[sdiy] Synth Keybards and Number of Keys

[Edward King]

Questions answered below.


----- Original Message ----- 
From: "Richard Wentk" <richard at skydancer.com>
To: "Edward King" <edwardcking2001 at yahoo.co.uk>
Cc: "Synth-DIY" <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, March 01, 2007 10:49 PM
Subject: Re: [sdiy] Synth Keybards and Number of Keys


>
> On 1 Mar 2007, at 18:53, Edward King wrote:
>
>> For the record, the construction is as follows:
>>
>> Keys are all wooden
>> Chassis is galvanised steel (2mm)
>> There is one universal pivot point which is 6mm hardened steel rod,
>> supported every octave and fed through the keys at the pivot point.
>> The keys have brass bushes so the wood doesnt wear / drag against  the 
>> rod.
>> The overall dimensions are: 1447mm x 680mm x 100mm (front) and  160mm 
>> (rear)
>> The displacement sensing is achieved through optical devices,  actuated 
>> by
>> steel linkage mounted at the bottom of each key.
>> Velocity sensing is through normal means (timed changover)
>> Aftertouch is achieved using QTC pills, feeding multichannel ADC's
>> MIDI protocol is NOT used at all internally, but a midi handler is 
>> designed
>> to take inputs and outputs and map them to the higher definition  signals 
>> of
>> the keyboard internals.
>
> Out of interest, what did this monster cost in the end?

Wood (including factory costs to have the wood cut into 2 x sets of 88 keys 
+ 4 octaves for spares, mistakes and experimentation)
=£35
(& have to mention the company on my website (?!) and if I build more, they 
want me to use them over a competitor)
+ brass bushes = £4
+ 1.5m pivot bar (hardened steel) £0.65
+ galvanised steel chassis (2mm) (factory made) £15
+ 88 x QTC pills (aftertouch sensors) £23
+ bolts (already had an abundance of these)
+ PCB's (have lots of pcb board left over from other projects)
+ Springs (engineering company) £free but I had to fix their network :o)
+ Lever mechanisms (factory made) £5
+ optical switch vanes (factory made) £free, but I have to mention them at 
some point on the website I havent yet found the time to build!!!
+ slotted optical switches (displacement sensing) £65 (bulk purchase)
+ bus bars (2 of, both gold plated) £50
+ felt (upper and lower buffers) £3

Which isnt bad for a keyboard with velocity, displacement and individual 
aftertouch sensing.
There are other electronics costs, but these would be pretty much down to 
individual requirements. For example, some people wouldnt bother with the 
displacement sensing or individual aftertouch. Each to their own.

I got very high grade components and the best wood I could buy, so I know 
that it is possible to do this even cheaper.


>
> If it wasn't for the weight I'd consider marketing it.

Weight can be lost from the thing in the following areas:

1) The chassis was built with far too much material. 2mm galvanised steel is 
very tough and very heavy, but I allowed far too much room for the PCB's 
under the keyboard mechanisms for heat dissipation and protection from 
ambient light. Further analysis of this in Fluent (Computational Fluid 
Dynamics Software) demonstrated that I can lose over 1/3 of the weight from 
this area alone.

2) Material can be removed from the rear-underside of each of the keys. I 
experimented with this some and unless my scales are buggered, approximately 
100grams can be lost from each key (8.8kg total). I didnt get around to 
doing that, but I think I will have to.

>Interest in  poly AT and a good keyboard action is small, but not 
>insignificant,  and I can see a steady run of sales if you can get some 
>decent basic  marketing together.

Im not intending selling this commercially. The synth part of my project is 
the result of over 15 years of design and so I am very excited about finally 
finding the time to build it. It would not be a commercial success because 
the synth components are built up to a spec, rather than down to a price and 
you really, really dont want to know what the synth components are costing 
(unless you particularly enjoy nightmares). The synth is designed for my 
needs and they dont seem to coincide with what the general consumer desires.

I would be more than happy to throw a few units together for list members 
who wanted one, but I have an income thanks and Im not really interested in 
making this into a business.
I would also be happy to forward schematics and 3d design work to any who 
want it. Some of it needs updating to reflect the differences between what I 
designed and the modifications I made whilst actually building it, but the 
gist is there.
Essentially, I didnt need to do this. It would have worked out even cheaper 
had I just given the design work to the factory and let them get on with it. 
I did it because I wanted to do the work myself so that every time I play 
it, I know that it was my work that went into it. In a sea of so much 
factory manufactured plastic stuff, sometimes its nice to have a hand-made 
feel.
:o)


>
> At 80kg though it's more of a tough sell. Personally I think that  weight 
> and size are the real killer issues for large keyboards. I can  just about 
> squeeze my M-Audio KS88 Pro into the car, but if I had to  gig with it 
> regularly it would soon turn into a nightmare. 61-note  keys are much less 
> hassle in comparison, and this makes them much  more attractive. 
> Considering that most synth players aren't  classically trained, and even 
> if they are they're looking for more of  a multi-board control surface 
> than a piano substitute, the move to 61  keys was probably inevitable.

This is one of the core issues.
I absolutely love my Jaguar, but I cant use it to transport my stage piano. 
Even the jag isnt wide enough and doesnt have the facility to put the seats 
down so I have to drive the family "workhorse" (and Im not about to embarass 
myself by saying what that is) to transport my gear around.
The situation is now even worse in that my homebuilt is even longer and 
wider than my korg stage piano.
Although its a pain in the arse, I would still do it even if it meant 
driving a Lada temporarily (although I would wear a bag over my head).
I think that in most peoples cases, 2 or more 61 note boards are probably a 
better solution and can be really effective when combined with a pedalboard 
for bass sounds.

Perhaps an even better idea is a keyboard which splits into two sections for 
transporting / storage?
Electronic coupling neednt be that complicated and it would remove what 
seems to be the biggest bugbear people have with larger boards.

>
> But I think studio interest in 88- and 96-note models could be 
> significant, even at a reasonable price premium. You might not sell  many 
> at $2k, but you could probably sell enough to the film composer  and 
> Hollywood crowd to keep a small business going for a while.
>
>> I am also experimenting with recreating string vibrato effects through
>> sensors on the key tops and would be interested in any work that  others 
>> are
>> doing in this area too.
>
> Again, this is something else that's of interest to a select few.

I agree. It is directly relevant to me though because physical modelling 
synthesis can use this and other mechanisms to great effect.

>
> As you say, the generic black-and-white keyboard is fantastically 
> limiting musically. Anything that extends the expressive  possibilities 
> can only be a good thing.
>
> Richard


		
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