Crossbow Curve Gauge

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Project by bondogaposis posted 10-31-2013 12:23 PM 3693 views 17 times favorited 18 comments Add to Favorites Watch

I made this very simple jig for drawing curves. I have been using a spline and Spanish windlass to draw my curves forever, I use them enough that I thought I would make things a little easier and make a dedicated jig. I’m not sure where the idea came from, I saw it somewhere. Very easy to make, it took me about 20 minutes, I think I spent more time looking for the string than anything else. It is very easy to change the shape of the curve by just pulling on the string and setting it in the appropriate notch and also by changing out to a longer or shorter spline can be done as well as the spline is held in place w/ two screws. The spline is 3 ft long and the notches are one inch apart. Thanks for looking.

-- Bondo Gaposis

18 comments so far

View Scott Oldre's profile

Scott Oldre

1128 posts in 4397 days

#1 posted 10-31-2013 12:29 PM

Just what I’ve been looking for!! What type of wood and thickness did you use for the curve part? I have a project coming that needs some curves where this would come in very handy and it obviously takes zero space when you’re not using it.

-- Scott, Irmo SC

View RussellAP's profile


3105 posts in 3253 days

#2 posted 10-31-2013 12:38 PM

Genius! I will make one of these straight off. You wont believe what I’ve been doing, lol. hope I can find a piece that will bend.

-- A positive attitude will take you much further than positive thinking ever will.

View a1Jim's profile


118153 posts in 4543 days

#3 posted 10-31-2013 02:54 PM

Cool idea Bondo ,thanks for sharing.


View ShaneA's profile


7085 posts in 3565 days

#4 posted 10-31-2013 03:03 PM

Looks handy to have. Thanks for sharing.

View bondogaposis's profile


5926 posts in 3317 days

#5 posted 10-31-2013 03:09 PM

I used quarter sawn white oak for all the parts, just because I have some scraps around right now left over from another project. I don’t think the species is as critical as getting something that is straight grained as possible, so you get a consistent bend in the wood. I started out with the bow being 1/4” thick and that was too thick. Maybe for a longer bow that would work. The bow I have on there right now is 1/8” thick.

-- Bondo Gaposis

View RussellAP's profile


3105 posts in 3253 days

#6 posted 10-31-2013 03:17 PM

I’ve got some maple that might do the trick.

-- A positive attitude will take you much further than positive thinking ever will.

View mafe's profile


12844 posts in 4055 days

#7 posted 10-31-2013 04:16 PM

Brilliant idea!
Best thoughts,

-- MAD F, the fanatical rhykenologist and vintage architect.

View Diggerjacks's profile


2329 posts in 4105 days

#8 posted 10-31-2013 06:17 PM

Hello bondogaposis

An ingenius idea
I like it : simple and very effective

Thanks for sharing

-- Diggerjack-France ---The only limit is the limit of the mind and the mind has no limit

View SCOTSMAN's profile


5849 posts in 4551 days

#9 posted 10-31-2013 08:26 PM

I can use this idea for drawing lines until now, I have needed three hands to do it.I can also use it for a crossbow for defending us against the English football hoardes of hooligans who come over the border to Scotland LOL just kidding I love the English never met one I didn’t like,or couldn’t eat . Alistair

-- excuse my typing as I have a form of parkinsons disease

View pintodeluxe's profile


6290 posts in 3779 days

#10 posted 10-31-2013 08:30 PM

I have never had any luck with three point bending sticks. The curve never comes out fair because of the central pressure point. I have resolved to just calling the wife out to the shop to draw the line while I hold the stick.

I built an elaborate jig from Woodsmith magazine with threaded rod and a wooden frame. I think I used it once, then it got hung on the wall as I reverted to my most basic of techniques.

I hope you have better luck with your jig!

-- Willie, Washington "If You Choose Not To Decide, You Still Have Made a Choice" - Rush

View RussellAP's profile


3105 posts in 3253 days

#11 posted 10-31-2013 10:04 PM

I think I’m going to try this with some half inch aluminum. it’s about 1/16” thick and will bend nicely. Maybe even get a more perfect curve. Also a piece of acrylic will work well too.

-- A positive attitude will take you much further than positive thinking ever will.

View facecarver's profile


154 posts in 2642 days

#12 posted 10-31-2013 10:11 PM

Way Cool jig !!!

-- Dennis Stallings; I am what I am,And that's all what I am...

View bobasaurus's profile


3710 posts in 4150 days

#13 posted 10-31-2013 11:06 PM

That’s quite clever. I’ll have to save this for a future project.

-- Allen, Colorado (Instagram @bobasaurus_woodworking)

View gfadvm's profile


14940 posts in 3656 days

#14 posted 11-01-2013 12:44 AM

I use 1/8” Masonite for my fairing stick but your adjustable crossbow is my next project! Thanks.

-- " I'll try to be nicer, if you'll try to be smarter" gfadvm

View HillbillyShooter's profile


5811 posts in 3258 days

#15 posted 11-01-2013 12:50 AM

Outstanding jig—simple and effective. I really could have used this recently, so this goes on both my favorites and to do list. Thanks for this post.

-- John C. -- "Firearms are second only to the Constitution in importance; they are the peoples' liberty's teeth." George Washington

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