I am going to be tinkering with this thing for a while, but I did manage to get it reasonably in tune. The copedant is chromatic with the main tuning being a diminished 7 chord (low to high) G-A#-C#-E-G-A#-C#-E. Each pair of strings can be lowered or raised. L pedals lower R pedals raise. I go into more detail here viewtopic.php?p=3137278#3137278
This guitar started out as a test for my dovetail jig. I routed this one for a much deeper acoustic chamber thinking it would probably not get pedals. There is only about 1 1/4" to work with under the soundboard and nothing can be attached to the soundboard, so this took some head scratching and I fabricated a number of parts that I realized would not work. The biggest challenge was finding room for all the springs for all the lowers, and I had to remake all the bell cranks several times. I actually came up with a new design that will allow for the lower rods to pass through the raise bell cranks instead of next to them. The bell cranks on there now work but force the lower rods into a slight bow. This gets more severe as you get closer to the changer. All in all it seems to work, but is a bit janky and I really want to make another one! If you are wondering about the acoustic tone with the can resonator? I really love the sound and it is quite loud! It almost sounds amplified. The can acts as a soundwell and transfers the vibrations to the soundboard which is 3/32" plywood with ladder type bracing. This guitar actually sounds much better then my first guitar which has a Doug Fir soundboard and shallower body. I experimented with spinning some resonators, but they resulted in horrible, tiny, tinny sounds. Spun resonators need to be much larger to sound good I believe. I may try a dobro cone on my next one?
Thank you to all the very helpful people here! I couldn't have done this without the forum.
Last edited by Tim Toberer on 16 Feb 2023 11:07 am, edited 1 time in total.
Very nice. I’ve wondered how one of those deep cans would sound in a large body.
RETIRED
Former steel guitarist for Tracy Byrd & The Byrd Dawgs, Mark Chesnut & The New South Band, Mark Nesler & Texas Tradition, Wayne Toups & ZydeCajun, Belton Richard & The Musical Aces
"Technique is really the elimination of the unnecessary..it is a constant effort to avoid any personal impediment or obstacle to achieve the smooth flow of energy and intent" Yehudi Menuhin
I will try to figure out how to do that. Soundcloud seems to be popular, but a video would be better. Not sure how I feel about that cause I am shy I guess. I just sat and strummed through the myriad of chords available in open position which is pretty satisfying in itself.
Every combination of pedals is something, so impossible to hit a "wrong" note. It is all there. I am not quite sure what to do with it all yet. This will take years. This tuning is amazing. I am already seeing how I want to improve the overall mechanisms.
Jay Stainbrook wrote:This is awesome. Is that a can lid you're using as a resonator?
Edit: should have read through your post before I replied. Would love to see pics of what it looks like inside the box.
Thanks! Very fun project and I am relieved it sort of works. It is just a dovetail box with a groove cut for the internal soundboard. Nothing complicated. Good old pine and plywood. I used some straight grain spruce to run 3 ladder braces on the soundboard. I routed the top so the 1/4" plywood top would sit flush. I want to build another and tweek the dimensions a little bit, and use some nicer materials. This was really just a prototype of sorts. I painted it to cover up a lot of sins.
What is your copedent? I like mine for the same reason: virtually every combination of pedals gives a usable strum across the whole instrument. Definitely opens up some different playing methods!
Eric Moon wrote:What is your copedent? I like mine for the same reason: virtually every combination of pedals gives a usable strum across the whole instrument. Definitely opens up some different playing methods!
It is a diminished 7th chord. G-A#-C-#-E. By raising and lowering each note you can obtain a complete chromatic scale. If you follow the link on the top, there is a detailed description and discussion of the tuning. I haven't gotten as far as I would like with it, but there is a TON of low hanging fruit with this one. I plan on working out a list of "rules" I follow to obtain each chord. The most amazing part is no matter what chord you are playing the inversion is located 4 frets up or down if you shift the pedal pattern appropriately.
The thing is it isn't really a diminished tuning. It is universal 6th tuning. There are 8 different 6th chords available at the nut without even putting the bar on the strings. I have worked out the changes to a couple tunes and I tend to find the inversion that works best with the melody and start from there. Some work best with the 1 on top others the 3 etc. This also allows you to easily play the song in any key. Mostly now I feel limited by my instrument. Building instruments is time consuming! Now I have to learn to play it
Acoustic pedal steel not done.... Yesterday it all came apart again. It was tough to do because I was making some progress with the diminished tuning, but getting it in tune was more than challenging! The changer fingers wouldn't return to the exact same spot. No amount of oiling helped. When it comes down to it the instrument is only as good as the worst part and I had several big issues.
