This page was last revised 28 Jan 2012.

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Dumbbells
as Ringing Simulators

NwDumb.jpg - 59Kb

Mini-dumbbell, John Norris design, in production since 2003.
Current price £145

Introduction
Specification
Installation
Connecting to a Computer
Cost

Other Designs
Dumbbell History

A home dumbbell connected to ringing software on a PC to form a ringing simulator is an excellent aid to real ringing in the tower. It’s ideal for practising new methods and developing your listening skills and ringing by rhythm.
It’s also challenging, very satisfying when you ‘get it right ’, and even fun.

Ring whatever method you want, whenever you want, on as many bells as you want, without being dependent on the availability or skills of other ringers.

A dumbbell in the home has one outstanding advantage – it is always available,


SPECIFICATION

Not every home or garage loft has sufficient space and structural strength for a large and heavily weighted wheel but most homes can accommodate a mini-dumbbell, like the example shown above.

Ringing it is easy. It feels and handles just like a bell in a mini-ring and mastering the technique takes only a few minutes, even for a non ringer.

The design shown uses an MDF wheel, approx. 23" in diameter and 2" thick. The weighted wheel weighs approx. 18 lb, (5 lb for the upper half of the wheel with pierced quadrants; 7 lb for the lower half, plus 6 lb of attached steel weights). The wheel is mounted on a headstock in a wooden frame approx. 29" long and 17" wide, the overall height being 27". A ½" spindle through the headstock runs in self-aligning ball bearings and a papier maché bell is fitted to the headstock. The whole ensemble, including the papier mache ‘bell ’, loosely represents a bell in a traditional frame and the ‘feel ’ is similar to a 10 lb bell in a mini-ring .
[If desired, the papier mache bell can be replaced by a real bell, up to 10" in diameter.]

Unlike a churchbell, there is no need for a stay and slider.

The dumbbell is supplied complete with rope (non-standard sally colours available), ceiling boss, sensor and connecting cable.

For further information, or if you fancy building one yourself, see the downloadable DIY Instructions (5Mb)


INSTALLATION

To accommodate a mini-dumbbell to the above design, you need space not less than 29" (750mm) long, 17" (450mm) wide and 27" (700mm) high, plus a little extra to allow for access, and with sufficient headroom to stand beneath.
The loft hatch aperture needs to be not less than 600mm x 450mm

The recommended mounting position is in the loft, with the rope falling through a ceiling boss to a ringing position on the landing beneath.

[Reservations are sometimes expressed by potential purchasers about the need to cut a 2" dia. hole in the ceiling for the rope. Given the size of hole represented by a typical loft hatch, the small hole needed for the rope seems almost immaterial.
However, there may be alternatives, depending on the size of the hatch:-
For example:
Mount the dumbbell with the long wheel side, suitably supported, over the edge of the hatch.
Mount the dumbbell with the short, pulley end, of the frame over the edge of the hatch.
Mount the dumbbell wholly over the trap, either on a trolley on rails or on a short tower, allowing the rope to fall through the hatch while preserving access to the loft.
Mount the dumbbell over the stairwell.
Mount the dumbbell on a portable tower in a spare room.]


CONNECTING to a COMPUTER

(a) Windows PC

The computer can be a standard WindowsPC running Abel, Beltower or Ringing Master.
Any PC running Windows98 or later is likely to be adequate but visit the software websites for details of minimum spec.

The dumbbell is supplied with either a combined optical sensor and interface, specially designed by Alan Griffin, or an induction type proximity sensor, made to a design by Aidan Hedley. The two types are fully interchangeable; the induction type has the advantage that it is unaffected by ambient lighting level and so is more suitable if the dumbbell is likely to be used outdoors or in bright artificial lighting.
The connecting cable requires a serial port at the PC. If using a PC not equipped with a serial port, a serial to USB converter will be required, available from Maplin and other suppliers. If using Windows7, make sure that the converter comes with a Windows7 driver. The latest Maplin converter, currently on sale at £14.99, does.

The techie bit
(optical sensor):-

PWI.jpg - 70Kb

The PWI comprises sensor and interface in one small unit, 75mm x 50mm x 25mm, mounted on the dumbbell frame. A light source in the sensor projects a beam towards the wheel and a reflector strip on the wheel reflects the beam as the mock bell passes bottom dead centre. A photo transistor in the sensor detects the reflected light and the brief output ‘pulse’ is passed via the interface to the computer.

(induction type sensor):-

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The induction type sensor works like a metal detector. A tuned activator coil attached to the wheel passes a matching reactor coil in the sensor as the mock bell passes BDC. The oscillator in the responds and the brief output ‘pulse’ is passed via the interface to the computer.

There needs to be a delay between the moment when the reflector on the wheel passes the sensor and the normal striking point. This delay can be applied in software and Abel, Beltower and Ringing Master all include provision for this.

