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??? ??? tread mill motor

??? ??? animal

I'm getting tired of wrenching the belt tension adjusment out and back in every time I want to switch band speeds. Does anyone know of a mod for quickly setting belt tension without resorting to the crappy bolt on the HF4x6?

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??? ??? I second that , when I opened mine up it was bone dry & the seal was installed backwards & in the wrong place

??? ??? animal

Hi Karl

In order:

Yes, open gearbox cover when the saw frame is horizontal.? If it leaks like that, then the factory filled it before assembly when the sawframe was flat on a table.? Don't disassemble the pivot shaft to empty and refill, the pivot shaft is the heart of what makes the saw cut straight so best to leave it be.? Tilt the saw on its left-side legs to lessen the amount that drips out, then just open it and make a mess if you have to.? It’s only a one off, the thing needs no more oil than will stay in the gearbox when the sawframe is horizontal, that's about 80ml (2.7 floz) and the gear wheel picks up oil when there is 60ml or more in it, so 60-80ml is all you need.

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The top wheel back 1/4" is not a big deal.? OK to get them co-planar but tracking the blade on the top wheel is by tilting it, so that moves it out of plane again. To be honest, it’s not necessary and may stuff up where the blade tracks on the bottom wheel.

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As far as vertical cut squareness goes, the Xynudu video only tells a small bit of the story.

Cutting square comes from 2 things:

1. The geometry of the fixed and moving parts of the saw (the angle of the blade and vice to the?pivot shaft)

2. The dynamics of the teeth cutting metal (the direction the blade points, sharpness of teeth, feed, speed,? and blade tension)?

The horizontal and vertical squareness are mostly independent of one another.?Horizontal squareness is all geometry. Vertical squareness is a combination of geometry and dynamics.??

The saw cuts square, both horizontally and vertically, only?if:

1.??The workpiece (what you're cutting) is parallel to the?pivot shaft?in?both?plan view (looking down from above)?and elevation?(looking across the vice table)

and

2.? The blade is square to the?pivot shaft?in both?plan and elevation,?

The above is a bit useless unless you can measure the squareness, put numbers on it and tell if it’s getting better or worse.? There is such a test.? The geometry test is detailed (incl. photos) on pg3-5 in the document ‘Buying a Used 4x6 Bandsaw’ in the ‘Files’ section of the site.? The same test in ?” thick rectangular mild steel will show the dynamics. Measure them both and come back with questions.?

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The above squareness test is a modification of the test that Wilton show in their manual for their model 3130.? The document is called m_3130.pdf, also in the files section, and is far and away the best manual of any 4x6.? On pg14 you’ll see how to adjust the guide bracket properly. They use a 6” rule with a pocket clip but a clothes peg works as well.? Really you need 2 rules, one near lower guide bracket and the other near the upper guide bracket so you can sight across them both to see that both are the same. The rules need to be very flat or it doesn’t show (only one of the four I’ve got is good enough).

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You are right about the rear guide roller clearance.? They all say it’s critical to a wood bandsaw, but that’s because they run so fast and blade tensions are much lower than a 4x6.? 4x6’s are not sensitive to the rear guide roller position.? However, they should be set so that both rollers only touch the blade now and again as the blade turns. If you mark the outer races with lines from a Sharpie pen you’ll be able to see the rollers turning.? The blade back moves around a lot more on a 4x6 than on a wood bandsaw and the clearance will go from zero to 0.020” sometimes within the space of 9-12”. The blade will bend so it gets support from the rear roller when it’s in the cut.? If you set them so they touch the back of the blade you run the risk of them being too far forward, which can derail the blade

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John Pitkin chose 0.007” clearance to preserve the life of the side guide roller ballbearings. Unfortunately, that makes the side guide roller clearance part of the vertical squareness setting, where with 0.001" clearance it is independent. For that reason I use 0.001" clearance and a blade scraper per the doc 'Liquid Coolant Lube on a 4x6 Bandsaw .pdf ' in the Files section.

You can get the squareness to 0.003”per inch of cut, per the Wilton manual, only by the tweaking, trial and error you describe.? There are modifications you can make that separate all the squareness adjustments from one another and then you can reliably adjust squareness 10x better than the Wilton standard, but that’s another story.

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That little angle bracket is quite handy when you’re doing a lot of repeat cutting, as you don’t have to raise the saw to the vertical between cuts, but otherwise is not much used. The pin that locks the head from raising at all is a pita.- jv

I checked the gearbox – plenty of oil.

I thought the comment “check it with the saw horizontal” meant in the horizontal cutting position. Oil started leaking out when the gasket got loose, so I tightened it up quickly. In a few weeks I will pull the pivot pin and put the entire arm horizontal (with the plane of the wheels horizontal) and change out the oil as recommended.

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Zero offset

The top wheel was about ? inch back. I removed the wheel to add a few washers to shim it and found that the installed shim was a piece of thin walled (0.045 in) steel pipe with an ID of .66 over a shaft with an OD of .59 in. I made a new, properly fitting bushing out of some brass. I made it longer than needed, then gradually faced off the end until I achieved a zero offset.

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Blade alignment

I had a heck of??a time aligning the blade to cut straight.

Xynudu has a good video () showing what has to be done.

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I used a magnet to hold my 6 in gauge to the blade to make it easier to check for square. However, my steel machinists square would pull the magnetized gauge when they got close together. I got out my aluminum speed square, and that worked much better.

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Because there is not much room between the nuts that hold the guide bearings and the bolt that tightens the tilt movement, I kept knocking it out of alignment each time I tried to get the bolt tight. I replaced the hex bolt with and equivalent socket head cap screw and solved that problem.

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Guide clearance

I am having trouble understanding the clearance issues with the guide bearings. Everything I read about barely touching the blade makes sense for a vertical machine, but not for a horizontal machine. It seems to me that the bearings MUST touch the blade to provide the required twist to the blade.

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I set the clearance with feeler gauges (.030 for a .025 blade) before I installed the blade, then tweaked them just a bit to fine tune the tilt. I don’t see any other way to do it.

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Misc.

I have noticed a lot of machines have an L-bracket near the pivot that is designed to hold the arm partially upright. I have the notches in my castings, but the L-bracket was not included and not shown on the parts drawings.

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It seems it would be easy to make my own, but I was wondering if any body actually uses it. In all the videos I have seen, the bracket is just flopping away, and never used. It could be that it is used often in the edited parts of the video and already disengaged on the posted footage. Is it worth it to make and install that bracket?

?

Thanks to all for your comments.

Karl

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Mine had cast jaws but I had to replace one with angle because I couldn't get a 3x6" tube in there and I had a bunch to cut.

Here's pictures of the problem and how I fixed it.

Other bandsaw mods here

-- 
Jerry Durand, Durand Interstellar, Inc.

tel: +1 408 356-3886
@DurandInterstel

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I like the saws that have the cast vise jaws thinking they will hold better..The difference of $100. maybe internal as in bearings/bushing material as in plastic vs brass/bronze in the gearbox [if any at all] especially..Try to dig up the parts list on each to try to discern what they are, Good point on checking oil as stated in previous posts..One more note is on the electric motors..I have read that they sometimes get so hot they catch on fire! The motor on my saw of 37 years got so hot you couldn't touch it and you could smell the paint wanting to cook..Now it gets warm but not excessive and still has the original v-belt and bearings..

-- 
Jerry Durand, Durand Interstellar, Inc.

tel: +1 408 356-3886
@DurandInterstel