Re: Is Hydraulic feed really a good idea?
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Hi Len
Your hydrauic downfeed has no effect on the derailing of the blade, that's from some other fault. Hydraulic downfeed gives a much more stable cutting action which makes the blade is less likely to derail if anything.
In order to identify the problem you first have to know from which wheel (upper or lower ) that the blade derails from.? To do this remove the blade cover door from the sawframe (unscrew the two hinges) and turn the saw on and watch the blade.? Its designed to run so that the back of the blade just about touches (sometimes hits it and sometimes not) the rims of both wheels.
If its running so the back is clear of the top rim, then the tilt of the top wheel needs adjusting so the blade tracks properly (Slacken blade tension, then loosen the bolt that holds the top wheels axle, and screw the grubscrew below it in ~1/8th of a turn at a time, then tighten/retension and recheck tracking)
If its clear of the bottom rim but OK on the top, then its likely the outer bearing on the gearbox driven shaft has failed.? Tensioning the blade more will always make the blade run further from the rim, but if the bearing has failed (quite common) then not much extra tension is required to make the blade track off.? Conversely reducing the tension will make the blade track toward the rim. Changing that bearing is a bear but quite do-able.
Then set it cutting something on the slowest speed and watch which wheel the blade comes off first.
If tracking is OK and the blade only comes off in the cut then most likely one of the blade guides is too far forward on its adjustment slot.? This acts as a pivot when the blade starts cutting and levers the blade off one of the rims (usually but not always the bottom rim).
Let us know how you get on. Rgds - jv
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Re: Is Hydraulic feed really a good idea?
On Mon, Feb 17, 2025 at 11:38 AM, Len Sherman wrote:
It's just that in order to keep the blade on, I have to set it VERY slow.
I can cut with almost full head pressure on anything larger than about 2" wide. I had a few issues when I bought the saw but have not had issues for over a yeah. Maybe you probably have some blade alignment issues. My saw was sold by Harbor Freight and I can say with absolute certainty that many of there saws had the pivot point for the head drilled wrong. In order for the blade to cut through stock the blade guides had to deflect the blade downward. This is really a bad thing to do. The guides should twist the blade and and just touch the back of the blade, not push down. Your saw is not HF red so maybe this is not the issue.? If anyone has this situation shoot me an email and I'll tell you how to fix it.
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Re: Is Hydraulic feed really a good idea?
My Grizzly 5" x 6" came with a hydraulic feed
cylinder, and having one, was one of the reasons I bought the
Grizzly rather than other brands. I've run many larger saws, and
most all had feed cylinders on them. It is a feature that is
invaluable, especially when cutting small pieces, or things like
thin-wall tubing.
Perhaps you don't have a good enough control (needle valve), or
you are not adjusting yours correctly, but even so, if you are
popping blades, it sounds like an alignment problem, or
insufficient blade tension, not a problem with the feed. On larger
diameter & thick pieces, I open up my feed, and let 'er rip at
the max speed it will cut, and have no problem with blades coming
off the wheels. If I do, I adjust the tracking.
Other Bill
On 2/17/2025 1:37 AM, Len Sherman via
groups.io wrote:
I did the hydraulic feed mod to my saw years ago I now I’m
not sure it was a good idea. The problem is that hydraulic feed
controls the rate of descent, but not the pressure. I seem to
throw the blade more than when I had the old spring. I have to
set the drop speed very low, or risk throwing the blade. Maybe
this is due to another problem in my saw, but I don’t recall
throwing blades when I had the spring, and I think it’s because
the spring sets pressure, while hydraulics set speed. Any
advice?
?
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Re: Is Hydraulic feed really a good idea?
Great job, and congratulations on being able to use your inventory, especially after such a long time!
