Project Bandsaw – Planning


There’s a bandsaw shaped hole in my workshop and it needs filling.

Why Build Your Own?

Why not? Buying a commercial bandsaw is certainly easier and by the time I’ve finished this project it would probably be cheaper as well but this is about having fun. As long as I get a machine out the other end I’ll be happy and I don’t really mind if it cost more than a comparable commercial machine.

Why Design You Own, Don’t You Know X Has Plans for Sale?

This project isn’t about following someone else’s plans, this project is about learning, from scratch, how to do it myself. I’m happy I can do the woodworking needed, now I want to explore engineering. Having said that no one truly starts from nothing. I have no intention of re-inventing the wheel here so obviously I’ve studied existing commercial and homemade bandsaws.

What is in a bandsaw?

  • Wheels
  • Blade
  • Blade Guides
  • Table
  • Fence
  • Blade tensioning mechanism
  • Drive mechanism

Previous Home Shop Builds

Here is a list of just some of the previous builds that I looked at before. There’s no shortage of builds out there so I’ve tried to keep this list to the more notable ones.

Shafts – Size, Material, Etc

Bigger is better, at least that’s what I’ve been told 🙂

John Heisz uses 25mm, upgraded from 16mm. Matthias Wandel used 22m initially and then moved up to 25mm. This post indicates that 25mm should be considered about the minimum.

There are various materials that can be used for shafting, the cheapest will be steel round bar but without a lathe it might be hard to get it to fit the bearings. Ground bar is the most


Matthias Wandel uses a bike inner tube and this seems to be a common approach. John Heisz uses clear silicone, this doesn’t feel like it would be good enough but it seems to work for him. I’ve seen exercise bands used as well. I wonder if some sort of rubber paint would work?

Tensioning and Tracking

Tensioning is the act of tightening the blade, tracking is tilting one wheel to make the blade run true and not come off the wheels. The forces involved when tensioning a blade should not be underestimated.

Most bandsaws have a single mechanism that deals with tensioning and tracking although there is no particular reason to do this. Generally this mechanism is located on the top wheel with the bottom wheel only providing the power. A notable exception to this is John Heisz’s bandsaw which tensions on the bottom wheel and tracks on the top.

The tensioning and tracking system needs to be constrained so that it can only move in the directions necessary to tension the blade and rotate in the direction needed for tracking.

The tensioning mechanism needs to be sprung rather than rigidly connected to the upper wheel. A rigid fixing will cause vibration when the machine is running.


I’ve had a look around the web for commercial bandsaws and I think for this build I’ll target something like the Axminster AT2552B in terms of specification. This gives me a budget of around £1000 to work with, while I don’t need a trade rated bandsaw I’d still probably buy one. Approximate specifications are below.

Blade Length2,552 mm (100.5″)
Wheel Diameter350 mm
Blade Speed800 m/min
Blade Width Min\Max3 mm to 19 mm
Max Cutting Height200 mm
Max Width of Cut340 mm
Max Width of Cut with Fence300 mm
Overall L x W x H690 mm x 720 mm x 1,770 mm
Power750 W
Table Height on Stand1,060 mm
Table Size500 mm x 356 mm
Table Tilt5° – 0° – 45°

I have a 2311mm blade that I picked up cheaply from somewhere, I’d like it if the machine I build can take a wide range of blade lengths although I’m not sure how feasible that will be without making the machine ridiculously tall.

Useable Blade Lengths

I initially had the idea to design a saw that could use a wide range of blade lengths. Looking around it seems that most saws have about a 50mm range of lengths they will accept (see here). Lets quickly do some calculations to see if this makes sense.

Assuming the specifications in the table above. The diameter of the wheel is 350mm so the circumference is 1100mm. Half of each wheel is in contact with the blade so the remaining length of the blade is the vertical portion. This gives a vertical length of 726mm which is also the centre to centre distance of the axels.

Wheel Diameter (mm): 350
Blade Length (mm): 2552

Circumference: 350 * 3.14 = 1100 mm
Vertical Blade Length: (2552 - 1100) / 2 = 726 mm

Moving the top wheel up or down by 25mm would accommodate a blade 50mm longer or shorter. In other words the blade length range would be 2502 to 2602. Looking at a table of common blade lengths (for example) this adjustment range would cover the ideal blade, the next one longer one and that’s about it.

