Re: Base casting measurements?
I have the stand coming, says it's made from 14 ga (0.075") steel sheet, is it much of an improvement over the previous paper thin versions? 
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Re: Mysterious shift in saw alignment
I wasn't able to do everything I wanted to on my bandsaw today, but was able to do some preliminary stuff.? The first thing I wanted to do was to set the fixed jaw so it 's parallel to the pivot shaft, using Rick Sparber's method with a 1-2-3 block and some other bits.? The thing with these saws is that they have so much adjustment range that it is all too easy to end up on an extreme that interferes with some other adjustment...so I wanted to first establish some kind of baseline.
I was happy to find that the fixed jaw actually wasn't too far off.? And after minor adjustments to the fixed jaw,? I got fairly decent alignment on the horizontal axis when I did some test cuts -- but the frame still was contacting the base and preventing it from dropping low enough to completely sever work material.? It looks like the only way to get the frame to drop all the way down is to move it over so it clears the base enough (by tweaking the two bolts on the support arm):? but that will mean the horizontal cut axis will NOT be perpendicular to the pivot.? Rotating the fixed jaw so it's perpendicular to the blade is not all that big a deal, so maybe I'm overthinking this.? It won't take much adjustment to the vise, and, given the fact that adjusting it to get square cuts is a common approach, it appears it's in my bandsaw's near future as well.
Mark
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Re: Mysterious shift in saw alignment
I agree with everything you said.? That's what makes these things such a challenge to get right - jv
On Fri, Mar 18, 2022 at 07:56 PM, John Vreede wrote:
disentangle
Good choice of words. Respectfully, these are all good adjustment improvements or at the very least "logical" but the the entire blade guide setup is a bit of a guess and a compromise. Like when rotating the blade to vertical along it's center, it's impossible to know if you have deflected the lower part of the blade more than the top. Now throw in the gap between the guide rollers for the weld and you have another variable. The tongue and groove on the guides are not machined and the bar they are mounted on aren't either.? The ideal setup would be to have a blade guide float with a single bolt lock down (similar to the current) but have trunnions that control the rotation of the blade along the center axis. Sort of like a tilt on a table saw blade.?
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Re: Mysterious shift in saw alignment
On Fri, Mar 18, 2022 at 07:56 PM, John Vreede wrote:
disentangle
Good choice of words. Respectfully, these are all good adjustment improvements or at the very least "logical" but the the entire blade guide setup is a bit of a guess and a compromise. Like when rotating the blade to vertical along it's center, it's impossible to know if you have deflected the lower part of the blade more than the top. Now throw in the gap between the guide rollers for the weld and you have another variable. The tongue and groove on the guides are not machined and the bar they are mounted on aren't either.? The ideal setup would be to have a blade guide float with a single bolt lock down (similar to the current) but have trunnions that control the rotation of the blade along the center axis. Sort of like a tilt on a table saw blade.?
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Re: Mysterious shift in saw alignment
Yeah the?adjustments are hard to all get right at the same time.?? I've made a conscious attempt to remove unnecessary adjustments or disentangle them, especially where adjusting one thing affects another, and also to control movement of those adjustments. Like: - Removing the inside roller mount eccentrics from side guide rollers to disentangle guide roller clearance?from horizontal squareness .? If I need extra adjustment (and, I agree, you often do), then I file the slots in the Pivot arm casting to?get it.
- Pinning the fixed vice jaw to the base in parallel position to make resetting it, after angle cutting, a cinch.
- Using Ricks trick on the back of the guide assembly bracket to disentangle rear guide roller clearance from the front elevation squareness of the blade body to the vice table (per the pic).? This is a real no-brainer that everyone should do.
- Ricks adjustment screws to control the pivot arm casting to sawframe casting joint for fine horizontal squareness adjustment as already?shown
- Tiny set screws (M3) into both sides of the tongue&groove?joint of the guide-bracket-to-guide-arm, for precise control of the squareness of the blade body to the vice table (per the pic)
?- jv
On Fri, Mar 18, 2022 at 01:30 PM, John Vreede wrote:
You've got it MarkK. Moving the 'Pivot' (as its called) casting (#121) is what has made?your switch hit the?base casting and why it no longer cuts square horizontally.?