On Monday, February 17, 2025, 12:17 PM, crs6951 via groups.io <crs6951@...> wrote: I believe it is a very good idea, that's why it's utilized on every horizontal saw that is more sophisticated than the 4x6. What you are encountering is the ability to allow down-feed pressure beyond what the spring allows. I did this mod, but I have 2 control valves. One is a coarse adjustment to allow rapidly lowering the head to the stock. The other is a needle valve for fine adjustment of cutting rate. I rarely touch the fine adjust. Don't laugh, I know the cylinder is WAY overkill. Everything involved was stuff I had in inventory. Some of it for nearly 50 years.
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Re: Is Hydraulic feed really a good idea?
I have a needle valve as well. I can fine tune the drop speed with no problem. It's just that in order to keep the blade on, I have to set it VERY slow.
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Re: Is Hydraulic feed really a good idea?
I believe it is a very good idea, that's why it's utilized on every horizontal saw that is more sophisticated than the 4x6. What you are encountering is the ability to allow down-feed pressure beyond what the spring allows. I did this mod, but I have 2 control valves. One is a coarse adjustment to allow rapidly lowering the head to the stock. The other is a needle valve for fine adjustment of cutting rate. I rarely touch the fine adjust. Don't laugh, I know the cylinder is WAY overkill. Everything involved was stuff I had in inventory. Some of it for nearly 50 years.
?
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Is Hydraulic feed really a good idea?
I did the hydraulic feed mod to my saw years ago I now I’m not sure it was a good idea. The problem is that hydraulic feed controls the rate of descent, but not the pressure. I seem to throw the blade more than when I had the old spring. I have to set the drop speed very low, or risk throwing the blade. Maybe this is due to another problem in my saw, but I don’t recall throwing blades when I had the spring, and I think it’s because the spring sets pressure, while hydraulics set speed. Any advice?
?
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So, even allowing for the fault which I found with the misalignment of the pivot, I was still able to get the saw cutting square. 75mm SHS is about the largest I am cutting, aside from various flat bar. I am more than happy with it now and will move forward with a few mods.
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So ,finished setting up my saw today.? Spent a few hours fiddling with it and bugger me, it is cutting perfectly. Happy days!
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On Thu, Nov 28, 2024 at 07:53 AM, Old Boilermaker wrote:
Has anyone attempted to file or grind the base to bring it square to the blade over the full range of vertical travel? You can't adjust anything at the pivot point on these machines
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Hi This question is kinds?topical, as a few days ago I was looking at the article and noticed a few errors in it,?so revised it as attached.?? Will change in the Files section too? - jv
Has anyone attempted to file or grind the base to bring it square to the blade over the full range of vertical travel? You can't adjust anything at the pivot point on these machines
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There is a pdf file in the files section of this group written by John Vreede that goes into great detail on a fix for this.
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Following Rick Sparber's ideas,
it's way easier to make a sine bar to correct the angle of the bed of the vise area rather than milling, filing, or remachining the saw's pivot.
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Jonas
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On 11/27/2024 3:27 PM, alned03 via groups.io wrote: Has anyone attempted to file or grind the base to bring it square to the blade over the full range of vertical travel? You can't adjust anything at the pivot point on these machines What did you mean by "square to the base" ? Did you mean parallel with the long axis of the bed ? Or blade perpendicular to the bed ? If parallel , you can adjust the squareness of the cut by adjusting the fixed jaw of the vise . If the other , the blade angle is adjusted by rotating the bearing blocks . And there is some adjustment where the pivot arm bolts to the head casting . -- Snag Si vis pacem , para bellum
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I made eccentric bushings and a smaller shaft for the pivot on mine years ago. It was not worth the effort and if I had to do it again I believe it would be easier to glue some material to the base and mill it to shape accordingly.
Good luck!
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On Nov 27, 2024, at 3:53?PM, alned03 via groups.io <alned03@...> wrote:
? Has anyone attempted to file or grind the base to bring it square to the blade over the full range of vertical travel? You can't adjust anything at the pivot point on these machines
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Has anyone attempted to file or grind the base to bring it square to the blade over the full range of vertical travel? You can't adjust anything at the pivot point on these machines
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Re: severe blade misalignment
On Tue, Oct 1, 2024 at 09:32 AM, KURT wrote:
And in the context of us hobby users, "longer bearing life" means something like lasting until the year 2150.? A lesser clearance will still let the bearings outlive you.?
