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

Latest topics

» Yet another one
by Andy. Today at 4:25 pm

» Chinese crossbow with auxiliary string?
by c sitas Today at 11:34 am

» Crusader crossbow
by c sitas Thu Jun 22, 2017 9:41 pm

» Whamo showed up, prod replacement ideas
by kenh Mon Jun 19, 2017 4:25 pm

» Renaissance Sporting crossbow
by tony a Mon Jun 19, 2017 2:10 am

» 15th century saxon prods
by Geezer Sun Jun 18, 2017 10:46 pm

» loose laminate issues
by c sitas Sun Jun 18, 2017 8:42 am

» Of Bows and Torsion Engines
by c sitas Fri Jun 16, 2017 2:55 pm

» My second crossbow
by Daniel Levesque Fri Jun 16, 2017 10:48 am

» Need to locate Windlass Crossbow, pre 1600, in Rome, Venice, or Florence
by 8fingers Tue Jun 13, 2017 11:24 pm

» Crossbow Projectiles
by Geezer Tue Jun 13, 2017 8:10 pm

» Greetings!
by OnlyHuman Mon Jun 12, 2017 7:40 am

» Anyone know what this is?
by Yuki23emma Sun Jun 11, 2017 2:54 pm

» Prod specs
by Onager Lovac Mon Jun 05, 2017 4:25 pm

» Finished Crossbow
by kenh Sat Jun 03, 2017 8:34 pm

» The Arbalist Guild - Around the World
by Turnigy Fri Jun 02, 2017 1:25 pm

» Reverse draw "compound" build
by Turnigy Fri Jun 02, 2017 1:20 pm

» Casting Resource
by White Oak Wed May 31, 2017 2:28 am

» The Road so far......
by White Oak Mon May 29, 2017 7:17 am

» GLOSSARY OF TERMS
by Onager Lovac Wed May 24, 2017 6:41 pm

» Hello from Maine
by White Oak Sun May 21, 2017 11:06 pm

» Leonardo Da Vinci string with suport-rolls
by Oppenheimer Tue May 16, 2017 11:40 am

» Compact repeating compound project
by Phil Abrahams Mon May 08, 2017 2:10 pm

» Trying to reduce the power stroke in my next project
by octavioaugusto.oliveira Thu Apr 27, 2017 1:27 pm

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


    RDT crossbow project

    Share

    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    RDT crossbow project

    Post by jrdallmann on Tue Oct 28, 2014 6:10 pm

    First topic message reminder :

    Hello folks!
    First of all, I'm from Brazil, so sorry my bad English. I'm planning to build my first crossbow on next vacation, which begins within about a month. I've been doing a lot of research about it for the last few months. Since I own a car shop, I got everything I need to build my crossbow. 
    I'm inspiring myself on patandjali's rdt model. Today I started to search for components for my crossbow. I found a spring leaf from an old Willys which will be my prod and removed the valves and the valve guides from a VW engine head to use as axle and sleeve for the cams.




    The leaf is 40" long

    It's not a project I wanna do in a hurry, so I'll take my time. I'm open for suggestions.
    avatar
    ali.j
    Tinkerer

    If there is a will, there is a way.


    TinkererIf there is a will, there  is a way.

    Posts : 75
    Join date : 2013-10-30
    Age : 23
    Location : iran- shiraz

    Re: RDT crossbow project

    Post by ali.j on Fri Nov 21, 2014 5:47 am

    today...










    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Mon Dec 01, 2014 4:04 pm

    Hi guys. My vacation is coming soon, so I'm preparing everything to start working on my project. I already have almost everything I need. But, today, while working at my garage, I've thought about something.. what if instead of using an aluminum plate and working on it to build the cams, I use a pulley like the one below? I'd just have to work the "teeth" off and cut it to make the "entrance" for the string. what do you guys think?

    avatar
    ali.j
    Tinkerer

    If there is a will, there is a way.


    TinkererIf there is a will, there  is a way.

    Posts : 75
    Join date : 2013-10-30
    Age : 23
    Location : iran- shiraz

    Re: RDT crossbow project

    Post by ali.j on Tue Dec 02, 2014 3:06 am

    no. Not working. You just have to like me, you use cams. meterial appropriate for made cam is al Alloys. no 5000 or 6000 or 7075.

    this clip It may help you in making.

    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Tue Dec 02, 2014 7:50 am

    So the bowstring material kit i've bought just arrived yesterday. Since this will be my first time at making a bow string,I just want to clarify something.. In the picture below, the purple thread is dacron b 50 while the black one is serving material, right?


