RC India

General Topics => RC India Forum => Topic started by: Prakhar Verma on August 28, 2018, 01:40:41 PM



Title: Vacuum bag rc glider wings in India
Post by: Prakhar Verma on August 28, 2018, 01:40:41 PM
Have anyone ever vacuume bagged a glider wing? I am thinking of doing it but i don't have the required materials.can i find it in a hardware store(i am reluctant to buy it online)?if i can find it in a hardware store how much will it cost me?
Any help would be appreciated.


Title: Re: Vacuum bag rc glider wings in India
Post by: K K Iyer on August 28, 2018, 10:05:48 PM
@prakhar verma,

Haven’t seen anyone doing that in India yet.
Here’s a balsa wing I glassed.
48” span, 4” avg chord, 192 sqin.
(18gm/sqm glass cloth, 20 min finish cure epoxy, from Bob Smith Ind, via HobbyKing)
72gms raw plus 28 gms glass+epoxy. Extremely strong even with no dihedral braces.

If you don’t mind, I’m curious about why you are enquiring about vacuum bagged glass wings?
What’s the purpose?
Just experimenting?
Or are you already flying 2m gliders, and want larger ones...
Regards


Title: Re: Vacuum bag rc glider wings in India
Post by: pnkyjs on August 29, 2018, 10:29:02 PM
Very nice information ! Its New technology for me .


Title: Re: Vacuum bag rc glider wings in India
Post by: Prakhar Verma on August 31, 2018, 10:55:04 AM
Hello friend🙄,
 i was actually planning to make a 1.5m dlg but realised that it is better to just cover it with carbon fiber and fiber glass without vacuume  bagging.


Title: Re: Vacuum bag rc glider wings in India
Post by: saikat on August 31, 2018, 06:21:16 PM
if you have never done this sort of thing before - you will find it is much harder
than it seems on the internet.



Title: Re: Vacuum bag rc glider wings in India
Post by: K K Iyer on August 31, 2018, 07:28:55 PM
@prakhar verma,
You said you’re 9 years old. I’m 65.

Before you tackle a 1.5m DLG with carbon fibre and fibreglass, may I ask if you’ve built a chuck glider before?

Did you see this thread?
http://www.rcindia.org/kites-trains-free-flight-and-all-others/one-minute-flight/msg288481/#msg288481

If you’re really keen, send me a PM. I’ll give whatever help I can.
Regards


Title: Re: Vacuum bag rc glider wings in India
Post by: pnkyjs on August 31, 2018, 09:01:01 PM
Iyer sir, I wish I were there in your workshop !


Title: Re: Vacuum bag rc glider wings in India
Post by: K K Iyer on August 31, 2018, 09:11:42 PM
@pnkyjs,
Welcome. Provided I know more about you than just your handle ‘pnkyjs’.
My workshop is my drawing room!
Several young aeromodellers have actually come and stayed with me!
Regards


Title: Re: Vacuum bag rc glider wings in India
Post by: slaerom on September 21, 2018, 03:48:09 PM
That's a great build Sir.


Title: Re: Vacuum bag rc glider wings in India
Post by: IntheSky on September 30, 2018, 10:08:11 AM
Vacuum bagging depends on your construction method. If you're doing a traditional wood build (spars + ribs + sheet skinning) then you dont need vacuum bagging.
However, if you're going in for foam core wings then a CF/glass skinning would require vacuum bagging. The simplest is to look at vacuum bags for luggage (wherein you put your clothes, vacuum the air out to make it a smaller/lighter package). Or you could make it yourself from sheets cut to size, with double-sided adhesive at the edges along with a gel coat for air-proofing. Once done, you can select a convenient spot for the valve, mount it and then proceed with the airbagging.
Of course you need to spray the insides of the bag with mould release before bagging. This is not a trivial process and does involve a fair bit of involvement.

