My first bow - Questions

[ColonelSandersLite]

Well, it's actually my second, but it's the first to survive shooting anyways   .

Layout:
 

Full Draw:
 

Same with some idealized lines for reference:
 

Some detail shots (please forgive my crappy camera):

 
 
 
 

It's drawing 42# @ 26" (40 was my goal).  Material is quartersawn red oak from menards.  Backed with Drywall tape for safety and a thin layer of unbleached muslin to hide the tape.

So, questions:
1: I'm new to archery (only been at it a few months), and this bow was a 12 pound increase in draw weight over my previous bow, and it's also a different design (the old one was an english longbow, I didn't make it).  Would the increased hand shock I'm noticing be due to those differences or is it a problem with my tiller or tip thickness or something?  I'm afraid I don't have enough experience with bows to really say if it's a lot of hand shock or it's really just a little.  All I can say is that it's more.

2: From my research, I know that these mollegabets perform best when the tips are as light as possible.  Are mine too thick or about right?  This is my only working bow at the moment, so I'm not really willing to risk going overboard on thinning the tips down, but if someone with more experience than I have wants to give me some safe numbers I would be much obliged.  If I had another working bow, I would be more willing to experiment...

3: Pretty much everything I can find in regards to handle thickness pertains to bows with a cutout arrow shelf.  Conservatively, how thin can the handle be without one?  I don't have an interest in bows with a cutout, and the current handle just feels too thick to me at the moment.

4: I would love to hear any constructive criticism by more experienced bowyers than myself.

[macbow]

If your experiencing hand shock your right it has a lot to do with the tips weight.
I have not made this design but tip weight always adds hand shock. Doubt you could do any better with the red Oak.

The handle doesn't look bulky.

[KenH]

From the Mollegabets I've built, it looks like your tips are longer than optimal and the flat limbs shorter. I'd have made the levers 10.75 or 11 long and the flat limbs correspondingly longer.

That aside, I think your tip levers are still 'way too wide.  If I read your drawing right the levers are 3/4" wide tapering to 5/8".   I would have made them closer to 5/8" at the step down tapering out the 3/8" at the tip.

I have a 48" tip-to-tip Mollegabet that was a gift from a builder in Michigan, which is solid Red Elm, and the levers taper out to about 1/4" wide t the tip.

Otherwise, I think you'e got a good looking bow there.  Great first try!

[monterey]

You are definitely on the right track, IMO.

I think your outboards are way too thick and agree that they are a bit too long also.

that said, I've built only one molly, also a red oak board,  but the biggest take-away for me was discovering how very little wood is needed to keep those tips from bending.  The levers went from 3/4" wide down to just under 1/4" and it took only 3/32" to 1/16" additional thicknesses to keep the levers straight!

[ColonelSandersLite]

Originally posted by macbow:
The handle doesn't look bulky.

Maybe on the handle, I'm just spoiled by my previous bow.  Its handle was 1.25" wide and 0.75" deep, though it always felt overly squarish to me.  Looking around, I did find a new source though, and in that thread, he got away with a 0.75" wide 1.25" deep round handle.   http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=002064;p=2   I need to read that thread more carefully and in more detail, but it looks like I could thin my handle down by about half and be fine?


 

Originally posted by KenH:
From the Mollegabets I've built, it looks like your tips are longer than optimal and the flat limbs shorter. I'd have made the levers 10.75 or 11 long and the flat limbs correspondingly longer.

Looking around at your posted bows (I very much doubt I've seen every bow you made, what I did see where some pretty high quality bows though), you seem to make substantially shorter bows though.  I would think that with the already short working limb of the mollegabet with such a short bow, biasing the proportions towards the working portion of the limbs would just make good sense as far as load distribution goes.  In the research portion of this project, I came across the idea that static limb length + fade length should be equal to working limb length for a full length bow in at least a few different places.  I'm not saying you're wrong here, it's very possible that my varied sources are a case of finding people on the internet repeating info that's wrong from one central source.  Regardless, it's too late to change it now   .


 

Originally posted by KenH:
That aside, I think your tip levers are still 'way too wide.  If I read your drawing right the levers are 3/4" wide tapering to 5/8".   I would have made them closer to 5/8" at the step down tapering out the 3/8" at the tip.

I have a 48" tip-to-tip Mollegabet that was a gift from a builder in Michigan, which is solid Red Elm, and the levers taper out to about 1/4" wide t the tip.

