Star or Bus wiring?

[IanS]

loopy.jpg

I know the perceived wisdom is that you should use Bus wiring for layouts. I've tried very hard to create a layout with a bus but with limited physical capacity (mine) to crawl underneath to do wiring it is proving very difficult.

I also would like to run DC locos as well as DCC on the same layout (not at the same time). Block control is beyond my skill level and power gets to the track via multiple wires via track joiners from Peco. So far they've proved reliable, although I do recognise they're not ideal. I've also inserted multiple insulated joiners and some points are insulfrog and some electrofrog! (Because I already had a large number of insulfrog points).

The layout runs the length of a double garage and is 18ft long and 4ft wide tail chaser with linked smaller loops inside.

I've been wondering if using a star variation on the bus may be easier to re-wire and fault find.

My idea is to have 4 (or more) points where all the wires come together from various parts of the layout which would in turn be linked.

The image is of a very stylised version of the layout - the smaller inner loops contain more track and the points are not all the sharper Hornby ones but include long streamline ones from Peco. Some points are missing from the image to simplify it.

My question, after all the waffle above as background is 'Should I continue with attempts to wire it as one big track with insulated joiners to break up and sections or could a star system work better for this particular layout where each inner loop is effectively one point of a star?'

[Steve M]

Good electrical practice is to keep the droppers as short as possible, but with your 4’ boards the droppers will be 2’ if you have a bus that runs down the centre. A star bus wouldn’t be any better.
In my opinion you should consider two bus pairs down each side of the boards, just onboard of the outer mainline loops. This will significantly reduce the length of the droppers to around 6” or so. It will also be much tidier to facilitate troubleshooting.
At some point though, you will have to climb under the boards and while I would advocate soldered joints you may find something in the range of Wago connectors that may make the job easier if mobility is an issue.
Final tip is to follow a strict colour coding for the wires to help avoid short circuits.

[IanS]

Thank you for your observations. Currently the single bus runs down one side as the other is just accessible and I can't stand for long periods. The gap between the back edge (as shown in the image) and the garage wall is about 2ft - I'm close 18" from front to back at the relevant height! (and much more side to side!)

I've used Wago style (cheap Chinese copies but as they only handling the 14v or so from DCC or 20v max they will be ok as rated at 250v) connectors although I've managed to sold some lengths to the Peco droppers to extend them.

I need to clear the top surface as it has become a dumping ground for lots of things including recent loco purchases for conversion. I'm currently spending money on buying 2nd hand non-DCC ready locos and making them DCC ready by installing an 8-pin socket and blanking plate. (Hence the need to be able to run either as DC or DCC.)

[Brian]

As I see it you have three options for a Bus These Ive shown the idea below.

[IanS]

Again, thank you for your ideas. I wasn't aware that you could legitimately do a ring bus for DCC. (Or DC either). It's an interesting idea.

It looks like I need to clear out the top surface and somehow manage to re-arrange the existing wiring into a bus set down both sides of the table, either linked in a ring or separately to accommodate any of Brian's suggested systems. A cable down the centre is definitely not a possibility due to mobility issues.

[RFS]

Again, thank you for your ideas. I wasn't aware that you could legitimately do a ring bus for DCC.

Absolutely nothing wrong with a ring bus for DCC. After all, your track layout is full of rings is it not?

[Tricky Dicky]

Again, thank you for your ideas. I wasn't aware that you could legitimately do a ring bus for DCC. (Or DC either). It's an interesting idea.

The myth that with a ring DCC signals could arrive at the same point at different times causing confusion is wrong. It is possible but you are talking about distances in kilometres not metres.

Richard