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Tapering sides before bending?
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=25916		 Page 1 of 1
Author:  coke_zero [ Sat Feb 06, 2010 12:40 pm ]
Post subject:  Tapering sides before bending?
Something that I have been thinking about for a while now before I bend my sides is about tapering them. I have seen many videos on how to bend sides and all show different ways to go about tapering them. Some videos show people cutting their sides exactly to how the plans say before bending, some show them doing it after with what to me would be tools I cannot have access to and the rest kind of go between.

I have been told by some builders just to cut the taper and the length of the sides and then bend. However, I am thinking unless I bend in the exact spot needed, the side could end up being lob sided. If I taper the sides but don't cut to length I can avoid this, but then each side may be slightly different in the mould...

How do people here go about tapering their sides? I vaguely remember seeing a tutorial of someone bending the sides, then drawing on the taper with a pencil after, but I can't find that video anywhere (typical gaah )

I feel fairly confident about the actual bending of the sides (to a point) but I can't seem to think this one out beforehand.

Any pointers, pictures or videos would be greatly appreciated.
Author:  James W B [ Sat Feb 06, 2010 1:02 pm ]
Post subject:  Re: Tapering sides before bending?
Here`s what works for me.I`ve tried a couple different ways and have found a compromise between the two.Instead of trying to get the taper real real close before bending and oppossed to not tapering at all I get it tapered but with room to spare.For example if your going to build a guitar with a final depth of 4 1/8 inch at the butt and 3 1/2 at the neck .I`ll go ahead and cut the sides about 1/4 to 3/8 bigger than the final dimensionson at each end, depending on the radius`s used for the top and back.This gives me plenty of room to scribe in a radius dish ,and plane and then sand down to your desired dimensions.Pretty hard to goof up this way .Even for me. :)
James
Author:  meddlingfool [ Sat Feb 06, 2010 1:25 pm ]
Post subject:  Re: Tapering sides before bending?
It's easy to make a template as well. Get a big sheet of cardstock or construction paper and cut a 6"x 36" piece off. Tape it around the edge of an existing guitar. Draw a line along the guitars' back, mark the waist. Untape from guitar and flatten, hey presto, template!
Then as James says, cut your sides a touch oversize (I don't trim to length until after bending) and then they'll be very close to where you need to be for bowl sanding.
Cheers
Author:  truckjohn [ Sat Feb 06, 2010 1:42 pm ]
Post subject:  Re: Tapering sides before bending?
The whole thing relies on your own personal precision at the bender -- Can you get the sides bent with the waist EXACTLY on the mark? Can you get the sides bent exactly squared up on the bender?

Can you do it without bending 2-left sides or bending them inside out or backwards or getting the neck end switched with the tail end? These questions sound pretty dumb... but when it is all wrapped up in kraft paper and tin foil... it is a little harder to see.

On the Oakie guitar... I carefully thicknessed the sides so I would get the best possible bookmatch... Made sure everything was right, Marked the Inside of the sides with "Inside"... Carefully lined up everything in the bender... Then sure enough.... "Hey, why does it say 'Inside' on the Outside of my Guitar sides?"...

The "Bend them straight" then trim down once glued onto the neck and tail blocks is far more forgiving of poor technique, jigging, and alignment.... like mine! If you get the side's waist 1/2" off.. It doesn't matter too much because that mark was only there to make sure you had enough material to glue to the end caps...

The Taper/shape before bending is much faster if you have a very precise method of jigging things up so that the alignment is exactly right... I am thinking the sort of thing that Martin and Taylor would do... and some of the more experienced builders that don't end up bending their sides inside out...

Thanks

John
Author:  coke_zero [ Sat Feb 06, 2010 1:44 pm ]
Post subject:  Re: Tapering sides before bending?
I will be bending by hand with a pipe bender, so I assume it is less accurate than a Fox type bender.
Author:  WaddyThomson [ Sat Feb 06, 2010 8:03 pm ]
Post subject:  Re: Tapering sides before bending?
I've been building on a pipe, and have pre-tapered my last couple of sets. Came out fine. Just bend the waist at the right place and the rest comes out just right.
Author:  MikeG [ Sat Feb 06, 2010 8:43 pm ]
Post subject:  Re: Tapering sides before bending?
I'm working on my first guitar and what I did was bend them on my pipe bender then I made a template and put it around the sides after they were glued together. After that I just took a small hand plane and planed them. It took a little while but seemed to work out well. Keep in mind I haven't finished the guitar yet.
Mike
Author:  Parser [ Sat Feb 06, 2010 9:00 pm ]
Post subject:  Re: Tapering sides before bending?
I'm heavy into CAD so I drew it all up in Rhino, "Unrolled" the side and position a little tab right at the middle of the waist. That little tab lines right up with a slot in my bender....just bend and glue up the blocks. It gets me pretty close after gluing up the kerfing & helps cut down on sanding (I actually don't have to sand them at all before gluing kerfing up)

Trev
Author:  Colin S [ Sun Feb 07, 2010 5:49 am ]
Post subject:  Re: Tapering sides before bending?
It's quite common to profile the back edge of the sides prior to bending leaving the top edge straight to aid alignment in the bender, this is not so critical if you're pipe bending.

I showed a short tutorial on side profiling which ia a good way to profile the back edge and to make a template that can then be used to mark the top edge once the sides are bend and the blocks installed. You can find it here:http://www.luthiersforum.com/forum/viewtopic.php?f=10102&t=8117%22


Colin
Author:  coke_zero [ Sun Feb 07, 2010 7:57 am ]
Post subject:  Re: Tapering sides before bending?
Thanks everyone.

I will check out that tutorial now Colin, every little helps.

Pete
Author:  Bill Greene [ Sun Feb 07, 2010 9:45 am ]
Post subject:  Re: Tapering sides before bending?
Colin S wrote:
It's quite common to profile the back edge of the sides prior to bending leaving the top edge straight to aid alignment in the bender, this is not so critical if you're pipe bending.
Colin


Bingo!
Author:  Tom West [ Sun Feb 07, 2010 10:40 am ]
Post subject:  Re: Tapering sides before bending?
I bend,glue on the neck and heel block and then taper. I just find that easier. I think that folks should do what works for them.
Tom
Author:  Hesh [ Sun Feb 07, 2010 11:02 am ]
Post subject:  Re: Tapering sides before bending?
Bill Greene wrote:
Colin S wrote:
It's quite common to profile the back edge of the sides prior to bending leaving the top edge straight to aid alignment in the bender, this is not so critical if you're pipe bending.
Colin


Bingo!


And bingo once again... :)
Author:  James W B [ Sun Feb 07, 2010 11:45 am ]
Post subject:  Re: Tapering sides before bending?
I`ve also used Colin`s method and it works well.I just really enjoy doing a little planing with a low angle block plane.It`s Fun
James
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