General questions, questions, questions, on crossbow building

I have so many questions I dont know where to start. First off I am thinking of getting some cherry or oak 1"x6" pieces of lumber that are about 3-4 feet long and laminating them together for my tiller, do you all think this will be strong enough?
Also I would like to use a car leaf spring as my pro so what would be the best way to attach this to the tiller?
I can make my own bowstrings and I have material for this so I am thinking I can make my own crossbow strings as well so there should be no worries ther.
I have made my own arrows so i believe I can as well make my own bolts so again should have no worries there.
I do need some help with a trigger system though. I have many older books that show ticklers more than trigger type mechanisms. I would like something a little more modern like a rifle trigger. Does anyone have a symple drawing for such a trigger?
What is the best way to make the track for the bolt to travel on as it is released?
Finally where should I start???? Should I start on the stock the prod the trigger??? The prod will probably be the hardest for me to get right now as I cannot afford to order a premade prod from a seller and this is why I want to make one from a car leaf spring. So I will have to take some time maybe this weekend and go to some scrap yards and see if I can dig one up.
I am sorry for all of the questions but once I get a few crossbows under my belt I will definately pass on any knowledge that i get from you all to someone else who needs the help as well.
Paul(INDIANA)

Lots of questions! I will do my best to help you with answers.
-Oak and cherry are strong enough for the stock as long as you have enough wood where it's needed for strength. Laminating it gives you the advantange of inletting for the trigger before you glue it together.

-Probally the best way (strongest) to attach a steel prod is with bow irons, these can be purchased or made yourself if you are skilled at working with metal.

-I don't have a "simple drawing" of a rifle style trigger, but think of it this way: since the bow string has so much tension on the trigger mechanism, it takes some effort to break it free, hence the long ticklers on medieval crossbows for leverage. To get around the problem most builders use "transititonal levers" to reduce the effort. There is a page somewhere on this forum where triggers are discused, maybe someone can find it .

- I use a router with a "V" bit to make a groove, but there are other ways of guiding the bolt, but this is the method I prefer.

-Start with the prod first as this will determine draw length, then the stock with the trigger in mind.

Hope this helps, Todd

Archer,

The dimensions you are suggesting for your starting pieces seam very large. Have you made any full scale sketches of your project? This will help you get a better sense of scale.

I don't think one can overestimate that benefits of full scale sketches.

To me, oak does not seam like the best wood for the job. It's heavy, open grained and splintery. Most historical crossbow tillers were made of nut woods and fruit woods. In the absence of those, I would recommend maple. It's strong and close grained, and available at your local "Home Despot".

Mac

mac the dimensions I listed were just the starting dimensions of the available lumber at lowes or home depot, they come in 1"x6" being the thickness and width then various lengths... The 3-4' length was just thrown in there as what the board would be not what the tiller would end up. Even though I am a hoss of a guy I dont think I could muscle a prod that would bend far enough to make a 3-4' tiller necessary... Sorry for the confusion...

Hi,

The sequence will have to start with the prod. Once you have a properly tillered prod, you will know the draw length and poundage. From there you will decide how long to make the arrow track. The trigger can be made first or last, doesn't really matter, but having it before building/routing the track might prove more useful if building the track as a separate component. The stock comes last, especially if stock and track are separate components, but really the final fitting/adjustments are made when all other components are complete.

So basically:

Prod>Trigger x Stock ... for a crossbow employing a solid stock that has a track groove routed in it.

Prod>Track xTrigger>Stock ... for a crossbow with a laminated track(separate from the stock)

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To start with the prod, you can check out our Wiki(New Member & Useful Links on the side of the forum) where our friend basileus explains how to tiller a leafspring, how to make bow irons, as well as a few other helpful notes on building. Also there is an article from Popular Mechanics that has some plans. >>>Link
There is a download link called something like "Metal bowed Crossbow
Plans". Nice little article and has some info on what poundage to expect
from what prod dimensions, but other than that I would not go for their
trigger as there are much better designs.
I think it's also worth mentioning that leaf spring prods are notorious for occasionally snapping and possibly wacking one in the head...though it is rare that we hear "true" stories(mostly paranoid people yapping), but the few real ones come from bystanders, as dead men tell no tales. As scary as that may sound, an it is, I'm only saying this to get to my next point...precaution...a safety backing or cover is used to help avoid coming "head to head" with a prod shard. One may use several stainless steel wires layed out on the back of the bow and secured by wrapping with string(as was suggested by one of our members)...or leather sleeves can be sewn tight over he limb (like a corset ). There are a few examples here on the forum showing this practice...New World Arbalest crossbowyers do it and it looks pretty classy.

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The track can be, as Todd said, made with a router right in the stock by either using a V bit or for a deeper one(for groove allowing the use of three fletch arrows) a few passes with a thin U bit. If you have no access to a router and or want to make a track as a separate component, the track can be laminated out of wood/plywood and faced with strips of aluminum.



