mollegabet finishing bits [images fixed!]

[tink]

Hi All,

I'm finishing up a mollegabet (it's my 3rd bow), and i could use some thoughts from the wise ones...

It's a red oak board bow, backed with 3 layers of fiberglass drywall tape and TB3.  63 1/2" ntn.  The working limbs are ~ 1/2" thick, while the levers are about 3/4" thick.  I've got about 3 3/8" of string follow right now.

My questions are:
1. I know I need to trim the levers to get the advantage of the design, but I'm already noticing a VERY slight bend in them at 28". how much can they bend before i lose the advantage of the levers?

2. Is there a common handle type for this style of bow?

3. How's the overall tiller?

4. Is the string follow a product of the short length and the red oak?

braced
   

tiller stick @ 28"
     

full draw
     

Thanks for any thoughts!

[MoeM]

I`m not a selfbower, but the limbs seem to bend a very lil bit too much at fadeout, especially the upper. But generally tiller looks nice for my eyes...
To talk about set a pic of the unstrung is usefull- but I guess it`s mostly settled after the fades?!

[john fletch]

I agree.  The tips are too stiff and will greatly reduce the cast.  The bend is forced too close to the handle and I think one or both limbs will ultimately fail here.

[Bowjunkie]

I concur. The inner limbs are overworked, hence the string follow.

[LESKEN2011]

While the levers on this design are supposed to be stiff, it looks like they could be lightened up some which will affect speed and hand shock. That can wait till the end, though. I would get her bending a little more near the lever fades first to take the stress off the handle area.

[monterey]

A side view at rest and a frontal view would be very informative.  I've been playing with this design in oak as well but have not had as much success as yours shows.

[Black Mockingbird]

I'm gonna have to disagree to an extent...(unless you atrociously tillered it while making it)..which could be a cause too

The reasons for the string follow are first and foremost; its under designed...meaning you shouldve made the working limbs either wider or longer or both...and that's the main reason for your string follow...the second less and small almost insignificant reason is a slight bit too much bend out of the handle,but its not that bad actually for this design(pretty close actually,and good enough) because you should be getting more bend there than per say a normal flat bow because of the short working limbs,so you need to get as much of your working portions of the limbs working ...each limb should be tillered to an arc of a circle...I believe if you had designed it better and tillered it the same way you would've expereinced a healthy and normal set because the tiller isn't that bad to warrant that much set...and I've made countless "lever bows"

I'd like to know the widths of your working limbs and levers,and with a front profile pic...side view is unnecessary as we know it was a straight board to begin with

[John Scifres]

1.  Very little if any

2. I don't know.

3. Tiller looks fine to me.

4. Yes. Your set is caused by having less than 30" of working limb and it is red oak which isn't particularly strong in compression.

[tink]

Thanks for all the comments- they've been insightful.

I finished the bow up over the weekend, maybe...

the working limbs are 2" wide (and 1/2" tapered out to 7/16") and the levers are 3/4" square tapered to 1/2" square at the nock.  I shaved them down until i noticed a change in the bend that already existed, and now there's probably 1/8" of an inch of bend in the levers over the course of 14".

I'll get some  pics up tonight...

I've noticed that the set relaxes to about 2" after it's had some time to relax (though i imagine that this will change as the bow is shot in).  I've seen some mention of heat treating as a possible 'fix' for this- any thoughts?

(I know, I know- just make another one... but I want to play with ways to fix problems too!)

[Black Mockingbird]

Yuppers...your under designed...that would be good dimensions for osage, but not red oak...you only have 14" of working limb per limb and at only two inches wide isn't enough to handle the stress...hope it doesn't fret and holds up for you...you can temper it inducing a lil reflex to help counter the set your incurring...but it isnt a fix all cure all...and with it being under designed I dont know how much it'll really help in the long run after lots of shots and string time...if your going to temper it, it is best to do it before you start incurring set and or string follow..this helps keeps the wood more "healthy",and in turn snappier limbs and better braced and early draw tension...now if its closer to proper design you can temper it again after you have got it out to full draw and gain "some" benefits...its also taking a risk of ruining what you have already made as well...you could easily scorch the back unknowingly if your not careful and create a brittle back causing it to break in tension...there's always pros n cons...ya just gotta weigh which ones are best..or worst...if your up for experimenting and it doesn't mean much to ya then go for it...cus you can always make another   ...which it sounds like you already will anyways...and design the next one better  

[tink]

Here's an image of the front of the bow- not set on the purple, as i was hoping for something a bit more mellow...

