Woodworking in the great white north.

Archive for August, 2010

Marble Tower – the feet

Once again, my creativity (maybe it’s A-D-D) kicks in while I’m supposedly following a set of plans.  To go along with that, I’m posting this one completely out of sequence, although there is no ‘right’ place in the timeline of this project to put the feet on the tower, the reality is that the tower now has only some trim work and finishing to complete.  But I managed to do this step today despite starting off in a funk, so I couldn’t resist posting it.

In the plans, there are feet on the bottom of the marble tower, basically just little odd shaped pieces of wood that echo the 120 degree angles of the hexagon base.  I never really liked these and could not for the life of me think of what I was going to replace them with.  I was also running out of ash.

First I tried taking a few scrap pieces and trying to make some semi-circular blocks that could go on, or under each corner.  I cut them out and tried them in various arrangements with very little enthusiasm.  I have saved myself the embarrassment and you the indignity of having to view pictures of these fubars.  Just accept my word that this was a very bad idea.

I stood for a while pondering what I was going to do and realized that I only had a 12″x5″ plank remaining from my original milled stock for this project.  This was okay since everything else was already cut and installed, but it meant I had no room for error if I wanted to make the feet out of ash.

This is when my recent spate of blog viewing paid off in spades.

After seeing Shannon Rogers (The Renaissance Woodworker) working on some french feet, and Charles Neil do some similar bracket feet via The Woodwhisperer Guild video collaboration build on a chest of drawers project…I could not resist trying this.

Now…a couple of caveats here.  The legs I’ve built are pretty simple and basic, and very very small.  I didn’t try to get perpendicular grain arrangement as Shannon shows, not did I attempt ogees or splayed feet, but I did at least cut each pair of pieces from a linear strip of wood, keeping the grain lined up.  The grain in these legs is actually horizontal and for me this works better since they are very very stocky little legs.

With the 12″x5″ plank, I was able to rip down 6 strips 6″x1.25″ (3/4″ thick).  From these I cut out a wedge from the back center of each piece, keeping the grain on the face lined up as best I could.  Taking one piece, I drilled out a 3/4″ hole with a forstner bit to make the inside curve, then freehanded the rest on the bandsaw.  This became the template for the rest of the pieces.

Once cut up, I used some painters tape to glue them up and hold them in place.

More tape!!!

After a little while, with the glue dry enough, they got a light sanding.

Now comes the moment of truth, I wasn’t 100% sure that my hexagon base was accurately cut, it’s only been about a year since I started this project and I’ve learned a fair bit in that time.  I tried each of the feet in place and to my amazement, they all fit really nicely.

Overall, I’m pretty impressed with how these turned out.

I thought about putting an ogee in the face similar to what Charles Neil has on his chest of drawers, or having the legs splayed out like in Shannon Rogers’ bookcase.  The reality is these legs are only 1 1/4″ high and 3″ wide and they are going on a child’s toy, which is more than likely to get bashed around a fair bit.  I opted for both the easier option and the most rugged and stable solution.

I am now itching to try this on something more substantial.  Perhaps even carving some feet as well.

One thing woodworking teaches well is patience.  I recognize that I could do more with this first attempt at bracket/french feet, but learning to walk before running is a valuable lesson and having a small project in which to display my lessons is pleasure enough.  Aside from all that, I think they look damn good and they really hit the mark on what I think the base needed to finish it off.

Marble Tower – down the drain – part 2

Really, I was quite stumped to come up with a nice way to hold this funnel in place on the tower.  I toyed with the idea of just holding it there indefinitely, but I doubt anyone would be happy with that plan.

While I was mulling this over, my daughter came out to see what I was up to.  I was explaining the problem to her and I was holding the funnel by the rim (thumb under the outer rim and fingers over the top of the rim) when she says “why don’t you make a piece of wood that does that?”  She points at my hand and proceeds to make a ‘C’ shape with her own hand and hook it onto the funnel.  BRILLIANT!

I did a quick sketch and marked up a small block of ash with the ‘C’ shape and went off to the bandsaw.  I tried it out and lo and behold it works just as well as my hand does – better probably since I can’t attach my hand to the tower permanently.

One of these ‘C’ holders was not quite enough to hold everything steady, so I made a second one and tried it out in various places, ending up on an adjacent upright.  These were both screwed in from underneath (pocket hole style) to keep everything rigidly held in place.

Once the funnel was nicely attached and a few test drives with a marble I had to figure out how to get the marble from the exit hole of the xylophone spinning onto the funnel.

I tried a few approaches (cutting an angle directly onto a piece of rail that would angle directly onto a tangent around the rim, but I found that the results were less than spectacular, mostly the marble lost momentum quickly and dropped through the hole.  I ended up cutting some pieces of rail into little angled sections and forming a curve from which I could get both the downward angle I needed and the angular momentum to send the marble around the funnel.

Once again, the shallow depth of the cove in the rails came back to bite me on the angled strip feeding the marbles into the funnel.  On a regular basis, the marbles would skip over the edge of the rail and just drop right through the funnel, so I ripped very thin strips of ash and bent them around the top of the rail to act as a baffle to keep the marbles on track.  It works nicely.