I also epoxied aluminum angle on top...but a wooden track is fine.



There is an article on our Dear Departed Robin Allan's website, that touches ends on track groove dimensions and how they relate to arrow shaft diameter. >>>Link
A really nice site with some excellent articles that might answer quite a few of your questions, just check out the Hints&Tips section as well as it's extension Archives at the end of the Hints&Tips page.

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The stock is again another discussion, what kind feeds your soul?

There are a few designs that I can think of...

There is an open grip shotgun style...which is good for quick shouldering of the weapon, but a little more sensitive to the angle of the grip and grain of the wood....the more the handle represents a pistol grip, the more grain begins to play a crucial role.


Thumb hole/Pistol grip stocks...which are pretty cool. Thumb hole stock might be a little slower in shouldering(never really felt the difference though), these I heard are better for target shooting. Thumb hole stocks also have an added bonus, since a thumb hole/pistol grip stock can be made with a set forward grip - a more compact and better balanced crossbow can be made.



...or an over the shoulder stock pistol crossbow...


...or if you'd like... a bullpup crossbow(haven't seen too many of those running around)



We did a Custom Stocks topic on here, where I was able to translate an article which talks about how to take shooter's measurements. Here is a >>>Link

But then again there is "sort of" a way around it, I mean I try to cheat the system occasionally when explaining things to my brother, and we devised a way to get our shooter dimensions by feel, using a few carpenter squares(and the like) clamped together.



...which resulted in a pretty bad ass and surprisingly comfortable stock.
Template



Roughly shaped stock



Rough shaping was done with this little duo...



Finished and Primed



The cheek piece is a little out of place causing one to slightly stretch his neck to position the head properly for scope use, but other than that the kid is pretty happy and shoots the thing even though it's not finished.

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The triggers topic was moved to Basket since it was a damn mess and I
was thinking of splitting it into three or even four topics covering Medieval
Tickler triggers, Medieval Set triggers, Classical Triggers, Modern
triggers - covering each separately. I'll bring it back and it will be in the Classical
Crossbows forum until I write up better organized trigger topics.
However there are two basic under claw sear triggers I can think of off the top of my head the basic one for a openhandle/regular thumbhole stocks and one with an extended trigger for set forward grips, I'll sit down to draw them up as close as possible to functional blue prints and will post them in the new triggers topics, till then you are welcome to visit our first attempt at triggers topic.

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Well, hope I helped out a bit...I mean it's just general view on things and there is plenty for you to read up on and have a blast researching. Check the Crossbow Books topic(just use Search) and it will bring up some good info, one I find most helpful in regards to triggers was Man Powered Bullets.

Good Day,

Ivo

Here is a link to Robin's website that has some good trigger ideas:
http://www.thecrossbowmansden.com/Triggers.html
Todd

Been to robins web site its a great deal of info so was IVO's post above... There is alot to take in and I am just taking it all as I can. I have class next week for an apprenticeship and am out of work right now so it will be awhile I am affraid before anything gets built. Been working on melting some lead down into .45 cal balls for my slingshots so that keeping me busy for now. May have to look for another trade soon if work doesn't pick up.

That's no problem man...I just dumped everything into one post, so it's a bit overwhelming and may seem like "heh, try moving this mountain", but if you break it down to parts and plan your research, then that mountain will be on it's way becoming a really nice build.

I try to keep my suggestions cost effective and focused on easily obtainable materials for ease of interpretation and first time approach... "by the people, for the people" I always say.

Happy Researching, Building, and Happy Holidays!

Ivo

Maybe this can help you. In 1967 in High School I constructed my first crossbow. The point here is that I made my bow via a cars rear leaf spring. That information came from an article that was published in a magazine named "Popular Mechanics". The author showed and gave information which spring to use, cut the length to have this draw wt. Everything you wanted to know was in that article. Now if I can do it (I'm all thumbs) any body can do it. Just research that year and month out and guy you'll get a wealth of information. Oh yes; I still have that crossbow somewhere around here. Good Luck Now. Mike

In this topic I mention the information could be had in the magazine named Popular Mechanics. It came to mind another mag I use to read was named Mechanics Illustrated. It was either or. With a little reseach on the readers part you will come up with a wealth of good knowlege. Start with the year of 1966> Nov. 1967. Somewhere in there is pay dirt. Mike

In this topic I mention the information could be had in the magazine named Popular Mechanics. It came to mind another mag I use to read was named Mechanics Illustrated. It was either or. With a little reseach on the readers part you will come up with a wealth of good knowlege. Start with the year of 1966> Nov. 1967. Somewhere in there is pay dirt. Mike

Are these the plans you mean ?
http://www.vintageprojects.com/archery/cross-bow-leaf-spring.html
vintage projects also has the repeating crossbow plans.