    Hermit
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 245
    Join date : 2013-09-10

    Re: RDT crossbow project

    Post by Hermit on Tue Dec 02, 2014 8:04 am

    Hi Jrd,Ali is right your gear wheel won't work.A gear wheel has to rotate eccentrically(in balance,like a car wheel).Acam rotates eccentrically(out of balance)it would be just about impossible to modify a gear wheel,you will have to make the cams yourself.
                                                                              Hermit.

    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Tue Dec 02, 2014 2:55 pm

    I got it, haven't thought about that.. and what about the threads?

    Hermit
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 245
    Join date : 2013-09-10

    Re: RDT crossbow project

    Post by Hermit on Thu Dec 04, 2014 9:17 am

    Looking at my spool of Dacron(It's grey in colour)I would say that the purple is the Dacron.
                                                            Hermit.

    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Fri Dec 05, 2014 7:55 am

    ali.j why are there two holes in the center of your cams?
    avatar
    ali.j
    Tinkerer

    If there is a will, there is a way.


    TinkererIf there is a will, there  is a way.

    Posts : 75
    Join date : 2013-10-30
    Age : 23
    Location : iran- shiraz

    Re: RDT crossbow project

    Post by ali.j on Sun Dec 07, 2014 12:10 pm


    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Mon Dec 08, 2014 5:50 pm

    hey ali.j, can you tell me why there are 2 "center holes" in your cams?

    Hermit
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 245
    Join date : 2013-09-10

    Re: RDT crossbow project

    Post by Hermit on Mon Dec 08, 2014 7:23 pm

    The central hole is for the cam pivot pin,the off centre hole is for the string anchor pin.
                           Hermit.
    avatar
    hullutiedemies
    Workshop Savvy

    Did you see my tool collection?


    Workshop SavvyDid you see my tool collection?

    Posts : 177
    Join date : 2012-07-03
    Location : Fennoscandia

    Re: RDT crossbow project

    Post by hullutiedemies on Tue Dec 09, 2014 2:28 am

    jrdallmann wrote:Hi guys. My vacation is coming soon, so I'm preparing everything to start working on my project. I already have almost everything I need. But, today, while working at my garage, I've thought about something.. what if instead of using an aluminum plate and working on it to build the cams, I use a pulley like the one below? I'd just have to work the "teeth" off and cut it to make the "entrance" for the string. what do you guys think?
    ..

    You could use pulleys. Here is one apparently succesful build for example :
    http://thearbalistguild.forumotion.com/t774-compound-project

    but it is going to be a bit different design.
    Force-draw curve will not be as efficient. But you can have longer power stroke since pulleys can turn multiple revolutions.

    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Thu Dec 11, 2014 5:50 pm

    thanks for replying flinstone, but i'm not gonna use that kind of pulleys. Today I finally startes my crossbow. I decided to start from the most difficult part: cams. I mean, it's not that difficult, but toilsome. I wasn't able to finish them today because I only have time to work on my crossbow after job, and december is madness in my auto shop. However, is going well. I'm just a little bit worried because my aluminum plates are not exactly 8mm thick, they're little thinner, around 7mm, but  I guess that's no problem. Just to make sure, what is the thickness (approximately) of a crossbow string?

    jrdallmann
    Fresh Blood

    Doesn't mean
    I'm new to crossbows


    Fresh Blood Doesn't meanI'm new to crossbows

    Posts : 17
    Join date : 2014-10-15

    Re: RDT crossbow project

    Post by jrdallmann on Tue Apr 21, 2015 12:43 pm

    hey guys, I had to put my crossbow project aside for a while due to college, work and stuff. Yet, I finished my first cam and would like you to take a look and tell me waht u think, I'm a little worried about the thickness..





    PS: not finished, i still have to drill it and do the second little cam
    avatar
    ali.j
    Tinkerer

    If there is a will, there is a way.


    TinkererIf there is a will, there  is a way.

    Posts : 75
    Join date : 2013-10-30
    Age : 23
    Location : iran- shiraz

    Re: RDT crossbow project

    Post by ali.j on Thu Apr 23, 2015 3:31 pm

    Very Happy



    shooting test. 165 lbs/300 fps  Laughing















    Sponsored content

    Re: RDT crossbow project

    Post by Sponsored content


      Current date/time is Sat Jun 24, 2017 4:32 pm