Well, almost. I had a blade guide bearing fail on my Jet 5x7 last summer, after 14 years of hobby use. I replaced all six and darn near broke my budget! (snicker)? PGN Bearings # 6000-2RS $0.93 each in box of 10. The same bearings are used as blade guide bearings in my bandsaw mill. They don't last so long in the sawmill so I buy them in boxes of 10.
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?- Raymond
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Re: severe blade misalignment
"The blade is better supported with closer guide roller settings and won't wander as much, if you care about squareness, then ?use the OEM setting. ?If squareness of cut is not that important to you, then more clearance will make the bearings last longer."
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And in the context of us hobby users, "longer bearing life" means something like lasting until the year 2150.? A lesser clearance will still let the bearings outlive you.?
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Regarding set-up/alignment, I'm not saying it was the procedure mentioned above, but I followed one I got off some machining group and it took my saw from cutting less than 0.005 in/in squareness to about 0.040 in/in.? It was complicated, very involved, and counter-productive.? The process is inherently somewhat simple as there aren't a lot of places where you can make adjustments.? The bigger problem I found was that the fit of the parts wasn't very good. The most valuable thing I did was to square up and shim the moving surfaces on the guides to make sure that adjustment and tightening screws didn't move things around.? Then I used the procedure out of the saw manual.? It's back to cutting square, better than before.
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Kurt Laughlin
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Re: severe blade misalignment
Many many thanks for all this. I have my saw apart on the bench at the moment. I’ll study these responses, reassemble the parts, and hopefully post again when I have a better understanding of how these saws work.
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Hi Jack The OEM side guide roller clearance?setting is zero to 1thou over the blade thickness (which is very closely controlled to 25thou in all good blades) so 25-26 thou between the rollers? The blade cuts in the direction its back (the bit behind the teeth) is pointing, so any change in the angle of the blade back affects vertical squareness of cut.? When you twist the blade, the blade back slants across the gap between the 2 rollers and the slant changes appreciably with any change in the gap and therefore the blade squareness to the vice table changes too, and along with it the vertical cut squareness.
The blade does actually touch both bearings in each guide, it touches the roller inside the loop of the blade on its edge closest to the teeth of the blade, and the outside roller touches near the back edge of the blade (that's how it twists the blade). Old timers used to set the side guide rollers about 7thou?+ blade thickness apart to prolong the rollers life.?Even set at the OEM 0-1thou clearance, the rollers are not loaded anywhere near their load limit, but when swarf passes through the gap between the roller and the blade, it shock loads the bearings. At 1 thou blade to roller clearance the bearings are destroyed fairly quickly, while at 7 thou it didn't do much damage and the bearings lasted a lot longer.?? Fact is this was only really?a problem if you used liquid cutting lube, which makes the swarf stick to the side of the blade. Steel swarf cut dry doesn't?normally stick to the blade but occasionally a lump goes through which you hear as a bang.?Alumnium swarf is soft enough to squish but builds up quickly on the blade and rollers, robbing clearance until the rollers really do load up and fail. If top and bottom guides are not both the same then the horizontal cut blade direction also changes, and bang goes your horizontal cut squareness).?? The blade is better supported with closer guide roller settings?and won't wander as much,if you care about squareness, then? use the OEM setting.? If squareness of cut is not that important to you, then more clearance will make the bearings last longer.?? Anyway take the side guide roller clearance as a 'setting' (always do it the same, whatever you do), don't think of it as an 'adjustment'. You'll learn a lot more from John Piitkins early?doc? 'Blade Tracking and Adjustment for 4x6 Metal Cutting Bandsaws'.? It's not all correct but it's waaay better than OEM manuals. You can find it in the Files section (from the menu?on LHS of the 4x6 Bandsaw site home page) about 2/3 of the way down the first page.? Confusingly, in the list it's called 'Basic Blade Adjustment and Tracking -? rev-1.pdf' and it looks like the author is Walter Townsend (Walter transferred all the files from our old Yahoo site to??- Thank you Walter! Most of those under his name were written by other people) Rgds - jv I’m the original poster with the Dayton saw who, thanks to your responses, now understands that vertical alignment is set by twisting the bearing guide seats.?
