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Some of you may remember the bender that Brad Way presented in this discussion back in '08:
http://www.luthiersforum.com/forum/viewtopic.php?f=10102&t=15206&hilit=dry+bending
Since that time Brad has redesigned the bender to include cutaway bending capability.
I've been testing this prototype for Brad and find it to do an excellent job consistently bending highly flamed maple.
The tensioned band method supports the outer fibers of the wood to prevent tearing.
My challenge in the past has been the 7/8" (.875") radius bend in the cutaway which the Way Bender handles quite well.

Wow! That's an incredible piece of work. The bent side is nice, too! Thanks for raising the bar for the rest of us.

I remember the discussions and it looks like the machine has progressed a lot. Nice looking bend, how thick is that side at the cutaway?

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Steve Smith
"Music is what feelings sound like"

This thickness is .090" along with the rest of the side.
I found no need to thin the cutaway area.
Leaves a nice smooth bend with no faceting on the inside.
Nelson

Nice setup!

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Brad
Avon, OH

I can't really comment as much as some people can, as I haven't bend a 100th of the amount of wood as some people. However, anyone who designs something to make a job easier & quicker deserves a lot of praise.

I see the air line and the two pistons that tension the band, but what drives the bending caul into the cutaway?
Also, what pulls down the lower bout bend?
I presume you are using a heat blanket with this system, correct?

Hank

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Hank Mauel

That looks very nice. How much time does it take to change forms? Is the tensioning mechanism set up so that it can easily go from a Parlor to a Jumbo or do you have to readjust everything.

In other words, it looks fantastic if you are doing 50 sides before changing forms but would it be worthwhile if you change forms frequently?

Thanks for posting that.

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http://www.chassonguitars.com

That's pretty cool to have one available on a much more affordable scale for small shops. Taylor uses a similar method but on a much larger (and far more costly I'm sure) piece of equipment. http://www.youtube.com/watch?v=jxEqGqi4D-E

Superb creation Brad!

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Bill Hodge


One does not simply, own enough guitars!

My take on it was that the way it works, it only applies heat to the portion that is currently being bent in the initial stages. So, the blanket is only in contact with the lower bout while it is being bent then the waist, and on up the side to the upper bout, and, I assume, the cut-away. When the bend is completed the wood is in contact with the blanket at all points.

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Waddy

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I like the heat blanket at the waist caul that's simular to the Taylor idea.
Bill I think you could adapt these ideas along with the tension idea and possible use springs simular the Mike Doolins design.
http://www.doolinguitars.com/articles/bender/
Kent , it looks like to me from the other link that it would just be a matter of adjusting the waist caul and changing the body form as long as the slats have enough length to adjust.
I like it and can see where springs could be used with an adjustable tension type of screw adjustment. Or maybe a set shocks or struts. But then again what's the price of the pistons, some square tubing, flat plate and a small light duty wire feed welder. It really might be affordable to bulid one if you have the time and tools for metal fabrication.
Nice job with the design and execution Brad.
Now you have me thinking.

I'll let Brad respond to the questions.
After all, he is the inventor. I'm just the guinea pig.
I just know that it's an answer to bending difficult wood into tight radii.
Nelson

Looks like a dream come true to me!

Brad, are you going to be offering plans to folks who want to build these, or are you considering full scale manufacture of them?

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Bill Hodge


One does not simply, own enough guitars!

Great feedback. Here is some answers to a few of the questions. I will try to answer more later.

1) Changing forms - The body form can be changed as quickly as it takes to lift one and put the other one in the same positon (no tools required). The waist caul uses a quick change design that probably takes 30 seconds (no tools required). The cutaway caul take requires a few screws to be removed but could easily be improved. The use of air cylinders allows for using different form sizes without having to change the length of the slat. The prototype used a 3 1/2 stroke which covers all sizes with a simple shim but a 5" stroke would cover all sizes without a shim or any adjustments. (self adjusting)

2) Bending blankets - The bender uses one full length blanket (6 x 34) and (2) 6 x 6 blankets...one for the waist and one for the cutaway. The heat is always applied to be the inside of the bend.

