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. 

The Frame

I've been working on the frame for quite some time now. It's coming together really well. I came up with a height adjustment system using telescoping, perforated, square tubing I found at Lowes. 

I cut out squares for the tubing to fit into the wood. They will also be bolted down with brackets.

Here are all the parts for the height adjustments system. I'm painting all hardware black.

This is about 90% of the base structure of the frame. I won't put it all together until I sand, stain, and finish the wood. Not included in this picture is a support beam that will run the length of the board in the center along the bottom. The pedal will also eventually be attached to it.

Fine Tuning

The keys are finally completely done. The fine tuning process was meticulous. I first tuned each bar down to where my tuner was telling me was in tune, but I knew they were not actually in tune. This is because the ambient temperature in my garage along with drilling and sanding raise the temperature of the bar and cause it to lower in pitch. So when my tuner tells me it's it tune, it was actually around 3-5 cents sharp of the desired pitch. So I had to let the bars settle in room temperature for several hours and then check their pitches indoors. I made a table to make the process a little easier. each column represents different times I checked the pitch of the bars. For some of the columns I didn't make any adjustments. I just wanted to see if having the ceiling fan on or not affected the pitch, which it actually did to the degree of around 0.2-0.4 cents, which really isn't enough to worry about. For several times I repeated this process of making small adjustments, settling at room temperature, and then checking the pitch until all the bars were in tune. I tuned each bar to be less than +/- 0.5 cents of the desired pitch. I couldn't really tune more precise than that because my tuning app was so precise that it showed small differences just by the speed of the fan in the room where I kept them. But I tried to keep similar conditions each time I checked pitches. Here's a scan of the chart I made.

I don't really have any new pictures of the keys to show because most of the adjustments were so small. However on a few keys, I had to make drastic adjustments like this one:

As I type this I'm actually almost done building the main structure of the frame minus the resonators and dampening/pedal system. I won't have a picture of the frame put together until I sand, stain, and finish the wood. Then I'll actually fully assemble it.

Finishing the surfaces

So obviously I don't want my vibraphone to look like a scrap metal yard. So my next step was to smooth out all the surfaces of the bars. This is done by sanding only. I didn't want my bars to be so smooth that there are reflections on them. I did all the sanding parallel to the length of the bar to give it a uniform grain along the bar's length. The sanding process was done in 3 stages or layers.

First I used an 80 grit sanding belt on my belt sander. I applied all surfaces except the top surface of the bar to the flat part of the belt sander. The belt sander was good for quickly removing large scratches but was not very smooth. It was also great for creating rounded edges simply by applying an edge to the sander and then slowly pivoting about that edge. I did not apply the top surface because it produced an uneven grain because the surface of the belt sander was not perfectly flat and some portions of the bar would get sanded more than others.

Then I used 80 grit sandpaper. Even though it was the same grit as the belt sander it made the surfaces much smoother when done by hand. Using wet sandpaper lets the sandpaper last longer.

The final layer was done with 150 grit sandpaper. This completely smoothed out every surface and gave everything a nice "polished" look.

Here is the finished result. I was immensely pleased with how they turned out. There were a few dings and scratches here and there that were too deep to be removed, but I'm not too worried about it. Next up is fine tuning, which will require a good deal of patience.