Official Luthiers Forum!

Hi,

Been around here for a long time sponging up information, first time poster. I've made two acoustic guitars, buying sides pre-bent (Martin 000-style) with relative success. Been building solid body electrics for years. Not a seller, just a guy that builds and finds a free home for instruments and tube amps (...and bamboo fly rods). Here is what I want to do. I am going to focus on Martin style (D28) dreadnoughts for the next few years, nothing else. I'd like to attempt to get good at one thing only for now. So, I want to build a side bending machine...for Martin-style dreds. I want to stay as close to pre-war spec as is reasonable....reasonable. I'm just wondering who, if anybody, has the best set of plans for a Martin-style dreadnought, since that is what the bender will be used for. I'm speaking of a "Fox type" using heating blanket, slats, etc. Also, is there any big advantage in using Baltic birch ply as opposed to box store birch plywood? I'm gentle on tools and not in a production environment, but I like quality/effectiveness as much as the next guy.

I guess an accurate guitar plan/drawing is really my main concern at this point. That will guide my thoughts and pre-build/tool-up efforts. I'm in no hurry and budget is secondary (but I like building my own tools/jigs).

Thanks for any thoughts or input.

curtis

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"I need to hurry up, the years are going by far too fast"

There is no need to waste money on Baltic plywood for a bender. I've used birch lumber store plywood and mdf. If you go to Mike Doolins website you'll see his was made of particle board.

A single purpose side bender heated with a blanket is a very simple device -- here's one used at the Whetstone School of Lutherie. Make sure to have a timer in the circuit!

http://acousticguitarconstructionforum. ... ?f=8&t=104

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Ken Cierp

http://www.kennethmichaelguitars.com/

What the others have said. Here's your plan, as good as they come.
http://www.stewmac.com/How-To/Blueprint ... _Plan.html
Ken

Check out John Hall at Bluescreek Guitars. He will have everything you will need to build the bender and I'm sure he can provide you with a period correct tracing of a pre-war D-28 guitar. Great to deal with and good prices.
Cal

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Remember, there are no stupid questions, only stupid answers!

If you are using a silicone blanket, rather than light bulbs, you might as well go to a solid form rather than sides with bars between. Gives you better support.
Other than that , I use one like kenceirp shows with everything attached to the bending form rather than a separate frame.

John Arnold has a very accurate tracing of his 1937 Herringbone D-28. John Halls 1937 template by Waldron Instruments is really close to the Arnold tracing and John Halls exterior molds fit the template perfectly. Good Luck

Thanks all, I shall heed the above

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"I need to hurry up, the years are going by far too fast"

^^^^^^^^^^^^ what he said^^^^^^^^^^^^^^^^^^

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Say what you do, Do what you say.

I tried the bulbs and had problems then tried a blanket from John Hall and never looked back.

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Say what you do, Do what you say.

All our production benders are heated internally with light bulbs -- the trick if you will, is to capture "all the heat", messing with and inside slat beside being a PIA is simply not effective. Our forms are lined with aluminum and permanently covered with aluminum. which is a quantum improvement.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I think so too.
Use 550 watts of bulbs until around 150, then the blanket goes on, with both on until about 220/250 depending, then cut the bulbs back to minimum on the rheostat.
Have to switch them off around 20 degrees before max. temp is reached though or it overshoots.
For better support underneath the side, I use 2 bottom slats, holding spring tension on the lowest one.
I find this seems to help with cuping, especially if I have some rift to flat sawn pieces and am using damp paper rather than spritzing the sides.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

+1 for John Hall. I used to love jig building, and I built a lot of them. John is a got resource for this stuff and much more.

OK, so I am getting the tracing from J. Hall.

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"I need to hurry up, the years are going by far too fast"