Originally posted by monterey:
that said, I've built only one molly, also a red oak board,  but the biggest take-away for me was discovering how very little wood is needed to keep those tips from bending.  The levers went from 3/4" wide down to just under 1/4"

So, I got to thinking about this, and ended up puzzling over how in the world a 1/4" tip is possible with a string that's about 1/8" thick.  Now that I've thought about it some, I'm suspecting that the real culprit here just might be the style of string grooves I went for.  See, my previous thinking was, my string is 1/8" thick, meaning I need at least a 1/4" of wood to cut into to fully seat it and I would need at least another 1/4" of wood to hold the string.  Add an eighth for safety and bob's your uncle. But looking around, it seems that this style of tip may fit the bill better:

 http://s984.photobucket.com/user/isaacscr/media/Pyramid%20Red%20Oak%20Board%20Bow%20Build%20Along/HPIM2903.jpg.html

That would certainly allow me to thin the tips in width *substantially*, even if I like the way the current tips look better.  So the real question here is, can I still modify the tips in that fashion since there's already oil finish or is it just too late?  I figure that I should be able to shave down the backing at the tips and still have a nice gluing surface.  Then again, I would have to be pretty careful doing this, and it might be better writing that off as a learning experience.

 

Originally posted by monterey:
and it took only 3/32" to 1/16" additional thicknesses to keep the levers straight!

To clarify, do you mean thickness in addition to the thickness of the belly of the bow right before the fade?  You didn't mention poundage or bow length either.  But, assuming that clarification is correct and it's a comparable or stronger bow, would you say that belly thickness just before the fade + 1/8" would be a suitable conservative tip thickness? 3/8" + 1/8" would be 1/2".  Even without thinning the static limb width wise, that would be a mass reduction of 33%


So, keeping in mind this is the only working bow I currently have and really don't want to screw it up do you guys think this is a reasonable fairly conservative course of action or is it maybe too much:
Alter the tip width to 3/8" and smooth out the taper
Thin the depth of the static limbs down to 1/2"
Fit the tips with an overlay and carve new string grooves
See how it shoots from here

If that's a workable plan of action, without doing the full math on it, that would be something like a 40% reduction in mass on the static limbs and should make quite a difference I would think.


 

Originally posted by macbow:
Doubt you could do any better with the red Oak.

Originally posted by KenH:
Otherwise, I think you'e got a good looking bow there.  Great first try!

Originally posted by monterey:
You are definitely on the right track, IMO.

Hey, thanks.  I think I can do better   .  I did expect a few learning experiences, given that I'm so new to doing this.  Other than what we're already discussing, the biggest mistake I made here is that I misread my layout marks and accidentally carved my temporary string grooves where the permanent grooves where supposed to go.  This was supposed to be a 71" bow  :( .  Didn't even notice until after I got the first coat of finish on it and was double checking all my measurements after the fact to make some diagrams.

[monterey]

   
 So, I got to thinking about this, and ended up puzzling over how in the world a 1/4" tip is possible with a string that's about 1/8" thick.

I did mine by putting a small overlay on the back of the limb and notching only the overlay for string nock. The string loops layed alongside the limb edges.  I tapered the sides of the limbs slightly to be narrower at the bottom.  There were no ill effects.  The tips are the least likely place that your bow will fail unless you do something way to drastic out there.


 

To clarify, do you mean thickness in addition to the thickness of the belly of the bow right before the fade?  You didn't mention poundage or bow length either.  But, assuming that clarification is correct and it's a comparable or stronger bow, would you say that belly thickness just before the fade + 1/8" would be a suitable conservative tip thickness? 3/8" + 1/8" would be 1/2".  Even without thinning the static limb width wise, that would be a mass reduction of 33%

The bow I built came in at 29# at 28".  Not sure how close you are on your calculation, but it would be a good starting point wherein you may go even thinner from there.  Frequent visits to the tillering tree would provide your answer.

As your outer limbs are now, think of them as each being an additional arrow on the string that must be propelled forward by the working portions of the limb.  IOW, the mass out there is going to have the effect of shooting two or three arrows out of the bow at once.

The extra mass in the outer limbs definetley have a "cool" factor, but in the end, the ancients who designed the originals were only interested in food and protection.    
 

So, keeping in mind this is the only working bow I currently have and really don't want to screw it up......

Well, there is such a thing as being too protective of the project.  Go ahead and make mistakes.  They are going to be your best teachers!

[KenH]

My 48" Mollegabet uses pin nocks, not side nocks.  The nock is 1/4" wide at the base, 1/2" back-to-belly, and the pin is a whopping 3/32" wide.

I don't think I've ever showed one of my Mollegabets here at TG.  They were on one or more "primative" sites 6 or 7 years ago.

[ColonelSandersLite]

Alright, based on the feedback here, I've got a plan of action.  I'll most definitely post some pics once I see how it shoots.  It probably won't be until this weekend or early next week that I get to actually act on it though.  My "workshop" for this project is my back yard, and it's currently covered in a 3" thick white blanket of snow.


