Saw weapons are the most basic and ineffective form of spinning weapon.
If they are so ineffective then why would one want to build a saw weapon? Well for one they are hands down the easiest to put together as I have found. As a long time brick and rammer builder I felt a saw was the easiest way to “ease” myself into weaponed robots. I just wanted to get the basics like reliability, consistency and making sure I could handle all the added complexity right without really worrying about effectiveness. Trying to make a weapon of awesome power without regard to such things is basically buying yourself a one way ticket to failure.
But that isn’t to say a saw is a totally useless weapon. If you use them right they will work well enough. Take some example robots such as Kang, Inspector General and Scoopy Doo which all make effective use of their limited power weapons.
Kang and Inspector general both use saw blades set extremely close to the ground in a style known as the “undercutter” where the aim is to make the saw slash the wheels straight off the opponent therefore making it immobile. By setting the saw close to the floor it means it will be subject to less force from not ramming hard materials on the armour of another robot but otherwise attacking the much softer wheels. This allows the saw to escape with all its teeth and unbent. however if a saw does take a hard hit itll usually end up like this... aka buggered
Scoopy Doo however has its saw set vertically on an electrically actuated arm where it lowers it down at a controlled rate onto the top of the opponent. By doing this it can effectively use its smaller weapon to greatest extent and by controlling how fast the saw gets lowered into the opponent it can get away without destroying the saw blade.
Saws aren’t a particularly effective weapon because they have so many teeth. This means they slowly unload their energy into the opponent in a cutting action which is largely ineffective compared to the one giant instant hit of large spinners which is highly effective.
But what type of saw should be used?
Simple answer. Go down to your local flea markets and pick up some old mild steel saw blades. You will be able to identify them from their rustier appearance and they wont have little “caps” on the ends of the teeth. These caps are actually carbide tips which will break straight off. Avoid them at all costs.
The mild steel saw blades are best as they are much cheaper ($1 at the markets usually) they come in a larger variety from little 100mm blades to big 700mm blades and the teeth are always fairly sharp. When a carbide saw hits an opponent they break off leaving a smooth tooth behind which is useless. When a mild steel tooth breaks off it will leave a jagged remnant which is still good for sawing.
What type of motor should I use to power a saw?
Well there is no firm answer on this subject. But there are many tried types that you should look for (and avoid).
MAGNA TR FAN MOTOR – these are very light at some 700g, extremely powerful and low profile and can be had at the wreckers for $10 odd. However they are a poor saw motor choice if you want to run the saw straight off the motor as they consist of a copper plate and magnet stacked on top of it and any bending will smear the copper plate and kill the motor. Belt drive if you have to use it but then you might as well just use a bar instead of a saw blade.
NISSAN PINTARA / OLD STYLE SKYLINE – these motors are where its at for saw blades. BIG BAD and INDESTRUCTIBLE. Well kind of anyway hehe.
They weigh about 1510g so they are very large, and are quite a large motor in dimension too. But they have the advantage in that they will run a 1kg saw blade direct off the motor at 24v for 5 minutes non stop under combat load and wont die.
The motor also has a spinning plate like the magna TR motor but it is much larger. This makes it easy to just a bolt a blade right in via 3x m3 bolts. But I had my motors drilled out and tapped for m6 to stop the bolts breaking.
This motor has been used in scrap/orbit for about 4 events approximately and at least 2 in kang where it has been rammed into the walls full speed and flipped over by its saw blade and still runs fine.
These are just some suggested options, any method is viable really! Just use some common sense.
As far as total destruction, saws aren’t that good. But as far as being simple to set up, nasty sounding and instantly recognizable to the public as something nasty looking then saws are pretty hard to pass up.