First post!

Hello all,
I'm an SCA member who wants to build a couple of period style crossbows, for target archery (and combat archery, where they use modified bolts with special tips). I have never built a crossbow before, but I have been reading everything I can find on the topic.

I recently got a chance to examine a very basic crossbow someone had built for combat archery, and was given the chance to shoot it at some targets during the monthly archery practice. The release was a pin lift type (not sure of the correct term), with a lever on the top of the tiller, not a roller nut type with the lever on the bottom. The prod was made from a fiberglass boat stay, cut down into a longer and a shorter piece, with the shorter piece against the front of the stock. Both pieces were wrapped/wound with cord and secured to the tiller by a bridle. Shooting it, I noticed that it took a lot of pressure to lift the string to the point where it fired - so much so that it was difficult for my wife to shoot it, and this made aiming the weapon difficult.

The gentleman who built the crossbow was following plans he had gotten from somewhere online, and the main consideration was economy of price. He bought the string from an archery supplier (North Star Archery, I think) and the fiberglass boat stay from a local marine supply store. He used scrap lumber and such for the rest of the bow. His cost was under $50, and he intended it primarily for combat archery (where it might get damaged).

An afternoon of shooting his crossbow taught me several things - I want a roller nut release for target shooting, with the trigger lever on the bottom of the tiller where you can use a better grip to move the lever. I want to make my crossbow as inexpensively as I can (my budget for parts is very small) but I do not want to use the cut down fiberglass boat stay for the prod. I say this having read the detailed instructions for assembling his crossbow plan, and realizing that it is likely to be messy and potentially dangerous. I also want a stirrup on the bow so my wife (who is half my size) can cock the crossbow without injuring herself. Since we shoot at targets that are 20, 30 and 40 yards away, I need the crossbow to be strong enough to accurately hit the targets, but not so strong that my wife comes to hate her crossbow.

I intend to purchase a string from a supplier (rather than try to make my own), and I believe I can manufacture a suitable roller nut, release lever and tiller from scraps at work. My biggest concern is the prod.

Having said all of that (and thank you for reading it) here are my questions:

1. Is there a source for aluminum prods that you know of? I see Alchem Inc sells steel ones for $65, but that would pretty much demolish my budget, and frankly I'm not sure if any of them are light enough for my wife to draw!

2. Lacking a source for pre-made aluminum prods, would making my own out of aluminum flat bar stock (6061 or something similar) be a valid option?

3. Do you have any other suggestions for an inexpensive prod?

4. I have downloaded the plans offered at Alchem's website, which show the placement of the various parts in a roller nut type crossbow. If you have seen these plans, would you have any warnings or suggestions regarding them?

Thanks,
Gunnarr

Gunnarr: Welcome to the arbalist. That''s a lot of questions you've got there, and a general reading of back posts on this site will answere many of your questions. So I'll tackle the prod-question.
I make target and combat bows professionally, many go to SCA. The cheap, but effective answer to your prod-question is aluminum alloy: 70-75-T6 in particular. the 60-series stuff isn't springy anough. Mostly I buy my light prods from Darkwood Armory... they have a web site... prods will cost @ $45 a pop. You can make your own aluminum prod out of 7076-T6 if you have access to a bandsaw with a non-ferrous metal-cutting blade. Darkwood's prods are approx. 1 and 3/4 inches wide at center, tapered to half that at the ends. Length 28.8 inches before fabricating, thickness 190 thousandths of an inch (3/16) Given the low cost, you'll probably be happier buying a prod than making one.
Aluminum prods are efficient and cheap. They'll definitely give you a better cast than a fiberglass sail-batten prod. Life expectancy is in the thousands of shots... maybe 5000 before the prod gets soft and takes a bend. A steel prod will cost you @ 60 from alchem Corp. They aren't as efficient as aluminum-alloy prods, but they last mostly forever. If you can locate a source for Barnett crossbow prods, they're specifically made for archery applications. Should be good for a number of years of satisfactory shooting.
Good hunting. Geezer

Harumpf! That's what I get for not proof-reading. The aluminum alloy is: 7075-T6. I use 3/16 inch thick plate when I make my own 28.8 inch prods. This stuff is basically spring Duralumin, a material commonly used in aircraft fabrication. If you live near a shop that makes or maintains aircraft, you might be able to get it cheap.
Though I buy most of my aluminum prods, I always keep some sheet on hand, in case my supplier runs short. You can get the aluminum in partial sheets from Online Metals. They have a web site.
Geezer

I've bought from Online Metals before, actually. I fabricated a pair of Ginuntings out of 1/4 inch 6061 that I bought from them (my wife and I are both practicing martial artists).

At work I have access to a CNC router, which can mill aluminum as needed, if I have the cut path done up as a vector file. Your specs give me enough information to lay out a cut path I think. You specify band saw, is that simply to ensure a straight cut, or is it something to do with the actual finish of the cuts? How are the ends cut (for the string)? My machine spins a 1/8 inch steel bit at 50,000 RPM and its what I used for the blades I made before. However the blades aren't likely to be bent or stressed like a prod, so if there is a risk using a router to shape the prod please let me know.

