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Hey guys

I have a set of sides in the mold ready to be profiled. This has always been a bit tricky for me. What are your favorite methods for doing this?

I cut the profile first with bandsaw. I then just "bowel sand" them in dish prior to and after installing llining. Have less sanding to do for this process.

James, this is one part that I also still struggle with.
It takes me far too long to do what should be quick and easy.

I am not brave enough yet to pre profile my sides.

I always start by picking which edge will be my top, then using the joiner I make it dead flat.

Then I bend the sides full width.
Remove them from the bender and with a chip board template I scribe the line for the bottom and then cut the sides to length.
I then glue in the neck and tail blocks about 1/8th shy of the top edge. After they are dry I sand in the top radius (for me that is 30') then I flip the form over and using a very sharp chisel I carve down to about 1/4" inch from the line I drew showing my back radius. From there I clamp down the body form and finish with my sanding bowl.

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Lance@LuthiersForum.com

I alwasy profile after bending. I have patterns that slip between the mold and sides with neck and tail block glued in place. these patters are 1/16" over desired height. I use a pencil and scribe the top of the pattern to the rim remove the patters and use my foredom and a cut off wheel to cut to the scribed line. take a total of maybe 6 min

I pre-profile before bending, I make up the profile shape by placing the mold on the radius dish shimmed up to the angle and side height needed and measure down to the dish with my vernier calipers at 1" intervals. I transfer the measurements with a little extra added (1/16") to the template and join the dots. I mark the waist and add 1" to each end that I trim to size after bending. This only takes about an hour and saves lots of time and sanding later and it only needs doing once for each guitar shape. The wedge guitar was interesting to do as there is 2 angles involved, but it came out good. If you do a cutaway you of course need to make 2 templates so it takes a little longer. I rough cut the sides and then use the template with a pattern bit to cut the side to final profile.

I got this idea from one of the tutorials on the OLF and it works well for me.

Fred

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I also bend the sides unprofiled, and then quick and dirty like use a block plane to get very close to what i want, first by eyeballing it, then using the dish as a reference and marking high spots. Then I finish up by sanding with the dish. Takes about 7 minutes, so Michael P. wins by a hair.

You have to be aware of your grain direction when planing bent sides to avoid splits.

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Jordan Aceto
Ithaca, NY

Jim Olson has a really slick way to profile the sides & kerfing...you can see pics of his jig in the shop tour section of his website. It basically guides the router in a spherical path all along the contours of the mold.

I made a plywood side template that I use to profile the sides prior to bending. In CAD (I use Rhino), I can actually unroll a side and get the true shape...then I used this to cut my side template on the CNC. As was mentioned, there are manual ways to determine this unrolled profile as well; I've also seen techniques done using thick paper-board type of materials & the appropriate sanding dish.

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I always profile before bending. To make a template for profiling, take a scrap piece of wood that bends easily (something soft like poplar) and bend it (2 pieces, one for each side). Place it in your form and sand it in your radius dish until it is making contact with the dish for the full length of the piece. Make a reference mark on your form and on the piece you are sanding, so you know where it goes, and mark the centerline at the neck and end. Take the pieces out and unbend them. Now you have a profile template!

Once you pre-profile and see how simple it is, you will never go back

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John Ressler

I used to pre profile sides, but i felt it limited my flexibility. I don't always use the same style of doming, and i don't want to make profile templates every time i change something. Doing it by hand is fast enough that it would take a bunch of instruments for the time invested in making templates or jigs to start repaying you.

If have a standard dome and profile, it does make sense to make up a template or two.

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Jordan Aceto
Ithaca, NY

I do it exactly the same way as Jordan,although it takes me 8 minutes!
You gotta love low-tech!

This is a fantastic collection of methods. It's good to know I'm not the only one who struggles here! Or doesn't have the guts to pre-profile

To make myself seem even less sophisticated, how do you draw the taper?

James,

I do mine after bending, in the external form.

I mark the back side by propping up the tail with shims by difference between the depths of the tail and neck areas, dragging a marker along the surface of the dish, like this:

http://www.patfosterguitars.com/harvest2/pages/page_44.html?

and this:

http://www.patfosterguitars.com/harvest2/pages/page_45.html?

I use a belt sander to take the blocks down, and a spokeshave set to take big bites for the sides. Very low tech, but it works pretty well.

