Guest article: Fx Bricks switches
by Peer Schaefer
LEGO currently (2023) only carries non-current-carrying plastic rails in its product range, so that all current LEGO trains must be operated with batteries or rechargeable batteries. This deviates from the usual operating principle of model railways, which usually draw the required traction current directly from the tracks and are therefore independent of battery life. Until recently, however, LEGO conductor rails were only available second-hand via Bricklink or other trading platforms, but the Canadian company Fx Bricks is now once again offering conductor rails that can be easily combined with LEGO rails. While LEGO only offers curves with a (very tight) circle radius of 40 studs, the Fx Bricks product range also includes curves with radii of 56, 72, 88 and 104 studs (product designations R56, R72, R88 and R104 respectively). This enables considerably more realistic and visually appealing curves. Radii of 120, 136 and 152 studs are being planned. Straight lines with lengths of 8 and 32 studs are also available (product designations S8 and S32 respectively), and straight lines with a length of 16 studs are being planned.
The delivery of Fx Bricks switches has been delayed several times and put the patience of all fans to the test, but since the beginning of November they have actually been available (duty-free in the EU on JB-Spielwaren). As with the LEGO switches, these are simple switches with a straight main track and a branching track (a Y-turnout is apparently planned for the future, but is not included in the current catalogue). Otherwise, however, the geometry differs considerably from the geometry of the LEGO switches. In particular, the branching track has a curve radius of 104 studs, not 40 studs as with LEGO, so that the branching track is curved much more gently. The main track leading straight ahead has a total length of 40 studs (hence the product designation "P40", where the "P" stands for the British term "point"). Both left-handed and right-handed switches are available (P40L and P40R). Unlike the original LEGO switches, the switches from Fx Bricks have not just one but two movable points. This is not only more true to the original, but also ensures smoother running of the rolling stock when crossing the switches. No lever is provided for the mechanical adjustment of the switch blades; instead, a horizontal slider installed below the track level is available. The slider has a hole on each side that is compatible with the LEGO Technic system, so that corresponding mechanical elements can be attached there using a pin (a lever, a motorised rod, etc.). On the switches currently supplied, the slider is a little stiff and only engages with a little force, but as there is no spring mechanism, there is no risk of the slider jumping back to any "starting position".
The branching track reaches an angle of 22.62° over the length of the switch, which is slightly more than two R104 curves (these reach 2 x 11.25° = 22.5°). This unusual geometry offers the great advantage that two switches can be installed in opposite directions to enable a change between two tracks with an offset of exactly 16 studs without an intermediate piece. The difference between 22.62° and 22.5° is small enough to be able to combine a P40 turnout and six R104 curves to form a quarter circle without major stresses. If the branching track is to be routed parallel to the main track again, a return curve is required. As the usual R56, R72, R88 and R104 curves each cover an angle of 22.5°, there is a special R64 curve piece for this purpose with an adapted angle of 22.62°, the length of which is calculated so that there is a distance of exactly 16 studs between the main and branch track measured from track centre to track centre (as with the original LEGO switches). If straight lines or another turnout are added to the branching track without a previous return curve, the angle from the perspective of the main track results in track lengths with a broken stud length. To lead these back into the stud grid, Fx Bricks offers special track elements with a "broken" length of 1.6 and 3.2 studs. A crossing with an angle of 22.62° would be desirable to enable a curve-free crossing of the neighbouring track after a P40 turnout. Such a crossing was also included in a product study by Fx Bricks from 2019, but does not currently appear to be one of Fx Bricks' priority product plans.