   

Originally posted by monterey:
Well, there is such a thing as being too protective of the project.  Go ahead and make mistakes.  They are going to be your best teachers!

Well sure, but let's just say I'd be feeling a little more adventurous about it if my old bow hadn't lifted a splinter and sunny days where more common here this time of year.  If I had a bow to fall back on, it would be no problem to break the one under construction.  If I had more good weather and longer days to take advantage of, the choice between working on a bow and actually shooting one on a given day wouldn't be such a big deal either.  As it stands though, breaking my only working bow would probably make me stop shooting for a few weeks minimum.


   

Originally posted by KenH:
My 48" Mollegabet uses pin nocks, not side nocks.  The nock is 1/4" wide at the base, 1/2" back-to-belly, and the pin is a whopping 3/32" wide.

Unless I'm misunderstanding what a pin nock is, that would mean the string could be no thicker than 5/64" to fully seat.  My string is over 1.6X as thick as that.  I also don't feel anywhere near adventurous enough at the moment to try a string nock only 3/32" wide.  Though, once the weather has cleared and I have a couple more bows under my belt, I may well come back to this bow and see just where the limit actually is.  That sounds like a fun experiment to me anyways.  In the meantime, I'm pretty sure I should go with carving the string groove into an overlay.

[monterey]

I understand, my shop is the patio and a corner of my unheated garage.  A oak board pyramid sits in the corner waiting for an end to cold days as well as holidays!  

[ColonelSandersLite]

edit: ignore, I goofed here

[ColonelSandersLite]

Originally posted by monterey:
A oak board pyramid sits in the corner waiting for an end to cold days as well as holidays!    

A little ot here but, have you made a few of those? What dimensions would you recommend to get a 35# or so bow?  Having seen my shiny new bow, my father is thinking about trying his hand at making a pyramid bow.  I think he's seen mine and thought to himself, "how hard could it be?"

[mikkekeswick]

The handshock you are feeling is nothing to do with big tips. The tiller is out in your full draw picture.
I highly recommend making yourself a 'tillering gizmo'. Get your limbs bending correctly (elliptical tiller) and weaken the upper limb as the lower is bending too much.
Seriously don't worry about your tips for now - they are not the cause.
For sure reduce them down after you've got the tiller dead on.
An extra 1/16th thickness is all you need on the levers AND they should be thinning towards the tips. Stress reduces the closer you get to the tip.

[ColonelSandersLite]

Good feedback!

I've read elsewhere that handshock is primarily caused by either the tiller difference between top limb and bottom, or a mass difference between the two limbs.  In essence, one limb ends up moving faster than the other, and that's what causes the shock.  I have also been lead to believe that excess mass will exaggerate, but not actually cause, hand shock as well.

One clarification that I would make is that the upper limb is, in fact, bending more than the lower limb.  Unless perhaps you meant that the lower portion of the lower limb is bending more than the upper portion of the lower limb.  Is that what you meant?  I can see that in the photo, but it was not so apparent by the eye.

If that is the cause, I'm not going to do anything about it on this bow. The bow is at its target weight and I'm just not willing to whittle and work it down until I end up with a toothpick.  If that means I have to live with some hand shock, then that will just encourage me to make my next bow sooner.  Honestly, I didn't expect perfection on my first bow.  I may however be able to slow the faster limb via the addition of a small counterweight, or maybe even just changing where I'm nocking my arrow.  Hmm....


On your advice, I've looked into a tillering gizmo, and it looks handy!  I do see a major downside to it though, especially as it pertains to this sort of bow with its constant width working limbs.  The problem?  It only measures the curvature of the belly of the bow, whereas the back of the bow is the more critical side.  On a working limb with a constant width, that regulates its bend solely via a tapered thickness, that error may be quite significant.  If you like, I can draw a diagram of why this is.

Edit:  That last paragraph may have been the ranting ravings of my inner madman that I should not have allowed to post at 4:00 in the morning.  I'll have to think about that more.

[monterey]

Originally posted by ColonelSandersLite:
 

Originally posted by monterey:
A oak board pyramid sits in the corner waiting for an end to cold days as well as holidays!      

A little ot here but, have you made a few of those? What dimensions would you recommend to get a 35# or so bow?  Having seen my shiny new bow, my father is thinking about trying his hand at making a pyramid bow.  I think he's seen mine and thought to himself, "how hard could it be?" [/b]

Most of the pyramid bows I've done have been kid bows so I would hesitate to offer up a suggestion on dimensions for an adult size bow.  The one in the corner is destined for adult size but have not settled on final length yet.  

