Bandsaws and their blades

I am looking at 6 x 41/2” bandsaws and none of them seem to list the same length of blade, 1638, 1640, 1645, 1638.3. This gives me the impression they all have specific and individual blade lengths with the inference that one buys the makers replacements.

Am I right in thinking that the range of adjustment on these machines would enable them all to use a “1640” blade from any source?

Thanks for your advice.

Martyn

You can get blades made to whatever length you require. I always use Starrett but there are many others.

The difference between 1638 and 1645mm is a 2mm adjustment of the tension adjuster, which ought to have nearer 20mm of movement.

Neil

Or buy coils of bandsaw blade stock and make your own with a scarfed silver soldered joint. Remarkably it still seems to be sold in 100 foot tengths.

Russell

They're all 64 1/2" blades!

They are probably conversions from a feet and inches value (5' 4.5" with varying levels of rounding. The adjustment for the lengths in your post only requires 3.5mm of adjustment. There is usually a lot more than this in order to allow the wheels to get close together to allow easy blade replacement. I think I would assume that they all take the same blades and will have enough adjustment to cope with the natural variation that will present on replacement blades.

If you go to someone like Starrett they make the blades to order from a long length. You tell them the blade specification you want and how long and they cut it off and weld the joint. There are so many different blade lengths required that they would not want to have them in stock just in case someone orders one. They could end up with a lot of rusty blades that need to be scrapped off.

Martin C

I order my 6.x.41/2 bandsaw blades from Tuffsaws, at 65 1/4", in bi-metal stock.

This enables me to set the blade to something like the right tension.

They arrive in 48 hours and the prices are as sharp as the blades.

Here they are:

http://www.tuffsaws.co.uk/

Many thanks everyone. Thought that might be the position and am now clear to make my choice.

Martyn

Tuffsaws are good and will reweld your blade free if the joint breaks

Neil

Wait on a mo! Think about it just a tad!

These blades cannot all be the exact same length! Different tooth pitch will invariably mean a very slightly different length, unless the join has a fraction of a tooth!

IME they usually do

I have renewed the blades for my 6x4 bandsaw using a coil and silver soldering the joints for years now but some time back, I bought one of those hobby wood working bandsaws from Aldi and found that the blades supplied were very thin and useless for sawing straight. I then bought an assortment from Silverline which now work OK and come with a life time guarantee.

Have not used the guarantee yet but it must be worth considering if they supply 641/2" blades for the metal cutting bandsaw.

I've got one or these saws. and I love it. The skippy little oddment of tooth at the blade join makes absolutely no never mind. The join doesn't cut anyway.

When I first had the saw I was too mean to buy anything other than carbon steel blades, so I bought fine tooth (24tpi) ready welded blades in packets of ten, they lasted fine and I thought the world was a wonderful place. But my local tool shop changed suppliers, and the next batch I bought wouldn't cut steel at all, knocked the teeth off in seconds. The manufacturer refused to play ball, and just headed for the hills, so I bit the bullet and bought a bimetal blade to try. The finest I could find was 18TPI, but I'd use a blade of the same tpi in a hand hacksaw so that's what I've stuck with. If I'm cutting 40 x 40 x 3 box section or angle, for example, it cuts just fine.

But it's other job is cutting say 50 mm round EN8 or similar, and I find the blade jams in the cut. It maybe it needs replacing, but there's sharp teeth on there still, I want my money's worth. If I drip suds onto the cut it helps, but its a faddle to do and it makes a mess.

I cut some bits of 30 mm phosphor bronze the other day. Took for ever, and longer. Suds made it worse. I guess it just shows what a good wear resistant PB is for bearings!

How do others get on with these blades - do you use coarser blades? They seem to be more readily available, but I haven't tried experimenting much, they're expensive enough without buying them for entertainment.

Rgds to all

Simon

I have a band saw, like this one, different make, that drives me to distraction. I have tried everything I can think of but the blade still comes off

There just doesn't seem to be any grip on the big wheels. Are they supposed to be bare metal? I have heard a rumour of polyurethane tires, is it true?

