Misaligned: technique, experience, …?
Hi all,
I am fairly new to wood working, and as my first project of any substance, I am building a table for my small router. I have already built the table top and fence [photo attached], and am now building the rolling cabinet that will go underneath.
The problem I have is fairly simple: corners and edges don’t quite line up, despite my best efforts. I cut 3/4″ plywood via circular saw w/ a straight cutting jig to approximate size, then (tried) to square all the corners and get more precise cut sizes with (what was called in the magazine) a panel squaring jig [photo attached].
Part of my problem is that the plywood isn’t quite straight, and AFAICT, never is when I’ve bought it. But I also wonder about other things… like the panel squaring jig. When using it, I put a hand clamp on the 1×3, pressure parallel to the board being cut, but pushed down so as to exert a small amount of downward pressure. I tried to be quite precise w/ my measurements, and found that my cuts were generally as expected (at least on the side where the marks were made. In general the cuts appear to be square (according to my large square).
So why are most of my corners off by 1-2/16ths? Is this normal, and I should expect to hand-plane the edges each time? Is there a better way/jig to make these sorts of cuts (overall box dims == 32 x 31 x 24). Is this sort of imprecision something that will disappear with experience? I tried to be fairly anal about measurement and cut lines, but clearly I came up short.
Any general advice? Thanks.
-ben
PS — does everybody else have a tape measure that differs in length from other measuring device (ie, builder’s squares, combination square, etc.)? Both of my tape measures are slightly different than all of my stamped measuring devices.
PPS — also note, the first “gap” photo — the tops of the 2 pieces are not supposed to line up. The top of the back piece should line up w/ the rabbeted edge of the right piece. Sorry for the blur…
Replies
benomatic:
Welcome to the craft, it can be a pleasure and a pain. There are a myriad of things that can be giving your trouble. Being new to WW, are you using (or are aware of) the best techniques to get true and square? That is, are you checking diagonal dimensions for squareness, are you using a consistent point-o-reference for measurements?
It also appears to me that you are careful with measurements, but your guides/rules/references are not delivering. Have you checked to see that your saw jig is giving you square cuts? And I don't mean by using the large (carpenter, I assume) square. Those things are good for building houses, but you need more precision for WW. As for the tape rule: Yes, their quality will be all over the map relative to their cost. Finally, your assessment of part of the problem is correct. If you do not start with straight and true stock, the problem will propagate with you.
What you are going through is a bit unavoidable. You will get better as you do this more. Read and absorb all you can, it'll only speed up the learning process. I've been in your shoes. Sorry this reply might not help much, but you did ask for general advice.
Work safely.
In general, I am probably not aware of best methods for getting true and square. Is there a good book (or articles here) that makes for ####good starting point?In my case of trying to verify that my jig is square, I have a Try Square, a carpenter's square, and a combination square. The try only gives me 8" of "squareness" afa measurement goes, and the combination square does no better. Is there an option that I'm not considering? Does it cost < $50?After asking that last question, I started digging around, and found this: http://www.taunton.com/finewoodworking/ToolGuide/ToolGuidePDF.aspx?id=2814Now I'm frightened, since i'm 99% sure that I have the cheapo craftsman, and most of my surety of squareness comes from that tool. Sounds like yet another case of getting what you pay for, which means that many would recommend that I save up to buy a good Starrett combination square and a better tape measure.In any case, thanks for the advice. It's all greatly appreciated :)-b
Regarding the "cheapo craftsman" square you're using - is it basically just a flat "L"-shaped piece of metal with markings on it? If so, you can actually correct it pretty easily with a hammer and a metal punch. Someone suggested this to me a year ago and it worked like a charm:
If your square is greater than 90 degrees, punch the outside corner of the square. This slightly expands the metal there and has the effect of reducing the square's angle. If your square is less than 90 degrees, punch the inside corner.
