Crossbows - Everything about Building, Modding, and Using your Crossbow Gear

Latest topics

» Trying to reduce the power stroke in my next project
by octavioaugusto.oliveira Today at 1:27 pm

» The Road so far......
by Onager Lovac Tue Apr 25, 2017 4:07 pm

» Its good to be back!!
by Juan galeano Tue Apr 25, 2017 9:31 am

» The crossbow...What is?!
by octavioaugusto.oliveira Sat Apr 22, 2017 2:07 pm

» Compact repeating compound project
by jocky Sat Apr 22, 2017 10:46 am

» I need your advices on a new crossbow project
by Daniel Levesque Fri Apr 21, 2017 12:58 pm

» Reverse draw "compound" build
by c sitas Wed Apr 19, 2017 9:07 am

» The Arbalist Guild - Around the World
by harry6855 Tue Apr 18, 2017 12:26 pm

» Guidance Designing My First Slinger
by kenh Thu Apr 13, 2017 8:17 pm

» New member
by harry6855 Thu Apr 13, 2017 8:28 am

» Chinese style crossbow trigger 3d modeled with templates.
by Bs1110101 Thu Apr 13, 2017 6:14 am

» Crusader crossbow
by Anatine Duo Wed Apr 12, 2017 5:03 pm

» Berkhamsted Castle and Glasgow Museum wooden prod crossbow
by hullutiedemies Wed Apr 12, 2017 8:52 am

» Hello from Asia
by Daniel Levesque Wed Apr 12, 2017 6:49 am

» Medieval crossbow modeled in Tinkercad, with variant trigger design.
by Bs1110101 Mon Apr 10, 2017 1:42 pm

» New project"s"
by kenh Sun Apr 09, 2017 2:38 pm

» New member here!
by c sitas Thu Apr 06, 2017 7:49 am

» Fixing a bad delflex
by Daniel Levesque Tue Apr 04, 2017 11:13 am

» H L Bailey Plans
by ora8i Sun Apr 02, 2017 1:49 am

» Top of Crossbow (launch?)
by Geezer Thu Mar 30, 2017 9:41 pm

» Finished Crossbow
by SlingerDave Thu Mar 30, 2017 7:47 pm

» Split limb and Draw length
by c sitas Mon Mar 20, 2017 8:25 pm

» Starting a New One
by c sitas Sun Mar 19, 2017 5:24 pm

» Medieval Crossbow Shooting video
by Onager Lovac Thu Mar 16, 2017 3:32 pm

» First submission
by War Song Thu Mar 16, 2017 1:25 pm


    Grooves and depths...

    Share

    Stonedog
    Tinkerer

    If there is a will, there is a way.


    TinkererIf there is a will, there  is a way.

    Posts : 107
    Join date : 2012-07-04

    Grooves and depths...

    Post by Stonedog on Mon Sep 10, 2012 4:32 pm

    I am going to shoot 3/8" wide oak bolts with 2 feathers.

    How wide should I make my groove and how deep?

    Also, should the groove be half round, triangular or what?

    What are you using to cut them?

    avatar
    jds6
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 197
    Join date : 2011-10-18
    Age : 54
    Location : Dallas,TX

    Re: Grooves and depths...

    Post by jds6 on Mon Sep 10, 2012 8:08 pm

    Greetings Stonedog;

    I had this same question about eight months ago on my first build! A wise man on the forum gave me good advice, so I will pass it on.

    The basic dimensions of the groove will depend on two things

    1. String diameter
    2. Bolt/arrow shaft diameter

    The diameter of the string is important. You need to know how high the mid-line sits above the track surface. Measure diameter of the shaft you are using. Place the dimensions one over the other so the string contacts the nock in the center. After that plot your groove and you should have your dimension.
    You can find a diagram in the topic first build by jds6 in early medieval crossbows

    As far as the groove I guess it could be what you want. I use a half round. I chiseled out the groove on my first build and used a router bit on my second build.

    Good Luck,
    jds6

    chaz
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 290
    Join date : 2012-04-13
    Age : 68
    Location : Texas

    Re: Grooves and depths...

