The Arbalist Guild

Would you like to react to this message? Create an account in a few clicks or log in to continue.

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

Latest topics

» 12th Century Chinese Crossbow Chronographed
by stuckinthemud1 Fri Nov 24, 2023 3:50 pm

» Crossbow Stock
by kenh Tue Oct 31, 2023 6:19 am

» Colletiere a Charavines continuing experiment
by stuckinthemud1 Sat Oct 07, 2023 5:36 am

» Cocking - how
by stuckinthemud1 Thu Aug 03, 2023 4:24 am

» Questions around heavy crossbow lath buildin
by stuckinthemud1 Wed Apr 26, 2023 1:10 am

» Arab Crossbow
by stuckinthemud1 Tue Apr 25, 2023 7:57 am

» prod angle, and lever trigger for sale anyone?
by stuckinthemud1 Mon Mar 20, 2023 5:54 am

» flexible string
by jasper1978 Mon Mar 20, 2023 1:25 am

» [solved]Skane/Lillohus crossbow thread
by stuckinthemud1 Sun Mar 19, 2023 7:44 am

» jens sensfelder
by jasper1978 Wed Mar 08, 2023 11:58 pm

» 400lb Windlass crossbow bolts weight and accuracy shooting high.
by stuckinthemud1 Sun Mar 05, 2023 2:53 pm

» Codex Löffelholz crossbow
by stuckinthemud1 Tue Jan 24, 2023 4:14 pm

» Digitar prodsc
by stuckinthemud1 Sun Jan 15, 2023 2:42 pm

» Troubleshooting
by Andy. Fri Jan 06, 2023 12:29 pm

» Wood Prods
by stuckinthemud1 Fri Dec 30, 2022 12:47 pm

» Colletiere a Charavines crossbow
by stuckinthemud1 Fri Dec 30, 2022 8:54 am

» Simplified Löffelhotz speedloader
by stuckinthemud1 Fri Dec 09, 2022 4:05 pm

» Fiberglass H-bows
by c sitas Sat Nov 12, 2022 8:44 am

» Bad Antler
by drawknife Sat Nov 12, 2022 3:48 am

» Anyone make their own bolts?
by Juniper Mon Oct 17, 2022 8:20 am

» Josef alm in English
by Juniper Sat Oct 15, 2022 4:22 am

» Qin/Han lock drawings
by kenh Fri Sep 23, 2022 8:16 pm

» stirrup dimensions?
by stuckinthemud1 Thu Sep 01, 2022 1:49 pm

» Skane/Lillohus lockbow information needed
by stuckinthemud1 Sun Aug 14, 2022 6:23 am

» need help contacting le musee Dauphinois Grenoble
by stuckinthemud1 Sat Aug 13, 2022 3:22 pm


4 posters

    Skew of tiller

    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Skew of tiller

    Post by crusader Sat Aug 07, 2021 3:07 am

    Dear members,

     
    I want to determine the skew of stock.  
    on the front side.  
    where should the string touch the stock?  
    when he's behind the rollernut?  or at the BH height?  

    I would like to hear from you.

    Regards,

    Crusader
    kenh
    kenh
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!


    Posts : 883
    Join date : 2012-08-03
    Age : 75
    Location : Living Aboard a Sailboat in Fort Myers, FL

    Skew of tiller Empty Re: Skew of tiller

    Post by kenh Sat Aug 07, 2021 8:34 pm

    The string should touch the prod at brace not at cock.
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Sun Aug 08, 2021 8:02 pm

    Heej Kenh,


    prod must be stock I think?  
    I just thought it was the other way around.  
    why are the sides always chamfered? 
    along the draw length?

    Regards,
    kenh
    kenh
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!


    Posts : 883
    Join date : 2012-08-03
    Age : 75
    Location : Living Aboard a Sailboat in Fort Myers, FL

    Skew of tiller Empty Re: Skew of tiller

    Post by kenh Mon Aug 09, 2021 4:06 pm

    Yes -- prod in tiller.  Prod angled down so that string at brace is touching the bolt track.

    Sides are "rounded" along the draw length of the tiller because when the string is in the cocked position it is pushed downward onto the tiller and sharp edges cause unnecessary string wear.
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Tue Aug 10, 2021 8:34 am

    hey,

    Thanks for your reply.

    I thought if the string touches the tiller at BH,

    If you then bring the string back in a squard line with the prod, there is space created between the string and the tiller.

    So I thought wrong.

