Hello Guys. I got some marks from my gizmo by moving it side to side. I'm assuming I should only remove wood from the sides the gizmo marked. Cant see any twist but this should be a sign of one, even if its not noticeable yet.
i wouldn't use it in that way.im not sure you could really get an accurate reading like that. it's made to travel down the limb from fade to tip not side to side. I use mine by finding the weakest point of the limb or where it's bending most. raise the pencil till it's just not touching and then run it down and up the limb. best way to check for twist is to look down the limbs once strung or with a contour gauge
"I'm assuming I should only remove wood from the sides the gizmo marked." I'm sure others will chime in and help you out on that. I check for twist when the bow is on the tiller stick and lock in the string at say 16-18" or whatever and site down the limbs from the tips, I will always notice twist if any at this stage. I clamp the tiller stick in the vice, that way I can have a good look at it rather than using a pulley system having the bow flat against a wall or plywood.
I dont use a gizmo, I use a tape measure for final tiller when its at full brace works only on laminate bows not selfies with bumps and dips.. Works for me.
oooooopps double post
Go to trad gang main topic page home page. Scroll down to How To Section, then look for Tillering Gizmo thread by Eric Krewson. Instructions there.
Thanks guys. Wolftrail I use My tree the same way. I use a yard stick think I like it better. to many variables with the gizmo.
No No No.
The gizmo used correctly will give you a perfect bend.
Glass bows and wood bows are two different animals.
Pay attention rebel boy... :)
They way I understood it and how I use it. is to run the bow from fade to tip. That is after you set your pencil by finding the largest gap and adjusting the pencil so it barley touches. then run it down the middle then each side of the limb. remove wood only were the pencil marks are. I if you are getting more on one side of a limb then the other scrap that side. you can tiller in twist by shaving to much off one side. Don't ask me how I know. if you measure the limb thickness on both sides one will be think most likely.
"I dont use a gizmo, I use a tape measure for final tiller when its at full brace works only on laminate bows not selfies with bumps and dips"
Wolf, can you explain how you use a tape measure for final tiller? Do you mean just positive or negative tiller measurements from the fade to the string or something else?
BMorv, I put mine on the tree and pull it to different lengths then use the marks I put on the sides of the bow limbs to measure distance between limb and string. That worked great on my first 3 bows. Started using the gizmo started having problems. Most likely due to not using it properly but what do I know. I have a better understanding now, I think i was asking it to do things it wasn't designed for.
Gotcha John. Don't see why that wouldn't work, but never seen it done that way.
The gizmo is a simple but ingenious device that simply measures how much the wood is bending between the ends. It is incapable of lying. Match the gap between the ends of the gizmo along the length of the limb and you'll have a nice even bend. Do like Kelly suggest and you'll get side to side differences too. I can't imagine an easier method, unless you are experienced enough to see those small differences by just looking at it.
I even use it on R/D bows. The gap from the transition between deflex and reflex will get smaller, but it should be a smooth transition and both limbs should transition the same.
QuoteOriginally posted by BMorv:
"I dont use a gizmo, I use a tape measure for final tiller when its at full brace works only on laminate bows not selfies with bumps and dips"
Wolf, can you explain how you use a tape measure for final tiller? Do you mean just positive or negative tiller measurements from the fade to the string or something else?
This is how I do it..
http://myarchery.byethost18.com/bows.html
I guess you learn something new every day....More than one way to achieve a nice bend.
I like the gizmo, however I'm constantly wondering if the pencil moved is the lead getting shorter blah blah blah..... with a yard stick i know its constant. But then again I'm weird. I'm the hillbilly that shows up to an Appalachian pot luck supper with gumbo. :thumbsup:
I use a Gizmo mostly for difficult cases. Most everything else I do by eye. The Gizmo is a great tool but it is not a crutch.
Good point Pat.
Gizmos are easy. Yardsticks warp... :)
Roy if an ole coot like you can do it..... well ya know were I'm going with this right?
Were did that post ya made go to?
No?
I didn't think it was right so I edited it...
Go sit by the fire with Jack and think about it.
LOL
QuoteOriginally posted by Pat B:
I use a Gizmo mostly for difficult cases. Most everything else I do by eye. The Gizmo is a great tool but it is not a crutch.
X2
Regarding tiller induced limb twist, I have always pinched both sides of the limb and run them from the riser to the tip. It seemed obvious to me that the sides usually need to be the same thickness. I pinch and check constantly throughout the tillering process. Once you do it few times it becomes easy to tell any difference from one side of the limb to the other. When I started teaching others to build self bows I quickly realized it isn't obivious to most of the first time selfbow builders I teach, they struggle with keeping both sides even. Usually they have a dominate side (right or left) and apply more pressure to that side of the limb, thus removing more wood on one side and inducing limb twist.
QuoteOriginally posted by Pat B:
I use a Gizmo mostly for difficult cases. Most everything else I do by eye. The Gizmo is a great tool but it is not a crutch.
X2
Regarding tiller induced limb twist, I have always pinched both sides of the limb and run them from the riser to the tip. It seemed obvious to me that the sides usually need to be the same thickness. I pinch and check constantly throughout the tillering process. Once you do it few times it becomes easy to tell any difference from one side of the limb to the other. When I started teaching others to build self bows I quickly realized it isn't oblivious to most of the first time selfbow builders I teach, they struggle with keeping both sides even. Usually they have a dominate side (right or left) and apply more pressure to that side of the limb, thus removing more wood on one side and inducing limb twist.
John, you are over thinking the gizmo thing, pencil moved? got shorter? Too many variables? Yikes!
Eric, happens every time i learn to use something new. I'm starting to get used to it. I'm weird like that. I'm the guy who checks his level and tape measure and square for true every morning or at lunch just in case.
the gizmo is quick- way quicker than measuring- i used to measure before i was let into the gizmo secret.
besides as said above, the gizmo doesnt lie.
one word of caution with a tillering stick, i strongly advocate against using them- having a wood bow under tension( the longer the draw length the worse it is) while you study it- will lead to increased set- and in a few cases i have seen hickory bows blow up- while people sit there and take their time.
i won't use them anymore - just an unnecessary risk.
each to their own i guess- many ways to skin a cat! :bigsmyl:
Hey Fuji! How do you use a gizmo without holding the bow under tension for a while? A tiller stick or a pulley system seems like you would need to hold it there to run the gizmo up and down each limb. (I have never used a gizmo though. I do something similar with my card scraper and eyeball the gap.
Msturm
John one thing Eric taught me about the gizmo and probably the hardest to do is to trust the gizmo. Eric taught me how to build bows, but as I continue building the gizmo has actually taught me what proper tiller looks like. I just leave the last 6 to 8 inch of the tips stiff depending on the bow/my mood and get it bending a little out of the fades. The gizmo tells me what to do in between. I have messed up more bows than I like to admit but none was the gizmos fault. It's simple but very effective.