ThunderWave Ribbon Building Page


Here are the instructions for building ribbons for The Peasant's ThunderWave Ribbon Controller. You can also watch the following video for more detailed instructions.

Materials required for building ThunderWave ribbons:

First, you will need some type of bar or rod to build your ribbon on. For my build I used some salvaged 2 cm curved aluminum stock, but straight ribbon bars work fine as well. A variety of materials can be used for this, however, it helps if it has a bit of weight to it to keep it from jumping around too much as it is hit. Make sure that the bar is nice and clean so that the tape and glue will stick to it well.

Next, you will need a 10 turn precision wirewound potentiometer. I am using a Vishay/Spectrol 10K unit that was removed from equipment as defective. With use, the wiper in these devices eventually goes intermittant, but since we just need the internal resistive element for our ribbon this is not a problem.

When the resistive element has been removed from the potentiometer it will measure about 12k ohms from end to end, and this is the actual resistance value that the ribbon controller circuitry is designed for. If a significantly different potentiometer resistance value is used, then the control circuit may have to be adjusted to compensate.

Three force sensing resistors are required to measure how hard the ribbon is being struck. My build used Interlink Electronics type FSR-402. These sensors should be small enough to fit completely underneath the ribbon bar with no part of the sensor hanging over the edges.

You will need three small self-adhesive rubber feet. These should be a size that fit well on the force sensitive resistors, completely covering the active area, but not extending over the edges.

Here is a picture of some FSR-402 sensors and some rubber feet:

You will also need five different types of tape to build your ribbon. First, some copper tape is used for the electrical contact. I used some 6 and 8 millimeter types with conductive adhesive, that are commonly available for craft use.

Some double-sided sponge tape is needed as well, this should be 12mm wide type with 1mm thick, very dense foam rubber and very strong adhesive.

The next tape is double sided cellophane tape, about 12 millimeter wide. Double sided cellophane craft sheets can be cut into strips and pieces and used here as well. Make sure that you use a high quality tape with a strong adhesive. Finally, a small amount of standard electrical tape and masking tape is needed.

Here are the types of tape that you will need:

A ring lug and securing screw are used to connect a grounding wire to the metal ribbon bar and anchoring the electrical cable.

A couple of small brackets are used to keep the ribbon from moving sideways while in use. These can be anything that will hold the ribbon in place and will depend on how you design the stand that supports your ribbon. I had some salvaged "L" brackets on hand and used a rotary grinder to cut some slots into them so that wires could be run underneath them. You will also need some small bolts or screws to attach these brackets to the ribbon.

Two crimp connectors are needed to connect wires to to the resistive element, as these type of elements cannot be soldered.

Some ordinary small tie wraps are required for securing some of the wiring.

Some hookup wire is needed for the project, almost anything will work here. You should have at least five different colors.

Various sizes of shrink tubing are needed, including some of fairly large diameter.

Next is rubber tubing. For my project I used some 9mm exercise resistance banding. The higher strength types work best here, giving the most "bounce" to the feel of the ribbon, but the size and strength is not critical.

Some thin rubber sheeting is also needed. Again, exercise banding works well here, but the actual type is not critical either as long as it is fairly thin and flexible.

Flexible silicone sealant is used as an adhesive in various places, and some gel type super glue is used in construction as well.

Also needed is some plastic film. This film must be very thin and flexible, but also very strong and must not be capable of being stretched in any direction. For my ribbon I used some old drafting film that I had on hand.

Some foam rubber is required, the type that is used in furniture cushions works well. You must be able to cut this foam into thin strips that are as long as your ribbon will be.

Lastly you will need a 6 wire cable and connector to hook your ribbon up to the electronic controller circuitry. For my build I left the individual wires from the ribbon long enough to function as the connecting cable, slid some plastic mesh covering over that, and then slid a layer of old computer cable shielding over that. Having the silver colored shielding on the outside gives the cable a nice shiny metallic techy look. I then terminated the cable with a standard DB9 connector.

