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Main Boards => The Bowyer's Bench => Topic started by: EzellH93 on March 02, 2021, 05:14:41 PM
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I’m building my first form and cut a template first out of 1/2” plywood. I used a jigsaw and was extra careful during the cut. I am wondering how close to a perfect curve is really necessary. This was actually my second cut and I sanded the first one down so much that I messed up the profile. This one was much better right off the cut.
Other questions:
-what material is usually laminated on the form (bottom half) to smooth out the wood surface? I have a strip of Formica from
Bingham.
-Is this to correct minor imperfections in the wood form? I plan to use the template with a router to cut the actual form. I just don’t know how perfect it really needs to be in order to not mess up the bow limbs.
Thanks!
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Honestly, the form needs to be as perfect as you want your bow to be. However the top of that thing looks is how your limbs will look. Have a dip or a speed bump in there, so will your bow. You will have a very small amount of wiggle room for bumps between the wood and whatever you put on top to smooth it out depending on what you use. With something as thin and flexible as formica you will want it to be pretty much dead on as it could conform to divots in the form.
My method:
- Cut template and get it as perfect as I can
- Trace the template onto the form blank and rough cut with bandsaw (or whatever you have that accomplishes the same thing)
- Screw template to form on the lines and use the router with a pattern bit to smooth it out
- Fill any divots with EA40 (body filler or anything like that will work as well)
- Block sand the whole thing till buttery smooth
- Bond facing strip to form using EA40 and the air hose for surface pressure (I use 0.040" aluminum)
- True and smooth edges with sandpaper
Don't worry about burning through templates. Keep working at it until you are confident it is the best you can do. Templates are easy to make and cost very little to mess up. A couple sheets of 3/4" ply on the other hand...
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I make mine as perfect as posable.
any low spots on the Template can be filed with epoxy and high spots sanded smooth.
Take your time making the template.
START OVER :thumbsup:
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Yep what they said . If using the template with a router , my much preferred method, bend a piece of fiberglass or a steel yardstick around the curves and hold to a light. It will show dips and flats I can’t detect til I have the bow finished and out in sun . That sucks to get the bow finished and find she has a dimple you don’t want.
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I have a two HP router mounted in a table. Only used for forms and profiling jigs.Kennys idea with bending the glass over it to find high and lows. Do it on the template and get it perfect and form should be fine.
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Ezell - Are you making a form for take down limbs or for a stick bow? If you’re doing a one piece it can be helpful to lay the pattern out on a big piece of paper, trace along the working edges and then flip the template over to compare and get the profiles the same.
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Have you gone to kennym's website and checked out his form building instructions? I found it to be very informative.
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I agree with what most said...
Don't use 1/2 plywood for a template... Use that 1/8" thick brown board... Draw your lines so that they are perfect... Look at it a hundred times if you have to, from all angles and in different lighting... Sunlight might be best... Cut your template an 1/8" off the line and sand until you are consistently off the line... Never sand up to the line if you can help it... Use your eyes and use your hands also... run your hands over those curves a hundred times... They will feel any little bumps or dips... Take your time, everything has to be a perfect 90*...
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I agree with what most said...
Don't use 1/2 plywood for a template... Use that 1/8" thick brown board... Draw your lines so that they are perfect... Look at it a hundred times if you have to, from all angles and in different lighting... Sunlight might be best... Cut your template an 1/8" off the line and sand until you are consistently off the line... Never sand up to the line if you can help it... Use your eyes and use your hands also... run your hands over those curves a hundred times... They will feel any little bumps or dips... Take your time, everything has to be a perfect 90*...
He has a router shreddy :bigsmyl:
I use 1/2" or 3/4" plywood what ever I have for the template.
you don't need a backer on the form IF IT'S SMOOTH, any low spots from the router I fill with smooth-on and sand smooth, I use 3/4 coats of shellac on mine after it's good
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He has a router shreddy :bigsmyl:
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That's your first mistake... :laughing:
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He has a router shreddy :bigsmyl:
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That's your first mistake... :laughing:
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My bad, he's going to make the template by hand and use the router and template to make the form :thumbsup:
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I should know better than to let you 2 guys alone together in the same thread...
:wavey:
:laughing:
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Max - My bad, he's going to make the template by hand and use the router and template to make the form...
That's what I thought in the first place... :) ;)
Hey Royster, don't you have some whittlin' to do??
Max is "all right" the world is "all wrong"... :laughing:
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I guess MaxiBoy is ok....
:wavey:
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I had a firm cut out a 8 mm thick ( serious overkill) steel template with a computer guided laser cutter. If you have acccess to such a place it is probably the most accurate.
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That would be nice for sure if we could get Kenny to buy a CNC router then he could do our forms perfect. :bigsmyl:
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X's 2:)
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I d like to have one for sure !!
Has a buddy cut my master templates from 1/4” steel .
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steel for templates? how many bows is a wood form good for?
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Templates to make templates I sell...