Starting the next tri lam

[Zradix]

I HAVE NO IDEA.

Sorry bud..I've heard of some people doing it. I've never tried doing it myself.

just seemed about like the only option I could think of ,giving how thin the belly is, to make much adjustment to weight or tiller.

I'll tell ya right now...I'm no authority on bow making.
...unless you want to know how to break a few..lol

[Ice Mike]

Hmmmm...i know the glass guys do side tillering almost exclusively, but glass doesn't require as much thickness to width ratio being more flexible. Just not sure if it would be a great idea or not with wood.

I guess I could always just trap the back more to drop weight if need be. I did that on the last one to get past a popped splinter and it dropped the weight 8 lbs!!

[macbow]

Looking forward to seeing what weight you get. Adding sinew should add considerable weight.

The glass guys really want to hit weight without removing much material . It's all in the formula.
Side tillering is a last resort.  Trapping second last.

[LittleBen]

You've got time now anyway to think about your tillering approach cause that sinew will take a while to dry. Probably a month or more to get fully dried.

[Zradix]

really..wow..
had no idea it took that long.

[Ice Mike]

Originally posted by LittleBen:
You've got time now anyway to think about your tillering approach cause that sinew will take a while to dry. Probably a month or more to get fully dried.

Your right Ben with hide glue. I used TBIII. It will be ready for tillering in about a week. I say this one from experience because my last tri-lam was ready for shoot-in (sinewed it after tillering) after a week and its still doing great and tiller hasn't changed a bit. It will probably still gain some weight but not too much. Definitely not as much as it would with hide glue.

I didn't really add it for extra weight, just extra protection.

[LittleBen]

Originally posted by Zradix:
really..wow..
had no idea it took that long.

Depending on how much sinew you add, especially with hide glue as IceMike pointed out, it can take a long long long long time.

I had one that I dried for a month+, tillered to 45#, came back another 2-3months later and the bow had gained another 1/2" reflex and jumped to 56# .... where it began to fret, was retillered back to 45ish# where it now stays. So it can be way more than a month.

It makes sense when you consider that once the outer surface of the sinew gets a bit dry, I'd imagine much of the water from the sinew below the surface goes right into the wood where it takes a while to come out. So what I mean is you're not just waiting for the sinew to dry, but for the wood to dry again too.

[Zradix]

I understand Ben. Thank you.

like ya say.. the surface dries and more or less seals in the moisture for a while.

That must've been a surprise when your bow changed that much..jeesh..lol

[Ice Mike]

Ok guys I'm having a little hysteria here. I think I'm going nuts...

I started doing a little preliminary long string pulling on my my tri-lam this evening.

     


I got it moving about 6". I decided I'd try to keep the limbs even from jump street so I put a 4' level on top of the bow.

     

I though I would be smart and use my caliper to measure the distance along the tick marks I made on the level on both sides to ensure the limbs were bending evenly. I did this for a couple of scraping sessions. I was getting 2.3" deflection on one side and 2.6" deflection on the other at the same distance down the limb measured to the bottom of the level. I decided to turn the bow around on the tree to make sure that my long side moved...IT DIDNT!! I put the calipers on the riser block and measured every point I could and found that I had ground the back of the riser block a few hundreths out of square. I pulled all the points and marked it up and brought it to the belt sander and corrected that issue. I put it back on the tree and I still have the same issue. I don't know why it's giving me false readings but it is. The left side limb always measures longer no matter how I put the bow in the tree. I checked level from every angle on the tree itself..I just don't get it..

Should I just tiller it by eye?

Also, I'm at 55 lbs. at 6" inches right now so I gotta drop some serious weight. You guys had mentioned I might have that issue with the core being too thick and the belly too thin so my next question is...Do I start side tillering if I start getting too thin on the belly? I don't mind if the bow comes in at 60 or so (It's for myself anyways) but I'm not sure if this wood combo can handle that kind of weight at 1.5" wide..any suggestions? If I should start side tillering at some point, what is the best method to begin on that? Bring the taper back to the fades instead of mid limb?

Here is a pic of the bow drawn to 6" on the long string. I don't want to draw it too much further because, like I said, I'm hitting close to 55 lbs. right now..

     

Thanks in advance for any help!!

