Basic questions about bow designs.

Discussion in 'Slingbows' started by Jim_Holmgren, Dec 30, 2016.

  1. Jim_Holmgren

    Jim_Holmgren New Member

    Hello, I have some questions about different bow designs.

    If I have understand right a normal compound bow have a draw ratio to 1 to 2 so the 150lb limbs give a 75lb draw and only travel half of the length of the string.

    And a longbow/slingshot have a draw that get higher the longer you draw it, but a compound have cams that get the full draw weight faster, so instead of having a 75lb at 30 inches on the end the compound have it already at 5 inch?

    This is what makes a compound shot fast? right or wrong?
    Btw why have compound bows so low draw weight? I have never seen one over 100lb in draw:confused:.

    which of these bow designs which will be fastest do you think?
    All have same draw length and draw weight.
    1. recurve bow
    2. normal slingbow
    3. lever operated bow (which ratio limb to draw length is best for a leveraction bow?)
    4. pulley bow (no cams) 2 pulleys 2 to 1 ratio or 4 pulleys at 4 to 1 ratio.
    5. some other design I have not thought of? I are open for all suggestions on how one can get more power.

    If looking at the slingshot channel most of the crossbows/slingshots seems to be direct powered and dont have any mechanical assistance at all, must be a reason for a man with so skilled craftsmanship as Jörg Sprave to not using it:confused:.

    What is best, rubber or leaf-springs or coil-springs or vacuum as powersource for a arrow launcher?

    I have also thought of putting the riser behind the string so I get a longer power stroke, how far back from the sting can i have it before it gets unstable do you imagine?

    I thinking of building a compact bow (backpack size) in 50lb to 100lb draw weight and possibly a reverse draw.
    Also maybe only using one limb/spring/rubber instead of 2 and split the power from it would work??
    But if the performance is much better with a big bow then the size dont matter much.

    I am very grateful for all answers:)!
    Sincerely Jim H.
    Markus Oswald likes this.
  2. I think I can answer most of your questions. While I don't made my own bows, I have been shooting compound bows for a couple of years now.


    1. Yes, in a long bow or sling bow, the draw weigh increases as you pull it back ever farther. A compound bow typically reaches its maximum draw weight within the first 3-6 inches.

    2. I believe so

    3. I would assume brands don't make compounds with 100lb+ draw weight because the average archer cannot draw back that kind of weight. It seems like overkill for hunting, and just plain unnecessary for target shooting.

    4. At the same draw weight and draw length, compound is faster every time, no competition

    5. Never heard of a lever bow

    6. If you are looking to build a back pack sized bow, take a look at a few "takedown style" bows online. Reverse draw in that short of a bow- no

    7. I don't see how a one-limb bow would be effective.

    8. As for size, larger bows are GENERALLY more accurately for target practice. Think Olympic archery, they all use large bows.

    Hope that helps....

  3. Jim_Holmgren

    Jim_Holmgren New Member

    Yes a takedown would be nice, but it would be hard to make a compound as a takedown.
    A recurve would be easy to take apart, but I want to test something new and looking for higher performance then a normal recurve.

    The smallest compound i know is the Liberty #1 and I dont want to go bigger then that if i will use the bow for a backpack, I ride motorcycles and big bows is very bulky to carry.

    Maybe some kind of slingshot that use cams, and pulleys.
    I found this
    It seems to be a great idea! But it says it was a failure. Any idea what was wrong about it and what one could do to fix it?

    Im also really impressed of the performance of modern crossbows:eek:, could the performance be made in bows too?

    Anyway Im going to buy a real compound bow for comparison and test it out.

  4. The performance (accuracy) can very likely be replicated with a modern bow, but only in an experienced archer. Crossbows are usually easier to shoot accurately than any type of bow.

    As far as power goes, sadly no. High end crossbows tend to be 200lb+ draw weight, and NO modern bow comes remotely close to that draw weight.

    But you'll enjoy a good Hoyt..... I'm mean compound bow.
    ImageUploadedBySlingshot Forum1483143272.450329.jpg