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 Post subject: bag 机用勿 epoxy?
PostPosted: Sat Sep 18, 2004 1:27 am 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
Patrick,

我打算開始 bag 翼啦。
想問吓你係邊度買到 West system 既 epoxy.
又或者你建議用邊隻好D ?

bag 翼之後‧我重想玩 mould 机。 用既 epoxy 又係唔係一樣呢!


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 Post subject:
PostPosted: Sat Sep 18, 2004 11:11 am 
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Joined: Wed Mar 03, 2004 7:31 pm
Posts: 1026
:P Mak,
YC told me a year ago that West System's epoxy (# 206, or 602, something like that) could be bought at Sai Kung. Regards.


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 Post subject:
PostPosted: Sat Sep 18, 2004 2:29 pm 

Joined: Sat Jun 26, 2004 9:59 am
Posts: 207
Location: Hong Kong
Available at Sai Kung and the shop at Wanchai, CWB seafront where the boat club located. it is around 200 to 300 per litre. If you drive, just follow the road at the seafront past the wanchai ferry pier heading towards cross harbour tunnel. When you reach the road junction, take the left lane and there will be a small road leading to boat club. Be careful not to entre the right lane because that is for BUS only.


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 Post subject:
PostPosted: Sat Sep 18, 2004 11:28 pm 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
I've seen West system in that shop too.
but they don't seem to carry the full range of West-system. I'll go and check it up the next time I go there.
I understand there are many types of west-system epoxy with different code numbers. each have it specail application.
I'm looking for one that will run easily into FG, and should be very hard when cured.

I'm willing to try other epoxy too。


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 Post subject:
PostPosted: Sun Sep 19, 2004 10:16 am 
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Joined: Thu Feb 26, 2004 5:31 pm
Posts: 741
Location: 沙田
我曾經用過係西貢游艇會買既 West System epoxy (#105 resin, #206 hardener ), 唔太貴﹐ $185 一 套都可以用好耐, 我估個度有 1 liter 主劑。我曾經有系統地比較過 West System, ACP 既 EZ Lam 同國生行既 1101 epoxy, 發覺 West System 既硬度係最高﹐但 West System epoxy 好杰﹐唔係咁容易索淋 D 纖維布。

美國 handlaunch 冠軍 Phil Barnes 做 DLG 係用 Proset epoxy, 同 West System 一樣﹐呢隻 epoxy 係美國 Gougeon Brothers 生產﹐但強度比 West System 高﹐又無咁杰﹐仲有高溫品種( 戰鬥機同 Formula One 賽車用), 係專業材料﹐我問過西貢游艇會可唔可以同我訂﹐佢既答覆係 "West System 得架啦﹐我地D游艇都係用佢架!"。

West System 同 Proset 既詳細資料可以係呢度搵到。如果有朋友知香港邊度可以買到 Proset epoxy, 記住通知聲。

http://www.westsystem.com/webpages/prod ... .htm#resin

http://www.prosetepoxy.com/laminating_epoxies.html


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 Post subject:
PostPosted: Mon Sep 20, 2004 1:07 am 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
Thank you all. I'll give West-system a try!

Anyone know how to read technical diagram of the SuperGee II?
I don't understand some of the followings.
http://www.charlesriverrc.org/articles/ ... ergee2.pdf

AG455ct
6.5% t
2.2 % c
1.8% c
7.2"

AG455ct should be the airfoil, and 7.2" could be the cord length. However, what are the t and the 2 c in %?


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 Post subject:
PostPosted: Thu Sep 23, 2004 10:31 am 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
YC, Ah Mak, CM, the lateral tail wings I begged with blue foam, 0.75oz FG and the unidentified epoxy, only 15g. I think this combination possibly can do a good job in DLG.


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 Post subject:
PostPosted: Thu Sep 23, 2004 10:34 am 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
Ah Mak, forget about the percentage and the c or the t, they mean something but they do not mean anything for cutting a wing core, just follow the section AG45, 46 and 47 to cut the core, please do not foget to compare those core you cutted with the drawing, the curve close to the TE is ver important.


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 Post subject:
PostPosted: Thu Sep 23, 2004 8:04 pm 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
PatrickYellow wrote:
Ah Mak, forget about the percentage and the c or the t, they mean something but they do not mean anything for cutting a wing core, just follow the section AG45, 46 and 47 to cut the core, please do not foget to compare those core you cutted with the drawing, the curve close to the TE is ver important.


Patrick, how about the angle of the LE? I couldn't find any information on the SuperGee drawings!


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 Post subject:
PostPosted: Thu Sep 23, 2004 10:18 pm 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
According to the information, ZERO degree Mr Drela recommended.

You finished the begging yet? Still need the epoxy?


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 Post subject:
PostPosted: Thu Sep 23, 2004 10:55 pm 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
I might not have made myself clear.
It's the Leading edge swept-back that I'm trying to work-out.

No, I've ordered some 1 oz Kevlar for the hinge, and are still waiting for it to arrive.
What type of epoxy are you using? Is it easy to use?