The easier way would be to have the foam core wings with adequate CF reinforcements covered with a thin balsa skin and then glass it in.


Title: Re: Vacuum bag rc glider wings in India
Post by: samayaraj on October 01, 2018, 11:15:19 PM
Im doing composite DLG. Im new to this and Im nearing the fabrication techniques.

Im using Owens Corning XPS foam as core material reinforced with 220gsm Carbon fiber cloth in the leading edge and covered with 50gsm glass fiber cloth with Araldite LY556IN epoxy.

I used AG45Ct profile and weight of wing is 100g. See the attachment for reference.

I just followed this video https://www.youtube.com/watch?v=7FVO9WqKqB8



Title: Re: Vacuum bag rc glider wings in India
Post by: K K Iyer on October 02, 2018, 12:40:09 AM
@samayaraj,

Sir,
Please tell us more!
Do start a new thread of your own.

100gms? Span/area?
AUW of the DLG?
Many more queries...

My 48” balsa wing, root 4.5” AG03, tip 3.5” AG11, area 192 sqin, 18gsm glass was ~100gms.
But 12 Aspect Ratio too much for DLG (You may have seen the video of the discus launch. Disastrous!)
So shifted to histart, but that’s another story.

Regards


Title: Re: Vacuum bag rc glider wings in India
Post by: IntheSky on October 02, 2018, 07:07:26 AM
Looks great !! Hope you can post a video of its maiden when its complete !
All the best ! :)


Title: Re: Vacuum bag rc glider wings in India
Post by: samayaraj on October 02, 2018, 09:12:29 AM
@samayaraj,

Sir,
Please tell us more!
Do start a new thread of your own.

100gms? Span/area?
AUW of the DLG?
Many more queries...

My 48” balsa wing, root 4.5” AG03, tip 3.5” AG11, area 192 sqin, 18gsm glass was ~100gms.
But 12 Aspect Ratio too much for DLG (You may have seen the video of the discus launch. Disastrous!)
So shifted to histart, but that’s another story.

Regards


Dear KK Iyer ji,

This is my first attempt. So Im testing whether my fabrication techniques wokring good or not. After sucessfull completion, I will start posting videos of composite aircraft making.

Im making DLG with wing span of 1.1m, Aspect ratio is 10 approx., wing area is 0.11 m2 approx. Wing weight is 100 gms and total weight including all components 220 to 250 gms.

I will post many videos related to basics of carbon fiber fabric cutting, preparing prepeg by own, glass fiber laying, hot wire foam cutting, vacuum bagging etc which I exprienced so far.



Title: Re: Vacuum bag rc glider wings in India
Post by: Mehul Anand on October 02, 2018, 09:50:07 AM
This stuff feels interesting!!


Title: Re: Vacuum bag rc glider wings in India
Post by: saikat on October 02, 2018, 01:19:23 PM
Great stuff Man !

Where did you get the foam ?


Title: Re: Vacuum bag rc glider wings in India
Post by: samayaraj on October 02, 2018, 01:19:45 PM
Hello friend🙄,
 i was actually planning to make a 1.5m dlg but realised that it is better to just cover it with carbon fiber and fiber glass without vacuume  bagging.

Tell me about the materials you have decided to make. I think you may go for foam core. If so, you have to reinforce the wing with CF in both spar as well as in leading edge.


Title: Re: Vacuum bag rc glider wings in India
Post by: samayaraj on October 02, 2018, 01:20:52 PM
Great stuff Man !

Where did you get the foam ?

I got foam material from local insulation dealer. Its owens corning Fomular XPS foam.


Title: Re: Vacuum bag rc glider wings in India
Post by: Prakhar Verma on October 07, 2018, 05:35:23 PM
What is a local insulation dealer and Which shop are you talking about?


Title: Re: Vacuum bag rc glider wings in India
Post by: delmiss on October 02, 2019, 05:09:46 PM
Very nice information ! Its New technology for me .