Alternative designs such as David Bagley’s sensor and single bell interface (SBI) provide the delay in the interface. For further information visit David Bagley’s website www.ringing.demon.co.uk. The end result is the same.

[For DIY enthusiasts, constructional details of the ‘budget’ version of Alan Griffin’s combined sensor and interface are downloadable in two pages here:- Page 1 and Page 2. This is electronically identical to the version available for purchase, illustrated above, but is housed in a film canister with a non-detachable lead.]

(b) RISC OS Alternative

For RISC OS enthusiasts the dumbbell can be connected to an Acorn RiscPC or A7000 running the author’s ringing program Stringing.

A Bagley sensor (just the optical sensor, not the complete SBI) or an Aidan Hedley induction type sensor are needed, together with a Griffin RISC OS interface and a Watford I/O card. Details of Alan Griffin’s RISC OS interface are given in the Stringing Manual (750Kb). A Watford I/O card can be purchased from CJE Micro’s.

(Stringing will appeal to RISC OS enthusiasts and may be the program of choice if a suitable Acorn computer is to hand. However, it does not offer such a wide range of features as Abel, Beltower and Ringing Master.)


COST

PC Option:
Dumbbell, rope, ceiling boss, Griffin ‘Photohead With Interface’ and lead,
ready to plug into a PC serial port
£145.

(Not included: PC, ringing software)

RISC OS Option:
Dumbbell, rope, ceiling boss, Bagley sensor, Griffin RISC OS Interface,
Watford I/O card, Stringing and S/H Risc PC
£200.

The above prices do not include carriage,
typically about £40 by courier including return of the empty packing case.

For further information, enquire for details or telephone 07774 863184.


OTHER DESIGNS

Ringing dumbbells can be made in different sizes.

A full-sized dumbbell, i.e. with a wheel similar in diameter to a typical church bell wheel, is rung exactly like a church bell. Being slightly more ‘docile’ than a real bell it can be particularly useful for teaching bell handling. However, a dumbbell with a full size wheel, typically 4ft. in diameter, may pose significant space and stress issues for the average home. For details of such a dumbbell visit www.saxsim.co.uk.

For details of an ingenious alternative design, using counter-rotating weighted wheels to give ‘real bell’ feel with minimal stress on the supporting structure, visit http://jaharrison.me.uk/Ringing/DumbBell


HISTORICAL

The original dumbbell was a windlass-like piece of exercise apparatus in which, for successive pulls of the rope, a roller with weighted arms rotated first in one direction and then in the other. The ‘feel’ was rather different from a church bell hung for ringing but nevertheless there was a strong similarity with full circle ringing in the English style, in which for each pull of the rope a bell turns ‘full circle’ from approximately upside down to approximately upside down, rotating in one direction at one stroke and the other at the next.*

C17dumbbell.jpg - 83Kb

17th century dumbbell at Knole House, Kent
(drawing on p.58 of History and Art of Change Ringing, Ernest Morris)


The hand-held dumbbell used in weight training is believed to get its name from its resemblance to the weighted arms attached to the roller.


* Correspondence in The Ringing World in December 2010 touched on the degree of similarity between ringing a dumbbell of the historic Knole type, comprising a roller with weighted arms, and ringing an actual bell. It was noted that:-

“The operation and dynamics were somewhat different from a bell. It has no wheel, and the (relatively light) weights are counter-balanced. The rope winds around a shaft that is several inches in diameter, not several feet as in a bell wheel, so the shaft must rotate many times to achieve a realistic vertical rope movement.
With the weights more or less balanced, the dumbbell will not swing spontaneously from one stroke to the other like a bell, though the weight of the rope would gradually accelerate it, providing the bearings aren’t too stiff. There would be no difference between handstroke and backstroke either. The ringer, rather than gravity, would need to provide most of the energy to make it turn, and applying less effort would lead to it turning more slowly. So it would feel very different from ringing a bell.”

To put this to the test a modern mini-dumbbell of the type described above was modified by removing the weighted wheel and fitting a 3" diameter roller with weighted arms in the manner of the C17 example at Knole depicted above. Ringing the weighted-roller type dumbbell proved much closer, in the view of those trying it, to ringing a real bell of similar notional size than might be expected. The roller dumbbell is certainly harder work - as befits its use as an exercise apparatus - and the speed of rotation is more dependent on the degree of pulling and checking applied by the ringer. However, the ‘feel’ is surprisingly similar to a real bell. If a rope with sally is fitted it is not only easy to ring it with alternate handstroke and backstroke in the usual manner but it comes naturally to do so.

You can download a movie clip comparing a Knole type roller dumbbell with a ‘bell’ in the Wickham Ring. (The noise is from the turning of the slightly irregular roller, not the dumbbell in the Ring).



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