Register Control Boxes
I’ve been making a new register box for my Chiappa over the last couple of days, using the standard ‘catch’ design for the first time (I have made the sliding block type before, but fancied a change). There are so many different design variations I’ve seen of this basic catch principle, so thinking up how to construct this two-way box I’ve hopefully incorporated all the best features of each.
I haven’t got to the catch element yet, but the palleted ventil part and cancel puffs are finished, as is the backing framework. Pics as follows:
And part of the reason I haven’t finished it yet is due in part to the modern world of electronics in the form of digital cordless phones, now in workshop range…
… nothing worse to take one’s mind off the job! (other than my Dad taking the picture maybe?!)
Anyway, back to register boxes, what are the advantages / disadvantages of using puffs to lift each lever to the ‘set’ position compared to rectangular pneumatic motors? Deep puffs should have enough movement, and needing to get the fulcrum as far near the back as possible there’s not much point in utilising the hinge point of a motor by mounting the vertical catch lever straight to this. Hhence I thought the puffs would be the best option - any ideas or improvements? Hints and tips?
I did consider having the lower pallet forming the horizontal catch lever itself, but ruled that out on the grounds that there would be no ‘give’ to allow the catch to perform its duty properly while still keeping pressure on the lower pallet. Note the springs I’ve made from a hacksaw blade for this purpose to fit between the horizontal lever and the lower pallet (the upper pallets are spring shut so this spring needs to overcome the weaker spring inside) – only one shown in the photos though.
I hope what I’ve done so far will work successfully – the chest is certainly totally air tight with no pallet leakage (the advantage of springing them shut!).
I’ve found a few photos of other register boxes in my archives that I might post up here later for reference, but any other examples would be most interesting. The largest box I can remember being on open display is the one on the fantastic 89-key Leach & Overington Concert Organ. I think this was an 18-way one, and probably with a few spare for future expansion. It’s nice to see this in close proximity to the key frame, and it’s with this thought in mind that I’m going to fit the above box in the upper section of the Chiappa casework, where utilising Anna Page’s Perspex panel idea it will be seen. The other advantage of course, it can easily be accessed in this position when altering/adding the register controls to the music.
Cheers for now,
Nick
And part of the reason I haven’t finished it yet is due in part to the modern world of electronics in the form of digital cordless phones, now in workshop range…
… nothing worse to take one’s mind off the job! (other than my Dad taking the picture maybe?!)
Anyway, back to register boxes, what are the advantages / disadvantages of using puffs to lift each lever to the ‘set’ position compared to rectangular pneumatic motors? Deep puffs should have enough movement, and needing to get the fulcrum as far near the back as possible there’s not much point in utilising the hinge point of a motor by mounting the vertical catch lever straight to this. Hhence I thought the puffs would be the best option - any ideas or improvements? Hints and tips?
I did consider having the lower pallet forming the horizontal catch lever itself, but ruled that out on the grounds that there would be no ‘give’ to allow the catch to perform its duty properly while still keeping pressure on the lower pallet. Note the springs I’ve made from a hacksaw blade for this purpose to fit between the horizontal lever and the lower pallet (the upper pallets are spring shut so this spring needs to overcome the weaker spring inside) – only one shown in the photos though.
I hope what I’ve done so far will work successfully – the chest is certainly totally air tight with no pallet leakage (the advantage of springing them shut!).
I’ve found a few photos of other register boxes in my archives that I might post up here later for reference, but any other examples would be most interesting. The largest box I can remember being on open display is the one on the fantastic 89-key Leach & Overington Concert Organ. I think this was an 18-way one, and probably with a few spare for future expansion. It’s nice to see this in close proximity to the key frame, and it’s with this thought in mind that I’m going to fit the above box in the upper section of the Chiappa casework, where utilising Anna Page’s Perspex panel idea it will be seen. The other advantage of course, it can easily be accessed in this position when altering/adding the register controls to the music.
Cheers for now,
Nick
The motor forms the hinge point for the horisontal lever in this design. However, I want the fulcrum further back, so a pin-joint at the back of the box would be best (already made the support for this), with the levers raised by puffs towards the front end. I also have a better linkage between the horisonal and vertical levers in mind that allows the catch spring to be attached at the front. This is very much like the Irvin's Marenghi one detailed in John Page's excellent restoration article - see photos at the following link:
Despite a hectic weekend I managed to get the box installed and connected just in time to take the Chiappa out for its second event yesterday (see Photo Gallery section for pictures).