BBI build along, my first backed bow

[Roy from Pa]

My reaction to IPE was instant, well I was exposed to it for like 8 hours, then my face was burnt, my eye lids and eye brows were swollen like crazy. And now my immune system is over reacting to things that never bothered me in years, and it was 3 years ago that I got the initial reaction.

[bowhntineverythingnh03743]

Your immune system is breaking down Roy because yer OLD!!! lol

I was coughing and hacking and itching for three days... all set now but haven't touched the stuff since. Got a nice ipe board too just hanging around not being used. May try to cut a thin slat from it and use it as a core someday.

[Echatham]

hows this for shape? should i move the end posts on my form all the way out to the tips? i left them short so i could get clamps on the tip overlays, but thats gonna be a separate glue up now.

[Roy from Pa]

That could work but you have to understand that when you take the bow out of the clamps, it will spring back and lose some reflex. Your going to have to experiment and see what works for you. I would move them to the end and pull down a little more at mid limb to a solid post. Just like I showed in my form pictures. You do not add the tip overlays until the bow is cut out.

[Echatham]

i do understand that it going to spring back, and i am going to put a solid post under mid limb. im thinking a piece of 2x3 on it's side. going to move my end posts out to the tips today, and install the mid limb posts. then the glue will have to dry on that, so i will maybe start getting tip overlays ready even though im not there yet.  current plan for tip overlays is 1/8" x 1/2" x 2" layers of ipe and maple, maple on top. then i think should glue the two layers together and taper them down together where they will fade into the bamboo. then i can glue the pre-semi-shaped tip overlays on as one piece, and have minimal sanding shaping to do to the fades. does that sound like a plan?

so my form will be ready to go again tomorrow, and maybe i can get the final, no foolin, dry run done tomorrow night.

Is it desirable to have the mid limb clamps at mid limb? or are should i think about putting them closer to the tips or the handle? I know those are things to expirement with for my self, but i kinda want this first bow to keep to tried and true methods and dimensions.

[Roy from Pa]

Sounds like a plan and yes put the mid limb posts at mid limb for your first one.

[Echatham]

Thanks Roy

[macbow]

Roy is giving you great advice.
Some thoughts on the mid limb post.
Toward the middle (mine are usually 16 inches from center) is good for a hunting type bow.
Moving them towards the tips is more for a target style bow.
Sort of a power vs speed thing.

I don't add tip overlays till after the bow,is almost finished.
Just put the string grooves on as needed with the tips a little wide still. Go through the whole tillering,and,shooting in process. Tip overlays are almost last. No use wasting material and time till you have a shooter.

[Echatham]

Good to know macbow, yeah I was only going to work on tip overlays so I had something to do while my glue was drying on the form.  For the sake of my curiosity, and not because im going to go for one or the other with this bow, but what do you mean by speed vs power? in my mind they are the same thing, unless... here is a question, totally unrelated to the build along...
can two bows (hypothetical bows) shoot identical arrows at identical speeds, but one of the bows perform better with HEAVIER identical arrows? for example, bow 1 and bow 2 shoot a 500 gr arrow 170fps, but with 600 gr arrows bow 1 shoots 160 fps, and bow 2 shoots 150 fps?
just something i pondered when i was pondering your meaning of the word "power"

[macbow]

I'm not going to get into talking about speed too much.
Mainly because I don't know.
But the bow with the bend towards the center will certainly handle heavier arrows better, maybe not faster.
The one,with the bend towards the tips will be faster with light arrows.
The kids,bows I build I'll sometimes move towards the tips because they are pretty light weight helps zing those light arrows well.

[Echatham]

thats pretty interesting. i only used speed because i know no other way to measure performance, i wonder if anyone has done any tests to measure the difference in performance with the curves in different portions of the limbs. just going to put mine right smack in the middle and call it good.

[macbow]

This time just make notes on where you put the blocks.
Like I said I measure from center.
Then down the road you can experiment. Mine at 16 inches from center on,a,68 inch bow,are not quite center.
But if I chop off a inch or two to make weight then they are .

