Ever look at paintings from the 13thc? the cross bow prod looks very short. as apposed to my crossbow prod that is the size of a short bow.

I have a small but thick hunk of bow wood left over, its very short like 2 and 1/2 feet or less. Is there any way i could make a small but powerfull crossbow prod out of wood that short? Im worried that it would snap on me.

Maybe the crossbows in the paintings are lamanent with layors of stuff in them. Maybe i should hold off untill i get some cowhorn to make it a little longer...


http://www.medievaltymes.com/courtyard/images/maciejowski/leaf10/otm10ra&bdetail9.gif


http://www.medievaltymes.com/courtyard/images/maciejowski/leaf10/otm10va&bdetail3.gif

http://img.photobucket.com/albums/v653/DouglasTheBlack/others/maciejowskicrossbowman3.gif

http://img.photobucket.com/albums/v653/DouglasTheBlack/others/crossbowhuntingpainting.jpg


ok ok not from the 13thc but you get the idea

http://img.photobucket.com/albums/v653/DouglasTheBlack/others/guardroom17.jpg

http://img.photobucket.com/albums/v653/DouglasTheBlack/others/crossbowman.jpg
this guy seems to have one of those many layerd bows


now that i look at it my hunk of wood seems way too small but what the heck what do you think?

Too be honest i think they where Really bad at drawing :P and your crossbow looked ok to me doug this isn't saying much since i know nothing about them but its an honnest opinion ;)

Yeah, their artwork is exaggerated, like when they depict their longbows in the tapestries. Completely out of proportion, but the ones next to the battle axe look decent.

well its not that i dont like my cross bow its that i have a small hunk of good wood that i would like to turn into a crossbow ;D

 Greetings, DTB,                                                                            
     I understand your reluctance to throw away a nice piece of wood,
but my sense is that 2 1/2 feet is simply too short for a workable bow made only of wood ( not that I'm any sort of expert. ) I seem to recall reading somewhere that crossbow prods were made of steel, sometimes covered with leather, which might explain why they don't look like steel in the paintings. Certainly laminating the wood with horn or antler would make a big difference but would be a lot of work.
As I said, I'm hardly an expert ( I've always said "expert" is spelled:
"e-g-g   s-p-u-r-t" ) so I hope you can come up with something.    
      Thank you very much for the superb artwork, though. The hunting scene in particular brings back some great memories!!
                                                                               .......Dan

Don't throw that wood away! 2 1/2 feet (76cm according to google) is more than adequate. Most of my crossbow prods are that long or a little shorter. Remember that draw lenght on period crossbows was really short.

wrote on May 11^th, 2006 at 5:03am:

Don't throw that wood away! 2 1/2 feet (76cm according to google) is more than adequate. Most of my crossbow prods are that long or a little shorter. Remember that draw lenght on period crossbows was really short.

                                                                                               
   Demagogs! I stand corrected! If I dredge the bottommost sediments of my mind, I seem to recall that crossbow prods were indeed made of steel.......later. That is, into the 1400's  and later, but I confess I don't know what was common earlier. Is there a reference that you know of that we could consult??              .......Dan

Have confidence Doug. Go forth and make a awsome short prodded crossbow

How would making a crossbow that shot spears work?

According to the romans and Greeks, really well. They were called Scorpions and they fired what were essentially small javelins or huge crossbow bolts, that were said to be able to impale several men in a shot. there were forms that fired round shot in lieu of bolts, and some of the seige forms, if the proportions of their ammo is correct, were up to 40 feet tall and fired 18 kg (40 lb) round rocks at enemies' walls. Actually, while playing Rome:total war I have taken out goodly portions of the opposition with the ballistas and scorpions, including the enemies's generals. It's sort of funny to watch them fly off the screen after being struck with a flaming bolt or rock several times their size seconds before their army breaks up and flees screaming.

make this

http://img.photobucket.com/albums/v653/DouglasTheBlack/others/balista.jpg


then scale it up. Its not too hard to do truth told, The biggest problem i had was the holes i had to drill into the top and bottom of the ballista.


If you need any help on like the details let me know and ill try to help. I am planning for this summer to make a huge verson of the one above but wood is not cheap

:-/

Quite cool, what sort of cordage did you use for the torsion springs? And.... How's it shoot !:)?

Do you have any measurements (size or draw weight)? This sounds like a fun project.

