Primitive Archer
Main Discussion Area => Bows => Topic started by: Tuomo on February 20, 2014, 04:30:42 am
-
Hi! My name is Tuomo and I am from Finland. I have been making wooden bows over 15 years. My first “real” bow was ash flat bow, about 30# @ 26”. Since then I have hooked to primitive archery and I think I am using almost all of my free time to this “hobby”. I have made a lot of bows, selfbows and laminated bowsand arrows and so on.
My current big project is that I am writing the first comprehensive handbook of primitive archery in Finnish language. There will be about 400-500 pages and a lot of colour photos. It will be a book for beginners but also a book for advanced bowyers. I have started the project three years ago and there is still at least one year to go. Thera are very much different kind of things I have to clarify and examine. Many have helped me, including members of this forum.
The most exciting thing is that I have got real high speed cameras for use (Phantom Miro LC320S and Citius Imaging Centurio C100)! So, I have filmed many mysterious things, for example achers’s paradox, exploding self bow, etc. Videos are here:
http://www.youtube.com/channel/UCmVczwYUfq6sQQjCmKd2q5Q
Enjoy!
If you have questions, please ask. If you have interesting ideas you would like to see in slow motion, please suggest!
-
Excellent, thanks for sharing :)
I see you have one exploding on the tiller too! >:D
Hope it's ok, I've posted a link to your videos on Archery Interchange UK as it is so interesting.
Just seen the 'tiller off' video, brilliant, I think it shows how the bow doesn't care, it balances itself out pretty much. Maybe other people will interpret it differently.
I can see some great discussion coming from this thread.
It would be interesting to see a more extreme nocking point too high and too low maybe.
Again, thanks for posting.
I appreciate the time, work and expense of these videos.
Del
PS WHAAAAAAA :o I've just seen the dry loose slo mo. Superb... a must see!
This has to be post of year!
-
Thanks Tuomo, I have been hoping for slow motion vidios of primitive bow limbs for a long time. A little faster frame speed might be better but yours are still good to watch. I like the 3 at the bottom with the dry fire, 1000 grains and 350 grains. It does seem to dispel the arguement of limb timing.
-
Thank! Yes, it is ok to deliver the link.
Badger - frame rate could be higher but then resolution would be lower. I like more resolution is better because then you can see all the phenomenon more clearly. Then, one problem is light - you need every light possible, and more. For example, the apple video, there were about 4 kilowats of halogen lights directed to the apple, barely enough. And then, those Youtube-videos are quite bad quality, they are compressed to about one percent of original size.
I have filmed thumb ring release but I have to edit and upload them to Youtube, so please wait. What I can tell is, that bow hand motion is NOT the solution. Bow hand is moving but after the arrow has passed riser of the bow.
One project is filming and calculating the acceleration of the arrow (and dynamic "draw" force curve). It will be interesting to know, how different weigth arrows are accelerating.
Here is mandarin shot with judo point, useless but fun...
-
This is way cool !
Thanks
Guy
-
Very cool!
-
Very interesting videos Tuomo, thanks for posting these.
-
Thanks for posting the videos ,Tuomo! Very informative and fun to watch.
Is there a reason your arrows are nocked backwards to convention, with the cock feather facing the bow?
-
Lostarrow - yes, I like to nock cock feather in. One reason is these videos. As you can see, arrow clears the handle very well. When the cock feather is out (as it "should" be), there is possibility that hen feather is touching my bow hand. Arrow nocking point should be as low as possible and it can be lower, when cock feather is in.
As a matter of fact, the significance of this is very minor. Just one subject matter about to talk in competitions or shooting events!
-
Awesome videos Tuomo.
At 65 years old, all I do these days is slow motion archery. :)
Jawge
-
Those videos really are great.
I particularly like the videos demonstrating the difference in arrow making it past the bow at different brace heights. There was a significant difference between 12 cm and 16 cm.
Patrick
-
Great to see the "out of tiller" video - how was the handshock from that bow?
-
The behavior of the bow limbs is something we have not fully understood without the high speed photography. Thanks for posting the two videos of shooting a heavy arrow and a light arrow. The bucking limbs on that light arrow really show what happens when that stored energy is released.
I would really like to see the difference in limb behavior between FastFlite string and normal Dacron like B50 when shooting a light weight arrow. Recently there was some discussion about whether FF or Dacron would be easier on the limbs due to the difference in stretch. My theory was that the stretch of Dacron would dampen the limbs, but the other side of the coin was argued that the FF would not allow the limbs to "buck". Maybe a pair of videos on just this subject would set this to rest?
Thanks for posting on here. Your contributions to our art and craft is much appreciated. Good luck with your book, if I read Finnish, I would certainly pre-order one right now!
-
Those videos are great , thanks and hope to see more.
-
ooh cool stuff! I subbed. I would like to see different types of grips. I noticed that the thumb ring and the three finger caused the string to jump to the side when released. What about pinch grips? Some NA style grips?
-
Great stuff!! You've been very busy. Will watch more when I have more time. Good luck w/ the book. If you've been making bows for 15 years you must have started when you were 5 as young as you look. Thanks for sharing. Cheers, dpgratz
-
JW_Halverson, yes, I really want to see how string material is affecting bow limb vibrations. I have Astro Flight and Dacron, so I will make the comparison when I have time, I hope soon!
One thing I want to see, is how different spine bare shafts are behaving.
Bowtarist - born -77, not so young...
-
I would be very interested to see how molly style bows behave when shot compared to say a pyramid. Eg. how much the limbs buckle when shot. I would also dearly love to see what's going on with some of my hornbows when shot. I have a feeling that reflex/deflex bows/mollies have an advantage in speed over straight,whole limb bending bows because of their resistance to buckling when the string hits brace height after being shot.
