Bandsaw blades

[firebird]

Hi

I have one of these chinese bandsaws.

Actually it was a gift but with a good clean up and a coat of paint and a new blade its as good as new. I've done a bit of work with it , not a lot, and its gone through 2 blades already. Is this normal?. I'm using a 24 TPI blade. Should I use a courser blade. I'm cutting mostly steel with a bit of ally. Any help will be appreciated

Cheers

 

[Tin Falcon]

Firebird:
Here are some quick thoughts. the 24 tpi is probly good for 1/8 in angle or tube . For solid stock get a courser blade. You poblably need more chip clearance. A bi metal blade will last longer you may want to try one of those.
Back to basics.
propper speed and feed for the material
too much feed the blade wanders too liitle feed and the blade rubs and dulls.
too much speed the blade heats up and dulls.
propper coolant/lube will help.
In the pro shop I worked in we got a couple months out of a blade but we cut lots of hard steed RC 38- 40
Tin

 

[zeusrekning]

Check into a Lennox blade if possible. At work I switched to there Rx+ blade and it resolved alot of the problems we were having. Other than operator errors they last about 4 times the blades we were using before. And my cost is the same. Last week a guy indexed the matl while the blade was down to far and it bent a few teeth, I ground the bad teeth of and used the blade for the rest of the week.

 

[Circlip]

Hi Firebird, I checked Member info for your location, although with tinternet it doesn't make much difference' and THEN I noticed the 13A socket.OK either M.E. or M.E. workshop did a series of articles to turn your pile of Er bandsaw into a decent working machine. There was one of these at a place I once worked, nuts and bolts on stand used to work themselves loose - Loctite screwlock, did you get the table to use it a vertical unit? if not go back for it ;D If the blades that you have were the originals that came with the machine, bin them and go to W.H.Smiths and "scan" the woodworking mags for the ads for DEDICATED blade suppliers. With the mods and decent blades you'll be amazed just how good the thing is. Best regards Ian
Just thought of this one, take off the wheels, its too high and unstable for the tin stand it's on. You can lower the CofG and relocate them if you really need them.
And as a pps to our mates in TLOTF, the switch on the front of the unit is the one that I was telling Wareagle about, it's a No Volt Release type.

 

[firebird]

Hi

Thanks for the tips. I'll try a better/courser blade. Ciclip, I added the wheels because it has to be mobile. The wheels are of the braked type and I reinforced the tin legs (just visible in photo) With the wheels all locked the machine is dead stable. I didn't get the table with it but I can soon knock one up. There was no on/off switch fitted, the motor had been wired directly to a plug so I fitted the no volt release switch. As I said I was given the machine by a bloke who used it for cutting logs so the blade that was in it was a wood cutting blade that went straight in the bin. Most of the bolts were replaced with new ones and nyloc nuts.

Cheers

 

[shred]

If it's the same saw as everybody else has (and it looks very much like it), there are a couple designs for tables on here: http://www.homemodelenginemachinist.com/index.php?topic=733.0

 

[gilessim]

Firebird, I know this might sound strange but an old trick I learnt years ago, for my wood bandsaw ,is to hold an angle grinder very gently against the the teeth while the bandsaw is running on both sides, just a light touch works wonders!. whilst a wood bandsaw blade has "set" teeth,one left ,one straight and one right, you can reset the teeth a couple of times before re-sharpening (I have a friend near me who makes and re-sharpens bandsaw blades) most metal blades are not "set" but you can set them with a tool made from a piece of flat steel with a blade thickness slot cut in it and just tweak a touch like I said before, that way ,if you have the patience,you get a bit more life from the blade!, it just makes the cut a bit wider. I would say that 10-12 tpi is ok for the saw that you have there and if you can find blades made from sandvic stock, you're laughing! ..Giles

 

[Circlip]

First thing Firebird, many apologies, your machine is of a much stronger construction than the one I was thinking of, had a close look at your legs for the wheel fix strengthening and saw the top covers on the blade, the machine I used had bashed tin ones, However the table "link" highlighted another problem so I may be able to exonerate myself a bit. Cutting tension fall, big spring at back, one mod was to make a dashpot type adjuster which gives a finer control of the drop of the blade. There probably had been a switch between the motor and mains that the previous owner took off and would have had an adjustable trip so that when the blade had gone through the material, it switched the machine off. The design for lowering the unit I saw used the same locking type wheels and size that you have but the frame they fastened to meant that the bottom of the machine was only about 20mm (3/4") off the floor with the wheels outboard side to side of the legs, might even have been on this site, will have to try to get my mental hard drive working. ;D

Yes you'll definately get Sandvik over here.

 

[djc]

There probably had been a switch between the motor and mains that the previous owner took off and would have had an adjustable trip so that when the blade had gone through the material, it switched the machine off.

The adjustable trip is very simple. To the right of where the left hand end of the door you open to change the blade screws on, directly below the big plastic knob, there is a threaded hole. The trip goes in this. Usually, the NVR switch is mounted vertically, with the red button nearer the motor. As the saw drops through the stock, the trip just pushes the red stop button. You can see the trip on this page www.finelinehair.com/ home/bandsaw.htm (although he has no NVR switch).

I've had good blades from Dragon Saws - Google will find them. Rightly or wrongly, 90% of the time I use the coarsest blade I can on the highest speed. Only if cutting thin stock do I change to a fine blade. Generally, it's recommended that you keep three teeth in the cut.

Things to watch out for: if you mount your NVR vertically and you use soluble oil for coolant, make sure it is reasonably well sealed. The pivot can wear, which means it doesn't cut straight. To test this, you need to disconnect the big spring as its pressure disguises the wear. I think the pivot is 5/8", so I reamed mine out and replaced with 16mm silver steel. The bearings that guide the blade wear (especially with coolant) and cause the blade to do unpleasant things. Again, replacements from eBay are cheap and transform the saw.

 

[firebird]

Hi

thanks again guys, some good tips there

Cheers