Here’s a video of it at work:

I was a little worried that multiple marbles in the funnel at one time might collide and create chaos, but this doesn’t appear to be the case, they seem to spin around effectively avoiding each other and maintain their distance after them come out of the funnel.

Next…I deviate from the plan completely as I try to tie in the bell and the remaining space between the funnel and the splitter mechanism.

Marble Tower – down the drain – part 1

I mentioned in earlier posts that I was ‘stuck’ at various points and procrastinated a lot.  THIS, was the biggest cause of it.

Why was I stuck? 

  1. First:  I did not like the design of the spiral ‘funnel’ in the plans.
  2. Second:  I knew I wanted to turn a funnel, but wasn’t sure how I was going to do it.
  3. Third:  Once I’d made the funnel I couldn’t decide how to attach it.

The process of getting from the xylophone through to attaching the funnel was probably days of work, but months of elapsed time.

Part 1:  What to do instead of the planned spiral funnel?

The plans called for a piece of plywood cut into a spiral with the center pulled down and the whole thing attached to a block of wood spanning the width of the tower.  I thought this was kind of ugly and I had other ideas about turning a funnel instead.

Have you ever seen those charity coin funnels?  The ones where you drop a coin down a slot and it rolls around and around the funnel, gaining speed as it goes lower and lower until it reaches the bottom and is really whipping around before it drops out?  I figured I could do something like this for the marbles too.  I even went so far as to look up the physics involved in these funnels and try to figure out what the curve needed to be to get the most out of the funnel.  In the end, I found that the slope of the curve was going to be limited by the blank I was using and my turning skills.

Part 2:  How to make the funnel?

I wanted to make the funnel out of ash to keep it in harmony with the rest of the tower, so I settled on trying out segmented turning.  I had a couple of ash boards available still to use on this project, so I took one and started cutting segments at about 30 degrees each, giving me 12 segments to make up a circle.  This was very much design on the fly.  I cut enough segments to make up two 3/4″ thick ‘plates’.

My plan was to take the two plates and cut rings from them and stack the rings to make up the funnel blank.  I figured out that if I cut a ring from one blank, then staggered the next ring from the other blank, and so on, I would have enough overlap between the layers to turn the funnel.  Before gluing up the two ‘plates’, I realized that I would have a hard time cutting rings out of them once they were put together.  I ended up making four half circles instead and cutting the rings on the band saw.

I”ll interject here that I’ve never done segmented turning before (so, I get a check mark for challenging myself with a new technique) and only did a little bit of research on it before diving in.  I learned a few things in the process:

  • cutting the segments precisely in the first place is easier than trying to shave one segment down to make it all fit nicely
  • cutting the segments precisely in the first place makes the glue-up go much more smoothly
  • ensuring the glue-up is completely flat makes assembling the rings go much more smoothly
  • glue is not a substitute for a good joint
  • inserting accent strips between segments would be a good idea to hide the glue line – or choose your glue with glue lines in mind
  • once glued up the entire blank is a heck of a lot more stable than you’d think

I will probably try segmented turning again, but I’ll plan better and spend more time on it than I did with this one.

Once it was glued up, I put it on the lathe and decided to keep the outside ‘stepped’ to show the rings used.  The inside I tried my best to turn into a rough hyperbolic funnel.  I stopped a few times during the turning to try out a marble and was pleasantly surprised by the positive results each time.  In the end, I don’t think the shape of the funnel makes too much difference, what really matters is that the marble come into it on a tangential angle and have as much speed as possible.

I did experience some tear-out and the very bottom section was the worst for this.  In the picture above you can see that I lost a few small chunks in the process of turning it.  So be it, I did a bit of repair and once the hole was drilled into the bottom it was not as noticeable.

Next up, more going down the drain as I figure out how to mount it.

Marble Tower – makin’ music

After riding the rails around the tower, the marbles get to make some music.

After falling out of the rails the marbles will tumble down a xylophone staircase.  This consists of a base which fits between two opposing uprights, a pair of stair supports that the xylophone keys are attached to and some dowels to keep the marbles corralled along the keys before guiding the marbles through a hole to drop into the next section.

This looked simple enough to build, but once again I found reference in the plans to double check my measurements as my tower may not be exactly the same size at the same height as the one in the plans.  They were right and this was my first inkling that I was deviating from the plans (see the previous post where I talk about the mistakes made in the previous step).

Originally I thought I’d like to liven things up and paint the keys in bright colours to improve the appearance.  I lightly sanded, primed and enamel painted the keys.  They looked ok, but once I started running marbles across them, the paint began to show signs of distress.  Eventually I got a paint chip come off one key and decided to strip them back down the bare metal and polish them up a bit.

The keys came with a small hardware kit that Lee Valley carried, consisting of the xylophone keys and a bell (which gets used later).  The one flaw I have with the hardware kit was a lack of consideration for how the hardware was going to be attached.  The xylophone keys need a spacer that will not dampen the ring of the key too much, I made some out of some hard plastic tubing and attached the keys with some nice shiny screws used in the auto industry to attach car interiors.

Rails and xylophone video

Xylophone video from a different perspective.

The next step was to be a spiral track made from thin plywood strips cut in a spiral and glued to a cross-member to act a bit like a funnel.  Being interested in turning as well, I reached another point of delay while I debated whether or not to do as the plans called for, or try and turn a proper funnel.