Bandsaw types ?

[Jim F]

Thanks for the link, and indeed to folk who give me the clues. I think one reasonable plan is to try for one of the better engineered woodworking bandsaws. Changing the first pulley size to be larger only goes some of the way to the speed reduction needed. Then, change out the motor for a 3-phase, but with 4 poles instead of two. This halves the speed again. Then drive it with a vector VFD, which can slow it right down while still delivering good torque. If one wants to cut wood, then just dial up the VFD.

.. at least, that's the fond notion in my head. None of the portables, nor the HF 4x6 style seem very appealing. For those who only ever cut metal, the HF 4 x 6 style has potential to be a low cost starting point for some really great kit. There are a ton of mods and upgrades, many on YT videos.
I am only finding keeping the dual metalwork/woodwork capability concept attractive because I have a ton of woodworky stuff yet to come - starting with benches, French cleat storage, and much more.

@MrWhoopee 's great link lands on page #5. Have a look at page #1 for lots more.

it is easier to cut wood slow, than metal fast.............

 

[graham-xrf]

The comes the question of saw blades. I always thought of blades for metal having lots of TPI - like a hacksaw, but it seems fewer TPI, and running slow, works OK. I see we can even get tungsten carbide tipped bandsaw blades.

The width of the saw blade catches the interest. If the saw can take 6mm to 25mm (say about 1/4" up to 1"), do we always try for the widest possible, unless we are cutting in tight curves?

 

[jwmay]

I wish I had some help to offer. I got a screaming deal on a 7x12" horizontal metal cutting bandsaw years ago. We've had our struggles. I still haven't really figured out the trick to making it work as wonderfully as people say they do. For instance, two days ago I watched it cut four pieces of 2" round stock. Time in the cut was over an hour. I tried speed changes, blade changes, and feed and speed changes. Nothing really worked as well as I know it can. Then last night I watched Stephan G of Youtube cut similar sized stock with a portable bandsaw in less than a minute on a home made table. There are evidently some highly specific parameters which I haven't yet got my head around.
The point of that story of course is that I think you can use any of the available options and do perfectly great. OR... You can have pretty much the best home grade metal cutting saw available and fight it every time you use it.

 

[graham-xrf]

I wish I had some help to offer. I got a screaming deal on a 7x12" horizontal metal cutting bandsaw years ago. We've had our struggles. I still haven't really figured out the trick to making it work as wonderfully as people say they do. For instance, two days ago I watched it cut four pieces of 2" round stock. Time in the cut was over an hour. I tried speed changes, blade changes, and feed and speed changes. Nothing really worked as well as I know it can. Then last night I watched Stephan G of Youtube cut similar sized stock with a portable bandsaw in less than a minute on a home made table. There are evidently some highly specific parameters which I haven't yet got my head around.
The point of that story of course is that I think you can use any of the available options and do perfectly great. OR... You can have pretty much the best home grade metal cutting saw available and fight it every time you use it.

The thing about Stefan's home-made and modified designs is that you would be hard put to find a professional store-bought kit that can match it!

 

[projectnut]

The comes the question of saw blades. I always thought of blades for metal having lots of TPI - like a hacksaw, but it seems fewer TPI, and running slow, works OK. I see we can even get tungsten carbide tipped bandsaw blades.

The width of the saw blade catches the interest. If the saw can take 6mm to 25mm (say about 1/4" up to 1"), do we always try for the widest possible, unless we are cutting in tight curves?

The number of TPI on the blade to be used is dependent on the thickness of the material. The rule of thumb is that no less than 3 teeth should be engaged, and no more than 24 teeth be engaged. If there are less than 3 teeth engaged, you run the risk of knocking a tooth off the blade. If more than 24 teeth are engaged, you run the risk of filling the gullets and jamming or possibly breaking the blade.

Cutting curve diameter is dependent on the width of the blade. Wider blades are generally used for straight cuts or shallow curves. They cut straighter and hold up better as they move through the material. Thinner blades are used for tight contours. Most blade charts give the minimum radius a particular blade width can cut. A good general-purpose blade would be bimetal construction and variable pitch. M42 blades are the most recent addition. They contain more cobalt and withstand heat better. Most common for smaller saws are variable tooth10-14 tpi or 6-10 tooth.

 

[Mitch Alsup]

2 points:

Metal should be cut at 100-300 FPM, steel in the 100-150 FPM range, aluminum in the 250-300 FPM range.

You learn nothing about cutting with a bandsaw (speeds, feeds, pressure, time) if your blade is dull.

{Oh, and BTW: bimetalic blades are a god-send.}

 

[graham-xrf]

2 points:

Metal should be cut at 100-300 FPM, steel in the 100-150 FPM range, aluminum in the 250-300 FPM range.

You learn nothing about cutting with a bandsaw (speeds, feeds, pressure, time) if your blade is dull.

{Oh, and BTW: bimetalic blades are a god-send.}

Do tell about what is the property, or action that gives bi-metallic blades the advantage?

All I ever knew about bimetallic stuff was about the very reliable way the way bimetal laminates will bend with temperature, exploiting the unequal thermal expansion.

 

[projectnut]

Bimetallic blades have a carbon steel back and a thin high speed steel tooth section welded together

 

[StevSmar]

The Rikon 14” woodworking bandsaw I have, can now be purchased in a version that comes with a variable speed drive and DC motor.

Mixing wood and metal on the one bandsaw seems to be not a good idea to me, so I didn’t consider it any further. I’m thinking of getting a 4x6” bandsaw for metal, or maybe a portaband.

 

[graham-xrf]

The Rikon 14” woodworking bandsaw I have, can now be purchased in a version that comes with a variable speed drive and DC motor.

Mixing wood and metal on the one bandsaw seems to be not a good idea to me, so I didn’t consider it any further. I’m thinking of getting a 4x6” bandsaw for metal, or maybe a portaband.

Thanks for the mention about the Rikon.

If mechanically, the saw can operate at the speeds that suit the materials, then there seems no reason not to let them be used in either role. Unless the machine can be re-configured to change role easily, I can see why it might be inconvenient. It has been mentioned before in these posts that there is, at least for aluminum, an overlap where it can be used for either material without changing the blade.

My take is different. It is to change the machine to cut metal, but know that the change is not irreversible, even if it's a bit of a flap to do casually.