My question now is, if we are going to twist those guide seats to bring the blade perpendicular to the vise, why do we bother to first set the two side guide bearings so perfectly. As soon as we twist the seat, isn’t the blade going to ride on one of those bearings?
Hoping to learn how to set up my Dayton. On Sep 29, 2024, at 9:23 PM, Noel Hinz < n.h.hinz@...> wrote:
Thanks! Your mounting plate is very similar to what I had thought about doing. Very nice work. Noel <20210729_120534.jpg><20210731_154133.jpg>
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Re: severe blade misalignment
Hi Jack The OEM side guide roller clearance?setting is zero to 1thou over the blade thickness (which is very closely controlled to 25thou in all good blades) so 25-26 thou between the rollers? The blade cuts in the direction its back (the bit behind the teeth) is pointing, so any change in the angle of the blade back affects vertical squareness of cut.? When you twist the blade, the blade back slants across the gap between the 2 rollers and the slant changes appreciably with any change in the gap and therefore the blade squareness to the vice table changes too, and along with it the vertical cut squareness.
The blade does actually touch both bearings in each guide, it touches the roller inside the loop of the blade on its edge closest to the teeth of the blade, and the outside roller touches near the back edge of the blade (that's how it twists the blade). Old timers used to set the side guide rollers about 7thou?+ blade thickness apart to prolong the rollers life.?Even set at the OEM 0-1thou clearance, the rollers are not loaded anywhere near their load limit, but when swarf passes through the gap between the roller and the blade, it shock loads the bearings. At 1 thou blade to roller clearance the bearings are destroyed fairly quickly, while at 7 thou it didn't do much damage and the bearings lasted a lot longer.?? Fact is this was only really?a problem if you used liquid cutting lube, which makes the swarf stick to the side of the blade. Steel swarf cut dry doesn't?normally stick to the blade but occasionally a lump goes through which you hear as a bang.?Alumnium swarf is soft enough to squish but builds up quickly on the blade and rollers, robbing clearance until the rollers really do load up and fail. If top and bottom guides are not both the same then the horizontal cut blade direction also changes, and bang goes your horizontal cut squareness).?? The blade is better supported with closer guide roller settings?and won't wander as much,if you care about squareness, then? use the OEM setting.? If squareness of cut is not that important to you, then more clearance will make the bearings last longer.?? Anyway take the side guide roller clearance as a 'setting' (always do it the same, whatever you do), don't think of it as an 'adjustment'. You'll learn a lot more from John Piitkins early?doc? 'Blade Tracking and Adjustment for 4x6 Metal Cutting Bandsaws'.? It's not all correct but it's waaay better than OEM manuals. You can find it in the Files section (from the menu?on LHS of the 4x6 Bandsaw site home page) about 2/3 of the way down the first page.? Confusingly, in the list it's called 'Basic Blade Adjustment and Tracking -? rev-1.pdf' and it looks like the author is Walter Townsend (Walter transferred all the files from our old Yahoo site to 开云体育 - Thank you Walter! Most of those under his name were written by other people) Rgds - jv
I’m the original poster with the Dayton saw who, thanks to your responses, now understands that vertical alignment is set by twisting the bearing guide seats.?
My question now is, if we are going to twist those guide seats to bring the blade perpendicular to the vise, why do we bother to first set the two side guide bearings so perfectly. As soon as we twist the seat, isn’t the blade going to ride on one of those bearings?
Hoping to learn how to set up my Dayton. On Sep 29, 2024, at 9:23 PM, Noel Hinz < n.h.hinz@...> wrote:
Thanks! Your mounting plate is very similar to what I had thought about doing. Very nice work. Noel <20210729_120534.jpg><20210731_154133.jpg>
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John Vreede
Mark
@MrWhoopee