Lets Talk 6X4 Bandsaws !

[Richard Carlstedt]

Perhaps this has been said before, but let me rephrase the commentary that talks about rubber tires and crowned wheels.
There are two kinds of Bandsaws - and they are not the same- you must realize the difference !

The conventional Vertical Bandsaw ( that we mostly see ) has a crowned wheel and rubber tires. This saw uses the crowned wheel to center the blade and the rubber tires allow various width blades as the rubber does not destroy the tooth set and the "crown " centers the blades. The guide rollers or solid guides are adjusted to keep the blade in "its crowned wheel" setting and prevent forces to push the blade off the "crowned center" . When you replace the blade, the guides are opened up and the blade runs till stabilized , AND then the guides ( sides and rear) are brought in to support that width blade AT that position. Please note , the saw will cut without the guides (!) but the your forces will push the blade off the wheel

The standard Horizontal Bandsaw , Which I will call a "Cutoff Bandsaw" is an entirely different saw in setup and use , and requires one to know about the "Neutral Axis" of the blade ( Critical ) .
There are a few other issues to deal with , but lets say the wheels are aligned and that you have replaced the blade and all guides are removed . Now I want you to take a Crescent wrench ( adjustable spanner) and clamp it on the blade -which is now 45 degrees from vertical- and rotate the blade so it is vertical . You have now rotated the blade about it's neutral axis ! That means even though the blade is stretched by the wheels , you have stretched the blades leading and trailing edges, but the middle of the blade ( 1/4" in on a 1/2" blade) -Its neutral axis - is not stretched !
This is critical to understand tracking.
Now the problem with these saws, and I have seen it in many of them , is that the guides must do this and they don't . If in turning the blade 45 degrees, they stretch or move the neutral axis, you are forever plagued with , non tracking, breaking and short life. If you take a used blade out and it is conical, you have stretched the blade because of the guides. I have machined the guides on several saws to allow them to track the neutral axis. it is amazing to me the number of saws that "bend" the proper track and that the saw makers do not make the blade guides properly .

As mentioned, there are other issues with a Cutoff saw that need to be addressed, but without neutral axis control, all are destined to fail

Rich

PS The Vertical bandsaw never has a Neutral axis issue as the blade is not twisted

 

[Hopsteiner]

4 cams, sounds great. That’s what this saw needs.

 

[Hopsteiner]

Baron, what make of saw do you have? I wonder if parts from yours could be adapted to mine.

 

[BaronJ]

Baron, what make of saw do you have? I wonder if parts from yours could be adapted to mine.

Good question ! All I know is that it is a generic Taiwanese 6X4 bandsaw. Machine Mart here in the UK have all the spares needed to fit mine. Its also Identical to the Grizzly G0622 and the Clark CBS45MD. It seems that most if not all the parts are interchangeable.

 

[Hopsteiner]

Thanks for the quick reply. I’ll have a look. My guides just floating around relying on a nut to insure adjustment is just poor engineering.

 

[BaronJ]

Thanks for the quick reply. I’ll have a look. My guides just floating around relying on a nut to insure adjustment is just poor engineering.

Hi Hopsteiner,

I've had a look through the three parts manuals that I have and all of them say that the inner bearing support is fixed and cannot be adjusted. However they all say that the outer bearing support can be rotated to match the blade thickness. Only one the Delta manual quotes the blade thickness as 20 thou, but doesn't tell you that one of the bearing supports is a cam. In fact it doesn't even give you a parts breakdown.

This is a picture straight out of the Grizzly manual and is exactly as mine is.

 

[Hopsteiner]

Thanks for the pictures. I will be looking closely to see if I can adapt.

 

[goldstar31]

I'm wondering if there are several 6 x4 saws as I am on my second( similar) machine and the factory bits on BarinJ's macine are quite similar( or eve identical)
Relies from genuine ownwes of 6 x 4 owners only

Yes, I HAVE a wood bansaw and once owned a 3 vwheel job too.

Thanks in anticipation

Norman

 

[awake]

I'm wondering if there are several 6 x4 saws as I am on my second( similar) machine and the factory bits on BarinJ's macine are quite similar( or eve identical)
Relies from genuine ownwes of 6 x 4 owners only

Yes, I HAVE a wood bansaw and once owned a 3 vwheel job too.

Thanks in anticipation

Norman

My HF 6x4 saw has a different set up for the guide bearings - and I must say, much less robust than what Baron has shown.

 

[goldstar31]

My HF 6x4 saw has a different set up for the guide bearings - and I must say, much less robust than what Baron has shown.

Almost bearings for skate boards

 

[kop]

I don't know where I'd be w/o my 6 x 4 . (1/2 by .025-Inch, 10/14 64-1/2-Inch for ref) I don't have any pics atm but I do remember that I also had broken damaged parts throughout.

All the guide bearings were "cheese" . So happens that inline skates use the same bearing and there was a skate shop nearby.

