Example 1: Zimo MX648 (hard-wired) with Minnow4 speaker

Start by removing the 4 small screws holding the cab to the chassis. This then releases the cab unit. Now drill 4 small holes inside the 4 fixing holes then very carefully use a dremel cutting disc to join them thus releasing a section of the floor. Note: avoid the red base to the reversing lever. The picture shows the floor just after cutting. It must now be tidied up and squared off with a craft knife or file. It is important to ensure all burrs are removed otherwise the cab will not sit flat on the engine chassis.

Now we have to remove part of the section between the cab and the coal bunker. To give plenty of room for the chip remove this to the height of the cab doors as per the photo – it is not very easy to get at but if you use some clippers/cutters it is possible, be patient! There are probably some better tools for doing this. This leaves the top half of the section intact and if seen from outside the cab is still authentic.

The chip is placed across the cab and positioned using a small amount of Blue Tack and the speaker on top, again using a small amount of Blue Tack.
Tidy the wires and the cab should fit easily in position.
The speaker can be fitted in the smoke box which is removed by undoing a single screw but it is not easily replaced. The speaker wires can be fed under the saddle tank.

All back together...

Photos and words courtesy of Peter Blackburn

Example 2: Zimo MX648 (6pin wired) with SugarCube7 speaker

Similar, but larger speaker and retain the 6pin DCC socket... cab off to begin with...

Revove the 6pin blanking plug

Test-fit the MX648 decoder for size (we have removed the shrink wrap to make it smaller, but will need to protect it properly before installing for real.

A little bit of cutting of the plastic so that the decoder can slot into the top of the boiler.

Wrap decoder in Kapton tape and stick SugarCube7 speaker to the cab floor.

Back together, all out of sight.

Please note that these guides are provided as useful resources for you, as-is. YouChoos cannot be held responsible for errors in the information, or for any damage caused to your models or equipment if you choose to follow any of the steps detailed here.