You are probably correct John. I was thinking he had the same problem I did when he was talking about not making the switch. Fortunately my saw is is level and square but the pivot point it drilled too high. The pictures show my first attempt to make the saw head go down far enough to complete the cut. I ground the upper frame to clear the switch guard and the other picture shows the outboard part of the elevating plate I added. The rest is under the vise jaws and obscured by the blade.
?
Those jack screw would be a huge plus if you needed to adjust the horizontal squareness!? I disagree with the eccentric bolt on the blade guide rollers. Its a small amount of movement. Unless maybe your blade guides are made a lot different than mine you can move them where every you want anyway. Mine are a joke really...? they work well but are hard to get right.?
? 
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Re: Base casting measurements?
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Re: Mysterious shift in saw alignment
On Fri, Mar 18, 2022 at 01:30 PM, John Vreede wrote:
You've got it MarkK. Moving the 'Pivot' (as its called) casting (#121) is what has made?your switch hit the?base casting and why it no longer cuts square horizontally.?
You are probably correct John. I was thinking he had the same problem I did when he was talking about not making the switch. Fortunately my saw is is level and square but the pivot point it drilled too high. The pictures show my first attempt to make the saw head go down far enough to complete the cut. I ground the upper frame to clear the switch guard and the other picture shows the outboard part of the elevating plate I added. The rest is under the vise jaws and obscured by the blade.
?
Those jack screw would be a huge plus if you needed to adjust the horizontal squareness!? I disagree with the eccentric bolt on the blade guide rollers. Its a small amount of movement. Unless maybe your blade guides are made a lot different than mine you can move them where every you want anyway. Mine are a joke really...? they work well but are hard to get right.?
? 
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Re: Mysterious shift in saw alignment
You've got it MarkK. Moving the 'Pivot' (as its called) casting (#121) is what has made?your switch hit the?base casting and why it no longer cuts square horizontally.? As I've said many times, the heart of a 4x6 (or any horizontal /vertical bandsaw with a hinge in the middle) is the axis of the turning of?the pivot shaft (the centreline of the hinge, which here-after I'll call the pivot axis).?You figure the effect of every adjustment in relation to the pivot axis. The pivot axis is fixed immovably in the base casting but almost everything?else has some freedom of movement in relation to it.? To cut perfectly square, both horizontally across and vertically down through, the work, the workpiece has to be parallel to the pivot axis? in both plan?view?(looking vertically down) and front elevation (looking across surface of the vice table from the front of the saw)??AND?the blade body (the 1/2" bit above the teeth) has to be square to the pivot axis?in both plan view and front elevation.?? Let's?look at horizontal squareness?first, because this?is where your?switch hitting the base casting came from: Horizontal squareness?comes from looking at the workpiece and blade in plan view only.? - Getting the back of the workpiece parallel to the pivot axis is easy to set by moving the fixed ice jaw and clamping it when it's parallel.This needs to be set parallel as good as you can get it (certainly better than 0.008" (0.2mm) difference in distance from the?pivot shaft to the front face of the vice jaw at each base casting pivot shaft ear). I re-bushed the pivot on the fixed vice jaw and pinned it in this position, (with a taper pin through the vice jaw into the base casting), because you NEVER have to move this again in a properly setup saw cutting square. This returns it to the identical parallel position each time after doing an angle cut.??
