Post by: mmattockx on January 16, 2021, 01:00:15 PM
When tillering a wood bow one always has to exercise the limbs, working from a long string to brace and then out to full draw in stages. Is this done with FG bows as well or is there a different procedure to working out to full draw on the tree?
Thanks,
Mark
Post by: EvilDogBeast on January 16, 2021, 01:11:33 PM
Post by: Longcruise on January 16, 2021, 01:36:07 PM
Post by: kennym on January 16, 2021, 01:51:45 PM
Post by: Mad Max on January 16, 2021, 01:57:57 PM
I smooth the corners before shooting but no exercise needed
x2
Post by: Bowjunkie on January 16, 2021, 04:53:19 PM
Post by: Crooked Stic on January 16, 2021, 07:21:00 PM
I dont get full unless the limbs are fairly straight.
Post by: Mad Max on January 16, 2021, 08:04:49 PM
I need to get more setup like roy's tree
(https://i.imgur.com/hFWZN4h.jpg)
(https://i.imgur.com/jlR1MNl.jpg)
Post by: Roy from Pa on January 17, 2021, 05:02:58 AM
Plus gwass dust makes me itchy...
:wavey: :laughing:
Mike, Dynamic balancing is how the bow balances while being drawn on the tree or being drawn when shooting it.
Dynamic tillering is our main goal while tillering for equal limb timing.
Static balance is how the bow balances just sitting in the tree cradle.
Post by: Flem on January 17, 2021, 02:43:28 PM
Dynamic tillering is a good trick to use. I also like to try and mimmic a three finger draw with vinyl tubing over carabiners.
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Now I thinking maybe I should rig up a prosthetic arm to hold the bow and a hand to pull the string?
Post by: Crooked Stic on January 17, 2021, 04:22:14 PM
Dynamic to me is when you put tillering blocks on the bow and mat have to move one way or the other to get them without twist. Can also be done by deepening the grooves and side dressing. So start with wider width on the tips
.
Post by: Stagmitis on January 21, 2021, 06:17:26 PM
Post by: williwaw on January 21, 2021, 07:05:22 PM
is there a particular design you find works better if you build in stages?
Post by: Stagmitis on January 22, 2021, 08:26:46 PM
Post by: mmattockx on January 22, 2021, 09:12:26 PM
The only time I have excersized my hill bows is when I have built them in stages. If I build a stave and only glass the back then I draw it repeatedly while I tiller and align the string. When done I glass the belly.
What do you feel the benefits are of building in stages as you describe?
Mark
Post by: Stagmitis on January 23, 2021, 09:38:54 AM
Sometimes with a single glue up (Not always) a bow will give me fits with limb twist, string alignment and tiller right out of the gate even though I know my lams,nocks,dimensions were all as perfect as they could be. Occasionally I end up with a flat spot in the limb(not sure why) This really bugs me and even though I can correct it I feel like the bow just wont be right.
Because Hills have a deep core they are more subject to internal wood stresses especially with natural material such as Yew.
With a double glue up I can first excerise the limbs removing all stress, easily achieve string alignment and tiller and fine tune limb bend then add glass when everything is perfect. Few times Ive done this the bow seems to have a nice smooth draw and performs better.
Post by: Roy from Pa on January 23, 2021, 10:51:16 AM
What are you using for a form?
The fire hose method?
Post by: Stagmitis on January 23, 2021, 10:59:21 AM
Post by: Stagmitis on January 23, 2021, 11:01:33 AM
Post by: Roy from Pa on January 23, 2021, 11:02:51 AM
My mid limb posts are maybe 1/2" wide where the bow rests on.
I just had a brain storm here, I might grind a very slight concave surface across my mid limb posts.
Couldn't hurt and may help..
Post by: Stagmitis on January 23, 2021, 11:32:02 AM
Post by: Roy from Pa on January 23, 2021, 11:34:17 AM
Ya have pitcher of your form?
Post by: mmattockx on January 23, 2021, 11:57:45 AM
With a double glue up I can first excerise the limbs removing all stress, easily achieve string alignment and tiller and fine tune limb bend then add glass when everything is perfect.
Do you draw it to the full draw length while doing this? Do you ever see it take some set before you put the belly glass on? How does adding the belly glass change the tiller?
Mark
Post by: Stagmitis on January 23, 2021, 04:39:59 PM
Roy it could be clamp pressure even though you have a pretty good feel when tightening down the clamps. Ill get a pitcher
Post by: Roy from Pa on January 23, 2021, 05:26:43 PM
Post by: Stagmitis on January 24, 2021, 09:42:11 AM
[ You are not allowed to view attachments ]
Heres an old one that isnt in storage :banghead: On top of lams I use a 1/4" x 1.5" hard rubber strip, metal pressure strip and wood blocks running the span between clamps. Strip of glass against form that lams sit on.
Post by: Roy from Pa on January 24, 2021, 09:45:34 AM
Cool on form.
Post by: Flem on January 24, 2021, 10:48:42 AM
Thats how they did it when first experimenting with glass and other backings. I have never tried that method.
Post by: williwaw on January 25, 2021, 04:35:01 PM
Yes mark always takes set...I start slow excersizin often and eventually reach full draw.
Stag, are you able to tiller to a given weight and project what the finished weight will be after adding the belly glass? If you are willing to share a few numbers, I would like to try to see if it agrees with some calculations I have been trying out.
Post by: Stagmitis on January 26, 2021, 08:49:28 AM
I dont concern myself with weight anymore. If high, I used to trap,sand belly glass,maybe change width profile...It alters my design and reduces performance. I would rather build another than change those things to hit weight.
On a different note I was surprised the first time I did a double glueup. Without the belly glass the limb bend showed a hinge coming off the fades and the tips a tad whippy. I couldnt see this when glassed altogether. It helped me fine tune my tapers.
Post by: williwaw on January 26, 2021, 05:59:14 PM
I dont concern myself with weight anymore. If high, I used to trap,sand belly glass,maybe change width profile...It alters my design and reduces performance. I would rather build another than change those things to hit weight.
On a different note I was surprised the first time I did a double glueup. Without the belly glass the limb bend showed a hinge coming off the fades and the tips a tad whippy. I couldnt see this when glassed altogether. It helped me fine tune my tapers.
thanks for the details and observations.