3) Production...Nelson and I had a few good conversations about this. Much of the frame could be build from 80/20 aluminum parts. The air cylinders could be replaced with springs but air cylinders can be found on ebay for low cost. ($20-30 each).

4) What drives the bending caul into the cutaway? There is an arm (I call it the torque arm) that allows the cutaway bending motion. I will need to talk Nelson into talking a few pics to show how this works.

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Brad
Avon, OH

[quote="Chris Paulick"]Bill I think you could adapt these ideas along with the tension idea and possible use springs simular the Mike Doolins design.
http://www.doolinguitars.com/articles/bender/
quote]

Good obsevation....the design was the result of merging many of the concepts between the Doolin Bender (starting the bending at the tail end) and the Taylor Benders (using the tensioned slat). I will show more on the cutaway bending functionality later tonight which is probably more my own idea.

I am hoping this thread will add some creative juices to the process and see where it goes.

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Brad
Avon, OH

When I bend a side for my Resos I used my bender below that bent the side around the form and at the cutaway the caul just swung into the cutaway. I'm thinking that might be simular to your cutaway press? Or at least the concept maybe? You can see the side in the last picture sticking out I imagine like your slat does.
In a way this bender isn't too far off in the concept of how it bends then yours. Other then having the tensioner and heat blankets and bending wood.

I wonder how rigid one could make such a device if one used 80/20 extruded parts? It has aspects that are seen in Doolin's and Fox benders. Seems Rod True had a version of Doolin's that I REALLY liked. I do not understand the cutout caul. How is it pressed in?

Do you spose there is anything here that is "patented?" In other words, no one copy parts of it?

Mike

Why not just use steel? Cheaper then aluminum and the weight doesn't much matter unless you're shipping them. Heck you could probably make something from wood too. Although the Alu. is nice but don't let that stop you.

Chris....I would say that your pictures are a similar concept to how the bender bends the cutaways.

I forgot to mention that the other advantage to the tensioned slat method is that the side wood can be bent dry or minimal moisture. This helps reduce cupping, staining, or cooking off water.

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Brad
Avon, OH

I want one!

Hey Brad good to see you around - David and I were just talking about you (kindly of course.... ) last week.

If you get a chance how about reposting some pics of your other jigs such as the motorized radius dish etc? You have made some the coolest jigs that I have ever seen!

Hesh...still around and lurking! I haven't posted too much lately since I have been more busy repairing than building. I should blame David for this since I believe he is one of the guys that recommended repairing as a great way to learn! As for my other jigs I may post some other stuff later but for now I will keep this thread on the bender.

So here is how it works. Not all parts are drawn but if you look at the actual picture of the bender at the beginning of the thread and envision where the slats are I think you will get the idea.

This is the start of bending the cutaway.

Pressure is applied to the "Torque Arm" which pushes the cutaway caul into the cutaway.

This is the final position with the cutaway bend finished.

For non-cutaways, 2 bolts are moved from one set of holes to another changing the hinge point.

The upper fram moves down similar to my first bender.

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Brad
Avon, OH

Pretty Slick .

Very slick indeed. Yet, I cannot help thinking that you could do away with the expensive air cylinders and compressed air with some simple mechanism that uses another lever arm to pull the slats tight.

Mike

I have often thought about this. Typically cylinders can be purchased from Ebay for $20-30 each (in this size range) which isn't too expensive. Typically 60-70 psi is about right for bending. Translates it is 124lbs of force per cylinder (228 lbs total). I am sure springs could be used but then some sort of mechanism would need to be designed to release the springs at the end of the bending cycle. With the air you just release the air.

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Brad
Avon, OH

Brad, are you going to sell the plans? Also, do you ever find the two cylinders working against each other? And, what about my 80/20 question?

Mike