LinnStrument Darker Mod

[FranklyFlawless]

Credits

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This thread showcases a LinnStrument DIY hardware modification, and is heavily inspired by the LinnStrument Dark Mod by Lars Daniel. Special thanks to Roger Linn for assisting me throughout this project from beginning to end.

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Introduction

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The LinnStrument (128)'s current silicone inner playing surface has a few features designed to assist LinnStrumentalists when learning and playing on it:

• The inner playing surface uses an indented grid to inform the player when near and passing a note's outer boundary.
• The Braille-sized bumps across the inner playing surface indicate the "C" note within the 4ths Strings Layout when no other transpositions are applied.

However, these features also have certain drawbacks:

• The indented grid can produce inconsistent, jittery movement of finger slides across the surface, depending on the amount of fingers used, pressure being individually applied from them, direction(s) they are moving, and speed of travel. The grid's intersections exacerbate this phenomenon.
• The Braille-sized bumps lose their meaning when using other layouts, so in these use cases they either need to be repurposed or ignored.

Having a flat silicone playing surface with the current matted polyurethane coating would be an ideal solution, but as Roger stated in the Speedbumpy Surface thread, from General Silicones it costs:

• Approximately $11,000 USD for a LinnStrument (200) mold with a minimum 240 piece order.
• Approximately $6,500 USD for a LinnStrument 128 mold with a minimum 180 piece order.

With assistance from Roger over the last few months, and learning from Lars' own experimental hardware modifications, a more cost-efficient DIY alternate playing surface has been realized. After my own experimentations with various silicone playing surface revisions from Roger, as well as various materials from McMaster, CS Hyde, and Contrado from Sensel's Material Whirl article, I have decided on bamboo fabric as the basis for the playing surface, alongside other hardware modifications to supersede Lars' LinnStrument Dark Mod.

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Requirements

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• LinnStrument (128) with a steel top panel and silicone playing surface
• Screwdriver with a Phillips #1 (and optionally Phillips #2) driver bit
• Cutting board (wooden is preferred)
• Precision knife
• Bamboo fabric from Contrado (see below for measurements)
  • 18.4cm by 57cm for the LinnStrument (200)
  • 18.4cm by 40cm for the LinnStrument 128
• Set of 50 pan head screws from McMaster

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Instructions

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1. Outer Silicone Playing Surface
   1. Remove the countersunk top panel screws on the LinnStrument (128) using a screwdriver with a Phillips #1 driver bit, then place the silicone playing surface below the steel top panel on a cutting board.
      • If necessary, you can temporarily insert the top panel screws through the top panel and silicone playing surface to align the next task.
   2. Using the inner border of the top panel as a guide, use a precision knife along it and cut out the inner silicone playing surface below to the cutting board.
   3. Separate all of the components while carefully extracting the outer silicone playing surface for the next task.
2. Bamboo Fabric and Pan Head Screws
   1. Place the bamboo fabric on top of the touch sensors, then the outer silicone playing surface above it, and finally the steel top panel with the reverse side above that.
      • If necessary, you can temporarily remove the LinnStrument (128)'s wooden sides using a screwdriver with a Phillips #2 driver bit for the wooden side screws to make the next tasks easier.
   2. Align the bamboo fabric and the above layers along the edges of the LinnStrument (128), then, using the pan head screws, one at a time, slowly and carefully puncture through the bamboo fabric with them while keeping the fabric stretched. Use a screwdriver with a Phillips #1 driver bit to thread each pan head screw through each layer.
   3. Repeat this process until the entire bamboo fabric is tensioned across the entire surface, and no ripples occur from sliding your fingers in any direction using any amount of pressure across it.
   4. After this process, if there is excess fabric past the edges of the LinnStrument (128), you can cut them off using a precision knife. Then, if you removed the wooden sides, you can reattach them back to the LinnStrument (128).

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Notes

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Pros:

• The bamboo fabric has a very wide pressure range, and is a suitable substitute for the current silicone playing surface, with a similar coefficient of friction. Finger slides in any direction feel natural, and all row offsets are treated equally. Durability so far is excellent.
• The inner silicone playing surface can be overlayed above the bamboo fabric as a protective cover. Playing on either surface is possible by swapping between them if desired.
• The pan head screws distribute force more effectively than Lars' recessed countersunk screws, and does not risk compromising the structural integrity of the steel top panel.

