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I just stumbled across these videos on youtube of Charis Guitars and his side/cutaway benders. Very cool designs. It looks like he came up with a way to bend ala Taylor, but on a smaller scale.

You can show them here, it's ok.

Although, this is not the same as the Taylor style of bending machine, much closer to the new LMI machine. Good videos though.

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The new machine in the 2nd video is awesome.

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The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498

Todd if I was 20 years younger I'd build one of them. Really slick.

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Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498

It's the tension my friend -- the tension

as far as different goes I can also do the same thing on a pipe.

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Beautiful and unusual tone woods at a reasonable price.
http://www.rctonewoods.com/RCT_Store
The Zootman
1109 Military Rd.
Kenmore, NY 14217
(716) 874-1498

Nice indeed...Thanks for posting!

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JJ
Napa, CA
http://www.DonohueGuitars.com

Definitely agree, That bender in the second video is really nice. Putting the tension on that upper bout
is a really good way to avoid faceting on those tight bends. I'm thinking how to build something similar,
but it won't be easy because I don't have much in the way of metal shaping tools.

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Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

Looks like there was a bit of engineering involved in constructing that cutaway bender.

I really like the use of toggles to tighten it down. The only problem I see is not being able to adjust heat on the first waist bend, which gets over cooked it the process--a slight drawback of blanket use I also struggle with. Looks like it burned a little on his too. With light bulbs you have a little more control over heat levels on different areas I think. (Hope that makes sense).

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"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.

I've only bent on a pipe. I've been thinking about building a bender, so this topic is timely. Some features in the video fit with what I'd planned, some I hadn't thought of, some don't seem like they'd help. I have no experience here, so all of my comments are questions, not criticisms. I'm hoping that those of you who use bending machines will straighten me out.

I like the the side-loading feature. Any opinions on how this convenience might stack up against the possibility of twist in the sides? I have a heavy structural beam in my shop that I could mount the gizmo to, and I'm encouraged to think that might work.

I like the tension in the metal slats, but I don't understand the point of equal tension in both slats. Shouldn't all of the tension be on the outer slat? Isn't tension on the inner slat just pulling the wood away from the form? I understand that what is the inner slat at one stage, becomes the outer slat at the next, but wouldn't it be better to shift the tension when that happens?

I'd like to try to apply the heat to the inside of each bend. I could do that with heated cauls, or with separate, smaller, heating blankets. Am I being to cautious? Is this carrying the bending pipe analogy too far?

How sensitive is any bending machine to variations in side thickness? I'm thinking about the transition from inside cauls to outside cauls. With slats, and blankets, and wood, and paper, it seems like variations could add up to some faceting at the transition. Is this a problem?

Thanks all.

Pretty cool bender.
The inner slat is to support the waist bend/inner cutaway and the outer slat is to support the lower bout and upper bout. You are correct that the tension should always be on the outside of the bend and this is the reason the Taylor tensioned slat benders only bend outside bends with one slat. I would agree that you only need to apply heat to the inside of the bend but this isn't as easy as it sounds. I designed a similar process (tensioned slat) but different approach (Doolin style not fox) and found that the process works very well. Below is a link the thread about my bender which you may find interesting.

http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=26950&hilit=Bender


Good luck and let us know if you start bulding something.

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Brad
Avon, OH

Both the Charis and the Way bender look pretty slick, but they seem a bit out of reach for the average guy. I don't know how to weld, attach hydraulics etc., and I imagine
most of us don't. Mind you, I ain't knocking those machines, but something of that complexity is not strictly necessary. You can do a perfectly good cutaway on the benders you can get from Blues Creek, so don't think that they won't do the job.

I have a cutaway bender that is just a modded fox as well ... it uses a tensioned (springs) arm (ala John How's design) that holds both inner and outer slats, which is requried ony for venetians .... the arm tensions the outer for the first part of the cutaway bend, then the inner isstill tensioned enough to bend the second part of the cutaway, using the second press for the cutaway as he does. Have to admit .. with time andn space, his certainly is sweet, but mine hasnt failed me yet ...

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

I would agree with you that there are many ways to bend wood. There is no reason that a simple bending pipe can't work and certainly a fox setup has been proven to work well. My reason for creating a better bending machine was trying to eliminate as many variables as possible. When developing the process I found that everyone had all sorts of different formula's for bending different types of woods. (ie amount of water, what to wrap the wood in, super soft, temperature, number of heating blankets, and the list goes on). What I found is that with a good tentioned slat it is easier to bend wood without needing all the "black magic". Working with Nelson Palen (who builds archtops) he found that bending curly maple to a 7/8 radius was a challange on this fox style bender and often had to thin his cutaway sides to ensure he would not have problems. I bent a series of samples (dry with no water) to a 7/8 radius using .095 and .110 thick curly maple pieces with no problems which is what convinced Nelson that the process want improved over the fox process. Here are some of the pictures from the tests...

Curly Maple Sample

7/8 Radius Bend...

.110 thick maple bent to a 7/8" radius.

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Brad
Avon, OH

After bending about 100 sets of curly maple sides, (Yes, including the broken ones) I've found that the tensioned band method will produce reliable results as Brad indicates.
I honestly do not believe that it is possible to consistently and reliably bend 7/8" inside radius bends in full thickness highly figured maple using any other means.
Nelson

Is the top edge of a side really flat? Even with a 28' radius?

No, but it's not tapered as well as domed, so you can take it down with the dish easier than the back. Plus it's nice to have a flat side for registration, to make sure you are bending square to the form.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Wow! That is impressive!!!!! 0.110 maple, really?

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Ken

Brad showed me his prototype, which Nelson has now and I was VERY impressed with his design. Its truly unique and is a better "Way" to bend sides especially if you have a tight radius horn on your cutaway or work with highly figured troublesome woods. I was impressed that he was able to bend wood dry with zero moisture and had no issues. That's a totally new concept for me to grasp.

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tim...
http://www.mcknightguitars.com

Possibly. Depends. It's not unusual to build with an entirely flat rim set and a domed top.

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Wes McMillian
Santo, TX
http://www.wesmcmillian.com