The quality of the tracks offered by Fx Bricks is outstanding and is in no way inferior to the quality of the original tracks from Billund. The plastic base of the rails is injection moulded (no 3D printing), the plastic has a precisely matched dark grey colour (Bricklink designation "dark bluish grey") and the conductor rails are made of a weather-resistant copper-beryllium alloy. The high manufacturing precision and excellent clutch power, which make it possible to install the track segments in a bed of LEGO bricks ("ballast"), are particularly noteworthy. The switches have small sliding switches ("jumpers") on the bottom side, with which the main track and the branching track can be electrically isolated from each other or connected to each other. This offers a high degree of flexibility in the design and operation of the track system if the motor control is to be carried out via several central controlers. However, the Fx Bricks rail system will only be able to realise its full potential when the planned rolling current collectors are available, i.e. metal wheels that can draw current from the conductor rails. This makes it possible to operate the current-carrying rails permanently under the full 9V voltage and to control the motor not via a central controler, but - as with LEGO products - via a wireless remote control. In this respect, the conductor rails would act as a kind of "battery replacement" with unlimited runtime. Fx Bricks has not yet given a specific availability date for the metal wheels, but it is clear that these wheels, together with a motor that is also planned, will be a central element of the product portfolio.
The biggest drawback with the products from Fx Bricks is the price of the curves and especially the switches. The prices of the straights (calculated "per stud") are still quite reasonable compared to the used prices on Bricklink or eBay for a new and high-quality product (at JB-Spielwaren you can get eight S32 straights with a total of 256 studs for about 75 euros, which is ok overall). The prices of the curves are already somewhat higher and make larger circles in particular quite expensive (from a radius of R88, 32 curve elements are required for a full circle, which corresponds to four boxes with eight elements each). The switches then form the top of the price pyramid at approx. 170 euros for a pair. The special return curves (eight R64 for approx. 80 euros) and the short elements for broken lengths (10 x 1.6 studs and 10 x 3.2 studs for a total of approx. 90 euros) are added to this. These are very high prices. I assume that Fx Bricks has a very fair pricing policy in principle, but the long development time and various production and transport problems (including those caused by Covid-19) have undoubtedly driven internal costs through the roof and are now apparently forcing the company to pass this on to customers. It is to be hoped that this will normalise in the future and that prices for curves and, above all, switches will fall in the future with established production chains. Because these well thought-out and outstanding products are great fun and deserve to conquer a broad market.
Considerations on the switch geometry
To assemble a full track circle from Fx Bricks curve elements, a total of 16 elements are required up to a radius of 72 studs and a total of 32 elements from a radius of 88 studs and above. This results in an angle of 22.5° (360°:16) or 11.25° (360°:32) for the individual curve elements. At first glance, it would therefore have seemed obvious to choose a closing angle of 22.5° for the branching track of the P40 switch from Fx Bricks, whose branching track simulates a curve radius of 104 studs. For reasons of connection geometry, which Fx Bricks has explained in detail in a separate article "Why 22.62 degrees?", Fx Bricks has decided to let the P40 switch run out at a final angle of 22.62°. A return "R64P Curve Track 8864" with an angle of 22.62° is therefore required to lead the branching track parallel to the main track again. This is a geometrically flawless solution, but has the disadvantage that the R64P curve "only" has a radius of 64 studs. This means that the return curve is tighter than the curve of the branching track of the switch. In view of the small difference between 22.5° and 22.62°, the question arises as to whether the material has sufficient tolerance to allow two P104 curves to be used instead of the R64P curve?
In the aforementioned article "Why 22.62 degrees?" there is a reference that such a solution should be possible if a certain tension is accepted. This hint aroused my curiosity. During the subsequent experiments, it turned out that the vertical error (approx. 0.08 mm) was negligible, but the horizontal error (approx. 1.76 mm) was too large to immediately reconnect the two R104 curves to a track running parallel to the main track. It made sense to close the remaining gap based on Holger Matthes' smooth curve technique. Further experimentation led to the realisation that when using this technique, one rail element is not sufficient to accommodate the difference. However, two S8 elements from FX Bricks then provided the necessary flexibility without unduly lengthening the turnout area. The total length of the turnout area with the actual P40 turnout, the two R104 curve elements and the two S8 straight elements then has a total length of 96 studs (corresponding to three modules of 32x32 studs each).
Peer Schaefer | November 2023
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During the long wait for the Fx Bricks switches, I was in constant e-mail contact with Peer. Thank you Peer for your impressions.