Ever since I released my N scale kit for the DT6-6-2000 in 2014 I’ve been planning to release it in HO scale. The project has had a few challenges getting started but finally, it’s underway.  And the first place to start is the chassis.

As with the N Scale version, I’ll be using a ready-to-run chassis to make things easier, and more reliable.  I’ve chosen the Bowser Alco C628/C630.  It comes with a big central motor, two flywheels and lots of weight, which will be ideal for a model of a DT6-6-2000.  It also has a circuit board with a DCC socket which I also intend to use.

This particular chassis came from a Canadian Pacific C630M and has different trucks to the Commonwealth trucks used on DT6-6-2000, but when I purchased the locomotive I assumed the wheel arrangement was in the same asymmetric positions with different side frames.  However, despite appearances, the wheels are evenly spaced.

But the good news is I was able to order a set of Commonwealth trucks from Bowser with the correct asymmetric wheel arrangement.

They’re a direct replacement in the chassis and now I’m at the right starting point.

The main difference between the Alco C-628/C-630 and Baldwin DT6-6-2000 chassis is the asymmetric trucks are facing the other way.  With the N Scale Atlas chassis, the truck gear tower is in the middle so they can simply be fitted facing the other way.  But with the Bowser trucks, the gear tower is at one end.  Luckily the front and rear wheel sets are already in the right position.  The DT6-6-2000 has an overall wheelbase of 54’9″, as you can see in this original blueprint below.  (Clicking on the image will make it bigger).

Converting that to Metric and HO scale works out at 191.8mm which is exactly the wheelbase the new chassis has, so it’s all good apart from the fact that the center wheel is in the wrong place.

The good news is the truck side frames are separate from the truck centers which hold the gears in place.

My plan is to 3D print some new truck centers with different gear spacing allowing the side frames to be refitted around the other way.  I’ve already drawn the truck centers with the original gear spacings.

My next step is to work out the new gear spacings which I’ll share with you once complete.  Then I can turn my attention to the 3D printed body shell.