Kevin,
Thanks for the info. For some reason my postings sometimes have characters left out. I wrote 1/2 oz/sq.yd. for your 17mg/m2 but it was saved as 1 oz/sq.yd. Also, the 2cm tape we can get in the US is 1.1 oz/sq.yd. and that number got left out, too. Many people use the term unidirectional fabric for unidirectional carbon. It may be technically incorrect but it is descriptive. Besides, often, the unidirectional carbon does have perpendicular binding fibers.
So, in what country do you reside and where did you obtain the light weight prepreg? If you ever buy more, I would like to get some, too.
Thanks,
Leo
--- In Indoor_Construction_at_yahoogroups.com, Kevin Lamers <kevin.lamers@...> wrote:
>
> 17g/m2 is about 0.5oz/sq.yd.
> This is excluding resin. With resin it is about 28g/m2 (about 0.8oz/sq.yd).
> The material is indeed unidirectional so you are free in choosing the fibre
> direction. Obviously it is no fabric since all fibres run in one direction
> (see picture).
>
> The prepreg is stored in a freezer, that way it will be good for some
> years. At room temperature it will survive for about 2 months. Shipping
> will of course reduce this time by a week or so.
>
> I made two types of tubes:
>
> One layer in the length of the tube and then wrapped with a 2mm wide piece
> of prepreg in the hoop direction.
> One layer in the length of the tube and then wrapped with thin dry kevlar
> thread (there is enough resin in the first layer to impregnate the kevlar
> as well).
> The second being lighter of course.
>
> Kevin
> Op 6 mrt. 2013 00:08 schreef "Leo Pilachowski" <leop_at_...> het
> volgende:
>
> > **
> >
> >
> > This carbon fabric is very light. Is it unidirectional fabric? Is the
> > weight of the prepreg (17g/m2) with or without the epoxy. That is, is it
> > just the weight of the carbon or does it include the epoxy? 17g/m2 is a bit
> > under 1oz/sq.yd. In the US, we can commercially buy 1.5 oz/sq.yd.
> > unidirectional fabric but(2 cm wide) unidirectional tape is rare at times
> > and expensive.
> >
> > Also, how long did the prepreg keep? Did you refrigerate it?
> >
> > For light weight carbon tubes, have you played with wrapping individual
> > tows or carbon?
> >
> > Leo
> >
> > --- In Indoor_Construction_at_yahoogroups.com, Kevin Lamers wrote:
> > >
> > > Hi Kang,
> > >
> > > The carbon tubes (both the spar and hub) are made of IM carbon (T800)
> > > prepreg 17 gram/m2. The outline is made of UHM carbon (M60) roving.
> > > I have checked the individual weights and they are as follow:
> > >
> > > Blade (outline+ribs+balsa spar+covering): 0.074 gram
> > > Carbon spar (including aluminium bearing and actuator wire): 0.018 gram
> > > For 2 blades + spars: 0.184 gram
> > > Hub: 0.078 gram
> > > Total: 0.265 gram
> > >
> > > I now figure that I should half the length of the carbon spar and make
> > the
> > > balsa spar a little longer, to save some weight (and make the outline
> > > thicker)
> > >
> > > I haven't had the change to fly it yet since I still have to build the
> > rest
> > > of the model. I have made some F1D's a couple of years ago, in the mean
> > > time I was only doing F1B, and I figured it would be nice to give it a
> > try
> > > again. So here I am ;-)
> > >
> > >
> > > Best wishes,
> > > Kevin
> > >
> > >
> > >
> > > 2013/3/5 Yuan Kang Lee
> > >
> > > > **
> > > >
> > > >
> > > > Kevin,
> > > >
> > > > looks very nice. What materials are the spar and outline made from?
> > > >
> > > > Have you had a chance to fly it ?
> > > >
> > > > -Kang
> > > >
> > > >
> > > > --- In Indoor_Construction_at_yahoogroups.com, Kevin Lamers wrote:
> > > > >
> > > > > Hi Mike,
> > > > >
> > > > > I have to check tonight for the exact numbers, but by heart about:
> > > > > VP (just the centre, not the extended carbon tubes): 0.08 gram
> > > > > 2x blade + extended carbon tubes: 0.185 gram
> > > > >
> > > > > At least the total is 0.265 gram, see picture.
> > > > >
> > > > > Best regards,
> > > > > Kevin
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > 2013/3/5 mkirda_at_
> > > > >
> > > > > > **
> > > >
> > > > > >
> > > > > >
> > > > > > Hi Keven.
> > > > > >
> > > > > > What does the hub weigh minus the prop spars/outlines?
> > > > > > And what does the entire prop weigh?
> > > > > >
> > > > > > The design is interesting to me mainly because I HATE tying kevlar
> > > > > > hinges... LOL.
> > > > > >
> > > > > > Regards.
> > > > > > Mike Kirda
> > > > > >
> > > > > >
> > > > > > --- In Indoor_Construction_at_yahoogroups.com, Kevin Lamers wrote:
> > > > > > >
> > > > > > > Here a carbon hub I'm working on currently. The main tube weighs
> > 15mg
> > > > > > > including the bracket for the screws. The tube is 2mm ID and has
> > a
> > > > 0.05mm
> > > > > > > wall thickness (2 layers 17 gsm prepreg).
> > > > > > > I hope the attachment gets through.
> > > > > > >
> > > > > > > Kevin
> > > > > > > Op 1 mrt. 2013 21:13 schreef het volgende:
> > > > > > >
> > > > > > > > **
> > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > I vote that you show all of us your unproven hub so we can all
> > > > pick it
> > > > > > > > apart before you perfect it.
> > > > > > > > On a personal note, all this talk of carbon, kevlar &
> > fiberglass
> > > > has me
> > > > > > > > thoroughly confused. I need pictures.
> > > > > > > > Gary Hodson
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > > >
> > >
> >
> >
> >
>
Received on Wed Mar 06 2013 - 05:44:30 CET
This archive was generated by Yannick on Sat Dec 14 2019 - 19:13:47 CET