Modular Suitcase

About

From the beginning of 2015 on I started building some Eurorack synthesizer modules designed by Befaco. This, being one of those GAS related activities, easily gets out of hand of course and leads to the final question:
Where to put all of that stuff?
The usual answer to that question is to buy a premade suitcase (by Doepfer and alike) or a semi-fitting suitcase, that you can modify and put rails into.

Being a goat skinner, that obviously wasn't enough for me. So I started building a suitcase on my own (with some inspiration from Victor Mazón Gardoqui), trying to adhere to cabin luggage size limitations (40cm x 50cm x 20cm) for most airlines, just to learn that the goat skinner changed their suggestions when I was about to start building. Although being a suggestion, it is most likely that many airlines will stick with this new size limitation (55cm x 35cm x 20cm), which is sad, because with a little over 40cm you can actually fit in 3x 3 U into your suitcase! Nevertheless, I decided to move forward with my initial size limitations for my suitcase. It can host 6 x 19" of modular Eurorack goodness.

Note: My modular suitcase is designed to fit with up to four Befaco Power Busses and one accompanying 2A WEHO D-60 power supply. It can host modules of depth up to 5cm on the upper side and modules of a maximum depth of 7cm on the bottom side. This may or may not be what you are looking for.

License: All information, pictures and other files on this page are CC BY-SA 3.0 licensed.

Yadayada: This is all very nice, but take me to the Pictures!

Planning

I'm not a fluent CAD software user, so I decided to use Inkscape (a powerful, free and easy to use vector graphics tool) for planning the whole thing instead. The below pictures are taken from the created SVG files, which you can find here (right click and "save as"):

Front

Front view on modular suitcase (background)

Width

~ 45cm (without handle)

Height

19.6cm

Light brown

Plywood

Light gray (semi-transparent)

Closing profiles, casemaker, corners

Spirals (black)

Drill marker (rivets)

Side

Side view on modular suitcase (background)

Width

40.7cm

Height

19.6cm

Light brown

Plywood

Light gray (semi-transparent)

Closing profiles, casemaker, corners

Medium gray rectangles

Spacer bar

Spirals (black)

Drill marker (rivets/ rails screws)

Material

Some of the modifications to the above layered SVG files I have been doing while building the suitcase. So, if you want to build one your own, make sure to have the time for proper planning (and changing of plans).

Most of the materials you can either order via Thomann or find in your local hardware store. For some of the bolts/ screws I went to special stores though. Tools will be discussed further down.

Ready mades

Here's a list of things I bought for the suitcase:

Quantity	Item
5	Adam Hall 6106 (aluminium casemaker)
5	Adam Hall 6202 (aluminium closing profile)
8	Adam Hall 40402 (zink plated steel corner brace)
8	Adam Hall 4000 (zink plated steel corner)
7	Adam Hall Blind Rivet (20 x 4,8mm x 15mm blind rivets)
4	Adam Hall 1602TP (cheney-lock with eye, galvanized)
1	Adam Hall 4911TP (set of four rubber feet)
1	Adam Hall 3415 (handle)
12	19" rail (19" rack rail, without edge)

Screws, washers and nuts

The 24 rail screws need to be M5 (5mm screw thread, 2,5-3cm long). Choose proper steel screws with small (nugget) heads (around 8mm in diameter)!
The 28 screws used for the cheney-locks and the handle (also M5 I chose to be proper steel security torx screws (2cm long) with 28 accompanying self-holding nuts.
The Befaco Power Busses and the WEHO D-60 power supply will be attached to the suitcase by M3 (1,5cm long) screws with fitting nuts. You'll need 4 of each per Power Bus and 4 of each for the power supply.
For each applied blind rivet it's good to have a washer (applicable for M5). You'll need 140 of them (roughly 1,5cm in diameter).
Another form of washer is needed to be put between the 4 inner rails and the plywood. It has to be 347mm x 275mm x 1,5mm. I chose a very cheap aluminium bar in a local hardware store, that - aside from an edge I had to saw off - fits the description.