    Post by chaz on Tue Sep 11, 2012 2:25 am

    Stonedog,

    jds6 advise sounds good.

    Of course it would have to do with personal preference and if one was trying to achieve a period correctness, however, I.m considering the fact that I wonder about a "v" groove with a slot at the bottom to like wise accommodate a bolt with three fletches , making the crossbow abit more versitile. And then how deep to make the grooove would depend on what size the fletch is. This may be done easily with a table saw. Just something else to think about.

    Chaz
    avatar
    Todd the archer
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 581
    Join date : 2010-02-25
    Age : 55
    Location : sellersville,pa.

    Re: Grooves and depths...

    Post by Todd the archer on Tue Sep 11, 2012 2:35 pm

    Adding a third fletching adds another issue, that is clearance over the prod and how far down it is positioned below the top of the deck.

    With modern crossbow not so much a problem as most use two limbs bolted to a riser to give room in between.



    Todd
    avatar
    jds6
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 197
    Join date : 2011-10-18
    Age : 54
    Location : Dallas,TX

    Re: Grooves and depths...

    Post by jds6 on Tue Sep 11, 2012 10:06 pm

    Greetings,

    While on the topic of a 3 fletch bolt, what dictates that the third fletch needs to be in the downward position, riding in a deep groove in the center of the tiller? What if two of the fletches on either side of the bolt are positioned in the middle( bolt) and the third positioned in the center on top of the bolt. The side fletches riding just atop of the table on the tiller. Does such a bolt cause poor flight? Just curious!
    Thanks for any response !

    jds6

    chaz
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 290
    Join date : 2012-04-13
    Age : 68
    Location : Texas

    Re: Grooves and depths...

    Post by chaz on Wed Sep 12, 2012 2:42 am

    Salutations jds6,

    Seems that configuration would be off balance, don't know. However one needs to consider the bolt and bolt clip. Seems the three evenly spaced fletches with one on the bottom in the groove that the bolt clip would not interfere with the fletches by being positioned between them, but if the portion of the bolt aft of the fletches were longer that would not matter. Bet Geezer or Todd will have more enlightenment. I have not made any bolts yet. This is interesting though.

    Chaz
    avatar
    ferdinand
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 301
    Join date : 2012-04-24

    Re: Grooves and depths...

    Post by ferdinand on Wed Sep 12, 2012 2:52 am

    Hmm, this all makes me wonder what problems i will run into next.
    I am making a replica of a bow with ivory on top and no groove, just a 'rest' in the front with a half-circle cut-out.
    Any suggestions are welcome! As long as it doesnt take over the original topic.
    avatar
    kenh
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 699
    Join date : 2012-08-03
    Age : 68
    Location : Living Aboard a Sailboat in Fort Myers, FL

    Re: Grooves and depths...

    Post by kenh on Wed Sep 12, 2012 9:40 am

    A three-fletch arrow has the feathers equally spaced 120 degrees apart. That's OK for a vertical bow where the feathers only touch the rest in passing. But on a crossbow, a 3-flech bolt at the rear would tend to rest on the tips of the feathers, with the shaft of the bolt above the surface of the tiller, not down flat where the string can get to it consistently. Two feathers and the groove ensure that the bolt is always in the same place for the string to strike.

    chaz
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 290
    Join date : 2012-04-13
    Age : 68
    Location : Texas

    Re: Grooves and depths...

    Post by chaz on Thu Sep 13, 2012 6:29 am

    Kenh,

    Check out modern crossbows which use three fletches.

    Chaz
    avatar
    hullutiedemies
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 174
    Join date : 2012-07-03
    Location : Fennoscandia

    Re: Grooves and depths...

    Post by hullutiedemies on Thu Sep 13, 2012 7:42 am

    jds6 wrote:What if two of the fletches on either side of the bolt are positioned in the middle( bolt) and the third positioned in the center on top of the bolt. The side fletches riding just atop of the table on the tiller.