OK, that's it for materials. If you have difficulty finding some of these items, there are a lot of other alternatives that will work, so don't be afraid to experiment and be creative.

Before you build your ThunderWave ribbons:

Design and construct a support stand for your project. Each ribbon requires a small support area under the center of the ribbon and one towards each end, for the force sensitive resistors (FSRs) to rest on. The supports on each end should not be right at the ends of the ribbon or the FSR response will not be consistent between the sensors, so space them inwards by around 8 to 10 centimeters. If you prefer, you can experiment with the FSRs in various different positions to find the optimum locations for your build. Make sure that these support areas are all level and even with each other.

There will also need to be some brackets or supports to hold the ribbon assembly in place. To keep the ribbon from moving front to back, I placed vertical brackets at the same locations as the FSR supports. These brackets have some soft weatherstripping foam covered with heat shrink tubing between them and the ribbon bar. This foam "pad" should have enough side force on the bar to keep it from jumping around when hit, but should not be tight enough to restrict the ribbon bar's vertical motion at all. Heating the shrink tubing up and then sliding the cold metal bar in place to cool it back down works well to form the heatshrink into a snug, but not too tight fit.

You will also need brackets to keep the ribbon bar from sliding from side to side. I attached two small brackets to the bottom of my ribbon bars that extended down on either side of the central ribbon support, and put some shrink tubing over them for padding. These don't have to be very tight or snug, a few mm of gap between them and the support is fine as long as they keep the FSRs fully on their supports.

Make sure that your stand will be strong enough to endure being pummelled repeatedly, and that it holds your ribbons at a comfortable height. You can mount the electronics for your project on the stand itself, or house them in a separate enclosure as desired. Once your support stand is completed you can go on to build the ribbons themselves.

Here is a picture of the stand that I built, including the ribbon supports, but without the legs attached. You can see the foam/shrink tubing pads on the sides of each support area.

Building ThunderWave Ribbons:

Here are some diagrams to give you an idea of how the ribbon is put together. You can refer back to these for reference as you read through the directions if you need to.

Start with a clean metal bar so that the different adhesives stick to it well. I polished my aluminum bars with steel wool before building my ribbons, which made them look nicer too.

The first thing that you should do is drill and tap a hole in the bottom of the bar for a grounding connection lug. This lug should be located near the end of the ribbon that you intend to have the connecting cable attached to, in order to use it to help anchor the cable. Also drill and tap holes for whatever type of brackets that you are using to keep the bar from moving around.

After that, cut out two strips from your thin plastic sheet, to be used later in the construction process. One strip should be the same length as your ribbon bar and the same width as your double sided foam tape. If you are building a curved ribbon, you will need curved strips, so use the ribbon bar like a ruler to draw marks on the plastic sheet for cutting guides.

The second strip should also be the same length as the ribbon bar, but it's width should be one or two millimeters narrower than the ribbon bar itself.

The next step is to place a layer of double sided foam tape along the length of the top of the ribbon bar, from end to end and centered on the bar from side to side. Then carefully place the first plastic strip on top of the foam tape so it covers it fully from end to end. Press the plastic down firmly all along it's length to ensure good adhesion between the tape, plastic, and metal bar. A hand-held pressure roller works well here to help attach the film securely and evenly.

This ribbon has the foam tape and plastic strip attached:

Next you will need the resistive element for your ribbon. Dissassemble your wirewound potentiometer, starting with removing each end from the main body, removing the electrical connection lugs and screws, and then carefully prying out one end of the element with a small screwdriver. Then slowly and carefully pull the internal wirewound element out of the potentiometer body. Gently unroll and straighten the element out into one long strip.

Here is a picture of an element being removed from a potentiometer:

You will notice that the element has a slight yellowish color which is caused by the glue used to hold it in place. Use some scotchbright or other mild plastic abrasive to carefully remove this coating. Always keep the element under tension while cleaning it so, that it doesn't get bent and be careful not to damage or unravel the fine wire from the ends of the element. When it is clean, measure the element from end to end with an ohmmeter and confirm that it measures about 10 - 12 kilohms.

