Building things out of metal isn’t as difficult as you might think: V-slot and T-slot aluminum extrusions make frame construction easier. Join me as I tell you what it is and how you can get started creating something amazing.
What is aluminum extrusion?
Aluminum extrusion is aluminum that has been pushed out through a hole in a funny shape called matrix . Much like how much plastic and food is produced, hot metal is squeezed out through a shaped hole that yields a useful product. This is a somewhat simplified representation, so if you want to know the ins and outs of the manufacturing process, take a look here.
This may seem like a lot of effort, but it has many benefits. Extruded aluminum is actually stronger, lighter, and uses less material (meaning it’s cheaper) than its durable counterparts. Extrusions come in a wide variety of shapes, so you can often find one that fits your particular use case. Finally, aluminum is very easy to work with, using only basic tools. It’s often not suitable for heavy-duty applications (such as combat combat robots), however you might be surprised at what can be done with it.
V-slot vs. T-slot
There are many different forms of extrusion. The cross-sectional shape is called a profile. You will need two main profiles: T-Slot and V-Slot.
T-slot has T- shaped groove on each side:
The V-Slot is similar but has a slightly bevelled edge:
While this may seem like a minor difference, it has a big impact on how you use them. The V-slot allows the bearings and wheels to sit inside the profile, meaning it can also act as a linear rail, greatly reducing the cost of motion control parts.
They are somewhat interchangeable, but it’s usually best to stick to one type for each project. Basic parts like brackets and T-Nuts work great with either, however slightly more specialized parts like bearings or fancy connections can only work with one or the other. Also, if you mix and match parts, you may need to change or adapt your design and end up purchasing more lengths of one extruder or the other.
V-Slot was created by Mark Carew of OpenBuilds and is open source. While there are several other options available, this article will focus on the V-Slot. OpenBuilds explain their system in this video:
The V-slot comes in a variety of sizes and the range is expanding. It comes in various lengths and some distributors will even cut in length. Most popular sizes:
- 20mm x 20mm
- 20mm x 40mm
- 20mm x 60mm
- 20mm x 80mm
Even the smallest diameter parts (20mm x 20mm) are very strong and the largest parts are more than capable of working in tough conditions.
Cutting and working
You can cut the V-groove in a variety of ways. Manufacturers claim it can be cut exactly like lumber on a cutting saw, however I don’t recommend it — it’s a quick way to dull the blade, and if you don’t have a special blade for cutting metal, it may not work well. or.
The easiest way to cut it (even larger than 20 x 80) is to use a hacksaw (UK). Use the engineer’s square (UK) to mark the exact line, then cut it slowly (after pinning it to the appropriate desktop). Don’t worry about a junior hacksaw (even for small things) as they are often trash.
Any uneven areas or non-square cuts can be corrected with a file (UK). Be careful not to mark the edges of the aluminum.
You can purchase the V-slot in two finishes: raw and black. Raw is just aluminum as is, while black has been anodized, a chemical process that reacts with the surface of the metal.
The black ones look much cooler but are easier to tag or damage. Plain allows you to anodize in different colors at a later date. Paint is not suitable, nor is powder coating, as they both contain a layer of paint on the outside of the part, which reduces the effectiveness of the bearings.