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 Post subject:
PostPosted: Fri Sep 24, 2004 12:43 pm 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
How much for the 1 oz. Kevlar? I might need some if possible.
I also do not know the origin cos the supplier did not tell me, I guess it come from USA or Australia, it is clear and hard enough to do the job, you can see that last time in Lamma, the wings I begged these day all can keep below 55g each, and proved that it hard enough with some impact test, I am not trying to sell you but if it can help, I can share some to you to have a trail.


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 Post subject:
PostPosted: Fri Sep 24, 2004 8:10 pm 
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Posts: 1660
Location: Tai Po, HK
PatrickYellow wrote:
How much for the 1 oz. Kevlar? I might need some if possible.
I also do not know the origin cos the supplier did not tell me, I guess it come from USA or Australia, it is clear and hard enough to do the job, you can see that last time in Lamma, the wings I begged these day all can keep below 55g each, and proved that it hard enough with some impact test, I am not trying to sell you but if it can help, I can share some to you to have a trail.



We ordered the 1 oz. Kelvar from hi-tech material.
http://www.freeflightsupplies.co.uk/hitech.htm
It's 18.5 pounds per meter.

The wing you show me that day was very nice. Yes, I would like to try that epoxy on my DLG project.
You still didn't tell me about the swept-back angle of the SuperGee! What measurement's on your wing ?


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 Post subject:
PostPosted: Sun Sep 26, 2004 10:34 am 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
Ah Mak, sorry that I am too stupid to understand what is the swept-back angle, is it the angle for the centre line of the wing and the fuselage? If it is, you may try the origin design first, it is recommend ZERO degree, means both centre lines are parallel.
YC also want some epoxy too, 1kg for me can fabricate 40 pairs of AG wings, I think you may share 1kg with YC, or whatever you like!
Ring me when you need, I live in Taipo too, YC got my number.


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 Post subject:
PostPosted: Sun Sep 26, 2004 10:39 am 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
Ah Mak, did you place your order for the kelvar yet, or can you place another 1.5m additional order to them for me?


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 Post subject:
PostPosted: Sun Sep 26, 2004 10:51 am 
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Joined: Thu Feb 26, 2004 5:08 pm
Posts: 3084
Location: Hong Kong
Mak,

Please check the SuperGee II drawing. On the left side it shows the three section views of the wing. Note that there is a dashed line running through the three section. It means that the hinge line of the wing is on a straight line perpendicular to the plan of the section. This also defined the swept angle of the wing, i.e., the hinge line is perpendicular to the fuselage.


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 Post subject:
PostPosted: Sun Sep 26, 2004 11:34 am 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
PatrickYellow wrote:
Ah Mak, did you place your order for the kelvar yet, or can you place another 1.5m additional order to them for me?


Patrick, I'll ask YC to add 1.5m of Kavlar to the order for you.(add 15% for shipping charge).
These goods will be send by surface mail,so the shipment will take a month.

YC sent orders out a few days ago.If it can't be changed, you can have 1.5m out of the 3m I ordered.


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 Post subject:
PostPosted: Sun Sep 26, 2004 11:57 am 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
Thanks CM n Ah Mak, Ring me whenever you need the epoxy! CM too! I knew you making your secret weapon too! Be hurry, you need so much time to do the test throwing and flying!


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 Post subject:
PostPosted: Wed Sep 29, 2004 1:02 am 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
K.Y.Mak wrote:
PatrickYellow wrote:
Ah Mak, did you place your order for the kelvar yet, or can you place another 1.5m additional order to them for me?


Patrick, I'll ask YC to add 1.5m of Kavlar to the order for you.(add 15% for shipping charge).
These goods will be send by surface mail,so the shipment will take a month.

YC sent orders out a few days ago.If it can't be changed, you can have 1.5m out of the 3m I ordered.


Patrick,
YC couldn't change the order. The goods have already arrived.
According to YC's inspection. the 1 oz Kevlar are losely waved. not as good as some of the more expensive ones.
If you still want some, let us know.

Both YC and me want to try the epoxy, but we are busy with the coming F3F race, hence not be able to try it until we come back from Germany.


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 Post subject:
PostPosted: Wed Sep 29, 2004 1:15 am 
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Joined: Thu Feb 26, 2004 7:54 pm
Posts: 1660
Location: Tai Po, HK
CM Cheng wrote:
Mak,

Please check the SuperGee II drawing. On the left side it shows the three section views of the wing. Note that there is a dashed line running through the three section. It means that the hinge line of the wing is on a straight line perpendicular to the plan of the section. This also defined the swept angle of the wing, i.e., the hinge line is perpendicular to the fuselage.


Yes, the hinge line is perpendicular to the fuselage. However, I still can't work out the swept-back angle.
What I'm trying to work out is the distance of the TE from the baseline, for cutting of the airfoil.
eg. the Beetle's TE is also perpendicular to the fuselage, hence I can line-up both templets on the same base-line, and do the cutting.
However, the SuperGee's TE is not the same as the hinge-line. How can I work out the distance of the wing tip from the base-line for cutting?


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 Post subject:
PostPosted: Wed Sep 29, 2004 11:50 am 

Joined: Tue Jun 08, 2004 7:14 pm
Posts: 92
Location: TaiPo/TuenMun
Ah Mak,
We use AutoCad to measure those details, if you have the Cad, you may try to do so.
If the Kelvar is suitable to be the hinge, I would like to have some. Thank you.
Patrick


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