Back to work...

It has been a long time since I posted here. Unfortunately, it has also been a few weeks since I got any significant work done on the Marimba. I have been busy over the last few weeks with the Robotics, which will continue for the next six weeks, though I will be able to do some work on the marimba now that the competition is over. Also, my grandparents are in town this week which will enable me to get more work done faster with the assistance of my grandpa.

Phase 3 complete

its been a while since I posted here. this is because I haven't done alot of work on the marimba for the last month. this is soon to change, as the winter break will be a good chance to get more work done. next on the list is to create some sort of plug for the resonators and cut them to length... more to come.

Phase 3:

PERSONAL PROJECT PHASE THREE

Neil Merchant

12/8/2010

To complete my personal project, I used a variety of different designs and strategies.

At the outset of the project, I did not have any clear idea of what I wanted the final project to look like. Even without having a clear, accurate vision of what the final project was going to be like, it was still quite possible because the majority of the guides that I had looked at used the same general dimensions for the bars. Having said that, the first three keys that I cut were unusable because their dimensions do not fit well with any of the final dimensions that we used for the keys, so I am planning to use them either as backups in case any of the keys get damaged or lost, or as models for demonstration purposes of the various stages involved in realising this project. When I finally found the guide from makeamarimba.com, I decided to use that particular plan because of the extent that the guide described how to actually build the marimba—especially the frame—even though I originally did not like the way the marimba described in the guide looked. Originally I had intended to make a marimba with a much more triangular frame, but after finding the aforementioned guide I decided to switch to a design that was more of a combination of the type laid out there and my original plan. An important point to consider is that this is the first marimba I have ever built, so having a guide that contains some detail is very helpful in meeting the deadline that I have for the project, and makes it much easier to realise the final project.

In terms of materials, I had a few choices, a few of which would have had a major effect on my final result. The first material choice that I shall detail here is the choice of wood for the bars. I chose to use padauk[1] for the bars for a variety of reasons: it is recommended by many of the sources that I used, it is a very hard wood (helping it to create a nice sound when struck) and it is relatively inexpensive compared to other similar woods. Aside from this, it is used in many commercial instruments. In terms of marimbas, it is one step down from rosewood which is well known as one of the best woods available for marimbas. Unlike padauk, however, rosewood is very expensive, putting it out of my range for this instrument. Aside from this, padauk just looks good because of its intense color and grain patterns.

Another choice that was similar to the padauk is the material for the frame; I chose to use oak. The main reason for this is, to quote Sir Edmund Hillary, “because it’s there”. Earlier, an oak tree that was standing in the front yard of my house had been knocked down in a wind storm. Instead of burning or shredding the wood, however, we had it made into planks in the hope that sometime in the future we could use it for something. The marimba provided a convenient way to use this wood. I preferred to use this wood for several reasons: I would rather use local wood instead of shipping it from somewhere else, and because it is cheaper to use something I already had than to go and buy more from somewhere else. As well, I found it interesting to be able to turn raw materials (eg. Logs) into something refined. The final reason for using oak is the same as the padauk; the combination of the very light wood of the oak and the dark red wood of the padauk. the similarities in the woodgrain also add to the effect. The final material choice that I will describe here is the resonators. For the resonators, I decided to use two different types of pipe: PVC and ABS. the PVC is used for the larger pipes, where the ABS is used for the smaller because it comes in more convenient sizes.

In terms of design changes, I went through several during the process of creating this marimba, most due to material or tool-related problems. As I described before, the frame of the marimba went through several different versions before settling on one final version. As well, I have had problems with jointers. Throughout the process of creating the frame, I have managed to break three jointers, two with in the first five minutes of use. I believe this was due to a problem in the manufacture of the tools, but it set me back quite a while regardless. Another unintentional change of method was predrilling. At the beginning, I intended to use three separate drill bits to drill each hole; one thinner long one, one shorter thicker one, and one countersink. This plan quickly changed for two reasons: one, it would take way more time than I have to drill every hole this many times, and two, I found a single drill bit that tapered to a countersink, allowing me to drill each hole only once. The final major design change that I went through was the caps for the pipe. Originally I intended to use PVC pipe caps and PVC glue to seal the resonators, but this system has two major disadvantages. PVC glue is a risky thing to use because it will bond the two pieces of plastic in around 10 seconds. This is a bad thing because it does not allow much time to get the tuning of the pipes right. Aside from that, PVC caps cost about $2 each, making the total price for all of them that I would need greater than the total cost of the keys themselves. This is unacceptable. I have a few ideas for what I will use to seal the pipes, but as of yet do not have a final design prepared.

I am finding this project particularly satisfying to complete. It is very satisfying to be able to take a rough plank of wood (the form that the padauk was in) and turn it into a key, which can create a beautiful sound. As well, I have learned a variety of new skills during the process of creating the marimba: how to properly operate a variety of sanders, how to use a tuner, how to cut plastic pipe, and how to use a variety of power saws.

Throughout the project, there were several happenings which made it difficult to stay on track. Even with these problems, however, I have managed to keep to an approximate schedule and am on track to finish the project in time.

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[1] The spelling of this word is debatable. I choose to spell it with an –auk; it is also correct to spell it –ouk or –oak.