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I am in the process of building a few stands for my wife's "fish room". I am using 1.5" 14g square tube . On the larger stands (4' x 2' and larger) I am doing alright, square corner to corner (within 1/8 -1/6" - stop laughing - that's good for me! ), and when finished there is no wobble or play leg to leg. Today I was building a 4 tiered stand, designed for (8) 10 gallon fish tanks. The tanks are about 20"x10"x10". My design was for 2 tanks per tier, so the stand was square shaped when finished. I had a really hard time truing everything up and trying to achieve square. I am working off of a 3/8" 4x5 plate. I guess I'm looking for ideas on jigging to achieve repeatable results. I just don't have the experience or fitting skills to work "freehand", like the old timers at work. My welds are suffering due to the poor fit up of my pieces after tacking, cutting off, grinding off the tacks, taking some material off so I have more "adjustment room" etc....Long description for simple question - Anyone have a good jigging method for a garage based guy?I am using .035 solid wire, 25/75 gas @ 20-25cfh, Millermatic 135 XP (110v) at its highest setting with a 60-65 wire speed.Here is what I'm building - (pretend the wiring/fire hazards aren't there! - that's being addressed with the new stands) - Attached ImagesJust another clown trying to be cool
Reply:I can think of several thoughts that might help.1st what sort of corner design are you using, 45 deg miter? With tube you will have 2 choices, open corners and square cuts, which simplifies the build, or miters. On a 45 deg miter, it will be key to get the saw set right. If you are out 2 deg, then the gap will be 4 deg usually. You might think about doing the open corners and just filling the tube with plates. more work, but it makes the fit up easier for corners.2nd I'd build a jig to hold all the parts. For something this size and square, I'd use 2 or 3 sheets of plywood as the jig. Screw 2 pieces together and cut them exactly the same and square I'd make the size of this the size you want the inside of your frame to be. Now cut the 3rd piece larger than those 2, the size of the outside of the frames. It will be key to cut the inside pieces square and plumb as you will use this to set your tubes. The exterior piece doesn't matter as much, this is just to help clamp the parts. Now clip off all 4 corners at a 45 deg angle so that the line is say 1-2" past the intersection of the corners. This lets you weld almost everything and stay clear of the plywood. One issue with this is that you may find that the frame is hard to remove from the plywood jig if it warps badly. this can be solved by several methods. Cut the center jig into small pieces and then mount them. this allows them to be disassembled for removal. However this makes getting them back and square each time more difficult. Make the center jig smaller by say 1/4" and use a 1/4" filler strip on 2 sides. Usually you can just drive the jig out as the jig and the shims will slide. You could also build the jig from one base sheet and 4 pieces of angle iron screwed to the ply to form the 4 inside edges. This would let you unscrew the sides if needed. to remove the jig. Again it's hard to get everything square after removal. I suggest plywood because most people are well equipped to get nice square cuts in this and it's easy and cheap to work with. A bit of water will help if you get any fires, but with the corners clipped back that should take care of most issues. A friend with a table saw would make building the jig a matter of minutes.I'll Pm you some contact info. Give me a call and I can see if I can explain it better, or I'm not all that far from you I believe and we can work something out to give you a hand.Last edited by DSW; 03-07-2010 at 09:45 PM..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Tanks for attaching pictures.So for 8 small tanks your stand would be two tanks wide and four tanks tall? Tanks are 20" deep, 10" wide and 10" tall? If I have this right your stand will be about 25" wide, 20" deep, and 43" tall, allowing a 1" air space below the first shelf and 12" per shelf to access tanks? Am I close?Using the dimensions above, I would build the "front" first. Basically it would look like a ladder 43" tall and 25" wide. It should be as dimensionally close as you can get it, even if that means taking an extra 10 or 15 minutes to make it perfect. Using work points might make it a little easier. Then use the front as your fixture for the back. Put flat-bar or angle iron tabs on the front that will act as stops, two per tube, as close to the ends as possible without getting in the way of welding the joints. Keep in mind that you want the top of the shelves on the same plane, so put your tabs on that side of the tube. Also keep in mind that you don't want to have to beat your weldment out of the fixture with a hammer, so don not put tabs on in a manner that traps the parts in the fixture. Tack together as many fronts and backs as you need using the first "front " as your fixture for all. I will try to add a little scketch. Take the tabs off when you are done and clean up the tubes with a sander Then place a single front on your table and add the sides. Just clamp them on if you have enough clamps/flat-bar to do so. You will really only need to get the four corners up at first.Now you will have a "ladder" that is 43"X25" laying flat on your table with four 17" long legs sticking up from the four corners. Place a "back" on top of the legs and square everything up, then tack. After everything is tacked together, at least four tacks per joint, stand it up and see how it looks. Check to make sure the tanks will fit. If it all looks good, then weld it out. Do not weld one corner out completely, keep the heat moving around to minimize warping.Two last items; 1/8" to 1/16" out of square or parallel can compound quickly. If you have two frames that are 1/8" out of square in opposite directions, they add up to 1/4" out of square over all. And, no matter how square and perfect your shelves are, if the floor isn't level, the selves are going rock a little. Attached ImagesLast edited by 4on12; 03-07-2010 at 10:41 PM.Will |
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发表于 2021-9-1 00:35:54