Viewing 40 posts - 41 through 80 (of 82 total)
  • Homemade Carbon XC Frame – pics and details as promised!
  • crashtestmonkey
    Free Member

    in your internet travels you probably came across the article written by some spoke length calculator geek called Damon Rinard, who built his own bike out of CF many years ago…

    http://sheldonbrown.com/rinard/carbon_fiber.htm

    …and you probably know he is now a senior engineer at Cervelo…

    http://www.cyclingnews.com/features/photos/pro-bike-theo-bos-cervelo-s3/122755

    Fingers crossed!

    sugdenr
    Free Member

    richamars – most inpressed by your ingenious makeshift lathe!

    oliverracing
    Full Member

    Spazzolino – I did try heat shrink wrap, but I didn’t have much success with the results, as sometimes I got over-compression (crushed the foam core) – I found some 50mm cheapy electrical tape, which seemed to work the best as it had a good amount of stretch. I also used the method of pricking holes in it to allow excess resin to seep out. I used clingfilm and expandin foam mainly as a school experiment to pad my coursework a bit – it really didn’t give good results (strong but looked crap)

    Crashtestmonkey – TBH I have never actually considered a career with composites, as vehicle dynamics (primarily F1) is my main area of interest. – but I never know where my interest will be in 10 years time!

    lol – hadn’t seen the lathe – LOVE IT!!!! :mrgreen:

    jameso
    Full Member

    Impressed, good work..

    Not sure what I’m more impressed with, the ride-able end result or the fact you did it in a garage that makes mine look tidy and not many do that.. I struggle to build bikes there never mind make a frame )
    I was looking up info on making some small parts in carbon a while back, feeling inspired to get back onto those ideas now. Thanks – great project + post.

    FunkyDunc
    Free Member

    Looks great!

    I assume it also doubles as a life vest if you happen to find yourself in a lake (having all that foam in it) 😆

    oliverracing
    Full Member

    jameso – I will admit I was lucky with the weather and did 99% out the front of the garage as you do need space to work with carbon, I worked on the folding table with green + orange paint. The disassembled jig to the right can also be seen 😀 – if the weather had have been bad I would have cleared the garage out as you need 360 degree access when building. In terms of small parts – I have made my own bash out of a flat sheet of carbon (works great), I did try a bottle cage but that wasn’t as successful – but will try again with a new bottle 😀 (it stuck last time)

    FunkyDunc – no foam left in it – I moulded the main tubes around pvc pipe, and the small parts I melted the foam out with acetone – as I did internal cable routing I needed clear routed though the frame 😀

    Dickyboy
    Full Member

    fair play to the OP, great to see this kind of stuff 🙂

    its as much as I can do to bolt a bike together from its component parts

    tenfoot
    Full Member

    Mightily impressed.

    Good for you!

    richmars
    Full Member

    The lathe didn’t work very well, but did produce a massive amount of dust. It does show how crude you can be but still get something that works.

    rs
    Free Member

    how about doing some destruction testing with the other tubes that didn’t make the frame…

    crashtestmonkey
    Free Member

    but I never know where my interest will be in 10 years time!

    well I went from postdoc research into superplastic aluminium alloys intended for the Eurofighter/Typhoon to being a copper…. 🙄 😀

    oliverracing
    Full Member

    rs – all tubes went well so that sorta stuff that…

    crashtestmonkey – haha – nah definitely want to do something engineering based, I love doing things like this so why not make a career out of it!

    rs
    Free Member

    I thought you mentioned you used some other techniques that didn’t work so well, would be good to see them being hit with a hammer 🙂 or make a few spares and hit them with a hammer!

    AlexSimon
    Full Member

    Fantastic stuff.
    I keep thinking about trying something largish as a project.
    A canoe is currently winning in my head.

    richmars
    Full Member

    A canoe is currently winning in my head.

    Easy. Big block of foam, curved to a canoe shape. Lots of carbon (might be a bit expensive), lots of tape. Dig out the foam when cured.

    carbonfiend
    Free Member

    Bloody brilliant & not sure whats best the actual build or ‘..two weeks intesive testing in the alp..’
    Cap well & truly doff’d

    DT78
    Free Member

    wow, hat off to you

    oliverracing
    Full Member

    A canoe is currently winning in my head.

    I was actually thinking about doing a full suss sometime in the next few years… let the designing begin!

    AlexSimon
    Full Member

    richmars – Member

    A canoe is currently winning in my head.

