Materials & Considerations
Traditionally, pedal harp columns are made from laminated maple, chosen for its strength, stability, and natural beauty. The best practice is to alternate the grain direction between layers to maximize strength. But, luthiers select grain orientation carefully, especially if the final finish is a clear coat or stain. With a visible grain - consistency matters. If the column will be gilded, painted, or covered, mismatched grain or internal layer variation is less of a concern.

An excellent alternative is ¾" Baltic birch plywood, particularly in B/BB grade. Look for versions with 13 plies, which is nearly double the layers of standard plywood (typically 5–7). The high ply count improves strength, dimensional stability, and appearance. Personally, this is my preferred material for both pillars and necks—but that’s just my opinion.

Solid pine can technically handle the string tension of lower-tension harps. The prototype OpenPedal harp, for example, uses a 45mm x 55mm pine board sourced from a local hardware store. While functional, it’s quite bendy—an issue that becomes even more pronounced when you need to hollow the column for rods or cables.

Some modern harps use carbon fiber tubes embedded in wooden columns for added strength and reduced weight. These also serve as convenient pathways for internal cabling. Off-the-shelf carbon tubes in the 2.5"–3" diameter and 6' length range are available but can be expensive and thin-walled. A more affordable DIY option is to wrap a PVC pipe in carbon fiber tape soaked in epoxy, applying it in an overlapping spiral. Once cured, cut it to length and use it as a central spine inside the column.

Column Dynamics: Compression & Torsion
Most pedal harp columns experience off-center compression—downward pressure on the left side and tension pulling on the right. This results in torsion, or twisting force. Some harp designs attempt to reduce this by adjusting the string path or column angle to centralize the string tension, but torsion is always present to some degree—it’s just a matter of managing it.

Making a Column Hollow
Creating a hollow core in the column is essential for pedal rods, cables, or electronics like in OpenPedal-style instruments. There are several methods to achieve this:
1. Split & Hollow Method
After you’ve turned the column in a lathe, cut your round blank into two halves. Route or carve a semicircular (or your preferred shape) groove down each side, then join them together. If using a carbon fiber tube, embed it during this step and use epoxy resin to fill voids and secure the tube in place. I normally use wood glue for column construction, but epoxy is essential here when bonding wood to composites.

2. 45-Degree Cut Method
Cut your blank into four long pieces using 45° bevels on a table saw. When reassembled, this leaves a square hollow in the center of the column. A square carbon fiber tube can be inserted here, though they’re harder to fabricate DIY-style. If this is your route, I recommend purchasing the carbon square tube pre-made—it’s worth the cost.

3. Drilling
Only advisable if you just need to run small cables or wires, like for OpenPedal-style electronics. Use a long spade bit with hex extensions to drill through the length of a solid column. It’s slo w, messy, and very hard to keep centered. A drill press with the table removed can help, but even then… 2 out of 10—would NOT recommend.


Role of the Column in Tonal Quality
The column's primary function is to withstand the immense tension exerted by the strings and to house the complex pedal rods and cables. Its contribution to sound production is indirect. The majority of the harp's sound emanates from the vibration of the strings transmitted through the neck to the soundboard, which then resonates to produce audible sound.Therefore, as long as the column is constructed from a material with sufficient hardness and density to fulfill its structural duties, its impact on tonal quality remains minimal.

Material Considerations: Wood vs. Resin
While the column's material doesn't significantly affect tone, it can influence the instrument's overall resonance and feel. Traditional hardwoods like maple, walnut, and cherry are commonly used due to their strength and aesthetic appeal. These woods provide the necessary structural integrity without dampening the instrument's resonance. Rees Harps Inc.

Conversely, using a material like resin for the column could potentially alter the instrument's resonance characteristics. Resin, being less dense, less hard and more absorptive than hardwoods, can dampen vibrations. This effect is somewhat analogous to attaching a mute to the bridge of a violin, which adds mass and dampens high-frequency vibrations.


