Years back when I first got into O scale narrow gauge I pretty much bought anything, after a while I got more focused. One of those early purchases was a brass Westside Models Heisler. I wanted a Heisler so I had at least one representation of all the geared locomotives that were popular, little did I know then what a mess that model was. The two big issues with the model is that it had a huge open frame motor and that it was actually not O scale.
When Westside had the model designed and built they told the manufacture to copy the HO version they did. The manufacture just doubled all the dimensions, after all HO means "half O", wrong. What happened is that the model is just too big.
The issue with the motor is that it drew too much current, and had to run at very high RPMs. My first attempt to replace the motor was just to use a 5 pole can motor I had left over from my HO days. The original gearbox used two worm gears to transfer the power from above the cab floor to below the cab floor. the original motor ran fast enough to work with the double worms but the can motor at top speed just crawled. My second attempt was to install a Faulhaber motor and a chain drive, which worked Ok but it was still very slow and there was not enough power, bucking downhill was also an issue with the chain drive. I decided to put the project away and move on for now. that was 2016 and now I have more tools in my toolbox, one of which is a 3D resin printer.
I pull out the Heisler and decided to take another run at it. This time I was going to 3D print gearboxes to test, with hopes of coming up with a drive line that I can use for my future Shays I plan on building. I pulled out a good sized can motor (it was a NWSL that I had) and started to design a gear reduction drive that would use some Athearn parts I had on hand. it took several tries but I finally got a very good running drive.
The motor was moved from the tender to up inside the boiler. I cut out the bottom of the boiler just below the running boards to clear the motor. The gearbox was designed to fill in the void in the boiler , basically plugging the hole I just cut. The boiler backhead was created to be the gearbox cover, which included a limited amount of details printed on it. The basic drive I settled on was an Athearn worm which drives an Athearn axle gear (from the blue box years) mounted on a "vertical" shaft. One Athearn bearing is at the top of the vertical shaft with a thrust washer. The vertial shaft passes below the cab floor and drives a Grandt Line small bevel gear from a Shay repower gear set. The lower line shaft has 3mm sleeve on it which has a Grandt Line large bevel gear and crossbox. The vertial shaft goes into the crossbox and the retainer is pinned in place with a small brass pin, this keeps the gear mesh where I set it, it is common for these gear retainers to "creep" and then say hello to a stripped gear. The line shaft is centered with two more Athearn bearings, one of which is filed to keep the shaft tight but not binding. The gearbox was 3D printed in black resin using my Epax X1 printer.
The oversized model was fixed by basically throwing out everything but the trucks, the cylinders, and the boiler. The frame was cut all to pieces and reassembled to new proportions. A new cab was photo etched and built to resemble Cass Scenic's #6 Heisler. The oversized smoke stack was hidden by a spark arrestor, the steam dome was cut way down as well. The boiler saddle was sectioned to lower the boiler and the entire model was shortened by taking a section out of the middle.
here is how it started, it look neat but it was an oil burner
this is the start of surgery
here is the cab being built
original cab and new cab
gearboxes, lots and lots of gearboxes
prepaint
final model