Note: Interestingly enough the aluminium bar used for the rails washers proofed to be very useful as an upright anchor for the WEHO D-60 power supply, too. To properly use blind rivets going through the casemaker on the side of the power supply for holding the anchor, it has to be 20cm long. The bar I used is L-shaped, 2,7cm high and 1,4cm deep. The rivets will go through the shorter side of the bar.

Plywood

To properly fit the above mentioned aluminium casemaker and closing profiles I recommend plywood of no more than 6,5mm thickness (especially if you still want to apply some paint).

Many hardware stores pre-cut plywood for you, but it might not be sufficently accurate. The following dimensions have to be accurate!

Quantity	Dimensions
2	43,2cm x 7,5cm
2	43,2cm x 9,3cm
2	38,7cm x 7,5cm
2	38,7cm x 9,3cm
2	43,2cm x 38,7cm

Building

For building this kind of suitcase you'll need proper tools, or you'll easily be very very frustrated (so, please take this as a warning).

At home I only have a small working area for soldering and such small activities, but no proper work bench. So I used a nice Hackerspace (of which there are plenty in Berlin) as workshop. c-base is one of the oldest (founded in 1995) and has many tools to offer (to its members).

Tools

You'll definitely need the following tools:

circular saw bench (if the plywood could not be cut properly by the hardware store, or you just want to do that yourself)
bench drill (choose this over a standard drilling machine for more accurate and straight drill holes)
- 5mm metal drill head
- 5mm wood drill head
- 3mm metal drill head
- 3mm wood drill head
sandpaper (80 & 120 or 240)
hammer (always good to have one)
metal saw (with thin - preferably a set of exchangeable - saw blades)
cordless screwdriver
GOP (or similar tool, for sawing in strange places)
rivet gun/ riveting tongs
a brush and matte paint (for the finish)

A note on cheap tools, especially cheap riveting tongs: If you buy the cheap stuff, it'll hurt your hands and it will break after a short while. The one I bought lasted around 70 blind rivets and then it gradually started to degrade and not get a grip on the rivet bolts any longer. Save yourself the trouble and find a space with a high pressure rivet gun or get high quality riveting tongs. It's worth it.

Sawing

Note: When sawing the aluminium casemaker and closing profiles, make sure to wear a mask. This kind of fine dust you don't want to breathe in.

You'll need the following quantities and lenghts of aluminium casemakers and closing profiles:

Quantity	Length	Component
4	33,2cm	Casemaker
4	37,7cm
4	2,65cm
4	4,45cm
4	33,2cm	Closing Profile
4	37,7cm	Closing Profile
1	20cm	L-shaped WEHO D-60 anchor

Make sure to saw straight and clip the material afterwards (the cutting edge will be sharp!). You might burn some saw blades on this. Aluminium easily smears when being sawed.

To make the Befaco Power Busses fit into the suitcase, a little opening has to be sawed off. For this you should use a tool like a GOP.

The rails washers for the top part of the modular suitcase have to have a little edge be sawed off. This is needed to be able to properly put a blind rivet for the corner there later on.

Rails washer with sawed of edge (from top part of the suitcase)

Once you're done with the metal sawing (and you hopefully already have the proper plywood parts done), you can start combining them with the plywood.

Combination of plywood, closing profile, casemaker and corners before drilling

Note: Four of the rails will have to have a slice of 1,5mm by 2,1cm be cut off. It has to be on the side where there's no nut rail (bottom side on the below picture). This has to be done, to make the rail fit properly in the suitcase right next to the plywood and thus ensuring 3 U also on the outer rack spaces (otherwise the corner casemakers push the rails inwards and thereby waste 1,5mm).

19" rail (without edge), as used in the modular suitcase

Marking

Mark all your components and their proper positions, once you have them pre-assembled. This makes drilling much easier. I numbered all plywood components with a fineliner and scratched in numbers on casemakers and closing profiles towards the respective piece.

