Author Topic: Let's Build a Trilam! (Finished pics on page 12... Refinished pics on page 13)  (Read 51326 times)

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Offline PEARL DRUMS

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Re: Let's Build a Trilam!
« Reply #150 on: January 25, 2017, 12:28:56 pm »
If I did anything, I would dust off that upper fade just a bit as A-a-ron suggested.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline ty_in_ND

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Re: Let's Build a Trilam!
« Reply #151 on: January 25, 2017, 01:01:10 pm »
Yeah, I thought I posted that thought from my phone, but I didn't hit the "post" button!  I'll gingerly scrape the fade (essentially the 6" I was ignoring when I hit the limb earlier) when I get home, put a bit on the shelf to simulate a rug (so make the arrow look "right"), and take a picture.
"The best prize that life has to offer is the chance to work hard at work worth doing."

Offline jeffp51

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Re: Let's Build a Trilam!
« Reply #152 on: January 25, 2017, 02:56:01 pm »
I would say if it shoots smooth with out hand shock, then I wouldn't fiddle with it too much beyond sanding it smooth.  It is possible to fix something to oblivion. To me it looks pretty good.

Offline ty_in_ND

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Re: Let's Build a Trilam!
« Reply #153 on: January 25, 2017, 04:27:17 pm »
Don't worry, Jeff! I had that same thought. I know from experience in my profession that there's a fine line between "almost perfect" and "... <insert favorite explicative here>" and while I would love to get it perfect, I think I'll call her good after I take a few scrapes from the top limb fade.

I didn't get a chance to leave work, so I'll get to it tonight when I get home from work.
"The best prize that life has to offer is the chance to work hard at work worth doing."

Offline PEARL DRUMS

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Re: Let's Build a Trilam!
« Reply #154 on: January 25, 2017, 04:33:51 pm »
I agree with both of you.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline ty_in_ND

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Re: Let's Build a Trilam!
« Reply #155 on: January 26, 2017, 01:27:44 am »
Well, I know it's risky business when working on the fades so late in the game (who doesn't want to deal with a hinge near the fade when the bow is close to being finished!), so I ever so slightly took a few scrapes off of that upper limb fade.  Here's how it looks now:



I think I'm going to leave it as is.  No sense in tempting fate (and the top limb is bending more, so I think mission accomplished).  After the shooting in and the adjustments to the upper limb, the bow is sitting at 49 lbs.  Not ideal, but not the end of the world.  Since I haven't posted these in a while, here's the braced and the just unstrung profile pictures:





I'm still waiting to hear about the leather dye (in the hopes it could get here on the early side), but at the least, I can start getting her sanded down and get a preliminary coat of something on the belly so that I don't have to worry about dye getting on other parts of the bow (maybe not a huge concern since I'm using a dark colored core wood, but good practice in any case).
"The best prize that life has to offer is the chance to work hard at work worth doing."

Offline stuckinthemud

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Re: Let's Build a Trilam!
« Reply #156 on: January 26, 2017, 05:33:06 am »
looking really good  :)

Offline PEARL DRUMS

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Re: Let's Build a Trilam!
« Reply #157 on: January 26, 2017, 08:00:54 am »
Get her sanded and sealed, Ty. Its a wrap.
Only when the last tree has died and the last river has been poisoned and the last fish has been caught will we realize we cannot eat money.

Offline Aaron H

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Re: Let's Build a Trilam!
« Reply #158 on: January 26, 2017, 09:29:26 am »
Yup, that's looking right nice now.   Great job Ty.

Offline Springbuck

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Re: Let's Build a Trilam!
« Reply #159 on: January 31, 2017, 12:56:14 pm »
I was just wondering if the high nock point was making the lower limb bend more. But something in my brain says it's the other way. Help?

DC, "read my wall of text" post above.  It addresses that.

Offline DC

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Re: Let's Build a Trilam!
« Reply #160 on: January 31, 2017, 01:28:31 pm »
I can't find it, can you post a link?

