Sawing Plate

I am planning to build the grasshopper beam engine currently being featured in ME. The text states “cut out the blanks, ideally with a bandsaw”.

I have both a horizontal metal cutting bandsaw with coolant, and a vertical bandsaw I use for woodworking.

I cannot see how I would hold the plate on the horizontal bandsaw, or how I would cut it on the vertical bandsaw without lubricant as I do not want to use coolant or lubricant on my wood saw.

Any guidance appreciated

Does your aversion to lubricant extend to wax or a wax-like material?

Beeswax, candle wax, etc. A trade name seems to be Addiwax.

Hoover it out before you start and after you finish. Put a new blade on when you finish and keep the old one for future metalworking.

If the surface speed is appropriate, and you're using blade of an appropriate tooth count then I generally find lubricant on a vertical bandsaw unnecessary for cutting mild steel.

Using an M42 bi-metal blade will make an appreciable difference to blade longevity and cope better with the higher surface speeds of a bandsaw optimised for wood.

Tuff-Saws are my preferred source of blades, and offer a well designed Vari-Tooth Bi-metal blade which has additional room for chips compared to conventional designs, resulting in less friction and heating anyway.

Alternatively PP Profiles offers a very inexpensive laser-cutting service for steel, and if you send them the drawing and a specification for the thickness and grade of steel, they will get you a quote back the same day.

I generally use them for any complex shapes as it's usually more economical than buying plate from the stockholders and cutting myself with the torch (which itself is far less faff than using a bandsaw).

I have spent a little time researching on YouTube and it would appear that a much larger pitch is required for a vertical bandsaw. A couple of them show 4 TPI, which is much greater pitch than I have tried in the past - but it co-insides with the advice above about the Tuff-Saws.

What TPI would you recommend for 10mm Aluminium plate ?

What would you use for Mild Steel ?

Have you considered a decent jigsaw and WD40 as a lubricant?

I can't recall ever using coolant on a band saw, just have a go with the blade you have got at the moment.

Tony

A bandsaw intended for wood will almost certainly have a blade speed that is too high for good general metal cutting but you might get away with aluminium. My home-made bandsaw runs at about 150 ft/min and uses the 1/4" carbon steel blades sold for DIY saws such as the Burgess etc. It cuts everything I need except I don't use it on stainless steel. My standard blade is 14 tpi 'cos that's the size Screwfix seems to stock mostly, and that's used for anything up to 1/2" mild steel, although that is pushing it perhaps. I've never used any form of lubricant.

4TPI will only have one tooth in the workpiece for some of the time. Not enough, so ignore those on youtube that suggest that tooth count is at all appropriate. One needs to be selective as to what you-tubers are competentband which might be numpties.

Is your woodworking bandsaw designed for timber? If so, the surface cutting speed is likely far too high for metal.

10 TPI would suffice, I would have thought.

My experience has been that TPI is more or less set by workpiece thickness independent of material, so it would be the same for both.

If you're cutting aluminium then you will be fine with the cheaper carbon steel blades, and may get away with using a wood blade if you want to chance your arm to get it done quickly.

Tuff-Saws also has a handy reference guide on choosing metal cutting bandsaw blades buried on their website; which I often use that as the starting point when selecting a blade (I keep a bunch of them on a hook, but can never quite remember what's most appropriate for what, I should probably put a chart behind the hook).

In practice you can "get away with" using a blade which is a bit finer than is really ideal most of the time, but not using too coarse a TPI on a thin workpiece (noise, terrible cut quality, broken teeth, blades jumping off bandwheels, etc.) So I would err to the finer side of what's considered appropriate if you're just buying a blade for a one off job.

Edit: accidentally linked to a vacuum cleaner on EBay rather than the reference page.

Edited By Jelly on 24/09/2022 12:07:33

I use my old woodworking bandsaw for cutting sheet/plate non ferrous and aluminium at the speed it cut wood at and with the same blades I used for wood. Prior to getting my Femi band saw I also used it to cut thicker section aluminium without too much of an issue. Both saws are used dry.

Here is a bit of 3" square 6082 done with the woodcutting bandsaw.

Tpi for plate will be much the same as it would be for sawing by hand, aim for at least two teeth in contact with the work. I think that bit of ali was done with a 10tpi Starret bimetal wood blade.

Or you could take a look at MEW 320 which has an article about converting a horz saw to vertical use then you will have lubricant and a saw better suited to cutting sheet/plate

Edited By JasonB on 24/09/2022 13:19:22

Just food for thought for the OP Philip:

I have used my vertical bandsaw for about 30 years now. It is an all steel framed machine originally made by a local machine shop for wood cutting. I adapted it for metal cutting by adding a pulley speed reduction setup to slow the blade travel to 150 feet per minute. I have never used coolant. I use a 12 TPI high speed steel / spring steel bimetal blade by Starrett. The combo of 150 feet / min and the bimetal blade will cut steel, aluminum, copper, brass, bronze and stainless steel metals down to about 1/8" or 3mm quietly and quickly, and will also cut wood of any kind. If blade speed is higher than this it will be fine for wood but the blade will burn if used too fast on metals. My blades typically last a few years used several times daily at the noted 150 feet/min speed. The bimetal ones do cost more than cheap blades but they work and they last.

The toolmakers at my old firm had a vertical bandsaw which was used for steel, aluminium, titanium, plastic and wood. All without any lubricant. The titanium was the favorite, especially when the apprentices were cut tooling lugs off it and the dust caught fire.

Edited By old mart on 24/09/2022 21:19:02

I have also cut some ali on my wood cutting bandsaw but only when the blade is near it's end of life. Mine does have the option to slow it down with the change of the drive belt position which is what the instruction say that the slower speed is for metal cutting.

That was before I brought a dedicated metal cutting saw

Does your metal cutting bandsaw allow rotation to a vertical position to cut plate. Many do. I've just recently cut some 1/8" plate on mine.

(it does help if you've made a larger support table for it).

I have a Clarkson vertical band saw which is meant for woodwork and it is ok with a metal cutting blade to cut brass, copper and aluminium but it is too fast for steel, iron, stainless, and many other ferrous materials. I have never used a coolant or cutting oil ad the drive wheels have a rubber tyre which will be adversely affected by them.

David