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Tejas

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Posts posted by Tejas


  1. If with stretchy material such as webbing, the failure of stitches under load tended to be towards the the direction of the load, then sewing parallel to the edge of the webbing versus orthogonal to the edge of the webbing seems to be counter intuitive. Wouldn't breaking the end of a parallel to the edge stitch-line tend to compromise the entire stitch-line?


  2. 41 minutes ago, TinkerTailor said:

    In reality once you get that much stitching the textile to textile friction due to surface area is what holds it.

    As for increasing surface friction, inserting a reinforcing piece of webbing between the two webbing layers apparently does that. Here is a link about  sailboat jack-lines (safety lines attached to the deck to which a harness tether can be attached while on-deck, especially in heavy weather).

    http://westpacmarine.com/blog/category/straps-and-webbing/

    I think I recall a similar article about strengthening parachute webbing joints but can't locate it.


  3. Practical sailor, April 2015, did test of various hand sewing techniques for webbing and concluded that seven parallel stitch patterns were the strongest, and that the joint, either the stitching or the webbing, would start failing from the ends of the joint. The objective was to discover stitching that had approximately the same strength as the the webbing.

    The article stated that rock climber's slings are load tested and that parallel "Machine-stitched bar-tacking is the norm for professional rock-climbing gear." The following link depicts an example.

    https://www.rei.com/product/830935/mammut-contact-sling-dyneema-cordelette-80

     


  4. 3 hours ago, suzelle said:

    Ghetto Girl here! LOL! After doing "Ghetto backstitch" I will add a little extra insurance by taking the thread tails and tying a square knot too, if I really want to be sure it won't come undone.

    A surgeon's knot, a slight modification of the square knot (aka reef knot), is more reliable than a square knot.

    https://en.wikipedia.org/wiki/Surgeon's_knot


  5. Folks following this link because of interest in the Juki LU-562 or 563 might also be interested in chapter 4 -- Sewing Machine Repair -- of the following link, which states.

    Your shop may have the Consew Model 225, the Juki LU-562, or the Singer Model 111 W 155 sewing machine. These three sewing machines are essentially identical, and all specifications and instructions are the same for all three sewing machines.

    http://militarynewbie.com/wp-content/uploads/2013/11/NAVEDTRA-14217-Aircrew-Survival-Equipmentman-1-C.pdf


  6. As for using WD-40, here is post from the link below:

    A study done by Machinist's Workshop magazine in their April 2007 issue looked at different penetrating oils to see which one did the best job of removing a rusted bolt by measuring the pounds of torque required to loosen the bolt once treated. If the study was scientifically accurate, it turns out a home brew works best!
    Here's the summary of the test results:

    Penetrating oil ..... Average load

    None ...................... 516 pounds
    WD-40 ................... 238 pounds
    PB Blaster .............. 214 pounds
    Liquid Wrench ...... 127 pounds
    Kano Kroil ............. 106 pounds
    ATF-Acetone mix....53 pounds

    http://www.practicalmachinist.com/vb/general/ot-penetrating-oil-196347/


  7. Quality matters.

    I lived in Japan for about 10 years and was amazed at the quality of products in my local hardware store, and disappointed when I returned to the US and experienced what seemed to be a decline in quality, not because of US, European or Japanese products, but because of the unavailability of those products. Essentially, lower cost, lower quality products, aka Chinese products, drove out reasonable priced, good quality products.

    Mazada Ford transmissions were a classic example that quality matters. Apparently American machinists set their machines at the closest tolerance and ran the machines until machine was at the least tolerance. Japanese machinists set the machines at the closest tolerance and reset the machines on each run.

    To me, an indication of the quality of some made in China products is the quality of the documentation. Amazing that a machine might be cloned but the documentation not plagiarized.

    http://www.specinnovations.com/ford-vs-mazda-transmissions-why-quality-matters/


  8. 11 hours ago, graywolf said:

    how would it handle a 20-30 foot long seam? But on the other hand can a triple feed machine do that without 8+ foot long tables

    I sew in a quite small room, and have four 4' x 2' fold-up, slick-top tables from Costco that when not in use are stored between the wall and the sewing table. The fold-up tables can be arrayed in various configurations in front of or behind the sewing table.

    The longest run I've sewed is replacing a zipper in a 50' jib cover -- four passes, two for each side of the zipper. I used a single fold-table beside me nested up against the sewing table on which the cover was layered in a stack and let the cover fall on the floor in front of the machine. It was necessary to ease the fabric forward, but there was no need to push or pull the material, the compound-feed pulled the material through.

    There is room for using only one table in the sewing room, and I have moved the machine temporarily to another room and used more tables to sew bigger, heavier projects such as replacing the UV panel on the same jib.


  9. 21 hours ago, Uwe said:

    I know little about the TuffSew brand and they may actually be of poor quality. At the same time I'm suspicious of a discussion forum on the Sailrite company website where somebody just happens to ask about the quality of a direct competitor brand.

    I agree in principal, but I've followed the Sailrite forum for a long time. There are many branded machines similar to Sailrite machines from the same factory at lower prices, but do not seem to have as bad a reputation -- Barracuda for example. Try the following in google and result is not as pejorative as for TuffSew:

    barracuda site:forum.sailrite.com

     

    Try others, I haven't.

    I buy supplies from Sailrite, but not sewing machines. Given the right situation, I might.

     

     

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