP hub. Construction mostly pultruded carbon tubing. The blade attachement tubes are still paper, as I'm working on solid methods to make them of carbon (so that I could use deliberate amounts of glue to attach prop spars and still would be able to use acetone to solve the glue). The inner prop blade holding wire (that also doubles as actuator meeting the cross bar) makes a 90 degree angle to go into the main tubing, the latter has a machined slot in it. Had to buy a cross-feed table to go with my drill press to be able to drill those holes, 0.3mm diameter bit into a 0.3mm ID 0.7mm OD tubing was a bit hard to drill free-hand. The hub weights about 130mg; a bit too much but it is also much stiffer than balsa construction.
Attached files Thumbnail(s):
Re: VP Hubs - for the techies among us
Logged
green-man
Gold Member
*****

Kudos: 5
Offline Offline

United Kingdom United Kingdom

Posts: 289


One of my F1D VP propeller hubs - weight 104 mg.



Ignore
« Reply #24 on: July 24, 2012, 02:53:54 AM »

Morning Tapio.

I know that Lutz and Brett sand the outlines to produce tapered square sections but I think you'll have to ask the carbon prop users in Belgrade the other questions - carbon props are bound to be one of the hot topics of conversation.

Nick.
Logged
Pages: [1] 2 3 4 5 6 7 8 9   Go Up
Print
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Valid XHTML 1.0! Valid CSS!