Tonal Insights from Lever Harps
In lever harps, where the construction is often more varied, the choice of wood can have a more noticeable impact on tonal quality. For instance, Dusty Strings notes that in their FH series lever harps, different woods impart distinct tonal characteristics: manufacturing.dustystrings.com

• Maple: Bright, crisp, and focused tone.

• Walnut: Softer, mellower, and warm tone.

• Bubinga: Loud and bold with a resonant bass.

These differences are more pronounced in lever harps and I personally have not been able to pinpoint why.


Column Internal Rod/Cable Systems
The pedal base houses the mounting for the pedals, but that's just the beginning of a surprisingly complex mechanical chain. Each pedal attaches to a rod or cable in the column that connects to the mechanism in the neck, creating what's essentially a 6-foot-long remote control system. The vertical movement works in reverse of what you might expect: pressing down on a pedal means you raise the rod or cable, which in turn presses upwards on the harp's action. Think of it like a seesaw—your foot goes down, the mechanism goes up.

Rod vs. Cable Systems vs. Electronic Solutions
Traditional steel rods were the gold standard for decades—they're direct, predictable, and give solid tactile feedback. But they come with their own headaches: they're slightly awkward in such an enclosed space and they can bind in the guides.

Modern aircraft cables, like what Camac uses, offer more flexibility in routing and are lighter overall. They don't bind the same way rods do, and they're more forgiving if your column has slight irregularities. The trade-off is that they can stretch slightly over time and some report more frequent adjustment, but that has not been my experience outside of regular regulations.

Then there's the OpenPedal solution, which throws tradition out the window entirely. Microswitches mounted to the pedal base send digital signals of pedal position to a microcontroller mounted in the neck. No mechanical transmission at all—just electrons doing the work. It's elegant from an engineering standpoint, though it does require power and introduces a different set of potential failure points from mechanical systems.

Rod Routing and Guide Tube Systems
Here's where things get genuinely complex for first-time builders: rod routing refers to the order in which the pedals are arranged versus the order in which they must connect to the action. The D pedal, for instance, is physically located on the left side of the instrument (according to player orientation), but the pedal extends across the base of the instrument—hidden from normal view—to the right side. The rod connects to the pedal and then has to "shift" or crossover other cables to get to the right order to activate the action at the top of the instrument.

This order is maker-specific, or at least action design-specific, which means you can't just copy one manufacturer's approach and expect it to work with another's action design. It's like trying to wire a house using someone else's electrical panel—the connections have to match up exactly.

Many older 1900s instruments used burlap as rudimentary "guide tubes" to help prevent friction and rubbing between rods, as well as limit vibration or rattling between the rods themselves. Over the years, material science has progressed and most harps now use guide tubes of plastic or a "slick" polymer—PTFE (Teflon) being the gold standard. This reduces friction, limit noise, and help guide the rods into their proper position.

Cables follow a similar solution but offer more flexibility (no pun intended) with routing. They can navigate tighter curves and are more forgiving of imperfect alignment between the pedal base and neck mechanism. The downside is that they may require more sophisticated termination hardware and can be trickier to adjust precisely.

Rod End Pieces and Adjustment Mechanisms

Rods and cables end in a clevis solution that connects to the pedal, while the top of the rod is usually threaded into the action arm connection. Most manufacturers use a right-hand thread at the upper action arm and effectively bottom out the rod there, which means all length adjustments have to happen at the bottom.

This is where things get tedious. Traditional adjustment requires removing the clevis from the pedal, then either rotating the clevis out (making the rod longer, which creates more tension on the discs) or inward (making the rod shorter), then reattaching to test. It's a process that involves a lot of crawling around under the harp and trial-and-error.

I've experimented with a left-hand threaded rod at the top and a right-hand threaded clevis at the bottom to make adjustment easier. This approach means you can adjust rod length without disconnecting the pedal—just rotate the rod itself to lengthen or shorten the overall assembly. It's a small change that saves enormous amounts of time during setup and regulation.

Keep in mind that this is a universal adjustment across all the action for that particular note—individual fine-tuning would still need to be done at the disc level, but we'll discuss that later in the regulation section. The goal here is to get your rough positioning right so you're not fighting the mechanism every time someone wants to change keys.