Bandsaw blades

[tongleh]

I picked up the new BS-5S bandsaw today, rushed of home and promptly put it together and set it up. First few cuts using the standard blade cut well but as I was only cutting 25mm x 1.6mm RHS I swapped the blade for a finer 14 tooth bi-metal I bought at the same time. After just a few cuts the blade lost a hell of a lot of teeth, I did a lot more cuts with the standard blade and lost no teeth, what am I doing wrong?

[Michael G]

Rule of thumb is that you should have a minimum of 2 teeth in the cut at all times (and preferably no more than of 10 - hard to do with really thick stock).
My only thought is that the standard blade was tough enough to stand a bit of tooth abuse, but the harder bi-metal blade snapped the teeth off. For a 1.6mm wall I'd be suggesting 18tpi at least and make sure that the downwards feed is light so that the tooth gullet is not being forced onto the material being cut.

Michael

[krisfarm]

Hi tongleh,
I suspect that you did not hold the blade back, cutting thin walled RHS tubing you have to slow down the drop rate, especially with a 14 tooth blade. The minimum of two teeth engaged needs to be followed. I recently cut up a lot of 50mm*50mm*2mm RHS and I slowed the drop rate using an 18 tooth blade otherwise you will end up with crooked cuts and missing teeth.
Bob

[tongleh]

Two teeth engaged, that's 32 tpi, any idea where I can get a blade that fine? H&F's finest is 18tpi.

[Michael G]

Try the 18tpi. Just make sure you have a light down feed.

Michael

[shedhappens]

I use 18 TPI on everything that I cut, I found that the 14 TPI Starett blades often didn't cut square so I just
stopped changing the blade for thicker stuff and don't have any problems, the hydraulic lowering cylinder
most likely helps tho.

john

[tongleh]

When I picked up the machine today I bought a 14tpi blade, that being the finest they had, the original is courser probably around 10tpi. I've just ordered a couple of 18tpi blades so I guess I'll have to be very careful until the new blades arrive. Dam, I hate being carefull: Bull - China Shop, that's more my style.

[peterbilt]

I have a BS-5 and initially lost quite a few teeth when cutting thin stock. Although you can lighten the drop pressure, I often hold the cutting arm on the first cut and listen/feel how it's cutting. I've found that saves the blade teeth and produces a nicer cut. If you're cutting a lot of material, this could get a bit tedious. The hydraulically lowered arms seem to have more pressure control than the spring counter-weighted arms on the BS-4s and 5s. They're still a good saw for the price.
Peter

[krisfarm]

tongleh

Today I had to cut a bit more RHS tubing on my band saw, the same model that you have, I did intend adjusting the black coil spring that is used to take some more of the arm weight. There are three holes in the arm body provided for adjustment,mine came set on the middle hole, the saw cuts fine on solid bar in this position so I attacked the problem from the other end by lifting the lower leg of the spring up and placing a wood packing piece under it. With a bit of experimenting I found that a 25mm packer slowed the drop rate down so that I could leave the saw to cut by itself and not destroy the blade or the squareness of the cut. This was on 2mm wall thickness RHS. It does cut a bit slower but this is not a problem, with your 1.6mm tubing you would need a bit more packing maybe. Give it a try.
Bob

[tongleh]

I'll try that idea, along with your blade twist mod.

[krisfarm]

tongleh
When you do the blade twist mod check that your clamping bolts are a good nug fit in the castings. When I first checked my saw out a few weeks ago this fit was very sloppy the casting had a lot of taper and excessive clearance on the clamping pivot bolt, I milled the castings out to 12mm and turned up a couple of short bushes to make it all nice and snug, it all works good now. I forgot to include this in my mod post.
Bob

[bosox]

For general cutting of wood, 4 TPI will make a fast cut and 14 TPI will allow for a slower cut, but will leave a smoother finish.
A general rule of thumb is that the greater the TPI results in a smoother but slower cut. The fewer or less TPI allows a faster cut with a slightly rougher end result.
Try reading this BLOG (http://bandsawblog.com/t-p-i/) . :U

[cba_melbourne]

I picked up the new BS-5S bandsaw today, rushed of home and promptly put it together and set it up. First few cuts using the standard blade cut well but as I was only cutting 25mm x 1.6mm RHS I swapped the blade for a finer 14 tooth bi-metal I bought at the same time. After just a few cuts the blade lost a hell of a lot of teeth, I did a lot more cuts with the standard blade and lost no teeth, what am I doing wrong?