    That is the traditional way of doing it.
    Cock feather should have the helix.
    Just leave space behind for bolt clip, if you use one .
    avatar
    Geezer
    Master Crossbowyer
    Master Crossbowyer

    Posts : 907
    Join date : 2010-01-12
    Age : 69
    Location : Austin, Texas, USA

    Re: Grooves and depths...

    Post by Geezer on Thu Sep 13, 2012 9:11 am

    Payne-Gallwey shows three-fletched bolts, with feathers spaced 90 degrees apart. I have used such bolts and find they shoot just fine.
    You might think having one feather off-center (one on top, one to each side) would make the bolts fly badly, and maybe they would given sufficient velocity, but at practicable velocities (150-250 fps) three adn 90 degrees fly just fine.
    Geezer.
    avatar
    mac
    Master Weaponsmith
    Master Weaponsmith

    Posts : 560
    Join date : 2010-12-23
    Location : Near Philly USA

    Re: Grooves and depths...

    Post by mac on Thu Sep 13, 2012 11:19 am

    I am surprised to hear that the Payne-Gallwey style three fletch bolts actually fly OK. I would have expected them to wobble. I always expect the worst of Sir Ralph's inventions.

    Mac
    avatar
    Geezer
    Master Crossbowyer
    Master Crossbowyer

    Posts : 907
    Join date : 2010-01-12
    Age : 69
    Location : Austin, Texas, USA

    Re: Grooves and depths...

    Post by Geezer on Thu Sep 13, 2012 11:36 am

    I have actually seen some old three-feathered target bolts... dunno how old, but not made recently. Indeed PG's bolts might wobble uncontrollably if you got them going fast enough, but given a reasonable amount of spin at moderate speed, they fly quite well.
    Geezer
    avatar
    kenh
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!

    Posts : 699
    Join date : 2012-08-03
    Age : 68
    Location : Living Aboard a Sailboat in Fort Myers, FL

    Re: Grooves and depths...

    Post by kenh on Thu Sep 13, 2012 12:38 pm

    Learn sumpthin' new every day... Ida thought they'd wobble too. Mebbe heavily weighted forward helps...
    avatar
    jds6
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 197
    Join date : 2011-10-18
    Age : 54
    Location : Dallas,TX

    Re: Grooves and depths...

    Post by jds6 on Thu Sep 13, 2012 6:48 pm

    Greetings all:

    While still on the topic of three fletch bolts, here are a few pics of my three fletch bolts. They seem to fly very well.







    jds6
    avatar
    mac
    Master Weaponsmith
    Master Weaponsmith

    Posts : 560
    Join date : 2010-12-23
    Location : Near Philly USA

    Re: Grooves and depths...

    Post by mac on Fri Sep 14, 2012 9:54 am

    A big advantage to using only two fletches is that the bolts pack well in your quiver.

    Mac
    avatar
    actionbow
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 125
    Join date : 2012-09-18

    Re: Grooves and depths...

    Post by actionbow on Tue Sep 18, 2012 4:05 pm

    I have a bow that was designed originally to shoot two fletch that I converted to shoot three by carving out the fin shape in the tiller top. Works well and is in fact my most accurate bow. It was painstaking work to carve the two extra grooves but well worth it. Looks great in the bocotye as a bonus.
    avatar
    actionbow
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 125
    Join date : 2012-09-18

    Re: Grooves and depths...

    Post by actionbow on Thu Sep 20, 2012 11:03 pm

    Here is the bow I am referring to.http://db.tt/Jiib3U1f
    It works really well. I recently got to try this bow (90 lbs@13") against a new 150# recurve shooting the same arrows. I got the same penetration with identical groups at 30 yards and my bow is basically sightless. In fact my buddy was able to shoot my bow better than his the first time he tried it. Add the fact that I can cock and load and put arrows on target in 1/3 the time with my slide cock mechanism and open tiller and it was an easy choice.

    Sorry...off topic, I love that bow.

    Sponsored content

    Re: Grooves and depths...

    Post by Sponsored content


      Current date/time is Thu Apr 27, 2017 4:30 pm