Construction Philosophy

[Donner]

An Explanation of the components and tecniques used in constructing BJFE pedals.


SIZE :
110x60x30 mm is a comfortable size. The height(30mm) is
about as high as you can comfortably raise a foot with heel still on ground, and still allows a 6F22 battery to be fitted inside; length allows for battery,
footswitch, in/output jacks and circuit board and leaves just about
the room needed for the foot operating the footswitch to not accidentily step
on the knobs; width allows for up to four knobs and leaves 9mm between the inner edges of the in/outputjacks. This size also fits in most guitar cases.

Position of Jacks:
The input jack is to the right so that input cable
wont be draped over pedal. The output is on the corresponding left
side in same height from bottom to make it easy to connect pedals on a
string.
DC-jack is a standard 2.1mm Marushinchassi female mount , so standard power supplies can be used. It is positioned to the right below
input jack so that if pedal rocks to the side, DC-connector is protected
by the input plug.
In this type of box, with more than one knob, it is the only place
this female type DC jack can be mounted. Some experimentation with other types of DC-inputplugs at the topside of box showed that a weak point would be created.

Position of Controls:
The knobs and LED were placed in an angled arrangement to allow
easy adjustment of the knobs and still have the LED visable -
this influenced the position of the middle knob. The knobs
(TK1122) were chosen for their size and visable markers.

Paint:
The first BJF pedals were painted in nitrocellulose for two reasons: First, it was available from the instrumental workshop near by and second because of the potential colors.
Specific colors are used on the pedals to reflect the sounds available and to
give suggestions of use as well as look good. The colors are chosen to
present a pleasant pallette. Nitro ages and wears down like on vintage instruments that are used and loved.
However the paint factory actually blew up! Other materials had to be found.
All BJF pedals made from 2002 and on are handpainted in oil. Oil is much
more durable than nitro but ages well. Having small numbers of boxes powder coated in several colors would present a
substantial cost and long delivery time, so if the pallette of colors were to remain and delivery time be controlled then they had to be handpainted.

The hand painted text is a trademark.

Inside:
The circuit board is wrapped in neoprene, which is a kind of
rubber used in diving suits and will withstand severe heat, water and
other fluids as well as act as a cushion. The circuit board itself is
covered in 'goop' and can be viewed as non user servicable. It can
be serviced or replaced by BJFE if required.

The sealed circuit board: Not every pedal manufactuer has a copycat
living nextdoor- I do.
There are several aspects to 'gooping':
Of prime concern is of course to protect trade secrets, but also the
material fixes the position of the components and makes the circuit less
vulnurable to impact.

There are safety measures taken to ensure that the circuit board is not injured from outside sources like false power polaity. If power
polarity becomes reversed, the circuit will not work, but will resume normal
operation as soon as correct polarity is applied. Input and output stages
are protected against fusing e.g. during power down and applied voltage.
Excessive input voltage up to 10Vs will produce less than optimum performance, but circuit will resume normal operation after overload is removed.
In normal operation, circuit is well protected against failiure and
should last at least fifty years.

Mechanical Components:
The box used for the standard models is an ELFA K-430 and is made by
Solna Pressgjuteri in Sweden. It is made from an alloy of aluminium and
zinc that makes the box strong and gives superior sheilding to plain
aluminium. It is also heavier than plain aluminium at 450 grams fully mounted and will stay in position fairly well even if not velcroed to a pedalboard.
All corners are rounded and screws are M5 Phillips type.
Some pedals (about 150 peices) were made in the all aluminium
Hammond/Eddystone case, which is easier to work on and weighs less and is less expensive ( and cheaper to ship internationally also).
The availability of this box proved to be most inconsistent; and
from an ascetical point the shape of the Elfas proved more pleasing and
the little extra weight put the pedal firmer to the ground with less probability
of rollover. Screw threads also fit more snuggly in the Elfas.

Wiring: All wires are allowed some 'slack' to ease servicing when changing a
mechanical part. Battery clip is secured to output jack for strain relief, and to protect against battery wire breakage if battery should fall out of the box during battery change.
The wire wrap under these conditions puts strain on both wires with
insulation as opposed to the more fragile point of stripped wire by the solderjoint to DC-jack.

Note for pedals using the insulated batteryclip: This clip has a hood
over battery terminals and makes battery pack about 1mm longer. This can, with some batteries, make it a bit critical where battery is positioned for bottom plate to line up in the case slots. If bottom plate cannot be closed correctly, slightly push the battery to the side opposite the gap and the bottom plate should close.

Potentiometers:
Alps series RK-09 miniature pots were chosen. These have a
proven long life and are all metal in the part that is exposed
on the pedals surface. Shaft also has a flange that protects shaft from
protruding inside box in the event of sudden impact from top
and so internal circuit is protected. Only three reports of scratchy
pots in about 3500 pots mounted. The miniature size on the inside makes
for mounting of several pots in a small case. These pots are sealed and
will not collect dust. When worn out as any pot will eventually be,
they are easily replaced. Since the terminals on the pots are small and
flexible the connected wires are draped over pot and glued so a safe
connection with little stress is established. The pots, jacks and
footswitch are mounted with locking washers to
hold these parts in place and ease retightening if needed.

Every component is well thought out and together the parts add up to a high quality long lasting product that should give the user dependable service for many years to come......Enjoy.

[mrpicard]

The enclosures also have clear self-adhesive plastic feet at the bottom. I presume that these are the 3M Bump-On ones sold by ELFA. Therefore, what size and model number are those? Thanks

[BJF]

The enclosures also have clear self-adhesive plastic feet at the bottom. I presume that these are the 3M Bump-On ones sold by ELFA. Therefore, what size and model number are those? Thanks

Hi,

Dimensions are Diameter 10mm and height 3mm model number is A9210290 and ELFA part number is 50-570-39.
There is likely a similar 3M type but not readly available here.

Do you need spare feet?

Have fun
BJ

[mrpicard]

Do you need spare feet?

Yes, I need a few more. I found another old BJFE pedal and I took the velcro off and now I need some more plastic feet

[Lifetimer]

Hi BJ!

what´s ELFA part number for the pedal enclosures?
i need one for the Folk Fuzz project.
thanks!

Antonio

OK, i found it myself, it´s here:

http://www.elfa.lv/cgi-bin/index.cgi?ar ... !50-001-04