Bend before or after profile?

[hummingbird]

I've been spending alot of time (too much) lately experimenting (I like to call it that) with side bending. I'll post my misadventures soon.
I've noticed that some people cut the side profile before bending and some after bending. I always thought that profiling before bending was the standard proceedure until I saw it done after bending on the Internet lately.

Not all plans have a side profile but it would be easy enough to extract the profile from the side view of the guitar to a bent side.

Its easier to cut a flat side than a bent side but if I don't place the waist and bouts in exactly the correct position, which is easy do do when it's buried in a heating blanket and slat sandwich the profile becomes useless. So bending an unprofiled over length rectangular side piece seems safer. Doesn't it?

I assume you would cut the bent side with a bandsaw but what if my bandsaw's cutting depth is not high enough. Could I use a jigsaw?

Can someone please shed some light on this subject before I waste anymore good wood. Thanks.

[johnnparchem]

I profile the sides close, giving myself 1/4 inch or so, before I bend. This allows the waist a little room to slip and still be OK but not so much that I am planing forever. The bigger mistake you can make with profiled sides is to make two of the same side.

I have cut bent sides that were not profiled. Once I used a table saw (with a really good blade) and once I used my bandsaw.

[Ken C]

John, I profile first.

Ken

[Kevin Sjostrand]

I also profile my sides before bending on an electric pipe. I also make my heel and neck blocks to size, I'm just careful when glueing it all up, and I take an insignificant amount off the rims when sanding to true them up.
Makes more sense to me then trying to cut them down and making them even after being bent and glued in.

Kevin

[David L]

Waldron sells side profile templates, don't think they'd be very helpful on sides that are already bent.

David L

[kencierp]

We always bend sides after profile. As a matter of fact the inner most point of the waist curve is a critical registration mark for placement in our bending machines --- and subsequent alignment in the mold. Ever since Ken Casper came up with the idea this is how we make our side profile templates -- perfect every time!

http://www.kennethmichaelguitars.com/si ... lates.html

[hummingbird]

Thanks guys So far your all saying what I thought in the first place. It makes sense I guess. But my Martin herringbone plan doesn't have a waist point on the profile and I can't think of an accurate way to extract it from the side or top profile. I cut out a piece of paper the shape of the profile and wrapped it along the top profile on the plan and marked the waist that way but I'm just afraid it's not accurate enough. Some plans don't even have a side profile. Is there a way to get it somehow from the rest of the plan?

[kencierp]

This is pretty close --- height at neck block 3-15/16" minus top and back thickness height at tail block 4-7/8" minus top and back thickness enjoy!

[johnnparchem]

Thanks guys So far your all saying what I thought in the first place. It makes sense I guess. But my Martin herringbone plan doesn't have a waist point on the profile and I can't think of an accurate way to extract it from the side or top profile. I cut out a piece of paper the shape of the profile and wrapped it along the top profile on the plan and marked the waist that way but I'm just afraid it's not accurate enough. Some plans don't even have a side profile. Is there a way to get it somehow from the rest of the plan?

I have not tried this, but run a string along the top profile in the plan mark the waist on the string, plus a few of other point taking height measurements on the side guitar view for each of the corresponding points on the string. Straighten the string and transfer the measurements and the waist location to the side profile. You can even do this on a guitar you are copying.

The top edge of the side profile is flat and the ends are square.

[hummingbird]

Thanks Ken and John. That is very helpful. Ken, what do you mean by "offset". Is that extra length to make up for errors. I would assume a little extra length is advisable.