Once the element is reasonably straight and clean, attach a different color wire to each end with the crimp lugs. Position the crimp lugs so that they are covering about 3 - 4 millimeters of the element at each end, with the connecting wire pulled in along side it. Make sure that you get a strong crimp connection as these parts will be buried deep within the ribbon and inaccessible when you are finished. Use an ohm meter to check that you have good connections by measuring from one wire to the other looking for that 10 - 12 kilohm value minus a few ohms that the crimp lugs take up.

The next step is to glue the resistive element to the plastic strip that you taped to the top of the ribbon. Start at one end and put small drops of super glue gel all the way along the plastic strip every centimeter or so. Hold the element over the plastic strip and position the crimp lugs so that they are evenly aligned from end to end. Put one of the the crimp lugs into position and hold it for a few seconds until the glue begins to bond, then place a heavy weight on top of it to keep it in from moving. Avoid getting any glue on your fingers as it will bond skin instantly. Start tacking down the element by holding it firmly down for a few seconds at each glue spot and work your way across the ribbon, placing weights on it as you go. Make sure that you keep the element well centered on the plastic strip. If you get any glue on the top side of the element, wipe it away as best you can.

This is how the ribbon looks with weights on it:

When you get to the far end of the ribbon, glue down the second crimp lug. Go back and check that the element has not moved from it's aligned position and adjust and reglue any areas that are not centered. Allow the glue to dry for at least 30 minutes.

Below are a couple of pictures of a ribbon with the foam tape and plastic film installed, and the resistive element glued in place:

Carefully remove the weights and recheck that the resistive element is still centered along the entire length of the ribbon. Run a fingernail along the top of the element checking to see that there are no glue spots on the top. If you feel any rough spots try to gently scrape them off with your fingernail or a plastic tool, until the entire ribbon element is smooth all of the way along it's length. Now check the resistive element again by connecting an ohm meter to each wire. Next, connect one lead of the ohmmeter to one of the ribbon wires and slide the other test probe along the top of the ribbon from one end to the other. You should see the resistance value smoothly changing as you move the probe along, with no breaks or jumps in the readings. If there are any bad spots on the element continue to carefully scrape away the excess glue until you get a smooth reading along the entire length of the ribbon.

Measuring the ribbon element:

When you are satisfied that the ribbon is free of glue on the top, it's time to add some silicone. Place a small bead of silicone along one side of the element and carefully smooth it out with a small screwdriver blade. The silicone should be just below the height of the resistive element at the center and should taper down to nothing at the outer edge of the plastic strip. There should be a smooth surface sloping down as it moves away from the element with no holes or gaps, especially next to the element itself. Slowly and gently running the screwdriver blade along the silicone will help give you a smooth result, and the silicone surface itself can be further smoothed by running a finger dipped in water carefully along it. When you have completed one side repeat the procedure on the second side of the ribbon. Wipe any excess silicone from the screwdriver blade on to the crimp connectors on each end. The crimp connectors will need to be completely covered with silicone to cushion them against any errant stick strikes when playing the ribbon, so add a thick layer on top and around them.

When you are finished applying the silicone run the screwdriver blade gently along the top of the element a few times to remove any excess. It is far easier to remove unwanted sealant from the ribbon at this point rather than waiting until after it has dried. Remove any silicone that may have ended up on the metal parts of the ribbon bar except at the ends where the crimp connectors are. When you are satisfied that you have a nice layer of silicone on each side of the ribbon that is not higher than the top of the element and fully covers the crimp connectors you can put the ribbon aside for at least four hours for the sealant to dry.

