Settings up Band Saw - Guide Block Problems

[VooDooPC]

I'm having some trouble setting up my band saw. The top guide blocks have pins on either side and a bearing in the back. The bottom has the same set up, two pins and a bearing in the back. The bearing in the back on the bottom has a groove down the center.

 

I understand the rear bearing on the top is used to prevent the blade from pushing too far away from me, so it hits and stops at the bearing. I'm assuming the two pins keep the saw blade from twisting off axis.

 

Here's what I don't understand:

 

1.) The bottom bearing has a groove, is the blade supposed to ride in this groove? I see no other reason for the groove but it seems like it would be bad for the bearing to be constantly spinning at the speed the saw moves or bad for the blade to be sliding in this groove.

 

2.) Should the blade be rubbing against the guide pins much? It seems when I cut, the blade likes to twist, even if I'm using the miter slot for a straight cut. If I move the pins so the blade doesn't move twist it seems like they are rubbing against the guide pins constantly, is this normal? It doesn't sound normal.

 

3.) My blade has a slight side to side deviation, what could cause this? Is it an adjustment in the wheels?

 

If anyone can help me out, it would be great.

 

This is my band saw: http://www.craftsman.com/shc/s/p_10155_12602_00921400000P?keyword=21400&sLevel=0&prop17=21400

 

I've been unable to find the manual online and it seems to have been... misplaced.

 

Thanks,

KJC

[bushwack]

I've cut thousands of pieces (cathedral door parts) at my last place of employment ,but it was on a much larger more industrial saw. Same thing but more durable and more forgiving. Still, I've seen new users break blades in 5 minutes, while I could use the same blade for 20 hours. It takes finesse.

 

I dunno about the bottom groove, but sounds like it's there for a reason. The one I used didn't have one, just large 2" bearings. Maybe there for stabilization, same thing with the pins, otherwise it would just go nillywilly all over the place. The one I used didn't have pins, but a solid slot in thick steel to keep the blade from twisting while you turn the piece, it's gonna happen.

 

Tightening the blade will take some of the slop out, but you dont want to over tighten the blade. or under tighten for that matter. There should be a gauge somewhere on the machine to indicate the blade slack between the rollers, but i guess it depends on the model. Cant tell much by the link.

 

Get some extra blades and eye protection, and dont where gloves and cut some practice pieces. Hell practice cutting strait first. I've seen a few people get hurt by these these things. R E S P E C T.

 

Remember, it takes finesse. If your no good with women, give this thing up before you loose a finger.

[VooDooPC]

I've cut thousands of pieces (cathedral door parts) at my last place of employment ,but it was on a much larger more industrial saw. Same thing but more durable and more forgiving. Still, I've seen new users break blades in 5 minutes, while I could use the same blade for 20 hours. It takes finesse.

 

I dunno about the bottom groove, but sounds like it's there for a reason. The one I used didn't have one, just large 2" bearings. Maybe there for stabilization, same thing with the pins, otherwise it would just go nillywilly all over the place. The one I used didn't have pins, but a solid slot in thick steel to keep the blade from twisting while you turn the piece, it's gonna happen.

 

Tightening the blade will take some of the slop out, but you dont want to over tighten the blade. or under tighten for that matter. There should be a gauge somewhere on the machine to indicate the blade slack between the rollers, but i guess it depends on the model. Cant tell much by the link.

 

Get some extra blades and eye protection, and dont where gloves and cut some practice pieces. Hell practice cutting strait first. I've seen a few people get hurt by these these things. R E S P E C T.

 

Remember, it takes finesse. If your no good with women, give this thing up before you loose a finger.

 

Well, I can't return it now!

 

Thanks for the info, I will move the pins closer, even if it rubs some while cutting. I guess if the blade didn't rub against the pins it wouldn't do a very good job of guiding the blade. I just wasn't sure if the metal on metal rubbing would cause friction and damage something, but if an industrial one has large steel plates and that doesn't break anything, I doubt four little pins would.

 

I will also look into properly tightening the blade.

 

Thanks.