Start out hitting the punch with light taps, rechecking the square for squareness after each tap. If you see no change after the first tap, tap a little harder the next time. When I did this, the first (pretty hard) tap overcorrected my square and I had to fix it in the other direction.To the man with a hammer, all the world is a nail.
The cheapo is the craftsman combination square mentioned in the article I linked above -- the one that mentioned as not being square out of the box.The real problem, afa fixing it is that I have nothing to use as a reference for true square -- I've been using that combination square and the my large framing square as refs for the couple jigs that I've built. It sounds like the thing to do here is to get over it and buy a good try square, and a good combination square, and then to follow up by verifying (and remaking as needed) my jigs.
benomatic42,
If you haven't realized it yet, we all feel your pain. It was but a few thousand dollars ago we were all pursuing solutions to the same issues that confront you. I also think each one of us has developed our own techniques and processes to achieve the accuracy. Some got to the objective more cheaply than others...I didn't.
I'd suggest you dump the crosscut sled idea for cutting your panels. A table top saw is going to have great difficulty providing adequate support for a crosscut sled cutting a panel that large...the slightest movement and accuracy is lost. Better accuracy can be achieved with a jig and a circular saw. I use a metal yard stick and a marking knife to set the jig and always use the manufactures edge to reference off of. However, another alternative is a frame and panel design...a bit more work but also a bit more control on top of the table saw.
Always use only one measuring tool..don't switch back and forth it doesn't work.
Ahh...specifics...Geometry will be your best friend, especially when your guides are failing you. To ensure that your panel is square, measure the diagonal dimensions. If they are identical, your board is square--assuming your sides are straight.As for the cutting jig, get a big piece of scrap board as big as you can cut on your saw. First rip one long edge to ensure you have parallel sides. Then crosscut in half on your jig. Now flip the cutoff over (so the bottom surface is up) and rejoin the cut edges together. If the cut edges meet, your sled is cutting square. If your cut is not square, you will see your cut edges meet in either a V or cone shaped gap. You are essentially multiplying your error X2 so it will be easier to see it.You'll find that in some cases, there are ways to eliminate the error in the rule/guide with a bit of geometry. You will also learn a lot from using lesser quality tools. Besides the frustration, it will add to your general knowledge, and to greater appreciation of fine tools.As for references...here, other WW communities, bookstores, libraries...I wouldn't know where to start you. They're all good. Hope that helps.
tufen,
I'll just point out that there is a four sided geometric figure that is not square, whose diagonals are identical. Imagine a pyramid, with its top cut off.
You can end up unwittingly producing such a panel, if your jig is off a bit and you flip the panel end for end to cut to length. You can even make a case of this form, if the top is through dove tailed and the bottom is half blind dovetailed, and they are cut to the same length. How do I know this, you ask? Hah, years of screwu---er, experience.
Yes, geometry is our friend, but he can be a devious so and so.
Ray Pine
Indeed. Had this happen to me once. Scratched my head for a while before I figured it out.
Talk of square -- I had a somewhat new small Stanley square and I had just bought for only a few dollars an antique Stanley square. Probably from the late 1800s or early 1900s.
Anyway I got my new and checked the old one. Wow, it was out of square a good bit. Way too out to be of use. I was disappointed that I couldn't use my antique square.
Set it up on a shelf and forgot for a year. During that intervening year I learned that many of the new squares (not Starret level) were not really square. I thought, self, maybe you should check and see which one is not square. In the meantime I had also purchased a very accurate engineers square.
Well, long story short, my relatively new square was the one out of alignment. My antique Stanley was dead on.
Alan - planesaw
PS Sounds like you are approaching woodworking correctly -- Keep asking questions. When you do -- your dead, even if your heart is still beating.
Edited 11/14/2006 8:30 pm ET by Planesaw
Welcome to the most frustrating and basic thing Square lumber. It is key to success If you have cuts that are not square the errors only multiply, and frustrate you. I started out like you with a circular saw and first table saw was a cheap Lowes table top saw with a fence that you could not align perfectly if your life depended on it. From the pictures you showed and remembering things that happened to me I would suggest the following.
