Building a model Train Part 1 - episode 163

At the start of this year my brother came to me with a thought that a train would make a good addition to the Christmas display he has on his front lawn. With Christmas fast approaching he hunted out a model that we could cut on the CNC and this episode is the start of the train build process. This train is going to be large when it is finally complete and if all goes well it will be motorised so that it can run on a track. The first step in a project like this is to get the train itself built so in this episode we start cutting out the model and get parts of it assembled.

Scaling the model (Box Method)

Scaling the model is a necessary part of making this model and i like to make things as simple as possible. That means not having to hunt around for a calculator to work out how much to upscale the model by. To make things easy I developed the Box Method of scaling which in my opinion the easiest way of scaling a drawing accurately snce you don't need to calculate anything.
There are just 3 simple rules to the scaling method.

1. The box must be larger that the item being scaled.
2. The box must enclose the entire item being scaled
3. One side of the boxes dimension must bear a direct relationship to the measurement being scaled. eg for a 3.4mm item I wanted to scale to 5mm I would make one side of  the box 3.4 metres long.

Select the new box and everything inside it.
Scale the dimensioned side of the box to the new dimension eg. If I wanted my 3.4mm piece to become 5mm the I would scale my 3.4 metre to 5 metres and the drawing will be automatically scaled to the correct size all without having to work out the scale factor.
Give it a try and see what you think.

In the next episode I will be showing how I layout the parts for cutting and how to use the 180 degree method to cut the remaining parts on the end of the stock.

Untill next time thanks fortaking the time to watch and read.

Cheers
Peter

Where did I get the cutters for this project?
The cutter I used were purchased from this supplier on Ebay
http://ebay.to/2xienoR


Other ebay suppliers of 1/8" down cutting bits.
http://ebay.to/2zfwxYY


They are 1/8" in diameter single flute down cutting spiral bits.
The length of the cutting edger is 10mm ( 3/8") but anything similar eg 12mm(1/2") or 6mm(1/4") cutting edge would work just as well. There is little point having a longer cutting edge unless you are looking to cut your material in one pass. The flute area is weaker than the main shaft so a longer flute just weakens the cutter in my opinion. In fact since I do not cut more than 1/8th per pass any flute longer than 1/4" is a waste.


Model used in this project
www.makecnc.com/steam-locomotive.php 
website:
www.makecnc.com