wood crossbow nut

I'm sure that describes most of the people on this forum but that's not where I'm going with this

I have been looking at some drop in triggers (locks?) but have decided they look too modern for my taste so I guess I will try my hand at building my own.  I am leaning towards a traditional crossbow nut with a two axle trigger (I think I got that right).  It will have a trigger that actuates a transfer bar that will engage with the nut.  That's about as complicated as I want to get.

I have questions about the nut material and size.  I read a few posts where they talk about a nut that is 1.5 inches in diameter.  Is that standard?  I have some elk antler but I don't think I could turn anything bigger than 1.25 inches in diameter with it.  How big are your nuts?    (this is just too easy!)

I could always make the nut out of wood.  I saw reference to wood nuts in some of the posts. If so, what kind of wood would you recommend?  I was thinking hard maple or iron wood (Hop hornbeam).  The latter is said to be some of the hardest domestic hardwood in the country.  I know from experience it is some very tough wood... almost impossible to split and hard on the chainsaw blades.

I am looking at a bow in the 150 lb range with glass or steel prod.

Thanks

Chuck

I do have experience with wood nuts. I have made several from walnut although I think any hardwood would work. Mine are 1 1/2" diameter by 1 1/2" wide which may seem wide but I wanted to err on the side of strength. I cut a slot and epoxy a steel plate in for the trigger sear. Just want to mention I believe the grain of the nut should run vertical when the nut is in the set position. This is for maximum strength.


Todd

Welcome!

What Todd said.  Diameter of 1.5" is a defacto standard, not set in stone as it were; 1.25" would be OK.  I built a crossbow pistol with a 1" diameter Delrin nut.  Hophornbeam would make a really good nut.  Better than antler certainly, and better than Maple (although Maple is good).

Lignum vitaei would work,said to be the hardest wood of all,suppliers can be found online,so dense,when it's in water,it sinks.
                                                 Hermit.

Lignum Vitae will make an excellent roller-nut. It's strong, self-lubricated, hard and durable.  It IS hard to work, almost impossible to glue, and you should wear a good respirator when working-particularly when lathe-turning, but it will make a superior roller... possibly even better than moose-horn, which is still my favorite.  Geezer.

Todd the archer wrote:I do have experience with wood nuts. I have made several from walnut although I think any hardwood would work. Mine are 1 1/2" diameter by 1 1/2" wide which may seem wide but I wanted to err on the side of strength. I cut a slot and epoxy a steel plate in for the trigger sear. Just want to mention I believe the grain of the nut should run vertical when the nut is in the set position. This is for maximum strength.


Todd

Thanks Todd, Yours was the post I remembered seeing but I couldn't find it again.  What is the weight of your bow?  If a walnut nut would work a hop hornbeam nut would definitely do the job.  

Hermit wrote:Lignum vitaei would work,said to be the hardest wood of all,suppliers can be found online,so dense,when it's in water,it sinks.
                                                 Hermit.

Thanks Hermit,

I actually looked up the engineering properties of wood today and found that Lignum vitaei was the densest wood on the planet. If I remember right the Janka hardness and elastic modulus were many times higher than any native hardwoods.  Still, if I can use some local materials I probably will... I have lots of hop hornbeam in my woods.

Chuck

I found Lignum vitae great to work with, as long as you wear a mask and have a powered sander. It gets a nice finished gloss even better than Ebony.  I used it as the pin bearing on my avatar crossbow, glued to the 100+ year old Southern Yellow Pine tiller as you can see here:


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kenh wrote:I found Lignum vitae great to work with, as long as you wear a mask and have a powered sander. It gets a nice finished gloss even better than Ebony.  I used it as the pin bearing on my avatar crossbow, glued to the 100+ year old Southern Yellow Pine tiller as you can see here:


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That is a really nice crossbow.  I'm thinking something a little more modern but not much.

I know some guys who do a lot of turning and the hop hornbeam polishes up nicely on the lathe.  It's not oily though so it wouldn't be self lubricating.  I have also read that hop hornbeam is a good bow wood if you can find trees without twist.  Maybe some day I can make a wood and sinew prod out of it.  I have the Traditional Bowyer's Bibles and lots of native bows were made with sinew backings.

In my browsing I haven't seen a trigger mechanism like that!  Am I correct in assuming you slide the string down in the groove behind the lignum vitae block and trap the bolt under the thin wood batten?  It looks like squeezing the tiller lifts that dowel up and pushes the sting up and out of the groove??

Primitive but it looks very durable! I imagine it has a very heavy trigger pull.

That's what we call a Skane lock or Pin lock action.  Simple but effective, and not that hard of a "trigger pull" because the tickler/trigger has a long lever arm.  A tickler really teaches you to squeeeeeze the 'trigger'.  BTW the small block in the photo, between the tiller and the tickler, near the pivot pin, is a 'safety bar' to keep the bow from firing until the bolt is properly loaded and pointed downrange.

Yes, with the tickler open and the pin down and locked, the string is pulled down into the notch. The bolt butt goes under the curved tip of the wooden spring.  Remove the safety, aim and squeeze.

The Lignum vitae block is set so that there's a half-channel for the Delrin pin.  The pin pushes the string back up and TWANG.  You can see more of my build here:  

https://thearbalistguild.forumotion.com/t945-loose-laminate-pinlock-build?highlight=pinlock

Thanks for the link Kenh.  That is one sweet crossbow. Two weeks ago I knew absolutely nothing about crossbows.  A couple hours on this site (well several really) and I feel confident I can build my own.

Seven bucks for a prod really has me thinking...might have to try that myself.  It would really look cool with some rawhide binding on the limbs.  Can you provide a little update on your bows performance?  How has the makeshift prod held up? have you had any problems or would you make some changes?  

Also, how have the improved knocks held up?  Are they pinned to the prod at all or are they just slipped on and glued with epoxy?    

Thanks,

Chuck

Several hundreds of shots later the prod is doing just fine.  The Mark II pin nocks were just sawn into the ends of the longest limb, and then covered with a layer of white/gray epoxy putty for strength and because it would look better than the raw sawn ends.

The fiberglass Chainlink Tension bars may be a bit hard to find.  If you want I can get one and mail it to you.

There is another, relatively cheap option for a Loose Laminate Prod, and that is what is called a Boat Cover Bow -- about 1.5" wide and 3/16 or 1/4" thick.  We discussed them here:

https://thearbalistguild.forumotion.com/t1215-fiberglass-for-loose-laminate-prods?highlight=loose+laminate

I've seen these bars for as little as $11 (but with $15 shipping) or I can get one for about $25 from my local West Marine store.