This ribbon has had the silicone completed:

Here is a close-up showing how the silicone should slope away from the ribbon element:

And here is a picture of a crimp connector safely covered in silicone:

While you are waiting for the ribbon to dry, get out the second plastic strip that you cut out earlier, and tape it down to a hard surface in a few places along it's edges using masking tape. Get out the 8 millimeter copper tape and cut a strip slightly longer than your ribbon. Leaving about five millimeters of tape extending past the end of the ribbon, begin removing the backing and sticking down the tape along the center of the plastic strip. If you are making a curved ribbon, don't try to press the copper tape down continuously as you apply it to the plastic strip. Instead, just apply pressure and attach the copper every couple of centimeters or so, making sure that it is in the center of the plastic strip each time. Continue applying the copper strip until you reach the far end of the plastic strip and make sure that you have at least 5 millimeters of extra tape extending beyond the plastic ribbon. Now go back over the ribbon and press down the copper tape firmly everywhere along the ribbon. Don't worry if you get some folds or kinks in the copper as these will not affect the operation of your ribbon and are almost inevitable, especially if you are building a curved ribbon. Do make sure that you do not tear the ribbon or fold it over itself while it is being applied.

Make sure that the copper tape is pressed down completely flat on the ribbon. Use a hand-held pressure roller to ensure that it is flat and adheres well.

Add a second layer of 8 millimeter copper tape and then three layers of 6 millimeter tape to the ribbon in the same manner. Use the pressure roller to flatten the copper ribbon after each layer has been applied. Make sure that the copper is centered on the ribbon and if you accidently tear the copper tape then peel that layer off and start a whole new one. When you have completed all five layers, carefully remove the masking tape and lift the ribbon up. Cut off the extra copper tape at each end leaving about five millimeters excess, which you can then fold over and stick to the other side of the plastic ribbon.

Next, solder some wires to the copper ribbon, one at each end of the ribbon on the side that the copper tape runs down. Try to solder the wire as quickly as possible so that the heat doesn't melt the plastic ribbon. The copper tape should tin very quickly, enabling a fast solder connection. In theory, you will only really need one wire to be connected to the copper tape, however, it is easy to add a second wire so that the ribbon is electrically connected at both ends. This way if you should accidently get a break or crack in the copper, the ribbon's operation won't be affected.

This ribbon is complete with the wires attached at each end:

When you have the wires attached, carefully set the ribbon aside on a flat surface. Try to keep the ribbon from flexing very much and do not allow the ribbon to fold over itself, as this will damage the copper tape.

Once the silicone on your ribbon has completely dried, again confirm that the resistive element is working correctly as before with your ohm meter. Ensure that there is absolutely no glue of any type on the top surface of the resistive element as this can cause dead spots on your ribbon. Clean any glue or silicone remnants from the top and sides of the metal bar.

Now get out the foam rubber and cut out two strips from it that are 5 millimeters wide by 5 millimeters deep and as long as your ribbon. Apply a series of small drops of super glue gel about every centimeter along the top edge on one side of the metal bar, between the plastic strip and the edge of the bar, starting just inside of the crimp lugs (where the actual ribbon element begins). Ensure that the drops are not too big so that they won't soak into and harden the foam, and wipe away any excess glue. Remember that super glue can bond to skin instantly, so avoid getting it on your fingers.

Starting at one end of the ribbon, hold the end of one of the foam strips down on the first glue drop for a few seconds until it bonds, and then continue to glue the foam strip all the way along the ribbon bar, being careful not to stretch the foam lengthwise at all. The glue should begin to stick to the foam after few seconds, allowing you to move along fairly quickly. The outside bottom edge of the foam should be even with the edge of your bar and the inside bottom edge of the foam strip should overlap the plastic strip by a small amount, causing the foam to lean outward from the center of the ribbon. This will help the foam to stay away from the resistive element as it is being compressed by the drum stick, so that it doesn't interfere with the electrical contact. The foam does not need to be installed beside the crimp connectors at each end.

