Simulator: components

The band has an old but usable computer with Abel installed on it, donated by Ed Donnen and the Washington Ringing Society, and a set of four muffles that fit the light four (1234).  This summer the band voted to buy a sensor setup, which arrived from England a few weeks ago.  Now it’s time to get everything set up.  Thomas started on this in earnest this week.

The computer · The computer is an old Dell Inspiration laptop, disabled by Ed Donnen so that it won’t do anything but run ringing software and has no attractive pieces for anyone to steal.  It sat in the bell tower unnoticed for several years.  When I first started it up it failed to boot due to some internal power storage having run down.  Ed said:  either press F1 when it offers that choice and see if it works, or leave it plugged in for a few hours to charge everything back up.  That worked.  I’ve left it plugged in and on since, to make sure no further problems arise.

Something to set the computer on · Computers don’t thrive or survive on the floor or stuffed in a corner, plus to use the simulator someone has to give commands to it.  My wife and I had an IKEA kitchen cart and not enough space to move everything to Virginia, so we donated it to the tower as a computer stand.  It’s the right size for the space and has enough area for the computer, some speakers, and the odds and ends of the sensor wiring.

The sensor setup · It consists of these components:

  1. (8x)  A reflector for each bell wheel, to give the optical sensor something to sense.
  2. (8x)  An optical sensor for each bell.  The sensor has a bright LED whose light the reflector can bounce back to the sensor’s receiver.
  3. (8x)  A cable from each optical sensor to the next piece.
  4. The Multi-Bell Interface or MBI, a box with eight jacks for the cables from the optical sensor and one jack for the main cable down to the computer.  The MBI multiplexes the sensor outputs onto one signal line, and probably does various other useful electronic tasks we need know nothing about.
  5. The main cable from the MBI to the computer.  It carries the multiplexed sensor signals down, and also carries power up to run the MBI and sensors.
  6. The small power supply for the MBI and sensors.

Someone had ordered a one-bell setup some years ago and the parts were still lying about the tower.  We shipped those back to David Bagley, who makes the sensor setups, for a discount on the price of our setup.  Everything arrived at the tower in July, where it waited until I had time to install it.

Bell silencers or muffles · My original plan was to construct a frame for each bell that fits in its mouth and around its clapper, preventing the clapper from swinging and thus the bell from sounding.  But moving troubles got in the way, and I never had time to make them.  The backup plan is to use the four muffles Ed Donnen made for the tower some years back.  These are sections of motorcycle tire that fit over a clapper.  Each has two flaps cut in it to let the clapper through and hold the muffle in place on the clapper.  If the tower finds it needs to run the simulation with more than four ringers, perhaps Ed will make more muffles for them.

Simulator: why it’s useful

We’ve been planning for some time to set up the tower for simulated ringing.  This involves:

  • a computer running Abel to produce appropriate bell sounds;
  • a configuration for Abel telling it how many bells we have and which pitch each one sounds;
  • an optical sensor for each bell to detect its motion;
  • wiring and electronics to connect the sensors to the computer;  and
  • a table of time delays for each bell to accommodate its natural period of swinging.

When everything is set up properly, each time a bell swings, its optical sensor detects the motion and sends a signal to the computer and Abel.  Abel waits the appropriate time delay and then plays an appropriate recorded bell sound.

Why is this desirable?  First, because the Miami tower tries to accommodate its neighbors and limit the amount of ringing they hear.  The simulator setup lets the ringers silence or muffle the bells, so the neighbors don’t hear anything, yet hear the simulated sounds that their ringing would have produced.  Thus the band can practice more often and longer.

Second, because the simulator can fill in bells that there are not ringers for.  In the past the band has often suffered from low attendance, with not enough ringers present to do anything.  The simulator can be set up to fill in bells for which there are no ringers, and sound each of those bells when a skilled ringer would have sounded it.  Using it a few ringers can work on Rounds, or Plain Hunt on any number of bells, or Plain Bob or more complex methods.  The band’s members vary in ambition and skill, like any band, and the simulator allows ambitious ringers to learn methods that the tower can’t provide a band for.

And finally, because the simulated bells strike exactly where they should be striking, enabling ringers who want to improve their striking above the band’s level to work as if surrounded by a band of skilled ringers.  In that context, any bell that strikes out of place is much more obvious, and it’s always clear which ringer was in error since the simulated bells are never out of place.

Clappers checked/realigned

Thomas checked the alignment of the clappers of the 3 and 6 and realigned the 3’s clapper.  These had worked loose and been spotted on 2013Aug13Tu and quickly realigned and tightened by Bobbie and Thomas, but we hadn’t had a tape measure and were pretty sure at least the 3 was not aligned correctly.  Thomas brought a tape measure today (and donated it to the tower) and using it aligned the 3’s clapper properly and confirmed that the 6’s had been properly aligned last week.

Nuts working loose

Bobbie and Thomas made a routine check of the bells before practice and found two loose wheel nuts (#1 and #5) and, much more seriously, two loose staple bolts whose clappers could no longer be kept swinging true (#3 and #6).

Each staple bolt is secured by two nuts, the lower of which holds the staple bolt (and thus the clapper) in place and the upper of which acts as a lock nut keeping the lower from loosening.  In both cases the lower nut had frozen in place, especially on the 3, and we first had to work it loose in order to be able to tighten it.  This took about ten minutes of back-and-forth with the 25mm wrench for the 3.  They need to be loosened and spun off, with the staple bolt and clapper supported by the staple bolt stand Thomas built for sawing off the 5’s lower staple bolt nut that had frozen in place.  Once spun off, the threads of the bolt and nut need to be brushed and wiped clean, coated lightly with lithium grease, then worked easy by spinning the nut up and down until the grease is spread and any roughness or corrosion is worked out.  Then each clapper can be realigned and the nuts tightened up again.

