Scale Calc
One of the most difficult things for most makeCNC pattern users and people dealing with Flat pack style CNC patterns or templates is dealing with thickness scales. Most makeCNC projects and patterns are 2d flat files in DXF format that are created using various CAD software at our design facility in Delaware USA. www.makecnc.com
Our Pattern files usually come in three thickness scales for both metric users and Imperial measurements (inch) these thickness measurements are based on the slot and tab method of construction of a 3d model from flat sheets of material usually plywood or acrylic or sheet metals but also many other types of sheet materials including foam core board, cardboard, plastics, and hardwoods.
Typically these slots or drawings will be scaled to three or more sizes that relate directly to the thickness of the material you are cutting the parts from. so that when you assemble the model the slots will have a nice tight fit. In the case of a laser doing the cutting you need to also consider Laser beam offsets also known as kerf.
Theses Slots will be in both metric and imperial (inch) sizes typically 3mm,6mm,12mm,1/8 inch,1/4 inch and so forth for laser cutters and CNC routers but will always be round numbers . In the case of Plasma cutting versions or templates they will typically be set to common sheet metal thickness gauges like 12 gauge = .1046 or 1.5mm,2mm .2.5mm etc .
But in the real world when a company sells you a sheet material product they may state that the sheet of plywood or acrylic is 3mm or 1/8th thick when in reality if you measure the actual thickness with a pair of calipers (Digital or manual) you will find that the 3mm turns out to be 2.850 mm and the 1/8th or .1250 sheet turns out to be .1210 or a little less or more than 1/8th so if you cut the model out using the 3mm or 1/8th CAD files (DXF) you purchased from makeCNC the slots would not fit nice and snuggly together and your model would be less than perfect and need lots of glue.
It is not really a huge mathematical problem to select the parts in your chosen CAD program and uniformly rescale the drawings in one shot to have the slots resized to the exact thickness your sheet material is but there are several ways that the most commonly used CAD software’s carry out these functions and unless you know the formulas for this it can be very frustrating trying to rescale a drawing a tiny amount or even a large amount to get slot to the exact size you require and we have had numerous requests for help with this from our customers and many other people asking how to achieve this quickly and easily.
The makecnc pattern scale calculator is a small program that is designed to allow the user to enter some simple data about the drawing and then in a click you will find the result you need to enter into your CAD or drawings software’s scale function boxes to quickly rescale your drawings and have the correct slot sizes for the material you are cutting the parts from.
This calculator covers the math functions specifically for use with vectric V-carve pro software’s scale functions for v-carve pro 7 as well as earlier versions of V-carve pro before the new scale by % command was added.
It’s also outputs data for use with Corel draw version X6 which uses scale by % in its command functions. The scaling calculator’s data will also be useful for most other CAD and Vector Drawing software’s that do not have the ability to scale by reference as more expensive CAD programs like AutoCAD.