 

I've backed with paper and silk... figured i'd try the fiberglass tape... don't think i'll do it again b/c it sure is ugly!

if 2" is too narrow, would 2.5" work, or is this a design that i shouldn't really attempt with the red oak? Is there a formula or some kind of guideline that considers wood density and square inches of limb or something?

Thanks!

[Black Mockingbird]

You would either have to go longer bow length(the better option),or wider limbs...I don't know of any formulas,rules or guidelines as to what your width etc. should be for a certain type bow other than experience is the best teacher..there is a wood list chart in a chapter in the traditional bowyers bible volumne one on suggested widths for a standard average 66" 50@28" flatbow design... but yes 2 1/2" would've been closer to ideal,although I would've made it longer personally...the shorter you make your working limbs the wider you will have to make them...a lot of folks say you need just as much working limb length in one limb as your draw length(which is a crock of crap mostly,and only a good general rule and guudeline for a novice,cus I've made plenty of great bows with less than half of that rule)...I think you also were a lil rough on it while tillering,which can also cause a lil more set than wanted...I forgot you had the drywall tape glued on there...so heating it up is a no no,as it'll release and ruin the glue line more than likely....take what ya learned from this one and make another...now red oak can make these types of bows,but they need to be designed right and just as importantly handled with care...I've done a couple lever bows with unbacked red oak boards,and they turned out great with minimal set and loss of my starting position...its doable,but maybe not as easy for a novice...

[John Scifres]

I have gotten away with heating backed bows.  I think I would try to toast the belly.  Here's one I did:   http://sticknstring.webs.com/fixit.htm

Don't expect miracles though.  Your basic problem will remain and you will not get the same draw weight and length unless you want the symptoms to recur.

Personally, I would not try this with red oak but I am blessed with lots of osage.  If you do, longer and wider are the only answers if you want draw length to remain the same.  I would also try to find a piece that doesn't need a backing.

[RedMan37]

Cool design tink! I'm only on my 2nd bow so I'm not much help. But I did my first with drywall tape. And yeah...mine is a little ugly on the back. But it does seem to make a pretty tough backing..even if it doesn't do much for cast. I have just applied 100% linen to my latest bow. I'm curious to see if there will be a noticeable difference in cast when I finish her. One thing's for sure...it looks much better.

[Grandpa Bill]

Linen will not help the cast of your bow...it will help it stay in one piece and/or keep it from exploding.  Only backing I am aware of that will increase cast is sinew...and I have never used it.

Grandpa Bill

[RedMan37]

Thanks Bill. I just thought that maybe it would improve cast a little due to less weight from only 1 layer applied of linen as compared to 3 layers of drywall tape. The linen has 2 layers of glue and the drywall has 3. I know the 2 different backings aren't supposed to do work unlike sinew as you suggested. I guess it'll be fun to see the difference anyway. Sam Harper suggested that having 3 layers of tape was a bit overkill possibly. But I like the extra safety of it though. I guess it's a tradeoff as with everything in archery. I'm still a newbie. So I think that I will attempt to add some reflex on my next bow. Hopefully that'll improve cast and hopefully red oak can handle it.

[LittleBen]

Personally, I'd say if you're going to make another, go antoher 2" in length at least, (maybe 4") and lengthen the working section by 4" (or 6").

So you'd have alot more working limb, a little less lever, but th elonger length should still keep as nice draw-force curve.

[scars]

On your next one I would at Have 60% working limb to 40% lever don't count the fades. You could go up to 70% / 30% if the wood is questionable. If you choose to do another red oak molly 2 inches at the handle fades 1/12 inches at the lever fades in width. 5/8 " thick at handle fades 7/16" at the tip  fade. And stay away from fiberglass sheetrock tape. At Home depot you can get a sheetrock tape called fiber fuse, once glued with TB3 it looks like a thin rawhide. If you are spending a lot of time looking for redoak go to a real lumberyard and have the staff in the dryshed order some white ash straight grain no knots you will get it in 2 or 3 days tops.