For all non-corner casemakers and all closing profiles their position on the plywood is easily determined (by the length of the corner pieces). They have to have a distance of 2,75cm to each side of the plywood their being put onto.
All casemaker corners must have a distance of 2,7cm to the bottom (of their respective side) of the plywood and a distance of 2,1cm to the top. This applies to both sides of the suitcase.
The rails washers have to be positioned 2cm from each side of the plywood and 4cm and 2,7cm from the bottom of it (for bottom and top of suitcase, respectively).

Closing profiles and casemakers on plywood with markings for casemaker corners

Closing profiles and rails washers on plywood with position markers

This is also the perfect time to mark the center of each drill hole. Those - like the markings mentioned earlier - have to be applied "from inside" the case.

Note: Use a pointy bolt for hammering in a little notch for each center point. Do this with the plywood in the casemaker and closing profile, else you will bent it!

Component	Length	Center of drill holes
Casemaker	37,7cm	1cm, 9,9cm, 18,9cm (from both sides and angles)/ each 1,2cm from the opening (for plywood)
Closing profile	37,7cm
Casemaker	33,2cm	1cm, 7,6cm, 16,6cm (from both sides and angles)/ each 1,2cm from the opening (for plywood)
Closing profile	33,2cm
Closing profile	33,2cm	top: 2,6cm/ 1,85cm and 6cm/ 1,85cm (cheney locks) (from each side/ opening for plywood)
Closing profile	33,2cm	bottom: 2,7cm/ 1,85cm and 5,9cm/ 1,85cm (cheney locks) 9,45cm/ 1,2cm and 11,9cm/ 1,2cm (handle) (from each side/ opening for plywood)
Casemaker (corner)	2,65cm	side with rail: 0,6cm/1,2cm, 2cm/1,2cm and 1,35cm/1,7cm (rail), from bottom
Casemaker (corner)	2,65cm	side without rail (from bottom): 0,7cm/1,2cm and 2,1cm/1,2cm, from bottom
Casemaker (corner)	4,45cm	side with rail: 0,6cm/1,2cm, 2cm/1,2cm and 3,35cm/1,7cm (rail), from bottom
Casemaker (corner)	4,45cm	side without rail: 1,0cm/1,2cm and 3,5cm/1,2cm, from bottom
Corners (bottom)	-	1,9cm from each side of bottom plywood corner (applies to every corner on both sides of the suitcase)
Corners (top)	-	0,3cm/ 0,75cm and 1,6cm/ 0,75cm from top plywood corner (applies to every corner on both sides of the suitcase)
Rails washers	34,7cm	top: 10,4cm/ 0,7cm and 11,3cm/ 0,7cm (rails) 5,05cm/ 0cm (cheney locks) from each side/ top of component
Rails washers	34,7cm	bottom: 10,4cm/ 0,7cm and 11,3cm/ 0,7cm (rails) 5,05cm/ 1,75cm (cheney locks) from each side/ top of component
WEHO D-60 anchor	20cm	1,0cm/ 0,9cm from each side and 10,0cm/0,9cm

Drilling

Note: Drilling should be as straight as possible. A bench drill is highly recommended!

Tape the components to the plywood after marking, so they won't move during drilling.
Using a 5mm metal drill head, one can slowly drill through closing profiles/ casemaker/ rails washer/ power supply anchor + plywood. The casemaker components have to be reattached to different pieces of plywood to finish all holes.

Two pieces of plywood with components taped to it and drilled holes

Pieces of plywood with components taped to it and drilled holes — Piece of plywood with components taped to it and drilled holes

Rails washers, casemakers and closing profiles after drilling. Chances are good, yours will look better (without the drilling fuckups in the corners)

After drilling a disassembly is recommended to clip plywood and aluminium components. This is also the best time for a preliminary test, if all components have the expected dimensions.

