Re: Entire head coming down at an angle?
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Hi all Mark's?idea does work!? It corrects mis-manufactured saws where the head comes down at an angle to the vice table! This is a game changer for all those saws that never cut properly and for ones with worn?pivot shaft?bearings. I have a Paykel RF128 saw that would only cut vertically square with a 1mm spacer stuck down the LHS of the vice table. Test cuts without the strip showed it was out-of-square to 0.011" per inch of cut (0.003"/" is a good standard) and you could see it wasn't square by eye.? At the first try now it?cuts 0.0013"/".? Pretty good by any standard and the process is so controllable,?it would be easy to take a bit more off and get it close to zero! Besides filing a ~1mm (0.040") relief on the pivot saft at the LH pivot shaft bearing in the base casting and drilling & tapping M6 grubscrew?(see photos), I had to flatten the vice table with a file (was just a bit hollow) and ease the diameter of the pivot shaft with a strip of 240g then 600g wet&dry at the LH end because it was tight on the pivot arm?casting.? I needed an aluminium drift to knock out the pivot shaft so as not to swell the end of it. I didn't have to block up the sawframe?casting (didn't even take off the blade or guard) it balanced quite nicely on the saw stop bolt with 1/2" rod through the ears to stabilise it while I?filed the shaft (NB theres a ~1/4" long tube spacer over the pivot shaft between the RHS of the sawframe casting and the base casting that you have to slide the shaft into each time!).?? It needed a 3/4" wide relief halfway around the shaft that was 1mm deep in the middle tapering to nothing at halfway),??though when I reassembled and tested this was not quite deep enough by about 0,17 mm (0.007").? It was easy to file with a?5/8" drill stop collar on the shaft (the pivot shaft is 5/8" not 15mm like? I said earlier), but looked a mess before I used the collar. The pivot bearings are now in the sawframe and the pivot arm castings. They're?almost twice as wide as the originals and unworn. There was enough wiggle room, of the pivot shaft in the old bearings on the base casting, to just?file one side of the pivot shaft?? The process is:? 1. Set the blade body square to the vice table (6" rule clipped?to the blade body) before you measure any squareness.? 2. Get some planed-4-sides 1x4" softwood joinery timber?as test?stock to do the vertical cuts. 2x4 construction lumber is normally not straight/parallel enough and twice as thick as you need so is slower.? Don't use?metal. 3. Find out how much you need to raise one end or the other of the test stock to get it to cut square, use strips of different shim (use a soft mallet to seat the test stock on the strips in a nipped-up vice).? This is the amount you need to file off the underside of pivot shaft at the same end as the shim is stacked? 4.
File the relief
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Drill&tap?for a grubscrew?in the upper side of the base casting ear, file a flat for the grubscrew?on the pivot?shaft 180deg away?from the deepest point of the relief 6. Reassemble and test squareness ?- jv ? On Thu, Nov 26, 2020 at 11:58 AM John Vreede via <vreededesign=[email protected]> wrote:
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John Vreede