Frame material question.

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  • #1313
    justforfun
    Participant

    Just wondering, has anyone tried making to Condor style frame from fiberglass pultruded tubing?

    I found a very inexpensive source (not free but close) ( http://www.mgs4u.com/fiberglass-tube-rod.htm ) for fiberglass tubing.

    The material is 1.25 OD x 1.008 ID x 8 feet long, smooth ID and OD, cost $12.00 ea. + some shipping. I ordered some today and ask that they cut to 4′ lengths, to save big time on shipping costs. Should still have enough for four frames, not that I need four.

    If anyone has tried fiberglass, let me know, if not I’ll let you know. For that cost, I just have to try it.

    Later

    Roy S.

    #31927
    riffraff
    Participant

    The only reason I could think of that fiberglass would not work, is fiberglass tubing will bend quite easily.

    It really depends on the resin-system they used in the material. The resin is what gives it the stiffness. I would think a frame built of fiberglass with the dimensions you stated would have quite a bit of flex. When you get the tubing, put it across your knee and pull lightly. If you can bow the tubing, I wouldnt use it for a frame.

    Not trying to rain on your parade and I hope I am wrong. It would make a nice and quiet shroud tube though.

    #31930
    justforfun
    Participant

    That may well be the case (bending), will it matter, who knows. We will know after I try it. 😀

    I plan to make a set up and do a load deflection test on both 6061-T6 tubing and the fiberglass tubing. Nothing fancy, just something to apply a given load and a dial indicator to see how far that load deflects the material. All thing flex, it’s a matter of how far under what load and does the flex adversely affect the function of the assembly.

    Most of the fun is in the trying, IMHO.

    Roy S.

    #32041
    mikemv
    Participant

    Roy,
    Sounds like an interesting project. There is always carbon fiber etc. Given the some of the very good composite stocks around there days it would seem composites could be adaped.
    Look forward to learning how things go ❗
    Good luck
    m

    #32047
    justforfun
    Participant

    Rec’d. the fiberglass material today, the material in glass/resin pultruded stock, 1.25 OD x 1.008 ID.

    The aluminum sample is 6061-T6 1.25 OD x 1.00 ID.

    Two V blocks placed 24″ apart, supporting the samples. A dial indicator was located under the sample. A load cell was place above the sample to apply a 6 kg force to the sample. Dial indictor reading was taken and photographed.

    Results:

    Fiberglass sample, bend = .005″

    Aluminum sample, bend = .007″

    Here are photos of the test samples, in the setup.

    1st photo is fiberglass sample

    2nd photo aluminum sample

    I would not have guessed that one. Once I held the fiberglass sample in my hands, I did not have to test, I knew it would work, IMHO.

    The fiberglass tube felt very stiff.

    I do not plan to go after a epoxy, heat cured carbon fiber tube for testing, the cost would be very high, unless you just happen to have a piece and I do not.

    Once I finish my .308 project, a glass gun will be next.

    If the fiberglass works, just think, someone without a metal lathe and mill might be able to build a Condor type rifle. Now that would be something.

    Roy S.

    #32067
    riffraff
    Participant

    Nice find then bro! That result does surprise me a bit.

    Whats the weight difference?

    #32079
    bodhisdad
    Participant

    😀 sweet, i know the fiber glass with thick walls can be very rigid. Thought the Ali would be stiffer as well. Go for it my friend, might i suggest asking YN about the durocoat paint finish system. Very easy to do, and yields a very hard topcoat. I really am impressed with the testing, might point guys in a new direction.

    Got any weight on the sections tested?? I suspect the FG would be lighter by a bit.

    Now what to you have planned for the trigger housing? Epoxy some flats together and then epoxy housing to frame tube? What about the inside of the tube where the spring/hammer will run. The AF frame is anodized and is pretty slick after a good polishing job. How will you address this with the fiberglass?

    #32090
    justforfun
    Participant

    I want to point out first, I made a typing error on my report. I typed 16 kg and it should have been 6 kg, for the deflection number I posted.

    A 24″ long section of fiberglass tube weights 6.7 ozs.

    The same length of aluminum tube weights 10.2 ozs.

    That assumes my scales are accurate, be the difference is accurate one way of the other.

    Once I get my current project parts made, I plan to make a silicone mold of the top (The part that connect the tube to the scope) and bottom rail (the part that connects the tube and holds the grip and trigger parts) (whatever they are called).

    I will then mold those parts using glass filled epoxy. Those will then be bonded to the tubing sections. So the plan is, subject to change.

    I have been reading about Duracoat, that is what I have planned to use for my .308 project gun.

    As far the hammer, I plan to use the barrel as the slide (guide) not the ID of the tubing.

    Since friction is more a function of area than weight, I had planned to use the barrel as the slide on my .308 project. Less area than the ID of the frame tube. 😀

    As per everything new, it might work.

    Roy S.

    #32096
    bodhisdad
    Participant

    Good idea have you seen Luepys site? there is a link for you if not, lots of good ideas.
    http://www.leupyscustomshop.co.uk/

    #32119
    justforfun
    Participant
    quote Bodhisdad:

    Good idea have you seen Luepys site? there is a link for you if not, lots of good ideas.
    http://www.leupyscustomshop.co.uk/

    I had not run across that site, thanks for the link. Some of the things shown there, I can not figure out what they do, just me I’d guess.

    They do some fine machine work.

    Thanks again.

    Roy S.

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