Help in squaring patterns made with laminates

[elizabeth]

Hi, guys:

Been trying all day to post this question with pics. Here it goes.

I'm having difficulty in squaring my designs after I have cut and glued. I have no reference point because of the shape. How do you cut it so that the four pieces are identical and the pattern is centered and perpendicular to the top and bottom?







Trying to cut the points off to make four square pieces is giving me trouble because I don't know how/where to position a ruler or square. Using the ends as a reference point hasn't helped if the glue-up on the first go is off a little. The pattern gets twisted. And when I finally manage to draw a square I can't cut it because the sides or edges are off and I can't place the piece against the fence or miter!



You see what I mean? It's hard to explain.



After cutting the four pieces "square" and of equal sizes for a box, the pattern doesn't always match-up with the adjoining pieces and I'm off square again and have to trim it one more time.



Having said so, I still don't have a reference point with the edges that I can rip on the fence nor crosscut with the miter.





How do you do it? I know I'm missing something and just don't get it.

My first little box (the one puppy ate), was originally going to be two little boxes from the same size blank as you see above. In trying to have all corners match (particularly for the bulls eye) I had to keep trimming away until I got it right. There's got to be a better way!



My intention is to glue two bottoms on the above (after it's right! ;D) and cut it in half to make two boxes. Then each will have a pull-up top. I've given up on hinges. Don't think I can put nails or screws into such narrow edges.

And Tim: If the glue-up goes just right I can make the design you tought me for an inlay!



Thanks!

[Leo Voisine]

I don't have any experience with that stuff, but what you are doing looks absolutely AWESOME.

I am in learning mode here.

[TDHofstetter]

'Lizabeth... let's try doing this:

Get hold of a manila folder, as for filing cabinets, and a plastic drafting square. Any other type of square word work, as long as it's VERY VERY ACCURATE; drafting squares are VERY VERY ACCURATE.

Draw a VERY SQUARE rectangle on the manila envelope, slightly narrower than one of your layups and as long as you figure you're going to cut the layups - minus the points on both ends.

Measuring very carefully, make a mark dead center at the top and another one dead center at the bottom. These two centering marks should be OUTSIDE the rectangle, just touching it.

Using the drafting (or other excellent) square as your guide, cut out the rectangle with an XActo knife & a fresh, new blade.

Now you have a "window". Lay it on top of one of your layups, carefully aligning the two center marks with the centerline of the layup, and with the bottom of the window corresponding to where you want to cut off the bottom. Trace inside your window onto your layup. Now you have quidelines on the layup, squared to the centerline (which is your one good reference from which to work).

You can now take that marked layup to the miter gauge. Lay a good steel ruler or your drafting square on top of the layup, carefully aligned to one of the end cutoff lines. Also lay that same straight edge along your sawblade (POWER OFF!) for alignment. Adjust your miter gauge until its angle matches the layup's edge. Double-verify that twice, then cut off the end.

Turn your miter gauge around in its slot so it points back toward you. Lay the SAME EDGE of the layup along it again and verify that the line you drew on it is parallel to the blade - it SHOULD be. Cut that end off, too.

Getting close, aren't we?

Now rip a scrap of thin plywood to get a straight edge. Lay your "window" over that straight edge so that the long side of the window barely touches the edge of the plywood. Transfer the two center marks onto the plywood.

Take your window back off the plywood and draw a line between the two transferred center marks, extended farther at both ends into a longish line. It'll be slightly less than half the width of one of your layups.

Stick a layup (the marked one) down to the plywood with thin double-sided tape, carefully lining up the centerline with the long line you drew on the plywood. The edge should overhang the plywood slightly, and the "rip" marks on it really should line up with the edge of the plywood. Verify twice, then "rip" off that edge.

The second edge is the easy one. Set the fence to one window's width from the blade and rip the plywood and layup together. The cut line will be right along your last "rip" mark.

Now that plywood will serve as a ripping jig; it has a centerline you can align your pieces to when you double-stick-tape them down. You may need another slim strip of plywood to buffer you away from the fence for the first "ripping" cut on each piece (since the layups will now overhang on both sides of the plywood).