Once you have one side completed move on and do the same thing with the second foam strip on the other side of your ribbon. Then carefully place a board or other flat object on top of the foam and add some weight on top of it so that it compresses the foam slightly. Leave the board on top for about 30 minutes to make sure that the foam bonds well with the bar.

Here is the second foam strip being applied:

This is the board and weights that I used to glue the foam down:

After that time, carefully remove the weights and the board, making sure that the foam doesn't stick to the board and pull away from the ribbon. Check the foam to make sure that it has bonded well and reglue any spots where it may have come loose. Use a small brush to sweep out any glue, foam, or foreign matter from the ribbon between the foam strips.

Here you can see how the foam leans outwards from the ribbon:

Next, place a row of small drops of glue along the top of one of the foam strips. Lay the edge of the copper/plastic strip on it, copper side down. The outside edge of the plastic strip should be about one millimeter inside from the outer edge of the foam, but also make sure that the inside edge of the foam is not covering the smaller width copper tape. Be very careful not to accidently get any glue on the copper tape while you attach the plastic strip. The plastic strip should now be held by the foam slightly off center on the ribbon, this will be corrected when the strip is glued to the second foam strip. Hold the plastic strip in place for a few minutes for the glue to take hold.

First side glued down:

Place a row of glue drops on top of the second foam strip and attach the other side of the plastic ribbon to it by pulling it over past the center of the ribbon and holding it down on the foam, aligned to the foam the same as on the first side. Work your way down the length of the ribbon bonding the plastic strip to the foam as you go. When you are finished, the foam strips should be holding the plastic ribbon and copper tape centered in place, about 5 millimeters above the ribbon element. Again allo the glue to dry for at least 30 minutes.

Second side glued down:

Cut a piece of rubber tubing to fit the length of your ribbon, here again it doesn't need to cover the area where the crimp connectors are. Apply a thin bead of silicone sealant down the center of the plastic strip and place the rubber tubing on top, keeping it centered on the strip. Wrap pieces of masking tape over the ribbon, holding the rubber tubing well-centered all along the ribbon, and let dry for at least four hours.

Below is a ribbon with the masking tape holding the tubing in place, and one with the tape removed once the silicone was dry:

When dry, carefully remove the masking tape and make sure that the tubing is still attached and centered properly. Cut out a piece of rubber sheeting about six centimeters wide and the same length or slightly longer than the entire ribbon including the crimp connectors. Lay the ribbon on to it's side and apply double sided cellophane tape along the top side of the metal bar, just below the foam strip. If you are building a curved ribbon put the tape on the inside of the curve. Then take the rubber sheet, and making sure it's centered from side to side, carefully attach it to the tape on the ribbon with most of the rubber hanging up over the top of the ribbon. Try not to get any wrinkles in the rubber, but don't worry if you do get a few small ones. Use the hand roller to seal the rubber down onto the tape.

Stand the ribbon back right side up and connect an ohm meter to one of the resistive element wires and one of the copper strip wires. Test the element and contact by gently pushing down at different points along the ribbon and checking for an appropriate resistance reading. At the center point in the ribbon, pull the rubber sheet up and over the rubber tubing and down the side of the bar that has no tape on it. Try not to pull the rubber tubing and plastic ribbon sideways as you do this. Add tension to the rubber until the ohm meter registers continuity, showing that the copper strip has been pulled down to and is contacting the resistive element. Ease off the tension on the rubber sheet slowly until the meter indicates that the copper strip is no longer contacting the element. Note how far down the rubber sheet needs to be pulled to reach this point, this will be where you want the rubber sheet to be positioned when you add the tape to the ribbon. Pushing gently on the ribbon should cause the meter to again show continuity.

Release the rubber sheet and move it back over the ribbon out of the way. Apply double sided cellophane tape along the second side of the ribbon bar the same way that the first side was done. At the center of the ribbon, again pull the rubber over the tubing and down the other side and press it into the tape at the same position that you had previously determined, first confirming that there is no continuity indicated on the meter. Confirm that a light pressure is all that is required to activate the ribbon.