    Best regards
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Thu Aug 12, 2021 6:17 am

    Skew of tiller Tough_10
    Skew of tiller Tough_11
    Here's a drawing of what I mean.

    What will be most efficient?

    maybe the string/tiller intersection in the middle of the draw length??

    I get to 15 degrees at the BH.

    and 7.5 degrees behind the roller nut.

    I think it's worth discussing again.. Smile

    let me know!
    kenh
    kenh
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!


    Posts : 883
    Join date : 2012-08-03
    Age : 75
    Location : Living Aboard a Sailboat in Fort Myers, FL

    Skew of tiller Empty Re: Skew of tiller

    Post by kenh Thu Aug 12, 2021 1:27 pm

    See the dot in the top sketch where you have 88.9??  Remember that your prod is curved when strung, and that dot would be about where the string should be, sitting on the surface, when the prod is at rest. Not where you show it aft of the 9.  If I remember correctly the angle is 12 degrees.

    If you set it up as in the second drawing, the string is going to scrape down the entire deck to the prod, wasting its energy and significantly reducing the energy transferred to the bolt.  Not to mention causing massive wear and tear on the string itself...
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Fri Aug 13, 2021 3:54 am

    Skew of tiller 1751_d13
    Okay,

    Here the design; what do you think?

    I think the degrees is too much. it is now 17.51 ​​degrees!

    so the bow doesn't hit the tiller BH

    There is now 10mm above the prod and tiller.

    As the distance increases, the degrees also increase.

    how many mm do you always wear for that?
    avatar
    stuckinthemud1
    Crossbow Junkie

    I live here!


    Crossbow JunkieI live here!


    Posts : 526
    Join date : 2014-02-05
    Age : 55
    Location : south wales valleys

    Skew of tiller Empty Re: Skew of tiller

    Post by stuckinthemud1 Sat Aug 14, 2021 1:04 am

    Don't forget string is flexible, it moves up and down and you lift and drop it as it goes over and behind the nut

    Up to a point, you need the string to slide along the deck as it needs to collect the bolt, not hop over it  this is where 'art' comes into things. Also, as the string pushes down on the table at BH, it acts as a brake helping stop the prod over extending. I think you have to accept a level of trial and error, my current project is too tight to the bolt table and is going to need adjusting, its a nuisance but only an afternoon's work to do, so not the end of the world.
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Sun Aug 15, 2021 3:16 am

    hey,

    I'm going to make a test model in pine wood.

    and see how everything behaves.

    if all goes well I will make it from a more expensive type of wood.

    Thanks for the responses.
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Sun Aug 15, 2021 3:19 am

    here are some more pictures of the slants in different designs and versions.

    As you can see there is a lot of difference between them.

    Skew of tiller Barbar10
    Skew of tiller Dan_sn10
    Skew of tiller Lindyb10
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Sun Aug 15, 2021 3:20 am

    Skew of tiller Lindyb11
    Skew of tiller Pinter10
    Skew of tiller Rus10
    avatar
    crusader
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 44
    Join date : 2013-07-04

    Skew of tiller Empty Re: Skew of tiller

    Post by crusader Sun Aug 15, 2021 3:20 am

    Skew of tiller Todstu10
    avatar
    drawknife
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows


    Posts : 37
    Join date : 2011-02-11
    Age : 74
    Location : Barnsley, England

    Skew of tiller Empty Re: Skew of tiller

    Post by drawknife Fri Aug 27, 2021 9:18 am

    First of all let us start with a few basics. A crossbow prod is not symmetrical when viewed from the front. Its top edge curves upwards from its middle and the string notches are level with or above the top surface when not braced. The angle needed to fit the prod to the tiller/stock is determined by bracing the prod and finding the angle the prod makes with the front of the stock when the string is just touching the top surface. as the string is drawn back towards the nut the string notches not only pull backwards but also curve downwards allowing the string to remain just touching the stock. (Try this by doing a V sign with the fingers of your left hand and holding your palm at a slight angle to horizontal. Pull your finger tips back with 2 fingers from your other hand. As your finger tips come back they also drop lower towards your palm). this is what should happen with the string notches on your prod which allows the string to glide without friction across the top of your stock. 
    The medieval crossbow designers were a clever bunch.
    ps It is not easy to explain what happens without a video but you could try it with a wooden model using a thin bendy strip. A shallow u shape should do the trick.

    Sponsored content


    Skew of tiller Empty Re: Skew of tiller

    Post by Sponsored content


      Current date/time is Tue Mar 19, 2024 5:12 am