Tuesday, 22 November 2011

Modular in a tool case

I had a day free on Saturday and set about putting a modular in a tool case. To be exact it is a Doepfer A-100 DIY kit #1 fitted to a Halfords engineers tool case. The point of this was to have an easily transportable demo system so I can take to shows, meets etc in order to show how lovely my CV Tools module is and to let people have a play.

In a follow-on to my cheap DIY store front panels post a few weeks back I used anodised aluminium angle strips in the construction from Homebase - the case is bigger than the 6U 84HP of the rack kit.
(Note to non-UK readers Halfords is a motor accessories store and Homebase is a DIY store)

Here's the case


Prep the case - remove separators, tool panel and unecessary fixings.

All done, ready to start serious modding

This will be powered by a 15VAC supply so a nice big hole for an XLR connector

XLR in place (EDIT: this is eventually replaced by a plug version as a power lead with exposed pins is bad karma)

A bit of judiscious foam cutting to neaten it up

Markout and drill the regulator boards fixing points - 4 x M3

Regulator screwed in place

I used M3 washers to spread the load - the case is just hardboard with a thin aluminium veneer

Position the bus boards and drill mounting holes - long M3 screws with tapped spacers fitted

All electrics now in place. Note this is temporary - there will be wiring to a front panel power switch on the next installment!

Next make the rack end pieces out of 10mm x 20mm anodised aluminium angle strip. These make the rack the perfect width to fit the case.

Similar to above I made top and bottom strips to fill the gap - I used 25mm x 25mm anodised angle, again an almost exact height fit - starting to look good.

Here's a view showing the fixings (ok I drilled a hole in the wrong place. Motto: measure twice, cut once!!!).

As I said a near perfect fit in the case. At this point just resting on the foam and not screwed in. That's in the next installment.

Loaded with modules and powered up. Take no notice of the modules selection, I've since changed it to a more coherent set.

Even a nifty scope showing VCOs, Synovatron DioDe and CV Tools in operation - now that's a waveform!

 Next installment will add a power switch and fixings to anchor the rack to the case. It will also make use of all that front panel space top and bottom for passive and buffered mults, bus access, simple LFOs, gate logic, 3.5mm to 6.25mm/RCA adaptors, etc etc (the thought of the lovely goodies that will get built in is going to keep me awake a night - so sad!!)

Here's a short clip of it working:-
video


14 comments:

  1. Very nice... and it looks like you can close it without unpatching everything too. (+1)
    Also a very nice oscilloscope, what brand/type is that and are there any (free) software scopes that you can recommend?

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  2. Thanks Pierre, yes you can close the lid and keep the patches :)

    The scope is by SEEED Studio, called a DSO Nano V2 and costs about 85GBP. I have not looked into software scopes but I'm sure they are available.

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  3. Wow! You made that case yourself? You're so good.

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  4. sweet case mate will grab one from Halfords :-)

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  5. Great case, I look forward to trying this myself.

    What kind of plug (Uk/Eu?) did the DIY Kit come with, is the XLR connector standard?

    Any news on the further instalment with the units along the side and mounting the frame securely?

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  6. Hi,

    Thanks for that. I'm pretty sure the power supply came with a euro 2-pin plug which I cut off and replaced with a standard UK mains plug. The 15VAC end came with spade terminals to plug into the regulator. I cut that cable and fitted the 3-pin XLR plug and socket that I had hanging around. Ideally the chassis connector should be a plug, not a socket (so that you can't accidentally short the 15VAC pins). I will be changing mine as it's good practice; Maplin has them (BW91Y and BW92A).

    I have been trying to find time to complete my case but no such luck yet. I have thought about fixings though - the simplest way to fix the frame to the case is to bond wood battens, e.g. (25mmx25mmx50mm), in the corners with epoxy resin - first remove the foam so you can bond to the hardboard. Then drill a hole in the aluminium frame in each corner and into the wood for self-tappers to screw down into the wood. Maybe this weekend I can replace the connectors, fit the battens, fit a power switch and add some mults.

    Let me know if you build one - happy to feature any pics you may have and any tips you have. A couple of people have expressed an interest in using the same case.

    Thanks and good luck

    Tony

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  7. Hi Tony
    Can you recommend a power switch to use?
    Incidentally, a good source for cases is a camera fair - there are lots of solidly-built cases in a variety of sizes for a few pounds each.
    Cheers, Nick

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  8. Hi Nick,

    I think I saw you at the Brighton meet in July but I didn't twig it was you at the time.

    I don't actually have a power switch on my case but have been considering using a simple SPST toggle switch from Rapid (75-0082); it's rated at 125V 5A and I'm switching 15VAC at less than an Amp although the Doepfer 15VAC transformer is rated at 2.5A there is enough headroom. Obviously if you're not using the Doepfer transformer and are switching mains then that switch is not suitable. A proper DPDT mains switch such as 75-0270 or 75-0280 would be better. Hope that helps but please feel free to contact me if you need further info. Thanks for the camera fair pointer - I would have preferred a case with a detachable lid :)

    Cheers
    Tony

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  9. hey i've built one and it works really well, but i was wondering if you thought about making the lid removable so that i could be used standing... as an alternative i thought about flipping it upside down but then i have to mount the modules reversed.

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    1. Hi grillo,

      Yes I have thought about it and I think I know how to do it but it would involve very careful hacksaw work and some filing on both hinge plates (the part of the hinge that fits to the main body) and also removing the hinge pin. My only concern is that it will weaken the hinges considerably and the lid might not fit so well. I probably won't do it but if I do it I'll post some pictures.

      Cheers
      Tony

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  10. Thanks for the help, Tony. Your suggestion on using XLR connectors for the power was spot-on. I have now completed my third case and bought a cavernous fourth at the weekend which will house the deepest of modules.
    Cheers, Nick
    p.s. yes, that was me at Brighton - next time I'll have a case or two to bring.

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    1. My gosh Nick, three going on four cases, that's great! I look forward to the next modular meet and seeing your handywork :)

      Cheers
      Tony

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  11. Hi Tony
    I didn't have a chance to thank you for your help at last weekend's meet - I arrived late, couldn't stay long and you were always busy. I'll try harder next time.
    Cheers, Nick

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  12. Hi Nick,

    I thought I caught a glimpse of you - yes it would be good to chat - looks like the next Brighton outing will be in September. Hopefully by then I will have more to show but time has a way of disappearing :)

    Cheers
    Tony

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