Rails

The rails used need some further modifications to be put in the suitcase. One, that has to be applied to the two outer bottom rails is an edge that has to be sawed off.

Outer, bottom rail with sawed off edge (but still with the 1,5mm slice, as mentioned in Sawing)

Another is drilling a hole through the two outer top rails at 0,9cm/ 0,9cm. This ensures, that the the lower of the two blind rivets on the corner pieces of the top part of the modular suitcase can be replaced by one of those M5 screws.

Rail from top side of the modular suitcase with hole drilled through for fixing with screw

A third is sawing off a little edge at the outer top rails, to give the lower blind rivet (parellel to the screw going into the nut rail) enough space.

Rail from top side of the modular suitcase with edges sawn off. Only the right one is correct, the left sawed off edge should be the 1,5mm slice, mentioned in Sawing

Painting

The paint job was quite easy. I applied two rounds of paint.

After the first paint job, I used the sandpaper (240) to smoothen the surface and then did a second round. The wood grain is still nicely visible.

Assembly

Now to the final (and fun) part. Assembling all that stuff!

The power supply can be attached to its anchor before all the blind rivets will be put in. For this you have to drill two more holes with the 3mm metal drill head. The drill location depends on the screw locations on the power supply. You will have to open its chassis and put two of the M3 screws there. I used a bunch of nuts to bridge the gap between the power supply and the anchor.

|d-60| power supply showing two |m3| screws going through the anchor — WEHO D-60 power supply showing two M3 screws going through the anchor (side view)

Putting in all the blind rivets is not so much fun. Therefore the fun from before.

Blind rivets: 4,8mm * 10mm (left) and 4,8mm * 15mm (right). Nearly 140 are needed of the latter.

Note: You might want to do this in two sessions, depending on what kind of tools you use, otherwise this might seriously hurt your wrists!

Attention: The upper blind rivet on each bottom corner casemaker orthognal to the rail should be a short one (4,8mm x 10mm), so it doesn't interfere with the rail!

The blind rivets can have an additional washer on the inside of the suitcase. This is not really necessary, but gives some extra stability (and weight), especially in the spots, where there's no metal involved on both sides of the plywood.

Blind rivets through a corner casemaker with additional washers and a rail with an edge sawed off.

Bottom half of the modular suitcase with all blind rivets put in.

Bottom half of the modular suitcase with screws for the |d-60| power supply — Bottom half of the modular suitcase with screws for the WEHO D-60 power supply

Bottom half of the modular suitcase with the |d-60| power supply and Sugru below the |befaco| |power_busses| |abbr_ic|. — Bottom half of the modular suitcase with the WEHO D-60 power supply and Sugru below the Befaco Power Busses ICs.

Pictures

Bottom half of the modular suitcase with some modules.

Opened modular suitcase, top half (left) and bottom half (right)

Bottom half of the modular suitcase with attached handle and cheney locks.

Bottom (right corner) side of (closed) modular suitcase

Frontal view on (closed) modular suitcase

Frontal/ left corner view on (closed) modular suitcase

Width	45,3cm (without handle)
Height	19.6cm
Light brown	Plywood
Light gray (semi-transparent)	Closing profiles, casemaker, corners
Spirals (black)	Drill marker (rivets)

Width	~ 45cm (without handle)
Height	19.6cm
Light brown	Plywood
Light gray (semi-transparent)	Closing profiles, casemaker, corners
Spirals (black)	Drill marker (rivets)
Red rectangles (semi-transparent)	Power Busses
Dark gray rectangle	Power Supply
Light gray rectangles	Rails
Red screws/bolts	Rails screws

Width	40.7cm
Height	19.6cm
Light brown	Plywood
Light gray (semi-transparent)	Closing profiles, casemaker, corners
Dark gray (semi-transparent)	Handle, Locks
Spirals (black)	Drill marker (rivets)
Spirals (red)	Drill holes (rails screws)