Offline ty_in_ND

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Re: Let's Build a Trilam!
« Reply #161 on: January 31, 2017, 01:44:30 pm »
  Here is what happened and I MISSED IT.  I was watching this thread, but you had plenty of help, so I wasn't thinking too hard as I read.

  You were tillering with the bow held flat and level, fairly securely balanced on two points above and below the throat of the grip.  That is the actual point of pressure from your hand, on the bow, when drawing.  Look at the full draw pic and you'll see your hand is pushing into the bow right in the deepest part of the grip and for a couple inches below onto the palm swell. If you tiller using that point as a fulcrum, the hook on your tillering string should be opposite the upper end of that zone.

Every bow has a physical middle, as measured tip to tip with a ruler, divided by two, right?   Every bow also has a DYNAMIC middle, where the forces pushing the bow forward and pulling the string back are balanced, nearly opposite each other.  Then, there is a balance point regarding the amount of bend, or the strain on each limb, if the bow is asymmetrical. Tiller usually has small compromises we make inherently.  You were GOING for DYNAMIC  balance close to the PHYSICAL middle, I think, but tillered to have dynamic balance ABOVE the middle, up by the arrow.  So, enough big words.......

 In this case, you were pulling the string back at the arrow, but the way the bow balanced on the tillering tree was several inches below that (maybe only 2-1/2", but maybe as much as 4).  So the pull force (string) is above the push force (grip), and the bow resting securely on two points on the tree couldn't tip to show you that.  So, that gave the string more leverage to pull against the lower limb, making it bend as much as the upper limb, despite being stiffer.  So, now you have a stiffer lower limb.

This is all fine if you plan for it, or know it's going to happen, but that is where I feel I/we failed to warn you, sorry.  The fix is simple, though. You just gotta weaken the upper limb a bit, or stiffen the lower limb a bit.  I suggest the former.

 Since the curve looks good on the tree, crayon or pencil mark the whole upper limb and scrape it clean, then check the full draw again.  This, unfortunately means your finished draw weigh will be a couple/few pounds lighter than intended.  Happens to me all the time.

Good luck.

Here you go, DC :)  And it'll be something I take into consideration in the future (the tiller tree bit).

Also, there will be some pictures coming in a bit, just a heads up ;)
"The best prize that life has to offer is the chance to work hard at work worth doing."

Offline DC

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Re: Let's Build a Trilam!
« Reply #162 on: January 31, 2017, 02:13:48 pm »
Thanks

Offline Springbuck

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Re: Let's Build a Trilam!
« Reply #163 on: January 31, 2017, 03:39:44 pm »
WHHHOOOOOOPS!  I tried to edit that post days ago, and it LOOKS like it didn't take,  I'll bold the corrections.

From my long post........ "In this case, you were pulling the string back at the arrow, but the way the bow balanced on the tillering tree was several inches below that (maybe only 2-1/2", but maybe as much as 4).  So the pull force (string) is above the push force (grip), and the bow resting securely on two points on the tree couldn't tip to show you that.  So, that gave the string more leverage to pull against the UPPER limb, making it bend as much as the LOWER limb, despite being stiffer.  So, now you have a WEAKERlower limb.

This is all fine if you plan for it, or know it's going to happen, but that is where I feel I/we failed to warn you, sorry.  The fix is simple, though. You just gotta weaken the upper limb a bit, or stiffen the lower limb a bit.  I suggest the former."

Sorry.  Anyone who read it, I was on the right track early and late, but got the concepts flipped in that one paragraph.  This is what comes of writing a long post piecemeal over several hours, while on mobile so I can only see a little of what I wrote.

My apologies.



Offline ty_in_ND

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Re: Let's Build a Trilam!
« Reply #164 on: January 31, 2017, 05:06:12 pm »
I noticed that, but I was sure you meant what you typed just now 😄
"The best prize that life has to offer is the chance to work hard at work worth doing."