[Echatham]

thats what im going to do, keep a journal, because i get the feeling im not going to be able to stop once this one is done. already thinking about the next one!

[Echatham]

wish i could work more on it during the week. i got the form adjusted and the glue is drying. I am on duty over night tomorrow, so i probably won't get to do the glue up til Thursday. thats ok, no need to rush, but im pretty excited about it.

[Roy from Pa]

Compared to having the mid limb posts centered at mid limb, the following is fact.

By moving the mid limb posts closer to the riser, you cause more of the limb to work when shooting an arrow. Thus that design will cast a heavier arrow, not necessarily faster, but the bow has more thrust to propel a heavier arrow.

By moving the mid limb posts out more towards the limb tips, you cause less of the limb to be working, and with that design it will cast a lighter arrow faster because less of the limb is working and it recovers quicker.

So basically you need to decide what style of bow you want before ya glue it up. So a happy starting point for a new bowyer would be mid limb. And yes take notes. Wish I had taken notes. Still think I should start taking notes. But I'm old and keep forgetting to leave myself a note to start taking notes:) LOL

And while I am typing, Thank You For Your Service To Our Country. ^5

[Echatham]

Thanks and you're welcome Roy, but there are no thanks required. You have all already thanked me by paying your taxes and giving me a paycheck to buy bowbuilding supplies!

[Echatham]

well before i left for work yesterday morning i threw it on my newly dry form to see what the shape looked like. I like it. not extreme curves by any means, but thats not what im going for. what do you guys think? the center posts are actually half an inch closer to the center than the tips, doesn't look that way in the picture though.  Tomorrow Im working the night shift, so i will have all day to my self, wife and kids at work and school, so I should be able to get the glue lines perfect on my power lam (i know its probably fine, but it bugs me) and get her glued up. got my unibond 800 from three rivers on monday... has anyone used it yet? what mix did you use and was that by vol or weight? it gives a "slow" mix and a "fast" mix... would i be right in assuming slow is better? also, it says 70 degrees and up for curing.... my house stays about 65 this time of year, and the basement (workshop) about 60. I plan on leaving the bow on the form for over 24 hrs anyway, so do you think 65 would be fine, or should i stick it in the bathroom with a space heater for a day, and get it up to 80 something? thats what I am leaning towards.... but it will come with complaints from my wife about "running up the bill" and leaving all my "archery crap" around    
 

[macbow]

Looking good Eric,
You will loose just a little of the bend when the clamps come off.
Be,sure to start clamping,at the middle and work towards each tip. I clamp the middle then add a couple of,spring clamps on each side. Then concentrate on the ends of the power lams with some,small c clamps. Then the mid limb clamps.

As for the temp. It really does make a difference. It will set up at 65 but will be a,little soft. I put a 100 watt light near the middle under a wire basket then cover it all up with sleeping bags.
Alternative would be to take it from the form after a,day and store it in the 80 degrees for a day.

[bowhntineverythingnh03743]

Looking great Eric. I would buy the wife a little gift for putting up with the bow in the bathroom with the space heater. The temp will make a difference in the glue curing.

When I mix up my glue I do it for the fast setting and have had no issues with it. My mixture is by weight and is as follows: 100 grains of resin to 13 grains of powder. That is what I was taught and it works so I haven't changed it since.

Use a toothing plane or a hacksaw blade if you don't have a toothing plan to put grooves in the wood before gluing. Wipe them down with a hand broom. Ipe is really oily and if you put anything on it it will draw more oils to the surface.  Make sure you coat both the boo and ipe with glue before putting them together. I put a good coat of glue on each and when I squeeze them together with clamps the extra just comes out but make sure you wrap the bow in plastic wrap or freezer paper (shiny side towards the bow) to help with keeping a clean work area. Use some sort of blocks or rubber stripping to protect the belly and boo from the clamps. Set it aside and then find something to do with your time while the glue cures. I go stir crazy waiting of the glue to set up.

Just what I have been taught with all this so far. Take it or leave it but your bow is look good... Keep up with the pictures.

Respectfully,
Justin

[vanillabear?]

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