- Getting the blade square to the back of the workpiece is more difficult.? This is primarily set from the joint between the the pivot arm casting and the sawframe?(your piece #121 and the sawframe at the back left hand side of the saw).? Slide the pivot?arm casting forward in relation to the sawframe, and when you tighten the bolts the sawframe will pivot left and the switch hits the base casting.? The angle between the blade and the back of the work tightens so this is the way you move it when the angle between the back of the workpiece and the horizontal cut face of the workpiece is obtuse (>90deg). Slid it the other way?of its an acute (<90deg) angle.? ?To get horizontal squareness exact you need to be able to micro-adjust the slip across this joint and the best way is with Rick Sparbers adjustment bolts per the picture attached.? You can get additional adjustment range from this joint by filing?or machining out the bolt slots in the pivot arm.?
- Horizontal squareness is also affected by the adjustment of the clearance between the blade side guide rollers ONLY IF you have eccentrically adjustable rollers?on the inside of the loop of the blade.? This is annoying so I've changed the inside rollers on my machine so they?rotate on concentric mounts, to remove this adjustment.??
And that's it for horizontal squareness, there are no other adjustments?built into the?machine that affect horizontal squareness.? I have a saw where the pivot axis was bored 'not square' across the base casting at the factory, and this has been a real mission to correct, but generally this is OK in most saws
Vertical squareness is a whole other ballgame that doesn't concern?your problem, but basically looks at the parallelism?of the bottom of the workpiece (essentially the surface of the vice table) and the squareness of the blade body to the pivot axis in front elevation only. The squareness of the blade body is just an adjustment, but the parallelism of the vice table to the pivot is built into the machine at manufacture and is very often wrong (upto 2 out of 3 depending on mnfr. I'd guess) and is a major problem to fix. One of the contributors to this is the base casting warping and twisting after machining while it sits in its box (or in your shop), as Roger describes, but the major one is poor machining at the factory that?Mark2 and Howard talked about.? These 2 have to be corrected BEFORE you pin the fixed vice jaw to the base (the 'properly setup saw' caveat in point 1 above). - jv
Last night I had a thought about what _might_ have happened, but I need to confirm it.? I remembered that I had? tipped my saw over to open up the gearbox and replace the gear oil (I supported it with a plywood plank at the right height).? This would put some sideways rotational force on the frame, and in the right direction if something in the support arm assembly was loose.? The bed casting isn't all that rigid either so there could have been some flex in there that caused something to shift..? One observation that supports my theory is that, while I was able to adjust the blade guides so the saw cuts pretty square in the vertical plane, the blade clearly is misaligned on the horizontal plane (and the direction is consistent with my problem).....and it WAS properly aligned at one point.
To be more specific, I'm talking about part #121 in my owner's manual for the HF #93762 bandsaw.? There it's called the "left pivot" but it also has been referred to as the "support arm".? The left end of the pivot shaft passes through it and on mine it's secured by a grub screw in the support arm.? Two adjustment/fixing bolts attach it to the frame and the support has two slots in it to permit adjusting the frame so it is horizontally square to the pivot shaft.
More later....
Mark
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Re: Base casting measurements?
Measured at the lowest point, where it attaches to the legs, I measure approximately 26¡± x 7¡±
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On Mar 18, 2022, at 9:00 AM, terry keeley <tkee@...> wrote:
?Any chance someone with a Jet HVBS-56 could measure the length and width of the base casting?
I'm trying to see if the stand will fit my Jet Canada 4X6 model.
Thanks.
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Base casting measurements?
Any chance someone with a Jet HVBS-56 could measure the length and width of the base casting?
I'm trying to see if the stand will fit my Jet Canada 4X6 model.
Thanks.
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Re: Mysterious shift in saw alignment
Last night I had a thought about what _might_ have happened, but I need to confirm it.? I remembered that I had? tipped my saw over to open up the gearbox and replace the gear oil (I supported it with a plywood plank at the right height).? This would put some sideways rotational force on the frame, and in the right direction if something in the support arm assembly was loose.? The bed casting isn't all that rigid either so there could have been some flex in there that caused something to shift..? One observation that supports my theory is that, while I was able to adjust the blade guides so the saw cuts pretty square in the vertical plane, the blade clearly is misaligned on the horizontal plane (and the direction is consistent with my problem).....and it WAS properly aligned at one point.