[macbow]

If your 1 1/2 at and past the fades I'd start there maybe a couple of inches past the fades bring it down to at least 1 1/4'wide.
At first I would leave it wider at the fades because all your bending looks to be in that area.

Have you heard of the tillering gizmo that Eric K designed?
Make one, look it up on TG.

Since you added the sinew no way to thin back but maybe trapping if needed.

[Ice Mike]

Thanks for the advice macbow. I have heard of the gizmo and have made one..but I have a question on that. Since the profile of this bow is reflex/deflex, should I be shooting for a circular type tiller that the gizmo would produce? I was under the impression that I should be looking for more of a Holmegaard or elliptical profile tiller. Is my thinking on this wrong?

[Black Mockingbird]

#1. Shorten up your long string to where its pretty much touching the handle

#2. One limb is stronger than the other,and that's why it doesn't change when flipping it around

#3. Take the levels off and don't tiller by the distance from them...

#4. Since you did your thickness backwards with the core and belly,and have lots of weight to reduce you might lose too much of the belly(IMO you already don't have enough),and it could cause the belly piece to become overpowered and fret,and eventually fail possibly...if you lose to much you will have to take the while belly piece off,and then take some more thickness off of the core to where its no thicker than 1/8"...I taper my cores thickness 1/8"-1/16"...and then glue on a thicker belly lam..on tri lams I prep my belly to 3/8"-1/4" thickness taper(on standard normal bows)

#5. Sinewing that was a waste of time IMHO...and you just added to the complexity,and put in more work than needed and necessary...next time just use a proper grained and chosen backer...

When first getting into wood bows its best to keep things as simple as possible,and learn the basics..learn how to walk before you try running...and that's about as short as I can make my post ..although I feel like I could write a small book mentioning and explaining everything thoroughly

[LittleBen]

I think Black Mockingbird is onto something.

I would not side tiller, I can guarantee you cannot reach your target weight by side tillering.

I would tiller on the belly ... just scrape away, and if you remove too much belly wood and go through the belly lam, then so be it. (this is almost certainly going to happen). In that case, tiller to maybe 10-15# BELOW your target weight, but make sure the tiller is very good, take your time.

When you're done tillering your bow will be very underweight.

Then add a new belly lam of maybe 1/8" or so, and recheck tiller. Make tillering adjustments as necessary.

This will get you proper tiller, and sufficient belly lam thickness, but will take a substantial period of time.

[Ice Mike]

I've got it on full brace and pulling to 52 lbs @ 21". Here is a pic of the tiller up to this point.

   

It looks a tad off to me but I'm not quite sure if it's my eyes playing tricks on me or it's really a tad off. Where do you guys think more wood need to come off?

[Roy from Pa]

Looks pretty even to me, I would just remove wood evenly on both limbs. Do you have a positive tiller in mind or how are you going to tiller it?

 

[Wolftrail]

She is getting there. Just go slow to avoid any hinges or cracks.

[Ice Mike]

Thanks for marking that up Mr. Roy. That makes its a little easier to see.

I'm going for an even elliptical tiller I think. I shoot 3 under.

Do I have that right. Positive tiller for split finger and even for 3 under?

[Roy from Pa]

Yup that's a pretty close assumption, Mike..

[Bowjunkie]

The reason you thought your draw weight was way too high was because of the long string. The long string gives a false reading on draw weight, and shows the outer limb to be stiffer than it will be with a proper length string on it.

I still use the long string, they can be very helpful, you just have to keep those things in mind.

[Ice Mike]

Well I'm done with wood bows I believe. I popped a splinter in this one on the backing where I had trapped it a little to drop some weight. It's fixable, but I just don't have the desire to keep babying wood to try to make it become a bow. If it's that sensitive…If it's that finicky, and it's that critical to have everything just perfect or it's going to break…which has been my experience for 6 bows so far now….Then how can I ever feel confident with one of these when I am in a stand and getting ready to draw on deer where it counts?

I'm ordering some fiberglass monday. I give up on all wood and will now try my hand at making a more reliable style of bow that has been proven time and time again…

Thank you guys for all your help during the progression of this thread. I may fix this one and finish it somewhere down the line…but the desire for building a reliable wood bow for me is like Elvis right now…It has left the building!! LOL