Cons:

• The bamboo fabric easily gets dirty. Wash and dry your hands with soap before usage to reduce maintenance. You can use the inner silicone playing surface cutout as an overlay/cover for the bamboo playing surface. When necessary, lift the LinnStrument vertically and lightly brush the bamboo playing surface to remove debris. Washing the bamboo fabric will cause shrinkage and make reapplying tension across it significantly more difficult.
• Slides on the X-axis are more difficult to precisely perform, but with practice, can be counteracted with the slightly raised spacers between each row which defines the upper and lower Y-axis boundary of each row's notes.
• Due to their design, pan head screws stick up from the steel top panel, and are not flush like the countersunk screws. You can take advantage of them as general references to columns, similar to fret markings on a guitar.
• The LinnStrument (128)'s Touch Sensor Prescale value may need to be readjusted depending on how much force the touch sensors have against the upper layers.

Improvement Concepts:

• Extended bamboo fabric (2 inches more in length) tensioned under the wooden sides, to increase vertical stretching.
• Washers from McMaster in conjunction with the pan head screws to distribute more force above the top panel and keep the bamboo surface under tension more easily. This may also increase the Touch Sensor Prescale sensitivity range compared to the current hardware modifications.

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[Shabdahbriah]

THAT is gorgeous! Well done.

[Roger_Linn]

It turned out very well, Frank. Congrats.

[FranklyFlawless]

THAT is gorgeous! Well done.

Thank you for your kind words. It feels even better than it looks in the photos, and is a pleasure to experience.

It turned out very well, Frank. Congrats.

It was an honour to work and collaborate with you throughout this entire project, and I am very grateful for your superb customer service. I learned a lot from you about hardware design in general, and that all design choices have tradeoffs.

The photos of the bamboo fabric shown in this thread have been tensioned for a third time. The first time was too loose, so I washed the fabric with detergent, and with great effort I retensioned it a second time. I did some light retensioning for a third time when I swapped the countersunk screws for the pan head screws.

[LarsDaniel]

Looks good. The fabric seems to be a great idea.
Does the bamboo fibre fabric have any particular advantage over, say, cotton or polyester?

[FranklyFlawless]

Looks good. The fabric seems to be a great idea.
Does the bamboo fibre fabric have any particular advantage over, say, cotton or polyester?

I have not tried either during my experimentations with different materials. The main reason why I sampled bamboo was because of the item description when choosing a fabric while ordering from Contrado:

Panda Woven Bamboo 115gsm
A stiff medium weight woven fabric made from viscose derived from materials from the bamboo plant. Material has a very smooth, silky slippery surface feel, with a stiff structure that softens repeatedly with washing. using softener will further soften the material, using no softener will help retain the stiff starchy feel.

My original objective was to acquire an alternate playing surface that was more slipperier than the silicone playing surface with the current matted polyurethane non-stick coating, so the "very smooth, silky slippery surface feel" description caught my eye. I also have prior experience with eco-friendly fabrics in general, so I already had a good idea of what the bamboo was going to feel like. I just never considered using fabric before because they usually require stretching in order to have a consistent performance across the entire surface. The bamboo is stiffer, so when you apply more pressure using your fingers across the surface, it does not warp or fold as much as other fabrics.

I also sampled the neoprene/polyester front from Contrado. There were issues with it that would not make it suitable as a replacement playing surface. The polyester front surface, while more slipperier than the matted polyurethane non-stick coating, was also abrasive and generated some heat due to friction. The bamboo does not have either of these issues, but the amount of force required for finger slides is about the same as the silicone, while having a larger pressure range, so it is better suited for those who are more heavy-handed with the LinnStrument (128) and use a lower Touch Sensor Prescale value.

[t-IB]

Congratulations on getting it just how you wanted it! I had dreams of a brushed ally faceplate at one point - maybe I'll come back to this one day for inspiration to press on. Great to hear how well supported you were by Roger too, not that I'm surprised on that front - what a gent!