Always be on the lookout for wood being thrown away. A lot of times when construction is being done they throw out some really nice sections.

thats paracord that was twisted into 4 thicker ropes. Can you see the wood on the top? I put a pipe around that wood then twisted untill i started to hear the wood creak. Last i checked it pulled 50 pounds. I could shoot a pen very far, and bolts with fletching pretty far. The cool thing about it is how concistant it shot, i think after i mounted it to the picknick table the darts only had an inch or so varyation depending on how far back i drew it. remind me some time to get a pick of the bow arms. The rope was so tight it compressed the wood.  ;D

http://img.photobucket.com/albums/v653/DouglasTheBlack/others/balistafront.jpg

Thanks DTB :) That looks like thick wood that was getting bowed (sp?) Wow

Anyone know of some good sites for this sort of thing?

This is one of my next projects :)

Here is a paper on Teutonic Order and the importance of crossbow in their conquest of Baltics.

http://www.deremilitari.org/resources/articles/ekdahl.htm
->
"Throughout the whole of the Middle Ages simple and cheap crossbows made from yew wood were used in the country districts."


Also about ballista- i'm building one right now, too. Just 2 days ago i learned that simple wood isn't enough to hold the twisted rope. The crushing force created by twisting the rope is tremendous- my random guess is at least 10-15 times the draw weight of finished ballista.
Ok, i'm off to find some at least 1cm thick round steel bar now.

1cm steel bar will twist a lot more than a 2x8 :-/
Good for reinforcement anyway..... and at least it won't snap into shrapnel.

Depending on the size, I was planning on doubling up 2x8's with bolts and nuts. Many vertical braces as well.

2 1/2 feet!? That's too long, not too short.  For a crossbow with an 8 inch draw, I'd use a prod of just under 20 inches.  Make it very thick, and taper it well.  Some people say that is too short, but my crossbows definitely work.
 Most crossbow prods in Europe were actually made of wood until the late 14th century - the wooden prods were a lot cheaper than composite or steel bows, both of which take vast amounts of time and skill to make perfectly.  Composite crossbows were far from rare, and the draw length could be drastically reduced, but a wooden prod would be typical, and should be short.  Think about it, DtB - the draw length of a normal bow is just a little bit under half the length of the bow itself.  Why not the same for crossbow prods?  Wooden prods are mentioned as a majority of the crossbows produced certainly in England until about 1450, according to Alm.
 In south-east Asia, tribesmen have used crossbows with disproportinately long prods, but they are not efficient.  Or wieldy.  Chinese crossbows have most often used self-prods or bamboo laminate prods with long drawlengths compared to European crossbows.  They are more efficient, I believe, with a longer drawlength.  

20 inches?! interesting thats a tiny prod there :) I based my first cross bow on the pic you showed of yours, how thick is yours? this short prod i just made is about 1/2 an inch thick at its thickest. Too thinn maybe? It would be great if you could get a pic of the short prods :)

All my European crossbows - so all the crossbows I've shown so far - have really short prods.  They should still be up.  20 inches is more than enough.  It's within safe parameters, and it's totally efficient.  Half an inch is quite thick, depending on the width of the bow.  I couldn't tell you how thick it should be, of course - I don't know what the wood is like, what draw weight you want... etc.  Just do it like a normal bow, just make it short.
 Think about it though: 8 inches is obviously 2 inches less than half 20 inches.  2 inches is ten percent of the length of the prod, and a bow should be about 9 tenths bent according to many English bowmakers.  Bear in mind too that the string on a crossbow, especially a wooden-prod crossbow, is slightly slack, or at least, nowhere near as tight as on a handbow.  There should be practically no tension.  A short prod, therefore, is absolutely fine.  I've had no broken prods that were made properly.

hmm so if they are slightly slack can i leave them strung?

Yeah, pretty much.  As long as there is practically no tension on the bow itself, then yep, keep them strung.

huh thats cool.  :) I was always afraide of the bow following the string :)

Why is the prod more efficient when it is shorter?

More energy can be spent moving the bolt instead of having to move heavier limbs.

Actually, I don't think the shorter prod is more efficient.  You can just get more brute force packed into a smaller bow.  Just thicken it, and taper it a little (this is a very rough science), and attach a truly huge string.  The longer bow's tips would have more time to reach maximum velocity and hence be more efficient, but efficiency is not really necessary here, where you don't need to keep poundage down to around 50 pounds.

