Official Luthiers Forum!

Fillippo,

Check McMaster-Carr. That's where I sourced my spring steel. Not sure about the stainless.

Steve

Picked mine up locally from Accurate Alloys. I dealt with a guy named Marty about four years ago. The stuff’s not cheap. Mine works great, but watch out for the perf steel leaving indentations where clamped. http://www.accuratealloys.com/ Good luck! Morgan

McMaster Carr has a lot more than perforated.

This is the stuff I use. http://www.mcmaster.com/#blue-spring-steel/=1v5m5g

If the link doesn't work, search there for blue spring steel.

_________________
http://www.chassonguitars.com

Fillipo, what size springs are you planning to use? I have the basics of the Doolin done (indexing at the butt), but never finished the spring arm because I couldn't figure out how much tension, how the arm should be, etc. Lame troubles, but mine nonetheless.

Filippo, Thanks for the welcome, I've been lurking for awhile. To answer your questions:

1. .010.
2. .017 with holes and spacing ~1/16".

I'm going to try wrapping the sides in tinfoil or craft paper and adjust the pressure at the waste on my next bend. Hopefully that will address my issue with the indentations.

Morgan

The tin foil will lock (for the most part) the steam in and can cause rapid cupping of the sides. The tin foil sort of negates the use of the perforated top plate. Just use the craft paper.

Filippo, that bender you're showing looks like it would be able to host different bending forms. I made mine with locater pins on the bottom of the bender in which each bending form locates on.

Don't know if you've seen my post on my Doolin style side bender or not, but there are some other details Brad Way gave of his in the post and some other good discussions about this style bender.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Filippo,
Your "Doolin" bender sounds like a great idea with a thermistor for the temp. Can you tell me how you mounted the termistor in it? Photos maybe?
The Doolin bender looks like a simple machine but some things I don't understand about it. The bending process on it looks backward compared to a Fox. There is a wooden lever with reference holes mounted at the upper bout clamping position that I can't figure out what it's for?
Is there a photo tutorial on how one uses this bender?

Dave

Dave, this should explain everything to you:

http://www.doolinguitars.com/articles/bender/

James,
Looked over the bender again and I take it that the wooden lever is to put different spring tension on the assorted body sizes?
Dave

That's correct, Dave.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

I would look at Toddstocks bending side tutorial, it works. Blanket on top.

Spring steel blanket, spring steel, wood/foil sandwich. You don't need perfsteel, the water will evaporate, slow enough in a sandwich.

I am doing some adjustment for minor springback, ill fit, but thats about all. I have bent a side,and its 'done' in 45 minutes, probably less, under 300 degrees also. (Hog)

I would not recommend my method of clamping, just swivel and pin lock it, but its fast and cheap.

_________________
Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I

Ok, question answered. Here's another one on this bender. If your first bending the lower bout, which is clamped down, then you pull down the upper bout, then you pull down the waist, how do you index exactly where your waist is going to be? The bender will pull your upper bout to make the waist bend. Wouldn't you have to have the sides extra long to compensate? Anyone have pics of one actually used?
Dave

Good question, Dave. The side indexes at the butt by stopping against a little bar screwed between the two slats. It offers a static reference that I find more controllable than trying to get the waist to line up just so so. It makes a good bookmatch much easier for me. If you look at my picture, you can see the butt stopping up against the bar. You can also see why the spring arm is nice. I have a bit of slack in the upper bout---the spring arm would eliminate that by pulling everything tight.

Yup, indexing off the tail end is much easier IMO than worrying about the waist being in the right spot. Also makes pre-profiling the side more appealing as you really get the side bend exactly the way it will sit in the mold.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Well I just found something from a post Brad Way did here, that really shows how the Doolin Bender would actually work. The post is named "Dry" Side Bending. It shows an air powered bender (looks like a Doolin) doing dry sides. Although I'd never try bending dry, his machine gives the idea.
My reason for building the the Doolin type is for space also. I like the idea, it's simple.
Dave

Where are the plans for the Doolin Bender?

BTW, go to a local Borg and buy a stainless steel back splash. 36"x36" for $30! Correct thickness. Then slice up on your table saw with a good carbide blade (disk).

Mike

OK, you can use it on the bottom.


And, asking again, are plans available for this bender?

Mike

Filippo, why the two heating blankets?

Mike