In this week’s post, as promised last week, I’m going to share with you which chassis I’m planning on using with my UP 900081 Rotary Snow Plow kit.
The reason why I plan on using a commercially available chassis is I want to make it easy to build and have reliable power pickup. This will make powering the fan on the front much easier. I can 3D print trucks, add contacts and fit metal wheels but when there’s something already available, which also has a motor and drive shafts, it seems the right way to go. However the UP 900081, and UP 900082, have two different trucks front and back and the truck spacing doesn’t match anything else so it’s not going to be that easy.
The chassis I’ve chosen as a starting point is made by Kato and can be fitted in to all sorts of things but I think it was designed for Japanese street cars. The 11-105 is the first of three including 11-106 and 11-107. All three are the same just with different trucks.
The chassis are fairly cheap and available in lots of places online and in local hobby stores. Plus they are great runners.
The plastic top is held on by four clips and simply pops off. Underneath is a motor at one end and a worm gear and truck tower at the other. There is a drive shaft connecting the two.
This means that only one truck in the chassis is powered by the motor, the other is free running but still picks up power, which is ideal for me.
With the top gear removed from the truck tower the chassis will become free rolling but maintain pickup from all the wheels. This then allows the fan to be connected to the drive shaft. This will also take a bit of figuring out as I want to incorporate a reduction gear box which will dramatically reduce the speed of the fan. Although I intend to convert this to DCC, which will be very easy, simply telling the motor to run really slowly may cause it to stall or seem jerky. Having a gear box will allow the motor to run at a good speed whilst the fan slowly turns.
All that quality pickup will also make it easier to install sound as well, which is an interesting option.
As I said before, there are a few issues with the chassis. Firstly, the truck spacing. This can be overcome by extending the chassis frame or simply 3D printing a longer one.
Secondly, the trucks themselves are the wrong type, and one doesn’t have enough wheels! But this too can be overcome and again it will involve some 3D printed parts. I haven’t decided yet whether to file down the existing side frame and stick on new ones or whether to 3D print a new truck outer section, but as the design develops that will become clear. At this point you may be asking what is left of the original chassis? Well, the motor and power pickup, which given the relative cheapness of the chassis is well worth it.
So I have a lot of design and drawing ahead of me on this project and next week hopefully I will have a bit more progress to share with you.