4QD controllers are used for model locomotive speed control by model engineers worldwide, both private and commercial. Indeed our DNO controller, and its predecessor the VTX, were designed specifically for this application. Our model locomotive customers tell us that our controllers give really smooth operation and are simple to install. Many have controllers still going strong after 25+ years. All our controllers have adjustable acceleration and deceleration ramp times which can be adjusted to give realistic locomotive speed control. The new Pro-160 has many new features and is one of the first controllers to include a readout of current, voltage, and temperature.
The model of controller you need depends on the power / current rating of your motors, and also the sort of loads that you intend to pull, any gradients on your track, and how long you intend to run for. You may also want to take into account other things like ease of set-up and adjustability.
As a general guide the following controllers are suitable for model locos:
DNO range – These are great for small / mid size locos up to 5″ / 7¼ ” gauge – with motors up to 100 amps. These are simple controllers that require the minimum of set-up, with adjustable gain and ramp settings. We see good results for locos pulling up to around 10 passengers with these.
Pro-150 – for mid size locos up to 7¼ ” / 7¾ ” gauge. Again good for around 10 passengers, the Pro-150 has a greater number of settings which allow the controller to be fine tuned to the operators requirements via the optional display / programmer. It will still work out of the box with the standard settings though [just like the older Pro-120].
Pro-160 – for mid size plus locos up to 7¼ ” / 7¾ ” gauge. The Pro-160 also does away with relays for long term reliability, and is ideally suited to those locos that will be worked hard pulling larger numbers of passengers for extended operating periods. With a 2 line display that can be mounted remotely the Pro-160 has features designed specifically for locomotive control, including a dead mans handle input, a slow / fast mode switch to allow new driver training, built in radio control input, and readouts of voltage, current, and temperature.
4QD range – for larger locos with motors up to 300 amps, these controllers can deliver serious pulling power. There are also uprated air and water cooling options available.
We have a list of all the locomotive sites and suppliers that we know about, please let us know if you’d like to be added to the list.
There are also some locomotive knowledgebase articles that address loco specific issues.
Here are just a few of the fantastic models that our customers have built.
From time to time we get asked if we can do special projects. Here’s a picture of a custom control box that we built.