Over the years, I moved up each time to better equipment. Keep in mind, today the key goal is as it was when I started out, cut it square and to measurement and the rest will take care of it's self. The big difference now is, I can just cut them faster. I went from the table top saw to a Radial arm saw, to a Shop smith all in one machine to today with individual pieces of equipment. By far the most I use and can reccomend to you is the cabinet saw. Once you have it set up and a good miter gauge it gets a lot easier. Don't feel bad at the frustration it's normal. I still have a few pieces that don't have edges that lined up with precision. I notice it all the time, but my wife would not take anything for them. I can look back and compare those to today and see a dramatic improvement. Some times experience is the best teacher. It also helps to have a wood stove for mistakes. Take care.
Edited 11/14/2006 2:26 pm ET by bones
I won't repeat the good points already mentioned, except to say that a good try square is quite valuable, and can be used to check all other squares for trueness. A try square isn't expensive.
The second point I'd mention is avoid using a tape measure- or indeed any other measuring device- to lay out multiple similar pieces. Most WWs and finish carpenters stroyboard or template such pieces. I don't have the plans for your project, but suppose you were building a small end table with a drawer. You would measure the first leg and cut it from milled lumber. Each subsequent leg would be laid out from the first- length, width, etc. This is much more accurate than measuring each piece to size. The same would be done with drawer sides, table top pieces, etc.
As a last comment, avoid buying your plywood from big box stores. The quality is generally low and variable. If there is a good wood supplier in your area, they may have a better level of quality (emphasis on may)- YMMV.
Glaucon
If you don't think too good, then don't think too much...
Buy the best measuring and squaring you can afford the Stanley fat max tapes are very good use the one tap[e for all your measurements rules and tapes can very in terms of try squares a German company called Ulmia makes superb tools they are available in the US once you get your measuring and squaring in order you should be right.
Regards from Melbourne OZ
You can make it fool proof but not idiot proof
Edited 11/14/2006 10:59 pm ET by Bolts
To check your square:
1. Select an edge of a workbench, counter top, etc that is straight (when you sight down it.)
2. Put a length of masking tape at about 90 degrees to the edge.
3. Guiding your square off the edge of the workbench etc, draw a line at 90 degrees to the edge on the tape.
4. Flip the edge against the workbench edge 180 degrees. That is, the same edge of the square should be against the workbench, but facing the other way.
5. Draw another line at 90 degrees to the workbench edge right next to the first one.
If the lines are parallel, then your square is accurate. If not, you can correct it as above or toss it and buy an engineer's square.
To see if the plywood edge is square:
1. Make a mark 3 feet from one corner on the end of the sheet.
2. Make a second mark 4 feet from the same corner on the long side of the sheet.
3. Measure carefully the diagonal distance from the first two marks.
If the diagonal is 5 feet exactly, the sheet is square. (A 3-4-5 right triangle.) If you're clever, you can use this method to mark a square line on a sheet that isn't square, then cut it square.
There are other graphical methods of bisecting lines and drawing 90 degree angles using a compass or set of dividers also.
Ben,
Welcome to the real world of woodworking. You have found out that it is not like Norm's world, in which you walk into the shop, and all of the expensive tools have been tuned, and all of the cuts have been set up, and all you have to do is run the board through!
You have gotten great advice from some great woodworkers on squaring things. As one of them said, you will get better with practice. As Joinerswork said, you will also run into problems in which you do all the checks you thought you should, and it still doesn't work. When that happens, relax and go talk to SWMBO for a while, and then come back to the shop and calmly try to figure things out. Woodworking is a solitary enterprise. It is just you. The most important think a woodworker learns is self-sufficiency. By that I don't mean that you don't need anyone else. I mean that you learn to depend on yourself to either develop solutions yourself, or get advice____ but you take full responsibility for making things work.
