Electro Pedal Steel Build

[Jacobus De Bruyn]

Good morning.
I announce my new project in January this year when I started working on it. I thought its time for an update.
Progress is slow but surely going forward. There however were some challenges to overcome from my originally Wishlist.
My Wishlist.
1) Guitar will have a stainless steel body which is laser cut. (Done)
2) The guitar will not have tuning pegs at the nut side but instead it will be tuned at the bridge. Done.
Strings will be adjusted with three methods.
a) Manually by finger. Done.
b) Manually using a small handle to wind, it's faster.
c) Auto tuning where the guitar will tune itself in auto tune mode. This will be a completely new concept. I already done some tests and it does work. Code 50% done.
3) The Guitar will have a touchscreen display, which will house all controls for tuning, chord select, changing from E9 to C6 and more. Touch screens done. Screenshot Attached.
4) This design will use stepper motors. installation completed.
5) With this design the strings will not be stretching to change the pitch. More later on.
6) The fret on the fret board on this build will be lit up in any colour, selected in the parameter list. Done see pictures.
7) The fret on the fret board will also be used as follow. When you play for example in "G" when you select "G" in the touch screen the corresponding frets will change to a different color. That will be useful when playing in the dark, or when in training or just because it looks nice. Done
8)Pedals A, B, C, D, and E will use "Hull sensors". My first build used potentiometers. Fone.
9) The communication from the pedals to the main panel will be wireless, as it is on the first build. Done
10) The guitar will be able to convert to C6 from the display. Code in progress.
11) The guitar will have a wireless headphones. Not done yet
12) The speaker outlet will be wireless as well. Not done yet
13) The head and tail will be rounded off with a dark wood finish, where the touch screen will be fitted at the top of the head stock.
The pick-up already done with wood. It came out quite nice.
13) To achieve the auto tuning I had to create a multi wind pick-up. One coil per string. Done.
Most of the code was tested before, but all need to be compiled into a functional setup and tested. Meaning there is still lots of hours to be spend before completion.
The code up to now did give me some major issues, but I'm getting there slowly but surely.
On the hardware side a couple of you had concerns about when I move the string cage that the fret bars will be offset. I originally did not realize it, but it however will be the case. So, the plan is when all is running, I will take measurements and electronically via the software compensate for the offset. I'm confident that I can correct it via the code.

[Al Carey]

This is truly fascinating. Bravo!

[Jacobus De Bruyn]

I thought I will give a brief progress before I slow down a bit with the built. The Guitar as it is currently is about 50-60% complete. There is unfortunately a however in the works as I struggle to get some things done.
The body and mechanical assembly went as planned but the part I struggle with, I might need to seek help.
The code to control the stepper motors currently give me problems as it just refuse to do wat is asked. I'm sure it is in the code so will work on it. I'm new to Code standards so still learning by error.
The sound and sustain also do not currently meet the steel guitar standards and will need some modification to get it up to standard.

Attach some photos up to where I am today. Last photo with my 3 Steels. Lap, first built and current.

[Carl Mayer]

Im glad to see the progress youre making on this! I had a couple more questions if you dont mind elaborating.

What are your mechanical tuning machines? is that something store bought or did you scratch build them? I havents seen anything like those but it makes for a nice compact setup.

For your changer, from the pictures it looks like youre just adjusting the scale length instead of the tension, wont that mess up your intonation (like if you have a perfectly tuned change in open position, the same change with the bar at the 12th wont be in tune because youre no longer at the center point the strings you adjusted the scale for), or is the movement small enough its negligible?

On your first build how did you do the tuning without the touchscreen interface you have in the second build? was it stable enough you just program the servo rotations once and you dont really need to mess with it after that? or did you have some trimmer pots hidden somewhere for tuning?

[Jacobus De Bruyn]

On the tuner I heavily modified an existing tuner, If you punch in the following in ebay you will see what I used as a baseline(6 String Headless Guitar Bridge Tailpiece for Electric Guitar Parts).

