Give your old box of track a second life

Benjamin | TrackDrawer.com · published 31 October 2026

A box of old track is almost always still usable. First work out which system you have, from its shape and its part number. Then count by part number, clean and check, and enter your stock: the Auto-designer then lays a track plan that comes exactly from that box, without you buying anything first.

Step 1: which system do you have?

Two questions get you a long way.

Is there anything between the two rails? A row of small metal studs along the middle of the sleepers is the Märklin centre conductor with stud contacts. Then you have three-rail AC: M track, K track or C track. If there are only two rails, it is two-rail DC, such as Trix C, Roco, Piko or Fleischmann.

What does the track base look like? A track base of pressed metal is M track. Separate plastic sleepers without roadbed are K track. A grey plastic roadbed is C track, or Trix C if the stud contacts are missing.

The part number confirms it. If it is still on the box or on the piece itself, look it up in the TrackDrawer catalogue. The number ranges differ per system:

The catalogue also covers Piko A track, Fleischmann Profi track, Tillig, Kato, Peco and Hornby. On the M track system page and those of the other systems you will find every piece with its length, radius and angle.

Step 2: sort and count

Sort by part number and stack identical pieces. This order works well: straights by length, curves by radius and angle, left and right turnouts kept apart, counter curves, crossings, terminal tracks, switching and contact tracks, buffer stops.

With curves, look at the angle, not just the radius. A closed loop needs a full circle of curves with the same angle: twelve 30° curves, or eight 45° curves for the small industrial radius. If you have six 30° curves and twelve 15° curves on the same radius, that is enough degrees in total, but the Auto-designer only lays a loop from curves of one angle, and it tells you so.

With M track it pays to look closely at the turnouts. The catalogue lists three generations with different angles: 5118 and 5119 (30°, on R1, 1957 to 1974), 5138 and 5139 (22°30', on R1, 1975 to 2000) and 5203 and 5204 (24°17', on R2). They look alike, but they do not lay a passing loop in the same way.

Step 3: clean and check

Old track is rarely broken, but often dirty. Work piece by piece:

• Railheads. Wipe the running surface with a cloth or a track cleaning rubber. Coarse abrasives leave scratches where dirt builds up again faster.
• Stud contacts and centre conductor. On three-rail every stud must still be there and clean; that is where the pickup shoe collects the current.
• Rail joiners. A joiner that has opened up or sits crooked causes poor contact or a bump. Bend it back carefully or replace it.
• Metal. On M track, check the base and the joints for rust.
• Turnouts. The blades must move freely and close properly. On an electric turnout, test whether the motor throws in both directions.

Then lay a circle from your curves and let a locomotive run. If it keeps stalling at the same spot, you know which piece to check or set aside. If it derails at a turnout, read train derails at the turnout.

Step 4: combine systems

If you have M or K track and want to extend with C track, there are transition pieces for that. A transition track bridges the difference in rail profile and height between the two systems. In the catalogue:

• 24951: transition track C to M, 180 mm
• 24922: transition track C to K, 180 mm
• 2291: transition track K to M, 180 mm
• 62922 and 62951: transition tracks for Trix C track, from Fleischmann Profi (180 mm) and to Code 83, Roco Line and Fleischmann Profi (47 mm)

The geometry differs per system. C track and M track are close: R1 is 360 mm on both, R2 is 437.5 against 437.4 mm, and the track spacing is 77.5 against 77.4 mm. K track is different: R1 is also 360 mm, but the second radius is 424.6 mm and the track spacing 64.6 mm. Double track with K curves on one side and C curves on the other will not close by itself. The differences between C and K are set out in C track or K track.

Do not mix three-rail and two-rail on one circuit: the current flows differently in each. A three-rail locomotive has wheels that are not insulated and will short-circuit two-rail track.

Step 5: enter your stock and let it design

Enter what you counted, part number by part number. The Auto-designer works per track system, so choose the system you have most of. You then lay the transition tracks and the pieces of the second system yourself in the editor.

What you get depends on what is in the box:

• Enough curves and straights: ovals, polygons or a dogbone, with the exact parts list.
• Turnouts with counter curves as well: passing loops, a station or a yard.
• Too few curves for a loop: an open plan from your stock (a line with buffer stops or a U shape) and the smallest oval that would work, with exactly how many curves of which number are still missing.

How the Auto-designer chooses and what it checks is explained in the Auto-designer.

Frequently asked questions

Can I still use M track alongside new C track?

Yes. Transition track 24951 connects C track to M track. R1, R2 and the track spacing are almost identical in both systems, which makes combining them straightforward.

How do I tell K track from M track?

Look at the track base. M track is pressed metal, K track has separate plastic sleepers. Both have stud contacts in the middle. The part number confirms it: K track is in the 22xx range, M track in the 51xx and 52xx ranges.

Finally

Count your box, enter the numbers and let the Auto-designer lay a plan made exactly from your pieces.