This is probably the most difficult part of the build, and may take a bit of practice to get right. If you have too much tension on the rubber sheet, you will get false triggers at incorrect positions when striking the ribbon. If the tension is too low then the sensitivity of the ribbon will be reduced. If the tension is not consistent along the ribbon from side to side then the sensitivity of the ribbon won't be consistent either.

Working your way along the ribbon from the center to either side, pull the rubber up over the tubing and stick it to the tape a bit at a time, making sure that the tension is consistent and does not make the ohm meter show a continuity reading. When you are finished, set the ribbon upright, and lightly tap the top, at every position from end to end, to make sure that it takes about the same amount of force to get a reading on the meter.

Pulling the ribbon over:

If you find that the tension is not consistent or that the ribbon sensitivity is too high or too low, then it's best to peel the rubber on one side off again, remove the old double sided tape, apply new tape and try again. If you peel the rubber off and try to stick it to the same tape a second time, it will not adhere well and will probably peel back off sooner or later. However, it you find that you have only one or two spots where the ribbon is slightly too sensitive and the rest of it is fine, then you can try gripping the top center of the rubber sheet at that point and stretching it firmly upwards for a few seconds. This can slightly lower the tension and allow the rubber tubing to center itself under the rubber sheet which may fix the problem.

This is what the ribbon should look like with the rubber correctly installed:

Once you are satisfied with the rubber sheet installation, seal it down on the second side with the hand roller. If you get a few folds or kinks in the rubber don't worry about it too much, and if you get a larger area where it doesn't stick, use a bit of super glue to reattach that area.

Apply shrink tubing to the brackets that attach underneath the ribbon, to cushion them from rubbing on the stand.

The next step is to install the force sensitive resistors and complete the wiring. Measure and put marks on the bottom of the ribbon bar where the FSR supports are located on your stand, so that you can install the sensors at the correct positions. Turn the ribbon upside down and temporarily place the FSRs at their respective locations. Using them as a guide, apply one centimeter long pieces of electrical tape on the metal bar underneath where their metal contact pins are located. Then apply double sided cellophane tape to the rest of the area where the FSRs are to be placed, to hold them in position. Don't worry if the tape extends past the edges of the sensors, this will be trimmed off later.

This is what the FSR locations should look like:

Attach your choice of a connector or wires to the pins of one of the FSRs. Both of the wires used here can be the same color, as FSRs have no polarity and so the leads are interchangeable. The manufacturer of the sensors that I used recommends using a specific connector to attach to the device, which should work well as long as that connector will fit underneath your ribbon. However, I prefer to solder the wires directly to the FSR pins and cover them with heat shrink tubing. If you decide to do this, keep in mind that this is not how the device is intended to be used and that the heat from soldering can very easily ruin the sensor.

Once you have connected the wires, carefully stick the FSR to the double sided tape at the position on the bar furthest away from where the ground wire attaches, with the active element facing outwards. If you use a connector for the FSR make sure that it is securly attached to the ribbon bar as well. Trim away any excess tape not covered by the FSR.

Gently pull the two wires from the top side of that same side of the bar over the end and use a few small drops of super glue to tack the wires down to the bottom of the bar. Continue tacking the wires to the bar until you get near to where the first FSR is located.

Now tack down the ribbon wires so that they are positioned on either side of the FSR as they run past it, but do not get any glue whatsoever on the FSRs themselves as this can stiffen them and reduce their sensitivity. Apply one of the self-adhesive rubber feet to the FSR, carefully aligned to the center of the device, and continue running the wires further along the bar. Make sure all of the wires are secured well to the ribbon bar, held tightly up against it at all places, and do not cross over each other.

When you get to the second FSR, install it and run the wires the same way as was done for the first one. Wire all three FSRs in parallel with each other, so that you end up with a total of just two wires for all three devices. Make sure that there is clearance for the wires to run past any brackets that you are attaching to your bar, and install those brackets as the wires are routed past their positions.