Adjustable Travel (mm): 25
Axle Centre Distance (mm): 726
Wheel Circumference (mm): 1100

Maximum Blade Length: ((726 + 25) * 2) + 1100 = 2602 mm
Minimum Blade Length: ((726 - 25) * 2) + 1100 = 2502 mm

It seemed odd to me that saws wouldn’t be built with more adjustment but if you stop to have a think about there’s a good reason for it. The inter-wheel distance determines the maximum cut depth of the saw. Assuming you aren’t going to squeeze in beside the wheel the absolute maximum cut depth of this saw would be 376mm since there’s a radius of each wheel blocking the path of the material through the saw. By the time you’ve fitted guards and taken into account the adjustment you’d be lucky to have 300mm of clear cutting height. In reality the saw probably couldn’t handle that so the 200mm given in the spec is entirely reasonable.

Wheel Diameter (mm): 350
Axle Centre Distance (mm): 726

Max Cut: 726 - 350 = 376 mm

My conclusion is that you have to build your saw to fit a particular blade length. You can probably make it flexible enough to handle a the next size up or down but after that you sacrifice too much for it to be worth it.

Rotation Speed

The specification I’m going by has a blade speed of 800m/min so from that we can determine the rotation rate of the wheels and if we know the rotation rate of the motor the pulley ratio needed to slow down the motor.

The distance the blade travels is independent of the number of wheels in the saw and the separation of those wheels. This means that the circumference of each wheel must be travelling 800m/min. Above we calculated the circumference as 1100mm or more conveniently 1.1m. The rotation rate of the bandsaw wheel therefore needs to be 727 rpm.

Target Linear Blade Speed (m/min): 800
Wheel Circumference (m): 1.1

Bandsaw Wheel Rotation Rate: 800 / 1.1 = 727 rpm

The motor that will be running this bandsaw is a 4 pole and therefore 1380 rpm (from the motor spec plate, often this is sold as 1400rpm) so an ideal pulley ratio would be 1380 / 727 = 1.9. I’ll go for a 2:1 pulley ratio as that it’s easy to find pulleys in that ratio. This will result in a linear blade speed of 759 m/min.

Motor RPM: 1380
Wheel Circumference (m): 1.1

1380 / 2 = 690 rpm
690 * 1.1 = 759 m/min

Required Tools

I’m not aiming, particularly, to restrict myself as to the what tools I can use. I don’t plan on buying any though and right now I mostly only have hand tools. The only large woodworking tool I have is a planner thicknesser which I’m sure will come in handy during this build.

Construction Material

At the moment I plan on making this mostly out of rough sawn pine which I will plane down do flatness. I can easily get 100x45x2400mm (e.g. 2″x4″) timber and I have a load of 18mm ply in stock.

Interesting Parts

This section is just a collection of interesting parts I’ve found while doing research.

Pillow Blocks

Useful for the lower axle where the wheel is fixed to the shaft and the axle has to spin. There seems to be a naming scheme for this type of bearing but I can’t figure it out. Example.

Shaft Collar

Used to stop an axle from moving along it’s length. Certainly useful on the lower axle, maybe useful on the upper axle too. There are several different designs of these. I prefer the single split design over the grub screw design as it doesn’t mark the shaft. There’s also a double split design for awkward locations. Example.

Flange Bearing

Useful for the upper axle since the wheel spins on a fixed axle. There are pressed steel versions that are quite low profile and include grub screws to lock the wheel to the shaft. Example.

Lifting Eye Bolts

Lifting eye bolts are readily available that have openings that match common shaft diameters. They seem to be widely used in the boating world as there’s a lot made from stainless steel. They are easily available on Ebay for a few pounds each and they seem come with a range of threaded shank lengths. They have rated working loads in the low hundreds of kilos and breaking loads well over 1500 kilos.

Fixing the Wheel to the Shaft

For the lower wheel it is necessary to firmly attach the wheel to the shaft. This has proven to be one of the more difficult problems to solve. Most of the other homemade bandsaw builds end up gluing the shaft to the wheel or angle grinding a V in the shaft and putting in a screw. I’m not particular keen on either solution, I’d like something that can be easily removed if needed.

What I want is essentially a wheel hub, the problem is all cars use a splined shaft to connect the axle and the hub, I can no more cut a spline than a key way. Trailer hubs are closer to what I need but they have fixed axles and with bearings in the hub – I need the hub fixed to the shaft. Go karts have almost exactly what I need and there’s even locking connections but they are incredibly bulky and expensive.

You can get shaft mounting collars like this but I think it’s unlikely I could buy them in ones and twos. You can get rigid flange shaft couplings but they only seem to go up to around 14mm, I think they are used for hobby robotics.

I asked about this on the Mad Modders forum and someone suggested I try and get hold of half shafts from either a car or a trailer. They have the benefit of coming with a hub and often already have a bearing fitted.