Hi Wheeler
Although they 'look' the same, I have never seen identical saws from different manufacturers.
Some manufacturers, like Rong Fu, make 'house' brands for different re-sellers and, yes, then they're the same, but otherwise, no.
All you need to do is look at the arrow on the sawframe casting.? If the arrow is different then they were cast from different molds, so not the same manufacturer. Some have got handles on the sawframe others haven't, fins on the gearbox casting or not, etc.
There is a simple fix for the tension knob being difficult to turn and better than making a bigger knob: Replace the knob&tension rod with a 5-6" length of 3/8 x16 UNC all-thread with a nut to lock it to the tension mechanism per the photo, then use a nut and ring-spanner to tension the blade. Much easier to turn.
However the real issue with the tension mechanism is the fact that the edge of the sawframe casting still has the tapered 'draw' on it that is used to free the pattern from the sand when they make the mold. (see Side elevation photo)? ?This angle is what makes the knob hard to turn, as its only bearing on one edge.? Also causes the plastic knobs to split. The saw in the picture has a 6.6 degree taper though I've measured others down to 3.5 degrees.? Make a tapered washer to fit in between the casting and the nut, but you'll need to measure your own casting to find the right angle.?
I cut shallow tapered pieces like this at precise angles by tipping up the infeed end of the workpiece with the nearest size drill, placed 4" from the edge of the table next to the blade (see photo).? Work out the drill size by trigonometry: Drill diameter = 4x(Tangent of angle). Most cellphones have a calculator with Tangents on it, if you turn them sideways.? The method is not mathematically exact but at these small angles it makes no difference.
The other thing that makes it easier still, is to use a needle-roller thrust washer in between the tapered washer and the nut.? Not strictly necessary as ordinary flat washers with plenty of grease work too, but it is nice. No point in using a needle-roller thrust washer if you don't correct the taper on the edge of the casting though - jv
?
John Vreede
