Paul Barrett":12qfqhnn said:OK - sorry for the really dumb question but I've never used a bandsaw before.........
2 speeds. One for metal, one for wood. Right? OK now for the dumb question. Which is for which?
Paul Barrett":1gsc4r5z said:
Paul Barrett":2o5tbfi3 said:
Curve cutting and ripping are sort of mutually exclusive. As soon as you use a blade for curve cutting you tend to induce drift so thereafter that blade won't really cut so straight as the act of turning it in the wood tends to alter the set ever so slightly. For straight ripping you want a wider blade partly for rigidity - that's why industrial resaws use blades 4in wide and upwards. There comes a point in blade width where you simply cannot get a very deep gullet - hook and skip tooth blades have a deep gullet to clear waste and they are the low tpi ones - that's why 3 tpi skip or hook tooth blades are generally unavailable below 1/4in wide, or if they are they're very weak. One trick to help cut sharp radii is to round-over the rear edges of the sawblade using an oilstone mounted on a stick (they're sold for this purpose) - this has to be done with the machine running so extreme caution is required.Paul Barrett":2wcqz2om said:
But the main problems with bimetallics (M42 or HSS generally electron beam welded to a carbon steel back) is that they're really quite expensive relative to carbon steel blades and that the range of tooth forms, sets and pitches is quite limited in comparison. For resawing they certainly do have their uses and the increased life expectancy of the cutting tips may well be worth paying for, especially if you cannot get stellite-tipped or TCT blades for your saw, but you probably won't find many fine tooth narrow blades available for wood in bimetallic simply because the target market tends to be engineering where wavy set (unsuitable for woodworking) is required. I've had conversations with a couple of bandsaw blade makers about bimetallics who are of the opinion that they (bimetallics) are also more prone to cracking on machines with smaller wheels, and by that they mean 18in or less wheel diameter.devonwoody":3ktlpiwj said:
Yes, but what sort of cuts are you doing, at what speeds, in what thicknesses? Because I cut timber in a business life expectancy and speed of cut are probably a lot more important to me as clean-up can always be done after sawing. Most of the stuff I cut is destined for further "processing" be that in a lathe, router, spindle moulder, thicknesser, etc and this is probably the case for a lot of bandsawn materials. That tends to make quality of cut less of an issue. If you run a wavy set fine tooth blade in 6in thick hardwood you'll need to feed very slowly indeed to avoid binding in cut as the very small gullets simply won't be able to remove the waste - in cutting slowly you run the risk of re-cutting swarf in the cut, a process which in turn leads to burning, particularly on end grain of species such as beech, sycamore and maple. In cutting metals (the real use for wavy set bimetallics) the feed rate is slow enough to accommodate this (it's also constant, another factor) and the heat build-up is often controlled by the use of coolant fluid - not really an option open to woodworkers. I think that in thin materials up to 3/4 or maybe 1in the wavy set will probably work quite well and deliver a good surface finish because you are using a fine tooth set - but I'd hesitate to use a blade like that on thick stuff because of the potential clogging problems.devonwoody":yl1ewkm4 said:Scrit,
I agree some of your comments are valid but when you cut a piece of timber with one of these type blades and the cut is perfect how can any negative points be valid
devonwoody":luwv2dh0 said:Scrit,
I agree some of your comments are valid but when you cut a piece of timber with one of these type blades and the cut is perfect how can any negative points be valid