Hello.
I have made 6 crossbows. One with steel bow and the others with wood bows.
I normaly use pine wood for bows, and it works well.
One problem with this kind of wood is that it must be over 1 meter in lenght, or it will breake.
I have used bamboowood for one of the crossbows and it worked great. It was only 80 cm long.
The steelbow I used was 65 cm long, and it was nice to shoot with.
The steelbow type I made, had a rolling nut type, and it had a long steel triger.
All the others was viking (peg type) crossbows. They where made as copys of the old whale crossbows (yes they where used for hunting whales :o)
I make and sel crossbows, but here in Norway it is a limited marked. Modern crossbow types is illegal here in Norway, but copys of the old types is OK (if I understand the law right ;))

Rebel, definitely invest in a piece of hardwood! From all my experiences with Pine, you're very lucky or very skilled. Do you know what weight the pine draws at?

Hello CanDo.
If I understand your question right, you wonder how powerful I make my crossbows.
I have never mesured the strength of the bows, but my last crossbow (with pine bow) is very hard to pul back.
I put a stear up (spelling?) in front of the crossbow for aiding when puling back the string.
I make the string out of linen string (the total string thickness is about 1 cm.)
The total length of the bow was 110 cm, and had a linen and leather backing glued on.
The tiller stock is about 70 cm long, and the distance from the bow to the lock is about 30 cm.

wrote on May 13^th, 2006 at 5:45am:

2 1/2 feet!? That's too long, not too short.  For a crossbow with an 8 inch draw, I'd use a prod of just under 20 inches.  Make it very thick, and taper it well.  Some people say that is too short, but my crossbows definitely work.  Most crossbow prods in Europe were actually made of wood until the late 14th century - the wooden prods were a lot cheaper than composite or steel bows, both of which take vast amounts of time and skill to make perfectly.  Composite crossbows were far from rare, and the draw length could be drastically reduced, but a wooden prod would be typical, and should be short.  Think about it, DtB - the draw length of a normal bow is just a little bit under half the length of the bow itself.  Why not the same for crossbow prods?  Wooden prods are mentioned as a majority of the crossbows produced certainly in England until about 1450, according to Alm.  In south-east Asia, tribesmen have used crossbows with disproportinately long prods, but they are not efficient.  Or wieldy.  Chinese crossbows have most often used self-prods or bamboo laminate prods with long drawlengths compared to European crossbows.  They are more efficient, I believe, with a longer drawlength.

9/10ths bent?! What the heck does that mean? That makes no sense. For the length of a longer bendy handle bow, take your drawlength, double it, then add at least 20 percent. Maybe as much as 30 percent if the lumber you are using isn't very good, like soft maple, some of the less dense elms, and black ash.

Maybe english, you are referring to the old longbow phrase- "a full drawn longbow is 9/10ths ( or 7/8ths) broken.". This means if you overdraw your bow by about two or three inches, more likely than not it will break.

DtB, I would suggest using all of the length you have, and adding another two or three inches to your drawlength. Another 6" of prod length isn't going to "slow you down" any- unless for some wierd reason you are hunting with it. A longer drawlength will shoot better.

Also, the reason you can have it "strung" with about a 1.5" brace height is that such a short heavy bow will take a significant amount of set, so there shouldn't be any tension anyway. DtB, I really suggest you make a bow first. It is easy, it will teach you about tillering, and if you can take some pics I'll walk you through it.


Rebel I can believe you are making them out of pine, if you are backing them with leather and linen as you say. I think a piece of hardwood like ash or elm would be better, but if they are working for you then its alright.

Ive made 5 bows, and the only reason im makeing such a short cross bow is i had wood left over from the last bow i made. Ive also made a cross bow before. This was just sort of a fun project so that i did not waste good wood :)

You're right, hellfire - short prods take large amounts of set.  But that is beside the point, and medieval crossbows were made to these very short specifications.  So they are authentic, and undoubtedly powerful.  The power comes, in a crossbow, not from efficiency of energy use.  When you can make a piece of kit like a goats foot lever or a crannequin to span your bow, you can take the draw weight up to about 200 pounds or more.  Who needs perfect efficiency if the thing is authentic, looks good, and shoots bolts well?  I'm not saying the European medieval crossbow prods were efficient... just that I wouldn't like to face one without a pavise.  Or a gun.
 I assume you've never made a crossbow?  They are good fun.