Edited September 24, 2011 by VooDooPC

[lousiest]

Sweet looking equipment that

[amertrash]

This is an excellent guide for setting blade tension(Fine Woodworking is excellent in general). As for your guide bearings, care to take a pic? Most bandsaws will either have a set of thrustbearings which the blade will ride in between and a third bearing that stops the blade from deflecting too much away from you. Here's a pic of that style.. Some others will use style, where metal or resin blocks keep the blade from deflecting left to right and a bearing keeps it from deflecting too far away from you. It sounds like you have something different, out of the 6 or 7 bandsaws I've used they've always used one of those two styles, kinda of curious.

[VooDooPC]

It's the later style. Instead of plates it's metal pins, maybe 1/2 to 1/4th inch in diameter with flat heads. Then imagine the bearing in the first style behind the blade.

Edited September 24, 2011 by VooDooPC

[amertrash]

Weird, would still like to see a pic.

As for:

 

1) Not sure what you mean - if you're referring to the bearing the prevents the blade from deflecting away from you as you push, no it shouldn't have a groove. When you provide pressure the back of the blade should hit the edge of the bearing causing it to spin - that's what it's meant to do. Depending on what you're cutting, how thick it is, and how much pressure you're using you may or may not even engage this bearing.

 

2) No, typically speaking the blade shouldn't be constantly pressing against the guide pins/blocks. Usually that's a sign of too little blade tension, or feeding to fast, or not having a course enough blade. You'd need to describe what you're cutting(species, thickness), how you're cutting it(straight, curved, tight curved), and the type of blade you're using(TPI, blade width, blade thickness, metal type).

 

3) If you have a noticeable deviation of the blade left and right of the wheels then you either lack tension or there is a serious run out problem on the wheels. Run out shouldn't be an issue unless there is something physically wrong with the tool. You can use this to check it. Excellent cheap tool, check your table saw, jointer head, planar head, router, shaper, among other tools.

 

From sounds of it you either lack enough blade tension or are cutting a material too dense/thick for your saw/blade(other then the bearing with the groove, I'd have to see a picture). I'd suggest you buy some extra blades, and cheap spring-steel or carbon-steel ones at that, and play with your tension - its a bit of art form to get the proper tension on your blade for what you're cutting without the blade snapping. Cheap blades you just throw away if they snap, if you have a nice bi-metal or carbide one you can send it in get it rewelded and sharpened. Also keep in mind that bandsaws love to deflect and the thicker/denser the material, the farther the guides, and the finer the tooth of the blade the more it will deflect. For setting your tension it look like resaw capability is 4 5/8", so I'd raise the guide to the max height and push my finger against the blade between the guide and the table, with moderate pressure it shouldn't deviate more than 1/4", if not closer to 1/8".

[VooDooPC]

I will see if I can get some pictures tomorrow, right now it's at work because I have more space there. I'm definitely now thinking there isn't enough tension in the blade from your description.

 

I'm cutting cylindrical plastic, I believe ABS.

 

I will let you know more tomorrow after work.

[amertrash]

Solid? Or Hollow? OD? Schedule(if hollow)?

 

Cutting round stuff(even more so if hollow) can be a bit iffy, it likes to roll and pinch the blade causing it to snap. For cutting 1/2-3" Schedule 40/80 PVC/ABS (the most common of the non-flexible plastic pipe) you'd probably be fine with a blade with fewer than 14 TPI, that little saw should mow right through it.

 

Also be careful or you'll have a frakken hand like me

 

Tho that was lost to a really large shaper doing something stupid when she kicked . Bandsaws are quite safe just beware of whats going on and be confident(as in with any power tool).

[VooDooPC]

It's not exactly tubing. It's a reducer for a vent that goes from a small diameter to a larger diameter. The OD is maybe about 1 1/2", the thickness of the wall is less than a quarter inch. The fitting has an angle on it, so I was able to make a jig to keep it in one place without any rotation.

[VooDooPC]

I took some pictures today. I apologize for the quality, my phone, for the most part, is a piece of junk.

 

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