I've been reading through the forum posts (and feeling very, very inadequate after seeing other people's examples of their projects). If I remember correctly, aren't you Iolo, of SCA fame? If so, I have downloaded your First Book Of Crossbows, too (and thank you for making it available).

I'll price the aluminum blank from Online Metals and see if it would be cheaper to buy and ship it, compared to just buying a prod outright. I found several 'replacement limbs' for Barnett and others, but I think they are all meant for modern pistol style crossbows, snce they are in the 15-18 inch width range. Looking at Darkwood Armory's site, I didn't see aluminum prods listed, but I'm at work on my lunch break so I may have simply overlooked it. Can you link them here for me?

Thanks for the prompt reply, too!

You can get fiberglass prods for under 30.00. I don't know what poundage you need, however the advertised "150#" prods are actually closer to 120 pounds at a total 13" draw (3" brace+10" powerstroke). At a shorter draw (11" total or 3" brace+ 8" powerstroke) weighs in at 95 pounds.
If you don't mind me asking what is your total buget. The reason I ask I am thinking of putting together a kit for people to finish themselves, although I admit I don't have any SCA knowledge or experience. It would be all cut and drilled out but the tiller would need shaping and final finishing.
Todd

@ Geezer - it appears that Online Metals only has 6061 (and variants), not the type you suggested. I'm looking for another source.

@Todd - where can I find fiberglass prods for $30? I'm trying to keep my out of pocket expenses at $50 or less (since that is what it would run me to build the fiberglass boat stay version I saw locally). If I can build one that is better than that version, for the same price or less, then I will consider it a "win" for me. (Incidentally, I have discovered that the type of release he had is called a 'notch lock' because the pin pushes the string up out of the notch. I'm really new at this, haha, does it show?) I looked up the parts for a full crossbow build (less the wooden stock/tiller) on Alchem and it comes to approx $135. The cheapest *combat* crossbow I have seen for sale (assembled, ready to shoot) is $180, but the maker never answered my emails, so I assume that is an old out of date price.

Gunnarr: Sorry to hear Online Metals no longer stocks 7075 T6. That's the right stuff for aluminum prods. I have tried 60-series aluminum with no success. Most metal-suppliers have pretty volitaile inventories. It might be worth checking back in a week or three to see what they''ve got on hand.
As for the $30 glass prods vs. the sail-batten prods, all the batten-prods I have seen were bad performers... not worth buying. As for making a bow for $50 in materials, that's gonna be hard to do if you want something worth shooting. Look at it this way: You're gonna put 20-40 hours into making your first crossbow... depending on complexity/type. If you cut materials to the bone, it's gonna look like crap. Generally speaking a few dollars extra on materials will make all the difference in finished product.
So yeah, you can make the stock out of yellow pine, and yes, you can stain your yellow-pine and varnish it, and buy it a bunny-fir bikini, but in the end, it's still gonna look like a crummy piece of pine. Enough mahogany/cherry/walnut/oak to make a nice crossbow will cost you less than $10 and even a halfway decent finish-job will look great. You can buy a $5 batten prod that will look like hell and shoot worse, or cough up a few extra bucks for something that will go Zoom!
How do I know that? Because every year, I have a few customers who come to me with cheapo crossbows featuring batten prods that won't shoot across my back yard. They want more power... so we rip out the batten prod with its pathetic bit of shoe-string for a bridle and fit an aluminum prod with a nice stout hank of hemp working over an oak bridle-block. And zoom! they're back in business. Every single time, the customer exclaims about the wonderful power. Truth be told, the same would have happened if they had fitted a barnett-type glass prod or one of those nice laminated wood prods that Elkridge Archery sells. Compared to a batten-prod anything looks great!
It's up to you, of course, but I tell my apprentices there's not much point in starting with crummy materials. You just end up with a crummy product.
Build it outa yellow-pine and fiberglass sail-battens and you'll end up with what you deserve. Geezer

Hi Gunnarr,

I have no doubt that you are not interested in those homedepo fiberglass rods Gheezer speaks about...they really are crap.

The fiberglass prods are easily found online...they used to be around $19 a piece(with string and plastic nock sleeves included), but now the price jacked up to the $30 range for the same package due to speculation and politics. I'm working on opening an online shop here as a part of the forum in hopes of offering items like these prods at the old price...it will be a while until everything is setup properly, so your best bet would be Amazon.com or E-bay.

Here is an Amazon link for the fiberglass prod...

http://www.amazon.com/New-Replacement-Limb-150lb-Crossbow/dp/B003X35C0E/ref=sr_1_2?ie=UTF8&qid=1301527484&sr=8-2

it does however also need a string and nock sleeves, but those can be made rather easily or again purchased separately.

http://www.amazon.com/gp/product/B002ATLAJY?ie=UTF8&seller=A1L0WOJA6MGS36&sn=The%20Hugo%20Shop

There is a better deal out there, but this one can be shipped in combination with the prod keeping the shipping charges down...just send the seller a message asking if it's possible. Good Luck!

Ivo

PS: CNC...that amazing acronym...what do you do Gunnarr?...if it's not a secret of course.