I'm sure there's room for improvement & refinement... but that should get you durned close. It can't come out exactly perfect, since nothing ever does... but it'll be really pretty good.

[Doug B]

Elizabeth, I am not help to you, but I just wanted to say that I absolutely love that pattern you came up with. That is just fantastic! Can't wait to see the box.

[rhull]

Apr 19, 2010 14:16:55 GMT -6 elizabeth said:

when I finally manage to draw a square I can't cut it because the sides or edges are off and I can't place the piece against the fence or miter!

For this, I'd probably use a small tablesaw sled (custom built for cutting small parts) and clamp the piece to be cut between the sled and another piece of wood to keep it from moving during the cut.

[elizabeth]

Jeez, guys, thank you so much for the comments and instructions. Will get to it ASAP and will let you know how it's working out.

Have a good one!

[rhull]

This is what I had in mind; note this is just a mockup I threw together from spare parts, I didn't actually construct it.

This little sled allows you to get a straight edge by referencing off your tablesaw fence.

Since you do a lot of small projects, the advantage of a little sled like this is that you can reuse it many times for other projects.








Sorry, this last one should be rotated 90 degrees clockwise.

[Ruffnek]

I like Rob's idea of a dedicated sled for cutting small parts. The only thing I would do differently is utilize toggle clamps to secure the pieces, thus keeping the sled one layer.

I' ve already got three dedicated sleds. I may have to make another one now.

[rhull]

Apr 20, 2010 9:31:11 GMT -6 Ruffnek said:

I like Rob's idea of a dedicated sled for cutting small parts. The only thing I would do differently is utilize toggle clamps to secure the pieces, thus keeping the sled one layer.

Toggle clamps would definitely be one of many ways one could make it into a nicer sled. I was just trying to propose a quick, cheap, reusable solution.

[elizabeth]

Thank you so much for the photos and the effort. Pics really make things clear to me. The sled looks very easy to make and versatile in application. I like Cody's idea with the toggle clamps, to have the sled in one level, and I could also attach a backing board to reduce blow-out on the workpiece. But I like the two level approach because I wouldn't have to keep unscrewing, drilling, and re-screwing the toggle clamps to accommodate different shapes and sizes. I may need to make several, small, dedicated sleds for various applications. I guess I have to give up the idea that one size fits all. None of my jigs and fixtures ever work out quite right.

For this particular project I will start with Tim's "window" to draw my centers and square the workpieces. His technique will keep my design centered and perpendicular all the way around the four corners. I think I can combine his method with the sled to make the cuts safer and repeatable.

BTW: Tim: When you place your center marks of the "window" onto the center point of each workpiece, you're talking about the glue-line, right?

You guys are really fantastic. Thank you. I wish I could think the way you do. It sure would make my work more expedient (and pleasurable). But let me give this further thought. I had hoped to get to the shop today but I'm stuck doing laundry instead!

[rhull]

If you really wanted to go all out, you could use a toggle clamp and several t-track paths, then you could slide your toggle clamps more or less anywhere you wanted.

www.rockler.com/product.cfm?page=19704&filter=toggle%20clamp

[TDHofstetter]

Apr 20, 2010 13:42:49 GMT -6 elizabeth said:

BTW: Tim: When you place your center marks of the "window" onto the center point of each workpiece, you're talking about the glue-line, right?

Yep, exactly - the glue line where the two "fletches" (not to be mistaken for "flitches") meet.

[Ruffnek]

Apr 20, 2010 16:24:54 GMT -6 TDHofstetter said:

Apr 20, 2010 13:42:49 GMT -6 elizabeth said:

BTW: Tim: When you place your center marks of the "window" onto the center point of each workpiece, you're talking about the glue-line, right?

Yep, exactly - the glue line where the two "fletches" (not to be mistaken for "flitches") meet.

Elizabeth, take care not to flinch when you align the fletch, not flitch, or the cut may be flawed. ;D

[TDHofstetter]

Apr 20, 2010 18:10:01 GMT -6 Ruffnek said:

Apr 20, 2010 16:24:54 GMT -6 TDHofstetter said:

Yep, exactly - the glue line where the two "fletches" (not to be mistaken for "flitches") meet.

