design of a hammond organ controller

Design Concepts
1

Hello,

I am starting an ambitious project, after my experience with a MidiBox (see http://www.midibox.org/forum/index.php/topic,9495.0.html).

It will be a hammond organ controller for my hammond xm-2 expander.

It will consist, basically, of Doepfer parts: 2 keyboards, a set of drawbars and mod/pitch wheels, and a custom MIOS application, using CORE, DIN, DOUT and AIN.

I have drawn a design using google sketchup, which you can see here:

http://picasaweb.google.es/julian.gregorio/Jamon7

I would like to build a wood box, and use aluminum panels for the controls.

My first thought is using plywood (9mm) for the box, and use Front Panel Designer for the panels.

Do you have any recommendations or experience using plywood? Can you think of a better alternative?

Thanks,

Julian

2

Lookin good man :slight_smile:

Ply is probably suitable for such a large device. Not all ply is the same though, so make sure you get nice stuff :wink:

3

Here is one that I built-

I have changed some things since that photo. The screen is no black, and there is a bit more brass trim. The whole thing works by housing a quad core PC and running VSTi’s natyrally with native instruments B4.

It is built in ply with walnut veneer, and a green leatherette/tolex cover. The reason I chose ply was because of the possibility to change the design schem, as I didn’t know exactly what the specs would be.

As you can see I chose to use a single fully weighted piano pulled from a fatar, so that it is not just limited to organ playing…basically I can play piano as piano etc.

Is that roughly what you are up to?

Oh yeah, the way I wired up the drawbars, which are a set of modded H series ones, is the best way to go, having done some serious research into all the possibilites of getting them to midi.

Would be pleased to help you in any way,

HG :wink:

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4

Just had a look at the Drawbars for sale by Doepfer, and I would have to qusestion there suitability, being rated at 47k!! Have a look around the forums :-[

5

Here is one that I built-

I have changed some things since that photo. The screen is no black, and there is a bit more brass trim. The whole thing works by housing a quad core PC and running VSTi’s natyrally with native instruments B4.

It is built in ply with walnut veneer, and a green leatherette/tolex cover. The reason I chose ply was because of the possibility to change the design schem, as I didn’t know exactly what the specs would be.

As you can see I chose to use a single fully weighted piano pulled from a fatar, so that it is not just limited to organ playing…basically I can play piano as piano etc.

Is that roughly what you are up to?

Oh yeah, the way I wired up the drawbars, which are a set of modded H series ones, is the best way to go, having done some serious research into all the possibilites of getting them to midi.

Would be pleased to help you in any way,

HG :wink:

Hi Henrygr!

Thanks for your post.

I am close to start building the wood box, and I feel confident using ply. I still have doubts about how to join the plywood, as I have read that drilling the edges may be dangerous.

I was looking specifically for a organ-like feel keybed, that’s why I choose these controllers. I already have a piano controller for pianos. I want to build something lightweight, and use my sound expanders in a rackbag. So the thing being built will be only controller. I will design the MIOS application to allow for high flexibility, so any of the two keyboards can control any expander. This may be a solution even for playing piano sounds, as I have played those keybeds and they are semi-weighted, so the solution may allow me to leave the piano keybed at home.

I had already seen the 47K thing… I have read that if cables are short, it may work with no problems. I will test them once I assemble the CORE/AIN modules. If problems arise I may put a resistor in paralel to lower the total resistance. I don’t mind the result is not linear, as I will be using calibration tables in my code to get the 16 positions of the Doepfer drawbars.

I will keep you updated about my progress…

Regards,

Julian

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6

I had already seen the 47K thing… I have read that if cables are short, it may work with no problems. I will test them once I assemble the CORE/AIN modules. If problems arise I may put a resistor in paralel to lower the total resistance. I don’t mind the result is not linear, as I will be using calibration tables in my code to get the 16 positions of the Doepfer drawbars.

Good idea. I reckon as long as the algrithm required to ‘straighten out’ the signal is not too complex, you are laughing.

With regards to the plywood, use butt joints. I came across this link in the forums some time back, http://www.smctek.com/B2MIDIControllerProject.html

I got in touch with the builder of the unit and he said that he used butt joints and 9mm ply, so I just followed his advice. BTW- the unit above was never competed and he offered it to me for $200. I delined, but said I would mention to anyone i knew bulding a similar project…Might be worth thinking about, but you will lose any touch sensitive action.

I have read that drilling the edges may be dangerous

As long as the quality of ply you use is good, there should be no problems. Have a look around for cabinet building sites, as I found them to be a superb resource- http://www.colomar.com/Shavano/ here is just one example.

Just make sure to use loads and loads of glue…

Best of luck with the project.

HG

7

Good idea. I reckon as long as the algrithm required to ‘straighten out’ the signal is not too complex, you are laughing.

Yeh, normally this wouldn’t be workable, but with only 16 steps needed it should be functional… A lookup table would be nice and fast, or you might be able to do some bitwise wizardry if you’re feeling clever :slight_smile:

8

Sorry,

One more think I wanted ton point out, and that is the lightweught alternaives to plywood that I intend on using the next time round.

One is shrink mousding. It is the precess by which Fender Rhodes built their cases for their pianos. Have a google.

The other, and I think more interesting, is to use the plastic alternative to wood that is mentiones on many cabinet building sites, (but can’t remember its name and my notes aren’t to hand) held together by aluminium extrusions. Another stronger material is the plastic fascias used ibn building skyscrapers. I will dig out all my old notes and try and get the names.

Also, before you start, I found http://www.adamhall.com/ to be a very good source for cabinet parts at a reasonable price.

HG

9

but with only 16 steps needed

Oh yeah,

only eight steps requires for Hammond stops… ;D

10

Thanks HG!!!

You gave me some very interesting links for the construction (Shavano in particular), I think butt joints seem the easier choice.

I also will have a look at your alternative materials, although I think they might be much more difficult to work with (plastics, etc.) and to find.

I have nearly decided to use an strong plywood, glued with phenolic WBP. I can get one standard sheet (250 x 150cm) for about 100 euros, which seems reasonable.

Now I am working on building something that can be easily carried, using flight-case accessories. I want to design the full box from the bottom thinking about this approach. See this photo for the idea:

http://picasaweb.google.com/julian.gregorio/Jamon7/photo#5173610618235711634

Thanks again!

Julian

11

Yep. That will do it. That is more or less the same design as my machine. I will try and post some photos later. The difficulty you will have is gettng the exact measurements, but you will figure that out.

Before you build, it is worth considering what handles you want to put on it- as some require cut-outs to be made in the wood. Also, what are you going to cover the finished product with?

although I think they might be much more difficult to work with (plastics, etc.) and to find

Not so. I meant to add that these are stuck together with alluminium extrusions, which is a method that can also be used with the plywood.

Extrusions- [Home | Adam Hall Group](Home | Adam Hall Group l–en p–project_27__b–6106S)

How they work (or a link to a flightcase- the penny will drop!!)- http://www.thomann.de/gb/thon_keyboard_case_i.htm

Ans, I remembered the name of the plastic- Astroboard. There are stronger. Just google astroboard, get the type of plastic it is made of- I thimk it is polypropelyne- and research solid sheets of it. I lost the notebook I had with all of the details I researched last year.

Astroboard- [Home | Adam Hall Group](Home | Adam Hall Group p–project_2 f–9)

Let me know what you think. For what it is worth, my intention is to build a new case out of astroboard and aluminium extrusion.

I will take more photos of my machine later and post them. It might help you with issues you may have.

One more great resource I found was http://www.blue-room.org.uk/ Here they discuss flightcase building in depth.

HG