[FranklyFlawless]

Congratulations on getting it just how you wanted it! I had dreams of a brushed ally faceplate at one point - maybe I'll come back to this one day for inspiration to press on. Great to hear how well supported you were by Roger too, not that I'm surprised on that front - what a gent!

Thank you, this project took quite some time and effort to refine. Aesthetics was just a small part of the equation.

[FranklyFlawless]

Today marks exactly one month since I installed the bamboo playing surface, so I have a few notes to mention about how much it has changed the way I play:

• My LinnStrument sessions are three times longer now. Before it used to be one hour a day on the grid, now it is three hours a day off-grid. The bamboo playing surface feels great and empowering to use, with no fatigue.
• I slide my fingers diagonally on both hands now much more frequently. On the left hand, I mostly slide chords polyphonically, as I originally envisioned, but occasionally I use one finger diagonal slides for quick access to an adjacent interval. For the right hand, I started sliding horizontally and diagonally within a string of adjacent notes using the same finger, so improvised licks have been heavily compressed to a few main fingers, instead of requiring four or more. This is a serious advancement to transferring my piano/keyboard skills to the LinnStrument, while also utilizing pitch bends.

For more frequent updates about my progress with transferring my piano/keyboard experience to the LinnStrument, I regularly post once every day or two in the Studio Log thread, as that has been helping me stay accountable with my musical ambitions.

[drake-n]

Do you have any videos of you playing with this surface?

[FranklyFlawless]

Do you have any videos of you playing with this surface?

I wish, but I just ordered the Bose L1 Pro32 from my local Long and McQuade a week ago, and still need to order the matching Sub2 Powered Bass Module along with it. I also ordered a flightcase from Swanflight and expect duties/import fees when it ships/arrives sometime within the next week. I will not have sufficient funds to order a nice cinema camera such as the Sony FX3 until at least the beginning of next year, and that does not include funds for its other related accessories.

I have a very detailed list of priorities to tackle, but the most important high-level goals for music are:

1. Translate piano/keyboard skills to the LinnStrument, while also fully utilizing MPE.
2. Prepare a live music setup with the LinnStrument and the Anyma Omega Desktop, then perform live in a local venue.
3. Prepare a cinema camera setup with the Sony FX3 with other related accessories, then showcase a video of my abilities on my own PeerTube instance, while releasing the video's assets under the Creative Commons Zero license.

[TigerBalm]

Speedbumpy surface guy here, your project looks fantastic! Nice work. I like how you used fabric so that the screws could slip through. If anyone else tried a material that needs screw holes up into it, look up a tool called a punch.

I too would love to see a video! Even a quick cell phone video at home would be good

[FranklyFlawless]

Speedbumpy surface guy here, your project looks fantastic! Nice work. I like how you used fabric so that the screws could through. If anyone else tried a material that needs screw holes up into it, look up a tool called a punch.

I too would love to see a video! Even a quick cell phone video at home would be good

Thank you Chris. You will need to be more specific than "punch", so an actual product would clear up this disambiguity.

I appreciate you supporting the idea of a video as well, but it will take some time to fund, organize, and produce. My smartphone's cameras are still under heavy development, so it is not ready to record video.

Some plans for the video have changed. I no longer want a PeerTube instance, since I am now doing my own front-end web design work on my web server. I will be uploading the video without the video assets since the latter would take up too much space.

[TigerBalm]

oops, the correct keyword is "hole punch" , great for cuttings small round holes into sheets thin objects

[FranklyFlawless]

oops, the correct keyword is "hole punch" , great for cuttings small round holes into sheets thin objects

Much better. That product referenced is a leather hole punch. There are also paper hole punchers, used in offices and schools which are more commonly associated with the term, and more uncommon ones that are used on cloth, plastic, and metal. When I have time, I will do some research on them to ensure that the holes they make are of the correct size for both countersunk screws used on the LinnStrument.

For those who have been intensely following my progress on the LinnStrument (and using my Darker Mod), I created a LinnStrumentalists' Log thread on Poly Expression, and will redirect future log entries to there instead of The Studio Log thread here at KVR Audio.