As you go on to do other things, when you get past problems like squaring, and you try things like veneering, you will encounter a wider set of problems, and then you'll solve those, and then you'll try carving, and the same thing all over again. The nice thing about woodworking is that there are enough new things to learn that you can keep this thing going the rest of your life.
So much for philosophy. The only thing that I saw in the responses to you that I disagree with is the use of crosscutting sleds. I tried and failed, and studied the situation, and got opinions from others. Then I bought a Dubby. You can find it on:
http://www.in-lineindustries.com/
The nice thing about the Dubby is that it is VERY precisely adjustable, and re-adjustable. I check it for square each time I use it. I adjust it by a small turn to an adjusting screw. Jerry Cole, the owner of In-Line Industries is a nice guy and easy to work with. I don't get any kickback from him, and I paid full price for mine. I am merely a happy customer. Look at the website. I have found it to be a very nice and versatile device which is easily "squarable".
Welcome to woodworking. Hope to see more of you on Knots. If there is one piece of advice that should be given to all new woodworkers, it is: If possible, find a local woodworking club, or at least find some local woodworkers. It is amazing how much easier things get when you have people you can talk to face-to-face, and who you can show your problem to.
Enjoy.
Mel
Measure your output in smiles per board foot.
I think it is time for a new saw...... Well that is what you should tell your wife. Feel free to tell her I said so.
Seriously though you are doing good and gaining valuable experience. There are too many thinks to point out in one post, and without reading the previous posts I am certain that there is a lot of good advice there as well.
The simple advice I have is that you should look for a book on table saw jigs and one on machine setup. i bet that your crosscut sled (panel squareing jig) is not square. the usual method for dialing one in is to cut a long board (12"wide by 24" long) using the jig. Then flip one side over remate the cut edges an check to see if the long edge is still straight. If not you have to think about which way it is off.
Personally i dont like using a crosscut sled. I prefer to use a shooting board. It is easier to move a circular saw over the panel than to wrestle a panel over a bench top sw.
Pardon my spelling,
Mike
Make sure that your next project is beyond your skill and requires tools you don't have. You won't regret it.
a draftsmans triangle which is inexpensive will help you determine if your squares are accurate. Staples ,office depot or any business supply store sells them for a couple of bucks apiece.
Many tapes vary slightly ,even in the same models. In the shop ,use the same tape or rule for all measurements. Many times a story rod is the way to go,especially on multiple pieces.
I would check the diagonals of the next piece you cut with the panel cutting jig. If there is a variation ,rework the jig. Make a base large enough to span both miter slots.Make or buy runners for the slots.Use a 5/4x5" piece of stable hardwood for the front fence of the sled.Saw or rout a rabbet 1/8x1/8" into the bottom of the front fence.This helps keep sawdust from accumulating at the front fence.
Screw,no glue, the front and back fences.Make sure the screws are not in a cut line. Just four screws at most for now. Square saw fence to miter slots with fence set at one edge of panel sled.Place runners in slots,shim up if needed to clear saw top.Put a thin line of glue on the runners,place sled on top of runners and against the fence.
Weight it down,probably 25 or 30 lbs of whatever you have will do.after a couple of hours or more, turn the sled over and add counter sunk screws thru runners into sled.Pilot holes will keep the runners from splitting,use screws of correct length.
Now with the blade all the way down, install sled onto table and miter slots.Make sure sleds pushes and pulls back with very little effort. Start the saw,raise blade slowly.When the blade is 1" or so up past the sled, push til the sled goes past the blade a bit.Turn saw off, check the front fence for square to the sawcut. Adjust if needed,tht's why I said four screws only. Once you are satisfied the sled is cutting square,add more screws,no glue ever.Wood moves,things can go out of adjustment.You want the capability to easily readjust the fence in the future.
The reason I use 5/4x5" stock for the front fence is for safety.The 5" height plus the sled thickness are about 2" higher than the blade.It is unlikely you would use the sled for material thicker than most sheet goods,but in the event you do the 5" height will add some measure of safety more than a 1x3.
mike
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