OTOH I suspect the bod who sold it to me had the same problem because it was peculiarly cheap. It may also be cursed having already cut me to the bone

I have a plan to replace all the ball races that guide the blade but I have scant hopes of success

I find with bandsaws you have to be careful because the metal cutting blades have more width, they tend to get pinched on a piece of material which causes the blade to jump off the guide wheels.

Michael W

Plain metal is fine.

Search 'John Pitkin bandsaw' on google and download the PDF of his adjustment guide. It's for the smaller saws but the same principles apply.

It will tell you how to adjust the tracking which is almost certainly the problem. I did this once and now only throw a blade.if I abuse the machine.

In my experience most owners don't even know the tracking is adjustable - I didn't!

Edit - just for clarity the tracking is NOTHING to do with the blade guide rollers. It's the alignment of the two big wheels to each other.

Edited By Neil Wyatt on 27/10/2017 21:27:51

Robin - They can be a sod to set up, but on YouTube is a film from a gent who goes through the whole alignment thing in a logical sequence. I'll try and find it and post it here. There is also a forum dedicated to making them work better. If you can't get the blade to track correctly it's probably the fault of the blade, not the saw. This is where throwing away bimetal blades brings tears to your eyes.

Start with a new blade, and remove the blade guides completely. Run the blade just simple round the two wheels. Incidentally to the best of my knowledge they are meant to be metal on metal contact. I do the blade tension pretty damn tight to make sure it doesn't slip, because the instant it does slip off it comes. You may need to fiddle with the alignment knob to get the blade to run quietly on the two wheels without tracking off. There's a small flange on the inside of each wheel, it is possible to get the blade to climb this shoulder but this wrecks the blade. The blade needs to sit on the perimeter of both wheels, secure against the flange of one (or ideally both) of them, with the teeth overhanging the edge of the wheels.

If you can't get the blade to stay on without the guides, there's no hope.

If the blade will stay on, now introduce the blade guides. These put quite a lot of force on the blade, but essentially the less the blade guides lead the blade away from the basic path of the blade the better. The guides should twist the blade into the vertical, not displace it sideways.

Don't make the rollers tight on the blade, they only need to guide the blade not pinch it. Set the top (depth) rollers first, now the inside roller, then the outside roller. On mine I had to file some of the slots to get all this to happen. Don't make the rollers tight on the blade. You should be able to turn them without moving the blade - but the difference between just right and too tight is probably 0.1 mm or so.

It's not true that the blade has to be precisely vertical. It only has to be vertical enough that the kerf cut by the teeth clears the back of the blade. It's the fall of the blade through the work piece that cuts true vertically, and the angle of the vice jaws that sets it square and true in the horizontal plane. So to get a square cut the work piece needs to be held square to the blade in two planes, one of which is parallel to the axis of the hinge. The guides make sure the teeth run in the bottom of the kerf. If the back of the blade rubs the kerf it'll cut round corners, and in a thick work piece this is guaranteed to jam the blade, off she comes. The blades suffer from forming a convex section anyway, unless the guides are adjusted just right not too tight.

The other fault these saws suffer from is that cutting abrasive or hard materials (e.g. stainless) knocks the set of the teeth off, now the kerf of the blade is reduced and the back of the blade rubs the side of the kerf. This is going nowhere!

Unless there is something really out of alignment in the frame (which the no guide test will show) it should be possible to adjust it to work very happily. It seems some of these saws are such a pain to set up they never do an honest day's work, just get sold on but making the adjustments in a logical sequence will solve all that. "Adjustment" may need to include modifying the mountings for the guide rollers.

Good luck, do let us know how it goes. It's worth persevering.

Edit - Neill beat me to it - again!

Edited By Simon Williams 3 on 27/10/2017 21:45:10

The idler wheel tilts for tracking and slides for tension. It runs wonderfully with the back open, everything is hunky dory until some time after the cut starts then blammo, the blade stops moving and then it come off in short order.

I look at the greasy mess that is the wheels and they seem to be crying out for, do you remember that belt compound you put on a flat belt to make it grip? Something like that.

If there is a blow by blow set up check list then I'll give it a go but I am not hopeful.

John Pitkin located and printed. I have a new blade. Next time I press the big go button on my CNC I will see how far I can get down his list before I reach the first compulsory shopping opportunity