Elizabeth, take care not to flinch when you align the fletch, not flitch, or the cut may be flawed. ;D

Pretty good, o flatulent fella!

[elizabeth]

you're too funny! ;D

[elizabeth]

Apr 20, 2010 15:09:46 GMT -6 rhull said:

If you really wanted to go all out, you could use a toggle clamp and several t-track paths, then you could slide your toggle clamps more or less anywhere you wanted.

www.rockler.com/product.cfm?page=19704&filter=toggle%20clamp

Thanks, Rob. Really cool!

I have the day off!!!!!!!!!!!!! Will be in the shop!

[dicklaxt]

Hi Elizabeth ,I'm new around here,glad to know you and BTW great work on the Chevrons.

If you are satisfied with the squareness of a stack of chevrons,make a small one layer sled,mark a projected centerline on the sled parallel with the edge of the sled/saw cut at a distance that correlates to the desired length of one chevron side piece,next lay a completed untrimmed chevron stack on the sled and align with the centerline,position two blocks against the upper portion of a chevron leaving an open slot and secure blocks to sled.This will give you a way to position and cut all chevrons identical,simple lay a chevron stack on the sled and push the inverted "V" portion into the open slot between the blocks ,hold firmly or clamp and ti push sled and captive chevron thru the saw,flip the chevron over and do the same thing to the other side.If the sled/jig build is spot on you can't miss.

dick

[elizabeth]

Dick:
Thank you. Nice to meet you too. You're suggestion is like what I've been trying to do with Tim's "window". Can you draw out what you suggest?. I'm having difficulty envisioning it.

I've been trying a combination of Rob's sled with Tim's "window". This is what my pitfalls have been:

• Should have ripped before cross-cutting.
  
  
• I still cannot achieve square pieces. I can get very close to square but not dead-on, which has messed up the mitering of the joints.
  
  
• Because I'm working with 1/8th laminates the saw tears out my workpiece (the little triangles) at the glue joints, leaving me with no option but to make the piece smaller and smaller. This is in spite of using an auxiliary fence, lowering my cut speed, and raising the saw high.
  
  
• I've tried supporting the "edges and ends" with painter's Blue tape. It works only sometimes.
  
  

Using double-sided tape to attach the pieces to the sled dead center on the scribed line works fabulously until I have to pry the workpiece off the tape. As I write, I'm re-gluing a section that broke off as I tried to remove it from the tape.

Having said this, my first little box is done and is currently drying from the oil/shellac. I'll show it when it's cured. I started with a 14" laminated workpiece and ended up with only a 1" square box. But you'll like it! This one's dedicated to all of you, but particularly to our dear curmudgeon, Joe who challenged me to do it.

I'm currently trying to make a Plexiglas template with scribed center lines to use with my uneven workpieces. My intention is to run it through the Robo-Sander to achieve the squareness I need and prevent the tear out of the saw.

But even with this, I still have the double-tape dilemma.

Any further ideas, guys? I'm using everything you've suggested to this point, and have made one box, but I'd like to make others without the pitfalls so I can get a little production going once the props and set-ups are done.

Thanks again!

[TDHofstetter]

Mmmm... lessee. Engineering our way 'round this... how about a clamp instead of the double-stick tape? Like in Rob Hull's third picture up there - this one:

[art3427]

When I am having trouble getting pieces like this to "fit" I find it easier to do my final trims on a disk sander instead of a circle saw. Cut one piece and get it square to your satisfaction. Now use this piece as a template to mark all other pieces needed. Rough trim them with a saw. (On stuff this small it would probably be easier and quicker to use a hand saw.) Once the rough blanks are cut align its pattern to the completed template piece and carefully scribe the cut lines. Final trim on a disc sander. If you don't have a disc sander clamp them in a bench vise and clean the edges up with a good sanding block. You could even put a little back relief on the glue edges so the face joint will be really tight on completion.

art