Cutting 25 x 1.6 RHS: When you begin the cut, you cut over the full 25mm - no problem. But as soon as you have cut through the horizontal section, you are only cutting the two 1.6mm thich side walls. That is where you loose tooth if you do not manually slow the downfeed. Do not worry, after a short while you just look at the object you are cutting, and instantly know when you need to slow down the feed rate. This is a supercheap saw with no hydraulic downfeed, all you can do is set the spring tension and control the downfeed with your had.

Yes, this means that you must NOT walk away, but stay there during the whole cut to control the downfeed, and also add some lubricant/coolant by hand. Another reason not to walk away during the cut is the cheap motor, it is not protected and may burn out in something goes wrong in your absence. Ok, after you gained some experience with this saw, maybe after 6 months or 6 years or so, you may feel confident enough to walk away and do something else nrearby. But not during the first months of ownership! If I think back before I had the BS, I spent hours and HOURS with the hacksaw and it was hard work. The simple cheap 6x4 BS is that much faster, it really is not too much asking supervising the cut and adjusting the downfeed as necessary.

I tossed away the original carbon steel Starret bandsaws I bought from H&F. They are good for wood and maybe PVC, not metal. I bought BiMetal blades from the US via eBay. One blade lasts me an average of one year. I use one pitch only, too lazy to swap blades for the little jobs I do. But one has to carefully control the downfeed, and that takes some experience. So it may be normal to ruin the first blade whilst learning.

Try to run-in a new Bi-metal blade gently cutting something like brass for the first 30 minutes, this is said to improve blade life. And watch out when you first time cut stainless, there you need slow speed and very high downpressure to avoid work hardening. You will very soon wonder how you could exist without a BS before...... Chris

[KBs PensNmore]

Hi Tongleh,
I get all my blades both wood and Bi-metal from Independant Saw Works on Torrens Rd Croydon Pk. Have done so for 20 years.
For the thick stuff I use 18TPI and the thin I use 24TPI. Pressure is left the same for all material. They can also show you how to fine tune it to get the best out of it.
Kryn

[tongleh]

That's great, I'll try them. The finest H&F list is 18TPI

[bosox]

Have you tried 18TPI?

[tongleh]

Yep, two 18 TPI blades arrived in the mail yesterday, they worked well.

[bosox]

Where did you get your blades mate?

[tongleh]

Hare and Forbes Sydney, however, KBs PensNmore suggested I try Independant Saw Works, so next time I need blades I'll go there.

[bosox]

Oh I see. I think they got good blades. I'm currently using Haltbar blades , efficiently working compared to my other blades.

[jatt]

Yeah I mostly cut thin stuff, about the same thickness and size of household guttering. Not a fun proposition. Making a jig to help hold its shape definetely helps, not to mention allows one to apply more pressure to the vise.

The round stuff can catch and spin quite easily, so I had to make up something to hold it better in the vise.

On the small unit I had to go to the saw doc to get a fine TPI. I cant run coolant on this unit unfortunately, which certainally doesnt help with the blade life. The tradeoff is its sml and lite enuf to put in the ute for site work. The larger unit with hydr downfeed and coolant runs an off the shelf blade from H&F.

Lower TPI blades were jamming in the work and sometimes losing teeth as a consequence. If anyone wants to know the TPI I can get the info next time I'm in the shop.

[Oldneweng]

I was recently cutting some 100mm stainless pipe about 1.5mm thick to make big egg rings for you know who. I had trouble holding it still and had to make a close fitting steel ring to fit inside for rigidity. I needed something to hold them in the lathe chuck anyway. I finished up mounting 2 clamps hanging off the motor end to reduce the pressure even more than the spring adjustment. I think I hung some weight off one as well. I am waiting until I get my new lathe installed before I start any new projects but I have a hydraulic downfeed controller in the pipeline.

Dean

[krisfarm]

Oldneweng,
Did you see my post *9 as a little bit of packing can be added and removed very quickly and you can adjust the drop rate to suit each application without the expense and complication of a hydraulic down feed controller.
Bob

[Oldneweng]

Oldneweng,
Did you see my post *9 as a little bit of packing can be added and removed very quickly and you can adjust the drop rate to suit each application without the expense and complication of a hydraulic down feed controller.
Bob

I did read this post some time ago and I have to admit I did not understand what you were talking about and I have not looked into it. I am not home at the moment but will try to remember to to look at my saw when I get home and see what I can do. I had been convinced by forum members that the hydraulic lift was the only way to go, and I was looking for projects I can do on my new lathe when I finally have it installed and operational. At the current rate this should be in about 2050. Many other things to do. I am in Melbourne at the moment and tomorrow while SWMBO is at an appointment I am going to look at H & F, Leda and Carba-tec. I am looking for a mill and table saw. This may give me the momentum to get things moving.

Dean