Dampener Bar Alterations

To my luck, the changes that needed to be made to the dampener bar were very easy. I knew that the bar was sitting too high against the keys. All I had to do was unscrew the square tubes from the A-frame strut that were jointed to the dampener bar. Then I just screwed them back in a little lower than they were before. This instantly fixed the problem.

I also added 2 more layers of felt to the dampener bar to add more dampening. Zip ties did the trick pretty well. And that's all that needed to be done. The dampener doesn't dampen the keys completely perfectly, but it's good enough for me. It just sounds like the keys are at a half pedal resonance when the pedal is up, which sounds pretty good anyway. Now the whole vibraphone is completely finished! More pictures will be coming in the next post.

The Dampener

I was hoping for this to be the final step in the construction. After finishing building and assembling the dampener bar, it proved to not work as I intended. More details will come on that later. So I have to go back and figure out some alterations to make to the way the dampener moves in order to get it working properly. So yeah, still not done. But in the meantime here is the post on building the dampener version 1.

Right off the bat I had do a pretty drastic modification to my frame. I had to cut the A-frame completely in half right down the center. This had to be done in order to drill parts into the sides of the struts on the A-frame. If they're connected there physically isn't enough room to fit a drill in there to drill guide holes for screws. It all worked out because the A-frame already had bolt hole locations where it attaches to the lower part of the frame, so the bolt holes still line up, there's just a little slit at each end of the board.

The first item I had to drill into the struts were these 2 little blocks that sit directly over the center of the pedal. These blocks will support the spring mechanism for the dampener and pedal. 

This is the spring I ended up buying on Amazon. 

I got lazy with the pictures for the rest of this. I just took pictures of all the parts after I finished it. The next part is the actual dampener bar, but the structural portion without any padding on yet. It's made from a 3/4" square aluminum tube. The wood blocks at the ends are what connect the ends of the bar to the A-frame to give it support. These are also hinged where they connect with the A-frame to allow the bar to rotate downward. In the middle is the spring mechanism. 

Here's a close up of the spring mechanism and how it's assembled. It works using an eyebolt holding the spring in place with a metal plate. The pedal will be connected to the hook of the eyebolt. The eyebolt is bolted into the square tube. When you push the pedal down, it pulls the whole bar down on the spring and compresses it. The rubber washer is there to eliminate noise from metal hitting against metal. adjusting the wingnut will allow you to raise or lower the resting position (pedal up) of the dampener. 

Here are some pictures of the dampener installed in the frame.

Next I connected the pedal to the spring mechanism with leftover square aluminum tube. It's hinged at the bottom where it connects to the actual pedal. At the top is a hook and eye turnbuckle which will allow you to raise and lower the resting position of the pedal to your preference or if you adjust the height of the whole instrument. 

At the top of the dampener square tube I riveted a long piece of flat aluminum bar. This is what the padding will be attached to. 

For the padding I bought carpet padding and black felt. The carpet padding is glued to the flat aluminum bar with epoxy. I then wrapped the felt completely over the flat bar and carpet padding and glued it to the undersides of the flat bar with epoxy. 

Technically the whole vibraphone should be done at this point, but when I put the keys back on, the weight of the keys caused the bar to sit too far forward and therefore not allow the accidental keys to be dampened enough. Also the whole bar sits too high and doesn't never fully leaves contact with the keys when the pedal is pressed. On the brighter side, with the keys off, the pedal behaves properly and the padding actually dampens the keys properly (at the least the keys it has full contact with). I have to go back and make adjustments to the default position of the dampener bar. Hopefully that isn't too challenging. 

The Pedal

At this point, the vibraphone is about 98% complete. All that's left to make is the pedal and the dampening system. If you didn't know, all vibraphones, in their default state, are dampened. This is done by a padded bar that pushes up on the keys in the middle of the frame where the natural keys and sharp/flat keys come together. The dampener is attached to a spring system that lowers it so that it's no longer in contact with the keys, letting them naturally ring when struck. This whole dampener and spring system is controlled by a pedal at the bottom of the frame that you push with your foot.

To make this pedal, I just happened to have a scrap piece of wood that was wide enough. I rounded off the corners on the end closest to your feet.

I couldn't just directly attach this pedal to the support beam running along the bottom of the frame because that beam sits a little too high and you would have to pick your foot up off the ground to push it. I had to build an extension to lower the resting position of the pedal. It's just small square blocks screwed into each other with another support beam connecting them at the bottom where the pedal will be attached. The pedal was attached using 3 door hinges.

Here is the whole instrument with the pedal installed.

Resonators Part 2

The next step is to rivet each resonator to two aluminum beams. Rivets are used because it's much cheaper to buy over 100 rivets than to buy over 100 nuts and bolts. Also they don't protrude into the inside of the resonator very much. 

I made these anchor blocks with slits for the resonator support beams to rest in. 

And of course, painted black. 

The only thing left to build is the dampener bar and pedal, which could be very complicated to design.

Resonators Part 1

It has been a struggle to find time to work on the vibe. In October I moved out of my parents house 30 minutes away. So I still have to go to their house to work on it. I decided to make the resonators into 2 posts just because it might be a while before they're completely done.

The resonators are being made out of PVC pipe as it's cheap and very easy to work with. It actually doesn't matter too much what your resonators are made out of to properly resonate the bars.

I tune them by sanding off bit by bit from the open end until I have the correct pitch. I check the pitch by hitting the capped end with a mallet. It isn't too big of a deal if the resonators aren't tuned as precisely as the bars were. In fact, the resonators were quite difficult to tune. Temperature affected them very much and I would get pitch readings all over the place on many of the pipes. I just tuned them as close as I could.

The pipes ended up appearing much shorter than typical manufactured vibes. But they are the correct pitches and they actually do a great job of resonating a note, especially on the low end. On the highest 4 or 5 notes, you can't really tell a difference between the sound of the note with or without a resonator.

I cut out these notches on the tops of each pipe. Eventually I will add a fan and motor system and this is where the fan rod will rest. But that's more of a stretch goal to tackle after the rest of the vibe is completed.

Additions to the frame

I added a support beam connecting each end board at the bottom for extra stability. The pedal will also eventually be attached to this beam.

The string hooks need some type of buffer between them and the keys, otherwise metal would be rubbing against metal. You can buy latex tubing on Amazon that works perfectly for this purpose. Even when the key are touching the latex, it barely dampens the bar at all. The tubing also elevates the bars even higher off the frame. 

I made a video to show how long these keys will resonate even without resonators. 

Next up: resonators. I've already tuned the first 6 of them as of posting this. 

The Frame, part 2 (staining & assembly)

Staining the wood was actually quite enjoyable. I've seen from many different sources that it is very difficult to stain pine evenly. I tested the stain on some scrap wood and I was pretty happy with it. For the stain I used the Minwax Dark Walnut stain.

 After the stain dried I applied 2 coats of Watco Danish Oil Wood Finish. My pictures with the lighting conditions don't show the stain very well. I was very pleased with the finished result. There were a few blotchy spots where the pine unevenly soaked up the stain, but it's not terrible.

I then had to assembly all the parts of the frame. It came together quite nicely for the first time. I did have to add 2 additional bolts on each end board to provide stability. I will add a support beam connecting the two end frames from the bottom. The pedal will also be attached to this beam. I also painted and screwed in all 88 screw eyes to suspend the bars. I bought black latex tubing that I will cut into small pieces and stretch over each screw eye to better suspend the bars and to serve as a buffer against the bars.

This is now the second big milestone that I've reached in the project. The first being tuning the keys.