On the changer side of things, yes as the tuner carts move the strings do go out of tune but I compensate that in the code. As you move the metal bar moves over the strings I measure between any string (same as on a touch screen) and that determine the compensate value. That work well, However...

The however is on the sound quality through the tuning carts. I lose quality and cannot get the genuine steel guitar pitch.
I am in the proses in making the call to maybe dump the carts and go back to the tuning fingers. I designed the buddy such that it can be changed.

On my first build the tuning are done manually as on a normal guitar. The string pitch changing are done by servo motors and program.

[Carl Mayer]

Yeah I’m speculating but I can imagine you loosing a lot of sustain and high end with the way the strings are supported if I’m looking at your pics correctly. Your string trolleys are held up on just strips of the sheet metal body(what looks like ~5mmWx1mmHx100mmL beams), those are going to be orders of magnitude more compliant than a regular ~15mm changer axle. That means more string energy is directed towards moving those beams up and down and not towards keeping the strings ringing a long time. It also looks like you have some black plastic for the trolleys to slide on, if that’s even a little soft/rubbery you’re going to loose energy there too(especially in the high end). Before you give up on the design and go back to a rotating changer you could try replacing or adding more rigid support under the trolleys and see if it helps. Or just as a test put a solid bar under all the strings as a temporary rigid bridge (to eliminate the changer) and see if you’re satisfied with the tone. if the sound quality is still not acceptable maybe the problem isn’t the changer but some other component altogether (like the single string pickups, the nut, etc)

[Jacobus De Bruyn]

Hi Carl. Yes your ideas are all valid and I did worked through it all. I did removed the plastic slewing and put more support at the bottom of the rails. I might take you on to add more support at the bottom and see how it go. On the pick-up side, I wound a single pick-up with 16K resistance which I use on my first build.
I am thinking more towards the trolley as there are too many touch points. (top pulley, top pulley bearing, lower pulley, lower bearing, the support bars and finally the metal that flex to the sides for support). That whole area needs to be solid.
Thanks for your support I will test it with a solid when I'm back home and see how it go.

[Jacobus De Bruyn]

Hi all. I am in the process to conclude my project and will sent a progress soon. As all the controls are done by software which needs calibration I need the following from you experienced. What is the perfect pitch for a 12string E9 and a C6 10 string. Also I need the values for the foot and knee levers. The reason for the 10 strings for C6 is when selecting C6 the system will adjust 10 strings and disable the top 2. I will be using a universal setup (suggestions on which setup will all be tested.).

[Jacobus De Bruyn]

Hi All you Steel Guitar lovers,

First of all, I would like to wish you all a good and restful Christmas season. I will be off for two weeks where I will be spending time on my latest Electro Steel Guitar.

To give an update on the build, I completed the body up to the following:

I completed the code for manual and auto tuning. The tuning is done from the touch screen at the front end of the Steel. Auto tuning will read the frequency and automatically adjust accordingly.

The next step will be to test and complete the Pedals. The Pedals are complete but I need to commission the stepper motors that move the string arms.

The bars will light up according to the chord played. The cords will light up in different colors to indicate the chords played, selected from the touch pad. (Done)

Completely wireless—power supply, connected at the foot Pedals, with control voltage going to the main body via the two front legs.

Sound to dedicated power amp via Bluetooth.

Sound to dedicated ear plugs via Bluetooth.

SD card that will store songs or back-tracks.

Tuning I will be using E9/B6/C6 universal tuning and as part of the auto-tune, the guitar can easily be tuned to C6 with the press of a button on the touch screen. When in C6, the two top strings will be disregarded as string one on C6 will be the second string.

Calibrating the knee levers and foot pedals will be through the touch screen.
Well that is all for now, talk soon

Attach photos.

[Tim Toberer]

It has been really cool to watch this progress! This is some cutting edge @#%$! I love the newest design and look forward to seeing more.