Install the third FSR the same way as the first two and then install the ground lug with it's wire attached. At this end of the ribbon, bring the two ribbon wires from the top around to the bottom, and attach them same way as the wires at the first end were done. Finish routing and gluing down all of the wires until they all come together near the ground lug, and then splice the two wires from the copper tape together to make a single wire. At this point you should have six separate wires to work with, one from each end of the ribbon element, one from the copper tape, two from the FSRs, and one ground wire.

This ribbon has all of the bottom side parts installed and wired up:

As stated earlier, for my build I left the individual wires from the ribbon long enough to function as it's connecting cable. You may prefer to splice in a multi-wire cable instead, just make sure that you anchor your cable to the ground lug when it is complete.

To assemble my cable, I first neatly gathered up the wires, slid some plastic mesh covering over them, and then slid a layer of old computer cable shielding over that. This assembly was then secured to the ribbon ground lug with some tie wraps.

After the cable is secured, cut out a pair of 2 to 3 centimeter long pieces of large heat shrink tubing and place them over each end of the ribbon. Shrinking them down seals the end of the ribbon and holds everything in place nicely. Make sure the tubing doesn't cover the active parts of the ribbon.

Lastly, install the connector of your choice on the end of the cable. Here is what your finished ribbon should look like:

And that's it, you are finished! Place your new ribbon on it's stand, and start making thunder!!


Troubleshooting

Here are a few helpful ideas in case you experience problems with your ribbon.

1. Ribbon occasionally plays the wrong or an extra note when struck.

This usually means that the rubber sheet covering the ribbon is slightly too tight at one point. Go to the spot on the ribbon where the rogue note normally is generated, and check that the rubber tubing is aligned in the center of the ribbon. To realign the rubber tubing and slightly loosen the rubber sheet tension at that spot do the following: With one hand underneath the ribbon, grasp the ribbon bar on both sides at the bad spot, holding the edges of the rubber sheet firmly against the adhesive tape and metal bar. With your other hand grasp the rubber sheet at the top where it rests on the tubing, and carefully but firmly stretch the rubber upwards for a few seconds. Slowly release the tension and check to see if the problem has been fixed. If doing this doesn't fix the problem, you will have to peel one side of the rubber off away from the ribbon, scrape off and replace the double sided tape, and reattach the rubber sheet to that side of the ribbon with slightly less tension than you did the first time.

2. Ribbon has dead spots

This may be caused by a number of things, including foreign matter trapped inside the ribbon, glue on the copper ribbon or resistive element, foam getting underneath the copper, or misalignment of the copper ribbon.

Carefully check the ribbon, and dissassemble and rebuild the ribbon as required to correct the problem. Repositioning the rubber sheet and tubing as detailed above may also help.

3. When tapping the ribbon lightly, some areas don't trigger while others do.

If the tension on the rubber sheet is uneven then the triggering will be uneven. Ensure that the rubber sheet is installed correctly.

4. Force outputs don't work well or are inconsistent from side to side.

This can be caused by too much ribbon support vertical friction, uneven force sensitive resistor mounting or supports, or glue contamination of the force sensitive resistors.

Ensure that ribbon bar is able to move vertically in it's supports without restriction. Every bit of extra force that is needed to move the bar downwards decreases the signal that the FSRs are able to generate.

If the supports for the force sensitive resistors are not flat and level with each other, the FSRs will each receive different amounts of force from the ribbon bar. Make sure that they are placed evenly and correctly.

Examine the force sensitive resistors themselves and replace any that may have been damaged or have glue on them.

5. Drum sticks make clacking sounds when striking the ribbon hard. Ribbon feels "dead" when hitting it.

The rubber tubing should be strong enough to prevent this and allow a nice bouncy feel to the ribbon. Make sure that you use high strength, dense tubing.

If you are still having problems that you cannot solve, send me a note and I will try to help.