-
Great stuff indeed! That is something I have wanted to do for awhile. It is like taking a microscope to archery. I love the inquisitive approach to it along with the stuff blowing up cool factor videos. Would be great to see your book in English.
I would love to see the difference in recovery of parallel vs tapered wood arrows.
-
I would like to see some very light flight arrows shot. For some reason I have to nock the very light arrows much higher than I would shooting a target arrow or I get the porpoising affect. Maybe 3/8" higher.
-
This high speed photography has great potential to show WHY things work the way they do. It can be an excellent tool for proving or disproving a lot of old wives tales!
-
This high speed photography has great potential to show WHY things work the way they do. It can be an excellent tool for proving or disproving a lot of old wives tales!
Careful with such fancy new Tech! It's likely to TICK OFF some of those old wives!!!
OneBow
-
Mikekeswick – the buckling of the limb is just residual energy of limbs. Dynamic draw force curve of the bow is telling more of the dynamics of the bow. Hopefully I can soon film acceleration of different kind of arrows. Or, filming is easy but analyzing is laborious.
Carson – I will film parallel and tapered arrows too. We have here in Finland now winter, which means that we have very little daylight. And I need more light to film arrow flight from bow to target. It will be interesting to see how bareshaft arrows are behaving.
Steve – I am flight shooting fan (personal best 300 yards with 52# bow)! I have a couple of flight bows, very light flight arrows, so I can try it. My lightest arrows are about 200 grains and my flight bow is about 60#. Could the reason be positive tiller? You should try it zero or even negative tiller.
-
Great videos! I'm glad that someone finally disproved the myth of uneven limb timing - thank you!
-
Great videos! I'm glad that someone finally disproved the myth of uneven limb timing - thank you!
Like you, I was so happy to learn that uneven limb timing was a myth....that is, until I began to ask JUST WHAT DOES CAUSE THE HANDSHOCK?!?!?!
-
Yes, uneven tiller is NOT the reason of handshock. Or not the most important reason, maybe a minor, depending on situation. That particular bow had no handshock - it was elm, about 42# @ 27".
Please, you have to wait a moment, I have new material of unbalanced bow limbs!
-
There is some new slow motion videos in Youtube. I was comparing string material differencies (Dacron and Astroflight).
I think, the best was this: http://youtu.be/GuvGkApgsm4
Release without an arrow and without gripping the bow. The bow flew about 3 meters away!
More is coming later!
-
I love the way the bow sort of moonwalks off doing it's own funky thing ;D
Del
-
I love the way the bow sort of moonwalks off doing it's own funky thing ;D
Del
;D ;D ;D
-
Bump to review the comparison of Dacron versus FF.
Does this prove that non-stretch diminishes handshock?
-
AWESOME!!! Thanks for posting and doing all the hard work for us Tuomo ;)
I may be stating the obvious, but per the out of tiller vs good tiller vids and the limb timing myth, did anyone else notice that the out of tiller bow actually rotates during the loosing of the arrow?? There's actually quite a bit of it when you compare to a well-tillered bow in the other vids. Not sure I see how that could cause the hand shock, but it may be it.
-
Wow! Lots to think about. This is hurting my head :-\. Thanks for the post.
-
K-hat - you are absolutely right! See this: http://www.youtube.com/watch?v=8pYVmrWzTP8 Same bow but tiller is much more unbalanced, plus there is 1500 grain weight in upper limb. The bow is rotating.
Hand shock is purely the residual energy, "waste" energy of bow limbs. Efficiency of the bow is depending quite many variable - limb mass, tip mass, etc. You can see how the bow is jumping forward.
-
How about a vid like the one where you let the bow fly forward, but with at arrow instead of dry fire. I'd love to see the comparison w/ arrow vs w/o. I know, easy to make the request lol
-
Another request :) ... Would love to see comparison of long and short arrow paradox. Short arrow being proper spine and cut to archers draw length. Long arrow being a 3-4" longer than draw length but also with proper spine, so stiffer than short arrow.
Great work. I am still not sure which looks better for limbs the dacron or fast flight. ???
-
Same thing happens when you let the bow go with an arrow. I was experimenting with a loose grip - a bit too loose. Bow flew about 5 yards from me and stuck perfectly upright in the mud. Was a little bit hilarious. It might fly a bit further on the dry fire.
-
I have been looking for this kind of stuff for a while. This is perfect! I just browsed your channel for about 5 minutes and have already learned a ton. I feel like this will greatly advance bow-building knowledge. Also seeing that arrow pass through that plum was pretty sweet!
-
thanks for the serendipitous experiment Bubbles! That's what i figured, i was curious as to how much energy difference there was w/ vs w/o arrow. I would have expected a bigger difference, however. ???
-
Yeah, I was surprised by how far it went. Maybe its a sign that my now isn't very efficient. :(
-
There is some new slow motion videos in my channel: http://www.youtube.com/channel/UCmVczwYUfq6sQQjCmKd2q5Q
Limb vibrations with different weight arrow, unbalanced tiller, etc. Just old stock, I had now time to upload those in Youtube. Now I don't have camera until April, and no new videos waiting. But I have ideas what I want to film and see, when I will hopefully get the camera again!
-
I have loaded the last 29 videos on Youtube. A lot of flying arrow and a few flying bows too...
If you have any questions, please ask!
-
Thanks !!!!
-
Great, now I need to purchase a high speed camera to see if my arrows are tuned properly.