Magnetic Action/Assisted Piano System - MAPS (Patent Pending)


I am convinced that the piano manufactures of yesteryear had little of the knowledge we have today.

Many old pianos had lead put in the back of keys of the sake of putting it there - for no good reason. Oftern the keyboard was made off site and thrown into the piano - touch weight as it falls!


MAPS is a system that fits retrospective into older pianos, allowing for the correction of touch weight adjustments even when the action is worn or incorrectly designed.


There are 3 ways to use the system, each piano will be different and a little knowledge and thinking is required when fitting any of the systems. These systems being:-

Magnetic Action Piano System,
Magnetic Assisted Piano System and
MAPS down & up weight.


Although the piano to be fitted with the system can be worn out it must be within tolerance as far as the regulation is concerned and measures to reduce friction must be attended to, too.

The touch weights are adjusted by the distance of the air gaps between magnet and key, adjusted by standard regulation tools. This makes it possible to re-set the touch weight with each tuning visit in as little as 1/4 hour. The touch on the piano will change as the felts wear and things move etc, maybe only 1 gram or so, now we can adjust it. (We still use the word weight when in fact we should use the words magnetic attraction and magnetic repulsion.)


One must understand the effect of gearing before starting with MAPS - some pianos have different gearing from black to white keys! - result - different touch weight, MAPS can help even this out. Sometimes the black keys need lead added to the front of the key to get within working tolerance.



UPRIGHTS

Normally I have only been putting one MAPS set into the keyboard, just in front of the caption screws.

Time required to fit the regulation screws to the keys is about 4 hours, fitting the magnets about 1 hour and first set up about an hour - 6 hours to have a very nice feeling keyboard. Plus pick up time etc.

Another method is to remove all the key leads (if the key naturally drops back), we need to think of the up weight here. If the poor design of the piano allows us to do this, very good, if it woun't you may consider putting a full set of magnets in the front of the key. This system is called MAPS - Magnetic Actioned Piano System, because the key action is working fully on the magnets.

Again, another method is to remove only a little lead (drilling) to get the weight within reasonable limits and then fit the magnets, this system is called MAPS - Magnetic Assisted Piano System - the magnets are assisting the correct touch - this is the system I find the quickest.

If the key leads can be removed, the first system is better as it reduces the energy required to move the key (key has less mass). This results in less fatigue on the player. On one piano recently I removed 5.72kg of lead from the piano !! (65gms per key). There is a very noticable difference between a key with lead and one without. The ideal is to aim for the weight of the key to be the same over the whole keyboard, ie not having some keys with two leads and then others with one etc. There is no problem if the key is left with a hole in it, the "missing" wood is not very heavy. Also the strength of the key is the same as when the lead was in.

One feature of the system is the touch weight reduces as the key is played (as the magnets move away from the key and the air gap increases). This allows for the weight of the damper spring and the effect it can have on touch. Some people set the damper spring early to make the touch heavy - now the dampers can be set lighter/later (for better stacatto). The up weight increases as the key is released. If an up weight close to the down weight is required (eg - up 55gms, down 45gms) a set of repelling magnets needs to be fitted to the key fronts, this being the MAPS down & up system. To regulate the up weight in an Upright piano is easy if the piano design allows you to get to the underside of the keyboard - some re-design here may be needed.


GRAND PIANOS

Put in the full assisted system, complete with up weight magnets. This being MAPS down & up system.

Some Grands have lots of lead in the front of the keys - in this case you would need to place the repelling magnets (used for up weight in U/R's) by the caption to control the down weight and the attracting magnets (used to control down weight in U/R's) at the front of the key to control the up weight. Fitting is the same in every way as the Uprights. Regulating the up weight is done with the action pulled forward from the piano and adjusting from the under side.


Allen Birchler
06 3569013