Prior to replacing the arm I did a proper repair . By proper I mean prepared, locked down, preheated, post heated/cooled, nickel repair rod, and a few decades of experience.

When the "new" part arrived it was a disappointment. It was in a word "unusable" as delivered. getting the pivot square to the frame was accomplished with a selection of slightly offset bushings. Like most of us here, since I just happen to know someone with a lathe, I did the bushings on a drill press with a file (I believe I've said it here one or twice, I'm a total hack compared to some of the talent here).

Ahh, the drive bits. My worm drive had been run dry and I nearly gave up. However on mine the worm and spur could both be inverted so that they ran on fresh metal. further the worm could be spaced to run even further in clean metal. The bearings were of course scrap and I just happened to have motorcycle bearings (front axle maybe) that fit perfectly.

Then the motor and pulley. Not only was the step pulley on the motor drilled crooked but the bearing in the motor was of course junk. I drilled and bushed the step pulley (this time on the lathe) , replaced the motor bearing. put the correct belt on it, and squared the motor to the driven pulley.

We're not done yet. The bearings in the guide wheels weren't just junk, the driven end either had a bushing originally or was cobbled in later. So off to the bearing shop once again.

The wheels were so caked with crap that at first I thought they were disintegrating (almost like zinc pest) . As I continued to clean I found there actually was real enough metal underneath and after countless hours I had them back to they're original diameter. No wonder the tension adjustment was so used up that I could barely get the blade on.

I still haven't made the time to finish the project. It still has the factory "non-paint" on it , the handles need replacement, and the vice could use the usual tlc.

In the end it cuts, it cuts rather well. It even cuts straight. It's reasonably easy on blades. I really don't know where I'd be without it. It's the right size. In a pinch it can be stored vertically on hooks (motor up) and still be pressed into service from there for light cuts. Actually I do know where I'd be without it. I'd be back at the Milwaukee PortaBand and 6" vice.

I will get photos one day. If for no other reason than to show off how butt fuggerly a saw can be and still work well.

 

[SmithDoor]

The good new the the ball bearing last for a long time.
I have saw outside and use ever day and they did give out.
The only item that die was the motor replace with USA motor.

Dave

Almost bearings for skate boards

 

[SmithDoor]

Grizzly likes there saws buy price. A 4x6 saw almost $400.00 plus shipping.
My HF 4x6 cost only $160.00 16 years ago. Today not on saw is $289.00just pickup at store and no Frieght charges.
https://www.harborfreight.com/horizontal-vertical-metal-cutting-bandsaw-93762.html
Dave

I don't know where I'd be w/o my 6 x 4 . (1/2 by .025-Inch, 10/14 64-1/2-Inch for ref) I don't have any pics atm but I do remember that I also had broken damaged parts throughout.

All the guide bearings were "cheese" . So happens that inline skates use the same bearing and there was a skate shop nearby.

Prior to replacing the arm I did a proper repair . By proper I mean prepared, locked down, preheated, post heated/cooled, nickel repair rod, and a few decades of experience.

When the "new" part arrived it was a disappointment. It was in a word "unusable" as delivered. getting the pivot square to the frame was accomplished with a selection of slightly offset bushings. Like most of us here, since I just happen to know someone with a lathe, I did the bushings on a drill press with a file (I believe I've said it here one or twice, I'm a total hack compared to some of the talent here).

Ahh, the drive bits. My worm drive had been run dry and I nearly gave up. However on mine the worm and spur could both be inverted so that they ran on fresh metal. further the worm could be spaced to run even further in clean metal. The bearings were of course scrap and I just happened to have motorcycle bearings (front axle maybe) that fit perfectly.

Then the motor and pulley. Not only was the step pulley on the motor drilled crooked but the bearing in the motor was of course junk. I drilled and bushed the step pulley (this time on the lathe) , replaced the motor bearing. put the correct belt on it, and squared the motor to the driven pulley.

We're not done yet. The bearings in the guide wheels weren't just junk, the driven end either had a bushing originally or was cobbled in later. So off to the bearing shop once again.

The wheels were so caked with crap that at first I thought they were disintegrating (almost like zinc pest) . As I continued to clean I found there actually was real enough metal underneath and after countless hours I had them back to they're original diameter. No wonder the tension adjustment was so used up that I could barely get the blade on.

I still haven't made the time to finish the project. It still has the factory "non-paint" on it , the handles need replacement, and the vice could use the usual tlc.

In the end it cuts, it cuts rather well. It even cuts straight. It's reasonably easy on blades. I really don't know where I'd be without it. It's the right size. In a pinch it can be stored vertically on hooks (motor up) and still be pressed into service from there for light cuts. Actually I do know where I'd be without it. I'd be back at the Milwaukee PortaBand and 6" vice.

I will get photos one day. If for no other reason than to show off how butt fuggerly a saw can be and still work well.