Primitive Archer
Main Discussion Area => Bows => Topic started by: superdav95 on July 04, 2023, 03:19:48 pm
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Well I’m no really sure what else to call his “thing” other then platypus. It’s essentially a reverse Penobscot bow…sorta…? I had a dream about this bow actually strange as it sounds and I could adjust the draw weight by slipping in these removable belly slats. Crazy I know I know…. So I decided to spend my afternoon dismantling one of my bamboo bows to try it. Well with some trepidation and safety glasses I drew it back and it actually shot very well. No weird noises or clicks or vibrations out of the ordinary compared to my others. It shot hard and fast. I thought to myself well let’s keep shooting. Put about 100 shots through it and no signs of any issues with the belly slats. My idea with this hair brained idea is to have slats that can be removed and added depending on what draw weight your wanting. These slats would have some sort of felt material on the underside glued to help with vibrations and potential noise. I would ideally have them friction fit in place in the concave area/void between the handle and the main limb at the handle for each limb. These slats would be sized according to weight/thickness and be swapped out as a set/pair. Some design issues obviously would need to be resolved yet but this proof of concept at least says to me is possible to have a bow that can be made adjustable almost on the fly. These particular belly slats I had a baked in reflex in them as can be seen with bow strung up. I wipped these slats up in about 30mins from scraps left over. I also glued mine in with my hot melt glue as part of the limb when re assembling the bow to test the idea. The white cordage is just old construction poly twine I use for little projects like this as temporary binding in case things blow up. It happens unfortunately. Let me know what you guys think?!?! My wife wasn’t around for any pics or video of me shooting it but I’m pleased with the result. Thanks for looking
Cheers
Dave
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Some more…
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Crazy cool Dave...I'll be watching for sure... :OK
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Nice work, it's fun to do different stuff... I mean we've only been experimenting for about 60,000, so plenty of stuff to try ;) ::)
It's a bit like a truck leaf spring ;D
Maybe add a thin piece of leather to stop the ends of the slats wearing the belly?
Del
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that's a very interesting test and i think Del provided an excellent hint
At first my concern was that a longer and/or stiffer slat would work only partially due to the bad tillering provided by the two contact points
But... by copying the idea of the truck leaf springs using many overlapping slats could be the way! A much more distributed load and better tillering :OK
I'll follow you with great interest
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Nice experiment! now, what if you don't try tu supress friction and noise? this bow could sound like the typical hollywood movie bow when drawn ::)
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Thanks guys. It’s a weird one for sure. Del, yes there is a small section of felt at the contact points but leather or suede would work too. I love the experiment of it all and yes the leaf spring is a great visual as to a working concept. I was even thinking that maybe longer and shorter slats will need to be tested. GlisGlis, the contact point on this working prototype is minimal I can lift up on the end with my fingers. It actually bends quite nicely with the main limb surprisingly. If I go with stiffer slats it may become more of a problem so will require more testing. Bob, yes it’s crazy and pretty cool 😎. Weird guy, I was thinking too that this seems like something from Hollywood and kinda gimicky that you might see in a movie. It’s so crazy it just might work! 🏹. Thanks for following along on this crazy journey. Dave.
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Interesting, Dave. Without experimentation where would humanity be. Keep it up. :OK
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I love it, cool to see people still experimenting.
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I love it, cool to see people still experimenting.
+1
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Cool stuff! Awesome concept. I know it's not primitive, but teflon tape (not the pipe sealing kind, but adhesive on one side, teflon strip on the other) might help on the contact points. Works wonders on slingshots to prevent band wear from the friction over the forks.
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Thanks guys. I like to experiment and not all work out but it is fun and passes the time. I’m gonna get to work and get building a working functional version. Thanks for following along
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I’m with Del on the truck springs. I like the way you think outside the box Dave!
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Made your style of bow year ago ,and it came out way to low in poundage, The slats were cut to thin. Today I built to inner slats for the bow ,and got the bow to 38lbs, and got the limbs balanced. I am happy with the weight , and performance for a short 38 lb. bow. It is a fun shooter now. You have found a way for me to use up those thin slats, and it was fun getting the limbs to balance. Good idea.
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Made your style of bow year ago ,and it came out way to low in poundage, The slats were cut to thin. Today I built to inner slats for the bow ,and got the bow to 38lbs, and got the limbs balanced. I am happy with the weight , and performance for a short 38 lb. bow. It is a fun shooter now. You have found a way for me to use up those thin slats, and it was fun getting the limbs to balance. Good idea.
Awesome bassman. Glad it worked out good for ya. More to come on this build soon. I’ll post updates soon.
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Here’s a quick update on this bow. Added a new stain job and redid the finish. I added some string pads (Buffalo leather), new yellow and black d97 string and buff leather handle wrap. It shoots very well and I may use this one this year from one of my tree stands with a rail. This should work out nice as it’s fairly short bow at 54” ntn when strung. Here’s a few pics of the bow as it sits now. I’ll have to wait till my wife gets back to do a full draw pic. Sorry. :).
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Few more…
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I really love your finishing work on this one!
Have you shot it through the chrono with the slats in? I'm really curious how this performs.
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Thanks Airkah Very kind. I haven’t yet but it seems fast. It was a 40lbs bow prior to the slats. If I were to guess it’s around 45-48lbs now. I’ll do some shooting it tomorrow and convince the wife to be my cameraman. 😀
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yes please some info on performance,,very cool bow
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No camera man today… but I did do some shooting with it today and got some promising results. With the slats in it is pulling 45lbs. It shoots about 5-10 fps faster then before at 10 gpp arrow. Readings today were ranging from 169-175fps. I compared this with another boo self bow similar draw weight with no added slats and numbers were about the same only marginally higher. Maybe 1-2 fps faster. Not a huge difference. I’m guessing this is due to the added mass possibility in the limbs. I also noticed a strange noise when shooting this bow some more today. The slats are sounding off when I release with a clap noise. I may need a better buffer then the little piece of felt I used. Other then that it dose shot well and I’m pleased with it. I will make another bow and take what I’ve learned from this one to improve this idea. Thanks for following along.
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That’s pretty cool Dave. And nice job finishing her up too.
Bjrogg
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Beautiful bow, and an interesting design. Has me thinking... you say there is a clap, so I wonder if the limbs are moving faster than the slat on the belly at release? I would think ideally the slat should be trying to recover faster than the limbs to help push them through the shot. Video would help to see the timing of that. Not sure what you could do to affect it though. Really cool idea though and the execution is amazing, really nice bow.
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Nice work.
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Thanks guys!
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Thanks for posting that! Pretty good numbers out of this design!
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Dave is there a way to mark the slats to the limbs of the main bow and check the he compression length? I know they stretch in tension about the thickness of the limbs.