I was glueing up a torsion box for a router table top and needed a flat place to work. The only thing flat in my entire shop is the table saw, or so I thought.
I put a 36″ straight edge across and found the table to low at the blade and high on the wings… How do I fix the cupping without having to shim the wings (shims would show up top!)??????
Andy
Replies
That's a common thing. I keep a pack of brass shim stock around for general use anyway. Available from http://www.use-enco.com mcmaster, mscdirect, etc. If you put them in right it won't show. Don't use cardboard or tape as it will compress and change. A $5 feeler gauge or two from the local auto part store will probably do the trick as well.
I had the same problem with my new PM 66 when it arrived. I spent hours filing down the edges of the cast iron wings, and putting them on and off many times before I got it right. It was well worth the work, as my saw is tuned nice, but I doubt I'd go through that work again. I'd probably send the saw back next time.
Jeff
So what is wrong with a shim that might show? These are tools, not show-n-tell items.
Notice that you didn't figure out that you had a problem until you measured. Apparently, it didn't show up in the performance of the tool.
> Notice that you didn't figure out that you had a problem until you measured <
And isn't that the issue!
We're working wood, guys - engineering tolerances are nonsense, most of the time.
Malcolmhttp://www.macpherson.co.nz
Malcolm said;
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We're working wood, guys - engineering tolerances are nonsense, most of the time.
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Well said. View Image
Cheers. Shawn
Thinking about 'engineering tolerances' while out in my shop jointing a stand for a tool box (coarse woodworking), it occurred to me that the standard should be a level of precision higher for our tools than our work. Errors tend to compound, right, so the more accurate the reference surfaces (tables, fences, jigs ...) the better the end result.
I was going to suggest we should apply the same level of precision to our machines and tools that we apply to our work (who marks out in thousands of an inch?) ... but then, the insight in the first paragraph ocurred to me.
And I gues one reality test is that while I do fiddle about with exact squareness, I've just cut some 4 inch dovetails on my Euroslider by sneaking up on a tight fit - no measurement at all!
Malcolmhttp://www.macpherson.co.nz
Malcolm,
While I generally agree with the "It's woodworking, ain't engineering" philosophy and approach, I think it's much easier to accept as a concept than a fact. Let's take Lumberjack's situation and investigate: what happens when he cuts the shoulder of a tenon on a 2' long rail on his TS....will both shoulders be nice and square? Or when he slides the tenon from the rail into the kinda square mortise on the stile...will he be introducing tension into the door panel and will it lie flat?
So while I agree with concept, as a relative newbie, I don't know which/what tolerances to accept and which ones to correct ...or else the cabinet door won't stay closed ...ugh!!
>what happens when he cuts the shoulder of a tenon on a 2' long rail on >his TS....will both shoulders be nice and square?The example you cite is probably the least likely to cause problems. You've got a 12-24" base and maybe a 1/2" height (the shoulder) on a triangle. Now assume a big dip like 1/16th of an inch. A little trig says the difference at the top of the shoulder is on the order of a few thousandths. It's still a good idea to get the wings level and parallel, but you have to keep perspective.Pete
Thanks for the lecture; what happens though when we're engineers working wood? ;)
Ha - you're probably conflicted!
Malcolmhttp://www.macpherson.co.nz
I just had to level the wings on my TS as well. Annoying, but not hard. Aluminum foil is what I used. After I had it flat, I just cut off the excess on top with a knife, and I don't think anyone will ever notice it unless they are searching for it. The rear took 8 folds, and the front 4 thicknesses. I did not measure the thickness, but when I put a 3' straightedge on the left wing, across to the right side of the main table, it was up about 40 thous. Now it just a couple of thou. off, and is fine.
Alan
http://www.alanturnerfurnituremaker.com
Edited 12/7/2005 12:01 pm ET by AlanTurner
Thanks Alan, that's the answer I was looking for.Andy
I had same problem. I was suprised how thin a shim it took to correct this. I used playing cards. You wouldn't notice them unless looking for them.
Thanks Brendan, I'm thinking that since such a small shim will make a difference, that maybe some of the gunk they ship those things with might be throwing it off. I'll pull it apart and have a look, if not it's time to shim.Andy
You might also want to verify that your straight edge is actucally straight. If there is any deflection/warp (wood or metal) that could also throw off your measure. Place it on a large flat surface, trace a line on one edge, "mirror flip" accross the line and mark again, the lines should match (closely). Kinda like checking to see if a sqaure is sqaure, but just checking variation along the length.
Donkey
Thanks for the tip, I'll use that...How do you check if a square is square??
Edited 12/8/2005 7:29 pm by LumberjacksSon
lay the short end of the square on a good edge (plywood, mdf, jointed edge of board, etc.) then trace a line along the long edge, trace with a very sharp pencil or scribing knife, a line along that edge - flip the heel (short) part of the sqaureso that it is on the opposite side of the line, from right to left or vise versa, trace another line, it is off if there "v" shape "v" point up the 90 angle inside is greater than 90, "v" angle down, 90 degree angle is smaller.
This is quick and dirty method of checking, but will get the job done.
Donkey
I'm making a router table (top and base). I've been borrowing ideas from the features the magazine reviews like and from the pros (Pats Warner and Spielman). Do you have a plan? My top will be 1/2" MDF on a sheet of 3/4" cabinet grade plywood. Base will be from 3/4" plywood. (The pros seem to keep it very simple...saw a guy on a TV router show and his fence was an MDF board held with C clamps). Any suggestions or hints? At this rate I won't know if I've done good or bad 'til its done.
I built mine with Norm's plans. I made one modification, I went with two 3/4 MDF pieces and it is solid and flat. The top is banded in 1" oak with HPL on top of that. It works well and has held up well. Go to the newyankee website, his plans are cheap and very detailed. I sold the plans after I built it, and made half the purchase price back. Good luck.
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