Pat

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I made a profile template for all the models I make after seeing the tutorial on how to do this. It just saves so much time to profile before bending, that I'd never consider going back to profiling after bending. Now it's just a matter of a light brush in the sanding dish.

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Allen R. McFarlen
Barron River Guitars & Ukuleles
Facebook
Cairns, Australia

i pre-profile the sides for the back only. i do the cutting on the bandsaw. then i bend and cut the sides to length. then when i glue in the blocks to join the sides, the sides are top down and sitting flat on my bench. both blocks are glues in about an 1/8th inch shy of the top.
then to profile the top edge i use either a block plane or a cheese grater (micro plane rasp) before using the dish. depends how friendly the grain is.
phil

Just as a footnote to this descusion, for those that cut a singular continuous taper then dress on a belt sander. If you use a domed dish to final sand then you have to leave the belt sander dressed height a bit proud because the height a various points along the perimeter of the rim to dome intersection change fairly dramatically depending on where measured. There is a slight rise at the waist valley and a fall off at the widest point of the lower bout and belt sanders make this taper all one plane. So you still have some sanding to do with the dome to make a true spherical dome intersection profile. if you don't come back and dome sand the you have to force the braced back to meet the joint. This is not necessarily bad if the discrepancy in minor but the smaller the radius of the dome the greater the variations are. I force my domed tops on medium and large body guitars on to a pure flat top profile but they are 28’ domes. My backs are 15’ domes and a pure flat plane would mean too much added stress in the waist valley for my liking so I cut the true profile shape into my rims + 1/16” that gets sanded away with the domed dish sanding so that my back plates have no added stress to the joint.

the other thing that hasn't been mentioned yet is that if you profile the sides before bending, you have to orient them correctly in the bender. I leave a little tab that sits in a 1/2" slot on the vertical strut on my bender....I've seen others just use a mark or some tape. Regardless, you have to line the side up right in there...

Trev

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http://www.bluescreekguitars.com/blog/ I also pre shape the sides and this is how I set them up for the build.
john hall

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blues creek guitars
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I profile the back edge of my sides before bending. How I make the profile template is well known, but for newer members the method can be found in this thread http://luthiersforum.com/forum/viewtopic.php?f=10102&t=8117&hilit=side+template

The top is left straight to make indexing in the side bender more straight forward and the waist position is marked onto the wood. Once the sides are bent they are placed in the mould and the whole is placed back down in the 15' radius dish, the stiff paper template is put into the mould against the side and the top profile is traced on to the wood. Then it's just a simple job of block plane to the line. After head/tail blocks and the laminated linings are glued in place a quick twirl in the radius dishes and we have radiused back and top.

Colin

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This is easy if you register at the centerline at the tail, no tabs, tape or marks to worry about.

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I don't actually profile the sides before bending. What I do is approximate the width at the tail and heel then rough cut the sides to a taper with a jig saw. Then I will use a block plane to profile the side to its final dimension after gluing. On my first build I actually did this without a radius dish. I just measured the plan then transferred the measurement to the side then used masking tape to tell me where to stop then used a block plane to final profile the side. Now I will just use the radius dish as a guide.

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One thing i do to make it go a little bit faster, is to glue the neckblock in with the back taper already cut, so the block ramps up, being lowest near the neck and higher towards the tail. I just aproximate the angle on the bandsaw.

It saves having to plane or cut through the block, just trim the sides down and you are mostly done.

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Jordan Aceto
Ithaca, NY

I made a plexiglass template for each model and profile before bending. Leave the top flat for ease of line up in the bender and do that with the dish after they are in the mold. Works for me.
Terry

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This thread is answering all of my questions.

For those of you who pre-profile, are you running using a routing table? I'm not set up for that, but I think I could just as easily trace the template and run the side through my bandsaw.

You can and not bad idea of routing it. I just use bandsaw after using grease pencil to draw. I just may try the routing thing with pattern bit. I plan out each build so if want something different can make a template for it. I just have found I am not into in starting a build and during construction trying something out. If want a thinner body or whatever most of my template work. I do make sure leave top straight and done on a joiner

I cut close to the line with a bandsaw and then clamp the side to the template and finish on the router table. I'll try to post a picture later.
Terry

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