    Easy. Big block of foam, curved to a canoe shape. Lots of carbon (might be a bit expensive), lots of tape. Dig out the foam when cured.
    Carbon fibre isn’t usually used on its own for canoes.
    Kevlar is the better bet.
    Although to be honest I’m leaning towards a cedar strip construction with glass fibre outside.

    benson330
    Free Member

    you mentioned bamboo – I thought this was interesting a few weeks ago;

    null

    ps. well done on your creation!

    oliverracing
    Full Member

    yeah – when I looked around oxford brookes uni a few years ago, they were doing the development and testing for these next door to the room I was in so I went and had a look around -They let me have a quick spin on it – and to be honest I was a bit disappointed, but probably didn’t ride it enough to see the benefits and might have been an early prototype. By then I had already started making the bamboo bike trailer for my a-level, so it was a bit late for extra credit/research.

    boltonjon
    Full Member

    Fair play mate – sounds like a great Uni project

    The best projects i could come up at Uni was designing an electric chair, determining, through statistical analysis, the number of women Bond had nailed and programming a computer to beep ‘Baa-Baa Blacksheep’

    Bolton Institute at its very finest 🙂

    BiscuitPowered
    Free Member

    Oliver – yhm with a proposition 😉

    oliverracing
    Full Member

    thought I would update this with the latest turn of events…

    so I went to cannock chase today with a few mates from uni, all going well till I have a bit of a nasty pedal strike (dented a m520 pedal kind of hard) so think nothing of it till about 20 mins later where it felt like I had bent a chainring but then realised the BB shell had parted company with the rest of the frame…

    It’s repairable at least, just need to go home from uni to access the correct equipment to do it – now this I promise to do a full photo documentation (hopefully)

    richmars
    Full Member

    That’s the bit I was always concerned about on mine. I used a layer of glass fibre between the shell and the carbon, as, in theory, you can get galvanic corrosion between the carbon and steel.
    Also, it’s not easy to get a good surface area contact between the shell and the rest of the frame

    oliverracing
    Full Member

    yeah – used the glass fibre method – but I think the hit I had would have cracked most carbon frames 🙁

    richmars
    Full Member

    If I was doing another one, I’d make a carbon tube, with an internal diameter a bit bigger than the shell, build the tube into the frame, then glue the shell inside the tube.

    oliverracing
    Full Member

    yeah – Hadn’t thought about doing it that way, but I guess that would give you the best chance of getting a decent bond

    compositepro
    Free Member

    a decent bond will only occur if you can get the fibreglass to stick to the aluminium anyway ,a bond is only as strong as its weakest element the fibreglass is not the weak element the interface between the aluminium and whatever epoxy or adhesive is used is(some adhesives are not epoxy based)

    Google FPL etch (still a bit old) and extrapolate from there or even CAA etch or the phosphoric (sometimes called boeing) process

    glassfibre …old hat chaps

    oliverracing
    Full Member

    compositepro – I have just looked at the failure in a bit more detail and it appears that it is infact the fibreglass-metal joint that has failed, I guess I needed to so a bit better surface prep that a bit of sandpaper before hand! – I have also realised that the way I have designed it the BB shell was only in contact with the carbon around the bottom 50% of it – so an upward impact would just push it up – both these issues should hopefully be fixed in frame version 1.1 🙂

    I have looked into both those method, but they seem a little out of reach for a shed-job – so I guess I’ll have to increase the surface area

    compositepro
    Free Member

    Aluminium is filthy in terms of materials to glue the ano and etch is more for future reference

    Any form of surface conversion is always a help but cleanliness is pretty much key

    oliverracing
    Full Member

    Latest update…

    so last weekend I took the frame home from uni to fix it so heres how it went…

    shell cut out

    shell fiberglassed and carboned in place

    first layer done

    sanded down a bit

    some carbon added

    electrical taped…

    done!!!!!

    mikewsmith
    Free Member

    sure it’s been answered but can’t see it, what is the cost of the materials? got a link to some good stuff?

    oliverracing
    Full Member

    to be honest – not sure I have said, so here I go…

    Carbon fibre – free 😀 – a composites company donated for a school project I did a few years back (15m^2)
    resin – £20 – clicky
    pvc pipe for moulding main tubes – £10 clicky
    other laminating kit ~ £50 – clicky (gloves,pots,stirrers,brushes,foam for mold, release wax for pipe)
    old frame for parts (bb shell, headtube, dropouts) – £?

    probably forgotten something major – but will update if I remember

    mikewsmith
    Free Member

    awesome – manic plot hatching going on as I have just got the garage sorted – well the beer fridge is in

    sugdenr
    Free Member

    I use this stuff West System 105/205, you can get graduated dispensers that screw in like soap bottles and give you the right ratio amount, saves loads of measuring hassle.

    richmars
    Full Member

    The soap dispensers aren’t great, I gave up on them. Just buy a cheap set of digital scales, much easier.

    mikewsmith
    Free Member

    any prices on the carbon fibre?

    I have been googling but i’m currently stumbling a bit in the dark

    sugdenr
    Free Member

    The soap dispensers aren’t great, I gave up on them. Just buy a cheap set of digital scales, much easier.

    Fairy snuff, last few years I found them excellent, except where you let the resin get too cold and wax up

    lightman
    Free Member

    Have you never tried Pallet/Shrink Wrap instead of the tape?
    I used tape to start of with, but once I tried the Pallet Wrap, I found it so much easier to use and wrap stuff.

    Mike, here you go.
    I got the £40 kit to get me started years ago. Its got enough to play around with for a while.
    If you need more cloth.

Viewing 40 posts - 41 through 80 (of 82 total)

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