I would suggest though that he get a good quality board and go with a handle in the eight inch range, maybe a bit more, and plan for an overall length of about 70".  This leaves him room to shorten it up a bit.  

The width on my ongoing is 2.5" with an eight inch long riser/handle section and the Thickness is a full 1/2" with length at 70".  My plan is to take it from there to see what the weight is at those dimensions.  

He should just go ahead and build it.  His final results will be his guide for future builds.  Also, keep in mind that predicting weight with all wood one piece bows is not as predictable as glass and wood lams.  The nature of each board is going to be different.

The general rule of double the width, double the weight and double the thickness, octuple the weight will apply to any given board, but specific dimensions will not always apply one board to the next.

[George Tsoukalas]

The feeling of hand shock is very subjective. You said this is your first. To what are you comparing your bow?

Typically, bows that are out of tiller show poor timing where the limbs do not return in unison, and when the last 6 inches or so are exceptionally thick contribute to shock. Thick nocks may result in loss of cast but hand shock...I don't think so.

I never made a mollie so I don't see how it is out of tiller. Can someone explain?

Jawge

[George Tsoukalas]

Also,  a bow that bends too much in the handle may be shocky. Jawge

[mikkekeswick]

On your advice, I've looked into a tillering gizmo, and it looks handy! I do see a major downside to it though, especially as it pertains to this sort of bow with its constant width working limbs. The problem? It only measures the curvature of the belly of the bow, whereas the back of the bow is the more critical side. On a working limb with a constant width, that regulates its bend solely via a tapered thickness, that error may be quite significant. If you like, I can draw a diagram of why this is.

When we talk about tiller we are talking about the curvature of the limb as a whole. I don't see what your point is when making a distinction between the back and belly bend.
Trust me on this point as i've made more than a few of these bows! Your tiller should be an elliptical bend - yours is too close to an arc of a circle. A circular tiller is appropriate for a bow with no thickness taper eg. a pyramid bow. your bow has parallel width 'working limbs' therefor it has to have a thickness taper. As wood gets thinner it can bend further. So your bow should bend only a little out of the fades with the degree of bend increasing as you progress along the thinning limb.
Your goal on a first bow shouldn't be hitting target weight it should be getting a perfect tiller whether that be 50# or 5#  

[ColonelSandersLite]

Originally posted by George Tsoukalas:
The feeling of hand shock is very subjective. You said this is your first. To what are you comparing your bow?

The first I've made and shot, not my first bow.  My first bow (now dead) was a 72" 35#@28 red oak english longbow that I didn't make.  Sadly, it is my only other point of reference at the moment.

I've only been shooting a few months, and less than I would like at that due to the sucky weather here this time of year.  In that time, I've met probably 50 or so local compound shooters two olympic recurve style guys, and exactly one other really traditional shooter.  If I knew some people around here who did this stuff, I could get some people who are more knowledgeable to actually shoot my bows and maybe try out a few other bows to get some more points of reference.  I'm sure there are others around here who have had the same experience.

Edit: Also, no bend in the handle here.  I want to try that soon though.  Maybe my next bow will be a fully bending elb.

[ColonelSandersLite]

Originally posted by mikkekeswick:
Trust me on this point as i've made more than a few of these bows! Your tiller should be an elliptical bend - yours is too close to an arc of a circle. A circular tiller is appropriate for a bow with no thickness taper eg. a pyramid bow. your bow has parallel width 'working limbs' therefor it has to have a thickness taper. As wood gets thinner it can bend further.

Hmm...  That's an interesting point that I had not considered.  You may well be right, however, that would be a *design* mistake, not a mistake in the actual carving of the tiller as I intended it to be circular.  I don't think a tillering gizmo will help there.  Unless I'm misunderstanding the gizmos design, it can only produce circles.

Admittedly, I didn't quite perfectly meet the design goal of a circular tiller on the bottom limb though.

 

Originally posted by mikkekeswick:
Your goal on a first bow shouldn't be hitting target weight it should be getting a perfect tiller whether that be 50# or 5#    

We're going to have to disagree here.  My primary goal, above all others, is to be able to shoot.  To meet that goal, the bows I'm turning out at the moment have to be functional.  Once I've got a few functional bows on the wall, I can switch my focus over towards perfection at the exclusion of all else.

[ColonelSandersLite]

Crap.  Got a little too aggressive with the rasp thinning the static limbs, and they're not too static anymore...  That's what I get for being in a hurry.  All I can think to do is back them with about 1/4 inch of wood, then thin them back down again, very carefully this time.  Not ideal, but might work.  Either way, I think I need to start my next bow sooner rather than later.