To be more specific, I'm talking about part #121 in my owner's manual for the HF #93762 bandsaw.? There it's called the "left pivot" but it also has been referred to as the "support arm".? The left end of the pivot shaft passes through it and on mine it's secured by a grub screw in the support arm.? Two adjustment/fixing bolts attach it to the frame and the support has two slots in it to permit adjusting the frame so it is horizontally square to the pivot shaft.
More later....
Mark
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Re: Mysterious shift in saw alignment
On Fri, Mar 18, 2022 at 09:18 AM, Howard Ng wrote:
When you adjusted the?guides so it will?complete the?cut, the blade pops off the?wheels.? I got tired of tinkering it. I lifted the workpiece?off the bed with a piece of 1/4" stock that is smaller?than the workpiece so it won't interfere with the vise jaws.
They definitely had an assembly problem at the factory. Probably a bad setup on a fixture and they drilled the holes for the head pivot point in the wrong place. I've sold a bunch of plates that sit under the vise. I'd have to count but I'd say more than 60 plate. They do the same as you did except it sits under the vice jaws. It has slots the same as the bed.?
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Re: Mysterious shift in saw alignment
I had the same issue. When you get the?saw to track and?cut nicely, the frame hits the?bed and it won't make a complete cut. When you adjusted the?guides so it will?complete the?cut, the blade pops off the?wheels.? I got tired of tinkering it. I lifted the workpiece?off the bed with a piece of 1/4" stock that is smaller?than the workpiece so it won't interfere with the vise jaws. Since?my saw doesn't drop straight down either, I've also shimmed the blade side of the stock to?get a more vertically square?cut. I don't regret buying this saw because?the price is really good, but man I just wish they would just put a couple more days into the engineering. I always say I will get a better saw. But at $1000+, I can get a lot?of tooling and stock for all the projects I?won't get to!
Howard
After taking care of my blade tracking problem and doing some cutting I discovered a problem I haven't seen before.? The saw blade was not dropping all the way down, to the point that the work pieces weren't being completely severed.? It didn't take much troubleshooting to find the source of the problem:? the frame now is cocked over enough that it's hitting the base and then stops cutting.? I did a "drag test" where I placed a plastic bag on the base, dropped the frame down and then pulled the bag to see where it was hanging up.? It turned out to be those metal brackets around the on/off switch.? I was able to get the frame to drop low enough to completely sever stuff I'm cutting by grinding notches in the frame (and grinding down those brackets a little bit), but I'm baffled by WHY my saw would start exhibiting this problem -- I've had it for close to 10 years and this is the first time I've encountered this problem.
Anyone have any ideas on what could be going on?? The saw hasn't been knocked over or abused, and the pivot doesn't have much play.? Certainly not enough to cause my problem.
Mark
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Re: Mysterious shift in saw alignment
First off just let me say I'm sorry group most of you here probably don't know me. I've been here for about 20 years and owned a welding service in Austin. I bought my first Harbor Freight 4 x 6 bandsaw somewhere around 1992 I still have it it runs okay it's not great but it runs okay. So I do have some experience with them I haven't had this exact problem but as a welder I can tell you the cast iron used in these bandsaws is not very high quality, or stress relieved so over time the cast-iron can crack and change its shape. that's why cast iron that high quality lathes are made out of. was left to set out for fifty years or so, so that it would stabilize and quit moving this may not be the cause of your problems. Though as it's actually fairly easy to torque these saws out of shape but assuming everything's just set up perfectly, they can still move on their own over time...
That's a great thing about groups like this what's the problems identified if get offered lots of solutions good luck.
Roger Hart ?:^)
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Re: Mysterious shift in saw alignment
I understand what you're saying, but that's not the problem.? The reason I believe that is because the bottom blade guide normally has to be set just a little under its maximum height, else it contacts the base behind the fixed jaw.? On my saw I can have the blade guide all the way up and it still is proud of the base.? It's almost like the rear of the frame now is sitting higher than it used to.? Something's shifted, but what???? How???