[Jacobus De Bruyn]

Hi everyone,

As I return to work after the holidays, I thought I’d provide a progress report before the pace of the build slows down.

The good news is that the build itself is complete. I am now in the commissioning stage, where I am adjusting and configuring the components (code base).

I have configured and completed the manual adjustment phase. To wind and adjust the strings, I am using the touch display.

The stepper motor setup went well, but I need to add Hall-effect sensors to define the home positions on the pull arms. While the steppers do return to their home positions, they sometimes get confused during the winding of new strings.

I still need to commission the auto-adjusting functionality and fit the knee levers.

Overall, everything went well and turned out as expected. Please let me know if you can think of anything that could be added or if there’s anything I could do better or differently. I did make several changes based on your feedback.

Attach the photos and one video.

[Jacobus De Bruyn]

Hi All,

I have a question and also thought it's time for another update on the build progress. In the previous status, I mentioned that I was commissioning the stepper motors that were to pull the strings. Well, that didn't go well at all. I ran into issues where the steppers kept losing steps, and the only way to fix it was to go with more powerful stepper drivers. As I have 12 strings, the drivers would take up all the space, so I went back to servo motors, which I used in my first project. I then redesigned the whole guitar and basically started from scratch.

I've attached the photos as of today.

I completed the servo commissioning, and the servos perform as expected. I also completed and tested the E9 to C6 conversion setup, and it works surprisingly well. I tune the strings to E9, and when I press the C6 on the screen, it moves the strings to C6 very accurately and almost instantly.

However, I have some issues with the pick-ups I wound. The pick-up closest to the bridge has a tone that is too high, and the front pick-up lacks volume. When I adjust the volume on the amp, it picks up noise. Does anybody have the specs for how many windings and wire gauge it should have for a 12-string pick-up?

[Carl Mayer]

Glad to see the project moving along. Regarding the pickups here are a few thoughts:

The signal output is proportional to turns so id keep that the same as a regular 6 string, like 5-10k ballpark. Since each turn on a 12 string pickup is longer id expect the measured resistance to be higher when youre done so dont worry about those numbers too much.

Distance to the strings makes a big difference on signal output and tone. Theyre usually ~3mm below the string. It’s hard to tell but i think yours look significantly lower from some of the pictures.

Tone is significantly affected by placement along the string length. The strings are vibrating at the fundamental and a variety of higher harmonics. If the pickup is at the string midpoint youd get the most fundamental and 3rd harmonic but no 2nd harmonic since the node of that frequency is at the midpoint. The closer you are to the bridge the brighter/thinner your tone will be. Try picking an acoustic at your pickup position (~20mm from bridge) compared to at the 12th fret to get a general idea. Hard to adjust since the holes are cut directly in the body but if you need to raise the pickups anyway maybe you can cut a big section out and have the pickups on a raised plate where you can try different positions or rails where you can slide them back and forth till youre happy.

I’m surprised you’re getting low output and noise for the front pickup since that one looks like it’s humbucking. Did you double check you wired the two coils with the correct phase/polarity?

[Jacobus De Bruyn]

Thanks for your feedback. Of what you mentioned I do not have enough winds on the bridge pick-up and the front pick-up I removed it and will rewind it as 2 of the single coils is open circuit. The humbucker winds seem to be connected wrong and also not enough windings.

[Carl Mayer]

If you’re starting from scratch I always wanted to play around with DIYing those alumitone pickups

https://guitarnuts2.proboards.com/thre ... sis-review

It’s a pretty neat concept, basically a single loop on the sensing side and an off the shelf transformer to step that low voltage up to where the amp expects it. It’s nice cause it’s easy customize for different sizes and shapes (extra long for psg, curved for upright bass, lightweight for acoustics, that kind of thing). Was actually daydreaming about machining the pickup loop directly into a metal body like yours for a flush streamlined look myself.

[Jacobus De Bruyn]

I also did look at that type of pick-up, will try it out for sure.