Building the Frame- Part 1

Hey everybody!

I'm happy to report some significant progress over the last few weeks.  Since I received my lumber order, I've been designing, re-designing and re-re-desiging the frame, but also I have finally broken out the table saw and cut out all of the pieces for the frame!

Lots of pics to follow...I'll explain what's going on as I show you what I'm working with.  :)

First, I had to construct the rails that hold up the bars and account for most of the length of the instrument (which really is close to 10 feet!).  Originally planning this one out was tricky.  Because I sincerely doubted the lumber yard's ability to keep nine-foot board lengths from bowing too badly, I decided to order pieces that would be half the length, and then piece them together to make long boards.  Unfortunately, much of the wood I received was cupped (which means it was warped along its width in a "cup" shape), and I had to be careful to select the straightest boards for this part.

Once I did, I cut four boards into eight lengths that were four inches wide, and I paired them up.

Lined up, the pieces looked like this!

After sanding them a bit (which I should have done a bit later, after connecting them...), I began work on the brackets that would fasten each set of two boards into a single rail.

 

I bought two pieces of 1/8 inch thick steel, each a 3 inch width and 3 foot length, and I cut them into quarters with a cutting wheel on a compound miter saw, so that I had eight pieces like those pictured above.  Then, I had to drill holes in these pieces where the would screw into the wooden boards I cut.

After cleaning them up and painting them black, they looked pretty good!  

I used these brackets as templates for where to cut the matching holes into the wooden rails, and then I pieced the four rails together with a bracket on each side of the joined, middle region.  In the end, I had four long, mostly straight rails that looked fantastic!

Here's a few in action, as I drew up the nodal lines on the natural, "white" bars.

As you can see, I'm putting some college texts to use...haha

Anyway, the next part was a lot of fun and really gave some tangible shape to all the designs I had been drawing up.  Next I had to select wood from the stock to use for the sides of the marimba!  Each side consisted of three sections: a three-ply top, a set of legs, and a three-ply bottom.  I had to cut out all of these pieces and fit them together like a puzzle.  I haven't glued or screwed it all together yet, but here is I what I have so far.

The top sections for each side of the marimba: two plies of ash, and one ply of cherry.  The bottom sections are the same arrangement.

All of the pieces cut out and placed in their rough location.

The middle ply layout, showing how the legs will fit together with the top and bottom sections.  I also cut out the section up top that will allow for the height change on the keyboard that lets the "white" keys sit lower than the "black" keys of the instrument.

I do want to mention that my design for the sides of the instrument saw major changes two different times.  If you compare what you see above to the the original model of the frame that my friend Nathan made based on my old drawings, you'll notice that the thicknesses of all the pieces have become much smaller, and that there are now more legs than originally planned.  Because my wood was cupped, I could not use as wide of pieces as I planned in the first place.  The new design that was implemented uses less wood, is practically free of warped material, and is still going to be just as sturdy.  

The next part was really tricky.  In order to cut slots for the rails to sit in on the sides, I had to use the rails to line up everything and place the bars on them in a way that their nodal points would be directly over the rails.  This doesn't look like it'd be that hard, but after adjusting the length of the instrument and trying to make the rails accommodate all the bars in their correct locations and STILL make it a playable arrangement, I say its a hard thing to get right!

I set up the tops of the sides that would support the keyboard, and I set the rails in their general locations.  I lined the bars up on the rails where their nodes would be over the rails, and I had to balance the rest of the set up based on that alignment.

After much trial and error, I marked the locations where the rails would sit on the top of the sides of the frame.  I already had marked where the natural bars would sit on one of the rails (the second one from the right in the picture above), and I had to make all my adjustments based on that.  Once I was satisfied, I took it all apart so the walkway would be clear for the evening.  lol

The next day, I set everything back up and checked to make sure that the marks I made were reproducible and still to my satisfaction.  I did not have to make any adjustments, but as a final test I decided to put ALL of my bars on the mock up to perform the ultimate alignment test...and also because I wanted to see all those beautiful bars set up in the way they'ed be on the finished instrument...  ;)

SUPER COOL!

I am so stoked to keep working on this monster of a project, and I'll be sure to keep posting as I make more progress.  I still have to assemble the sides I cut out and cut the rails to their final length.  There's still a lot to do, so PLEASE keep coming back to this blog as I continue to work.  Feel free to leave a comment or ask a question if you would like to know more about how I did something or about my future plans.  I love my readers!!  :)