Rope bosses remounted

Eoin and Thomas spent five hours pulling out the old anchors, redrilling the mounting holes, installing deeper anchors, and remounting the rope bosses with longer screws.  All are firmly mounted now and will not be falling down.

Eoin steadied the bottom of the ladder and handed things up;  Thomas climbed up and down, drilled the holes with the vacuum cleaner nozzle sucking up the dust, blew out the remaining dust with a squeeze bulb, and reinstalled the bosses.

The bosses were originally mounted in 3/16″ holes with lead strips as anchors and plated #6 steel screws.  At some point about half the lead strips had been replaced with plastic expanding anchors.  Some of the holes were crooked or out of round, unfortunately.  We remounted first the treble’s boss (2011Nov), which had fallen in 2008 and been down for three years, and later the remaining bosses (2012Apr), using new expanding plastic anchors for the bosses that weren’t holding and stainless screws for all.  We cleaned the bosses, some of which had fungus from the old days when the bells were left mouth up and filled with water that then dumped out and soaked everything the next time they were rung, and put soft plastic gaskets on the upper sides to absorb movement from the wood’s expansion.  This was presumably an improvement but bosses were still working loose and the 6’s boss fell, twice.

The second time the 6’s boss fell we redrilled its mounting holes to ¼” diameter, straight and perpendicular (two had been crooked) and deeper to fit the longer ¼” anchors, and remounted it with #10 1½” stainless screws.

Today we did the same for the remaining seven bells.

Recent steeplekeeping

The tower’s steeplekeepers have been busy lately.  Here is a summary of activity over the past few weeks.

The 6’s slider replaced

2013-05-14.6slider_4266The 6’s slider was cracked some years back and repaired by Ken.  A new slider was obtained later from Whitechapel but had never been installed.  Someone there had marked directions for drilling and cutting on it in ballpoint pen.

2013-05-14.6slider_42712013-05-14.6sliderI drilled the hole for the pivot pin, filed it to the right size, cut the far end off to the right length, and installed it.  You can’t slip the slider off the pin ordinarily, since the bell is in the way (that’s a good thing).  The trick is to unbolt the bracket for the pin, exchange sliders while the bracket is off and there’s plenty of room, then bolt the bracket with slider in place back onto the frame.

The repaired slider is sitting on the ledge above the 6, where the replacement had sat for so long, in case it is needed in the future.

Chains to hold upper hatch when it is open

2013-05-14.HatchChains_42692013-05-14.HatchChains_4270The upper hatch had been held by a plywood bracket on the back side of the raised sill around the ladder head.  This bracket had gradually worked itself loose so that the hatch was at risk of swinging too far and damaging the 4’s wheel.

Two chains now run from the inside of the hatch to the inside of the sill, and stop the hatch just beyond its balance point.  I couldn’t find stainless steel chains, so they may have to be replaced some years in the future, but the mounting hardware is stainless steel.

The chains display a tendency to kink, so each one has a wire bracket that lines them up so they usually don’t kink any more.

Sound absorbing panel fell in intermediate chamber

2013-05-14.soundPanel_4282 2013-05-14.soundPanel_4283I got a tube of construction adhesive and put it back in place, bracing it with ladders (that’s what was available) until the adhesive set.

Loose plies in the 7’s rope box finally all removed

2013-05-28.7ropeBox_4301 2013-05-28.7ropeBox_4309The 7’s rope box was the one most severely damaged by water in the bad old days when the ringers left the bells mouth-up and they filled with rain water, dumping enough onto the bell chamber floor that damaging quantities came down through the rope bosses and holes and soaked the rope boxes, bosses, and everything else.  The 7’s box had the most separated plies, and due to its height it was the most difficult to remove them from.  The last ones were pulled and pushed out at last.  A few of the larger ones are shown in the lower photo.

New rain awning

2013-05-02.awning_42492013-05-02.awning_4256 2013-05-02.awning_42532013-05-02.awning_4260 2013-05-02.awning_4263rainAwning.2013The first rain awning lasted about a year, possibly the life span one can expect from an awning home-made inexpensively out of plastic dropsheets and duct tape.  It did not survive being taken down for the removal of that awful galvanized gutter;  the duct tape peeled loose a bit and then restuck to whatever was nearby.  When I tried to unfurl it again, the plastic tore in several places.

I constructed a new one over several days in early May, first rigging together the rope harness to support it and then cutting sheet plastic to size and sealing it to the ropes.  I used color-coded ropes to make unfurling and lofting it easier:  red on one side, green on the other side, blue down the middle, white across from one side to the other.  Nancy helped with the sealing and with lofting the awning into place.

Last year’s awning was made out of the lightest plastic available (6mil as I recall), since it seemed at the time that a lighter awning would last longer.  This year’s was made out of the heaviest I could find, 20mil.

I tried silicone sealer this time since the onstruction-grade duct tape had started to come loose after a year, and once it came loose it would stick to any part of the awning it came into contact with, often causing a tear.  A small test indicated the sealer would adhere to the plastic.  I had to patch a few places where the sealer pulled free later using (of course) duct tape.

2013-05-14.awning_42742013-05-14.awning_42762013-05-14.awning_4277We lofted it into place and adjusted the various corners so that the lowest part of the awning was at the corner where the drain pipe was.

So far it seems to be working.  Some readjustment was needed to keep that corner as the lowest spot, to keep water from collecting in another spot where the accumulating weight could tear the awning apart.