Here is the link for the prods:
http://www.crossbows2u.com/product/C495-518/Fiber-Glass-Limb-for-150-Lbs-Crossbow-Prod-Bow--Free-String.html
Even with shipping it should be under 30.00
You can definitetly build one for 50.00. How are your wood working skills?
Are you in a hurry? Give me a week and I will show you what I am working on.
Todd

@Ivo - LOL, I work for a company that builds signs and advertising materials. Everything from big billboards and banners they decorate the Super Bowl with, down to those little POP displays you see on the counter of your favorite fast food joint. I'm the 'robot herder' for our collection of CNC (computer numeric controlled) machines. I have a Zund, AXYZ, Rosenthal and a RHO (printer sort of thing). Picture a really big billiards table with a big moving arm that travels up and down the length of the table on tracks - thats what most of them look like. My company doesn't mind if I use my minions to make things for myself, as long as I do it off the clock (before or after work, or during lunch). I can cut anything up to a half inch thick on one machine (does delicate work) and anything up to 2 inches thick on the larger machine.

@Todd - Thank you for that link! I have just ordered one, and with UPS shipping it came to $29.98. It looks very good in the picture, though it doesn't give the dimensions. I am positive that it will be better than a boat stay, however! I will sew up a leather cover for the limbs to cover it up, I think.

@Geezer - I agree completely on the 'start with junk, you will end up with junk'. I see this all the time from our customers who want me to fabricate a great looking sign...out of the worst possible materials. Thats why I don't want to use the sail batten if I can avoid it. We have a variety of wood scraps from different jobs (we build 3 dimensional signage, and wood is usually the interior framework for indoor signs). I should be able to find a decent piece of hardwood for my stock. My intention at this point is to make the stock from 3 pieces of wood. Two boards for the exterior/body and a third piece sandwiched between them (which will be where I run the bolt groove and cut away the interior areas for the trigger group). I can router the exterior surfaces to decorate it, and cut away the interor compartments with precision before assembly.

I went thru the photo essay of Lightly's crossbow build and that was time well spent. (If any of you haven't viewed it, go do that, it's good.) Her pictures answered several questions I hadn't asked yet, and gave me some good ideas on how to adapt my router tables for the production of my crossbow.

That's awesome Gunnarr! I've had my brush with cnc's and currently send out STL's on daily basis...running a dental 3d scanner and designing framework for zirconia crowns, bridges, that kind of stuff.

One thing that I really want right now is a cnc plasma table. ...got this itch to start making little Man-Kung style triggers out of 16ga.

If you cant find a suplier of 7075-T6 Al. The shields that the company formaly known as Mandrake Armory makes their premium shields out of 7075-T6 .090" you could drop them a line and get a sheet from them.
http://www.windrosearmoury.com/zc/index.php?main_page=index&cPath=30_27

Well, got my crossbow prod from Crossbow2U.com (the link that Todd gave me). I was getting concerned because I got the UPS tracking number saying it was ready to be picked up...then nothing for 4 days straight. I called UPS and they said 'its on a truck going to your address right now, we just didn't update the tracking for some reason...'. True enough, ten minutes later my wife called to say we got the package.

The prod is black, with the words 'Cross Bow' printed on either side of the center point, and came with a package of two tip covers and a bow string. It seems very strong, though, I'm wondering if its going to be too strong for my wife to load!

The height of the prod is 7/8 of an inch at the center point, tapering to 3/4 of an inch at the tips, which are 27 inches apart.

I'll have to adjust my template to accommodate the shorter prod height, and I'm trying to decide how far back I need to make the notch. First however, I have to figure out how to string the prod! (the little things you forget to figure, the first time you try to do something, right?)

... stringing the prod...it ain't easy.

However you can put the string on one tip, then put that tip over your foot, put your other foot in the middle of the prod...and while keeping pressure on the center pull back the unstrung tip and put the string on it. There is a video of how to do it here >>>Link (it's the last one in the list ) - Props to Dave for the Vids!

Ivo

I have dealt with Northstar Archery for bolt kits. Great service and they are in Gainesville Florida.
In combat archery a roll nut can be awkward to reload. I am looking at triggers like those on the Crossbowman's den website. I am thinking a lock that looks like a roll lock but only travels 90 degrees and spring resets might mean faster, fumble free reloads.
I saw some of my competitors using notch locks. To reload they grab the string on either side of the stock and just jam the but into the ground to pop the string into the notch. Very fast but roller nuts are more accurate.
Add some throwing hammers to your arsenal when you can. handy when you are unloaded and rushed, great for bridge battles.

Hi Gunnarr, I bought the same prod. You can string it like Ivo said. Even unmounted if you want. Just put it on the floor and put your foot on the middle then pull up one side and slip the string on. They call it a "150" but really is more like 120 pounds at 10" power stroke. If you go the post titled "looking for someone who wants to build a crossbow" you can see that prod mounted with a 8" power strokes where in scales at 95 pounds.

Todd

Talk to your local truck brake and spring shop. The up to date ones can turn out a prod for you, nicely tapered and nocked. This is according to a friend who works at one.