I think I will need to take some photos of the saw and post them.
Mark
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Re: Mysterious shift in saw alignment
On Thu, Mar 17, 2022 at 06:17 PM, Mark Kimball wrote:
Anyone have any ideas on what could be going on?? The saw hasn't been knocked over or abused, and the pivot doesn't have much play.? Certainly not enough to cause my problem.
I had the same issue. More than likely the blade guides were deflecting the blade downward before. When you adjusted them correctly the blade was higher up. I went through the exact same problem and even tried grinding part of the frame where the switch was to get it to drop a little further. I made a 1/4" think plate that sits under the vise that elevates the stock so that you can run the blade guides in the correct position. I have a youtube channel and a web store. I sell these plate but if you have the means to make a plate I also have a template you can go by.
https://drive.google.com/file/d/1OwFtZDsW_IjrLGnYdh1yr8x0jO8phkHE/view?usp=sharing?
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Mysterious shift in saw alignment
After taking care of my blade tracking problem and doing some cutting I discovered a problem I haven't seen before.? The saw blade was not dropping all the way down, to the point that the work pieces weren't being completely severed.? It didn't take much troubleshooting to find the source of the problem:? the frame now is cocked over enough that it's hitting the base and then stops cutting.? I did a "drag test" where I placed a plastic bag on the base, dropped the frame down and then pulled the bag to see where it was hanging up.? It turned out to be those metal brackets around the on/off switch.? I was able to get the frame to drop low enough to completely sever stuff I'm cutting by grinding notches in the frame (and grinding down those brackets a little bit), but I'm baffled by WHY my saw would start exhibiting this problem -- I've had it for close to 10 years and this is the first time I've encountered this problem.
Anyone have any ideas on what could be going on?? The saw hasn't been knocked over or abused, and the pivot doesn't have much play.? Certainly not enough to cause my problem.
Mark
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Re: Blade guide setup -- a question
Mark, Just had a chance to see your video, do you still have any plates for sale?
Wayne Sent from far far away
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On Mar 2, 2022, at 8:48 AM, Mark <mark21056@...> wrote:
?On Wed, Mar 2, 2022 at 05:18 AM, John Vreede wrote:
Unfortunately mis-manufacture?when drilling the holes in the sawframe and pivot arm, or base pivot holes is distressingly common. It must vary by manufacturer, according to how much emphasis they put on the quality assurance around the drilling processes. but I estimate from what I've seen?that between 1 in 3 to 2 in 3 (!)
I suspect they make these saw in batches and dismantle a lot of the jigs when they move on to another product. If they get setup wrong for the next batch then they may make 200,000 saws (totally guessing on the amount, maybe way more) with a miss aligned pivot point. What a shame!?
My approach to fixing this problem was the elevate the stock by putting a 1/4" thick steel plate under the vice. I sell these plates but if somebody want to make there own here is a template.?
NOTE:? Make the part under the saw blade longer (red line) and cut through it after mounting the plate.
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Re: Blade guide setup -- a question
On Wed, Mar 2, 2022 at 05:18 AM, John Vreede wrote:
Unfortunately mis-manufacture?when drilling the holes in the sawframe and pivot arm, or base pivot holes is distressingly common. It must vary by manufacturer, according to how much emphasis they put on the quality assurance around the drilling processes. but I estimate from what I've seen?that between 1 in 3 to 2 in 3 (!)
I suspect they make these saw in batches and dismantle a lot of the jigs when they move on to another product. If they get setup wrong for the next batch then they may make 200,000 saws (totally guessing on the amount, maybe way more) with a miss aligned pivot point. What a shame!?
My approach to fixing this problem was the elevate the stock by putting a 1/4" thick steel plate under the vice. I sell these plates but if somebody want to make there own here is a template.?
NOTE:? Make the part under the saw blade longer (red line) and cut through it after mounting the plate.
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terry keeley
John Vreede
Mark
