Hi All, I have been lurking and learning for a while now and enjoyed the discussions. I am a hobby ww’er and have built many items in the past from simple treasures to entire sets of tables for our home.
I am now in the middle of construction of the kitchen cabinets for my new home. I have built a cross-cut sled to cut and “square” the doors and panels on the TS. The problem I am having is getting the panels “perfectly square. On a door that is 18″ x 32″, I get the door within 1/32” on square by measuring the diagonals. Since the doors will be mounted on face frames, this is probably good enough. During my lurking, I have seen reference to the 1234 method of squaring sliding tables etc.. Unfortunately, I missed a thread (or two) but I have not been able to find the exact procedure for this squaring method. I currently use a drafting square on the fence to the saw kerf of the cc sled to obtain square. Can anyone explain this method to me? Please!
BTW
The doors are constructed of solid cherry with cherry raised panels. The rails and stiles are made with a reversable rail and stile bit. Works great. Panels are raised using a vert. rp bit mounted horziontally on the RT. Probably wouldn’t use the vert. bit again. It does not give a real smooth finish cross-grain as I would like.
Thanks
Matt
Replies
Are you referring to a 3,4,5' right triangle? Otherwise, Asquared +Bsquared=csquared, for odd lengths. Pythagoreum Theory.
Alan & Lynette Mikkelsen, Mountain View Farm, est. 1934, Gardens & Fine Woodworking, St. Ignatius, MT
Sorry, what I am refering to is a series of cuts using a panel (sheet goods) and a cross-cutting device to check the accuracy of the cuts, ie is the device producing square cuts.
Matt
Hey Matt,I'm not sure I know what the 1234 system is, but if you will rip, or crosscut adjacent corners, of a piece of scrap, then turn it end for end and pass it by the blade, you're out of square error will be compounded by a factor of 2, and should be easily visible. Just make your correction 1/2 the measured error.Tom
I haven't heard of this method. But you could test for square by cutting small stock or a piece of ply, then lay it on a table, trace the outline, flip it and butt it to one edge.Then check for square with a straightedge(long enough or double the stock size).
Matt,
I'll just type in a hurried reply here.
two ways to square up the fence to the slide/saw blade.
**** Rough and ready but still acceptable *********
1) Get a piece of scrap/offcut sheet material any length, about 36" works best for me.
2) Hold a reference edge hard against the fence and rip about 6mm off one end.
3) Flip the board 180º, hold the same reference edge hard against the fence and rip about 6mm off the other edge.
4) If the fence is square, then the distance between the two cut edges will be the same. If not, then readjust the fence and repeat
***** The 5 sided cut method. *******
Get a piece of scrap/offcut sheet material approx 36" square.
1)Hold one face against the sliding fence and rip approx 6mm/1/4" off one edge.
2)Rotate the stock so that the freshly cut edge is located against the fence of the board and rip approx 6mm off the freshly presented edge
3)Repeat this so that you've made four saw cuts in total
4)Rotate the test piece by 90º one final time, in the same direction as you've been going all along. Hold it tight against the fence and rip a final piece about 3/8" off the edge.
5) Mark on this 3/8" piece which is the leading and trailing end
6) Snap it in half and check the width of the offcut at both ends by putting them against each other.
7) If the fence is square, then both ends of the offcut will be the same.
If the fence is set too acute or obtuse in angle, then the error will be easily seen - one end will be a different width to the other. The fence needs to move by half the width of the difference.
8) If needed, readjust the fence and repeat this test.
(This is how trade machinists square fences)
Hope that this helps and,
Cheers,
eddie
Essentially you start with a factory edge on a two foot square piece of cutt-offs and or Ply. Mark the sides 1 to 4. Place side 1 against the sliding table fence (hereafter referred to as the fence), take a 1/4 cutoff. Keep rotating and taking 1/4" cut-offs until you have rotated back to taking a cut from side 2 (this should be the fifth cut) make this cut wider, about 1/2" instead of 1/4". Measure the difference with a micrometer between the front of the cutoff scrap and the rear, this is your error times four. Adjust and repeat till the error does not get any lower. I believe the error is then down around a hundredth or so. If this is not clear, I can send you a link to a more detailed explanation.
Thanks for the help. I initially understood the cut/rotate part but I was not sure what I was suppose to measure after I cut the heck out of a sheet of ply :). I guess I know what I am doing tonight.
Thanks again
Matt
There is some technique involved as you will see. Keep even pressure on the wood from cut to cut. Unless you have an industrial slider, you will influence the cut otherwise and chase your tail. Remember, when you do this you magnify small amounts of error significantly; it's both the up side and the down side of this technique.
If I miised this I apologize for the repetition. Before you do anything else make sure the blade is parallel to the mitre slots and secondly make sure there's no slop in the sleds rails. Make sure your fence is parallel to the mitre gauge slots. Rip a piece of plywood or mdf 6" wide and about as long as your TS is wide use a factory edge against the fence. Cross cut the ply with the sled in half. Flip one of the pieces the short way and stand them on edge on the TS butting them together along the cut line you just made. Any gap is error in the sled's fence. Adjust and repeat until there's no gap. This usually only takes a couple of trys. You're already pretty close at 1/32" which is well within the reach of a couple of passes with a bench plane.John O'Connell - JKO Handcrafted Woodworking
The more things change ...
We trained hard, but it seemed that every time we were beginning to form up into teams, we would be reorganized. I was to learn later in life that we tend to meet any new situation by reorganizing; and a wonderful method it can be for creating the illusion of progress while producing confusion, inefficiency, and demoralization.
Petronious Arbiter, 210 BC
Matt,
I would not be surprised if you were unable to improve the outcomes. On a 32" long raised panel door to have the diagonals out by 1/32"...might mean it's actually out by 1/64"...and sometimes wood moves that much after being cut fresh. Also, the face frame, will that be exact too...and the hinge? There is a point where ya just gotta use hand planes. good luck
I think you are correct. I think in the grand scheme of things, I have the sled dailed in pretty close and a few passes with a #6 or #7 should take care of the rest.
Thanks again to everyone for the info.. It seems that my cc sled is "close enough" now ( lots of trial and error.. read a lot of error), but I sure that this approach will get me there faster and possibly more accurately next time.
Matt
It's sort of tedious to describe. If you use the search function you'll find some threads.
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