I basically scrapped the entire undercarriage. The new one I am building is using square shafts and redesigned bell cranks using a butterfly design like a Marlen. They are still somewhat crude, but should function better and allow the lowering rods to pass through them. Also the stops for the lowers slot into them to prevent the rod from spinning when the tuner nuts are turned. This was one critical design aspect I missed. I will post pics when done. Also I widened the changer cavity slightly to accommdate some very thin shims punched out of soda cans. I will also be pulling my pedal bar apart and reassembling it so the is less friction. In addition I will be stringing it up with slightly heavier strings as well, which should help things return where they are supposed to be. The scale of the guitar is only 22.5 so standard C6 strings are a bit on the light side. I may also install a pickup of some kind. Oh yeah and I made all new stops with 8-32 set screws instead of 6-32. The 6-32 set screws are just too small and I had one strip out already.
All of this will hopefully yield a more playable instrument!
I had to flip the brackets that attach to the pull rods cause they were bending under the pressure. Now they are fine. You can see how the lower stops slot into the bell cranks. The lower rods no longer spin when I tune the nylon nuts at the end. I spent a ton of time making sure everything moved very freely! The guitar now stays in tune so far and is very playable finally. Switching to heavier strings has helped some things, but it seems to have hurt the tone of the guitar as the resonator now has more pressure on it and does not ring as freely. I may switch back to lighter strings next time, but for now it is fine. I added turnbuckles to the top of the pedal rods where they attach to the cross shafts. This allows easy adjustment of the pedals. I am learning a few tunes and hope to post some sound clips in the future.
One big thing I realized when tuning this was that the raise rods need to be adjusted differently in order for there to be clearance for the lowers.
They stay in tune relatively well, but with a resonator, the more you change the pressure on the strings you change the tuning of the other notes not being bent. My copedant limits this by only having 1/2 step bends. For an E9 type tuning with multiple long bends this may be a real problem. Maybe it wouldn't be as bad with a traditional top soundboard like an acoustic guitar with a sound hole? Anyway it is something to think about. Good luck and keep us posted on your progress!
Hi Tim just moving the discussion to this thread. You should be able to help that a lot by reducing the string break angle over the bridge, that angle dictates how much force is directed down on the resonator vs in line with the strings. So the shallower that angle the less the resonator (and other strings) should move with each change. Generally any floating bridge setup (resonator, archtop, violin family stuff) will have the same problem and they will get less volume but more sustain as the bridge angle decreases though so it’s a trade off. Resonators have an added limit on that if you go too shallow there’s not enough force to keep the resonator in good contact with the bridge and perimeter though so you’ll get rattles and such. That may be less of a problem for spider type resonators though, I’ve mainly messed with the biscuit ones.
If you’re designing a wood soundboard from scratch you can plan for this though, you want something really stiff in bending (to hold the sting downforce without deflecting)but flexible in torsion (so the string vibration still moves the top). Tall braces parallel to the strings would probably fit the bill but it would take some modeling or trial and error to get the sizing right
I had totally forgot about these. Interesting idea!
For the most part I created the largest break angle that I could while still clearing the back of the guitar. It is already a pretty shallow angle. This limits the experimentation to bridge height and string gauge. I feel like I got lucky with guessing the proper string gauge, but I want to try a slightly taller bridge made of aluminum. I am a having a little problem with rattles I believe are from the bridge. I did try a heavier gauge of string and it sounded horrible. No sustain killed all the resonance, so there is a fine line. The string angle will be even less with my new guitar because it has to clear the resonator cover, and the scale is a bit longer 24" compared to 22.5" on my first guitars. I am expecting to experiment with strings quite a bit before I add the pedals and such.
I had to flip the brackets that attach to the pull rods cause they were bending under the pressure. Now they are fine. You can see how the lower stops slot into the bell cranks. The lower rods no longer spin when I tune the nylon nuts at the end. I spent a ton of time making sure everything moved very freely! The guitar now stays in tune so far and is very playable finally. Switching to heavier strings has helped some things, but it seems to have hurt the tone of the guitar as the resonator now has more pressure on it and does not ring as freely. I may switch back to lighter strings next time, but for now it is fine. I added turnbuckles to the top of the pedal rods where they attach to the cross shafts. This allows easy adjustment of the pedals. I am learning a few tunes and hope to post some sound clips in the future.
