Cutting stock squarely

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I have some 1x1 1/8" thick tube I'm cutting up for a frame as part of my project. I bought a rigid 14" abrasive chop saw from home depot. I set the saw to 45 deg (using the aluminum part of my combination square, didn't trust the built in gauge. Also checked blade is square to the base.)After cutting the 4 pieces up and clamping them together, it was obvious something wasn't right. I eventually figured out the blade of the saw was deflecting outward towards the bottom of the cut. This is the stock abrasive blade that came with the saw, I believe 1/8" thick.I have a 1" wide HarborFreight belt sander, with a rough grit belt it eats metal well but its hard to get stock square since the belt isnt wide enough. Theres no miter gauge on it either. I thought of taking it back and getting a  4"belt/6"disc bench sander with miter gauge - this with the chop saw should be ok to make up square cuts.Or, would it be better to take the chopsaw back and get those 4x6 bandsaws? After proper adjusting they should cut square right?This is for my tinkering in the garage, not any major production work. I've already spent more then I thought I would need to. I got the rigid saw instead of an HF one in hopes it will cut more square, but it seems the deflection is due to the blade diameter. Would a smaller diameter blade chop saw do any better? I've seen a 6" one. Sorry if I'm rambling. I just am a bit frustrated, didn't think getting a square cut would be this tricky.
Reply:Not trying to dodge answering your question but give this thread a look. Very close to the same issues.http://weldingweb.com/vbb/showthread.php...ng+square+cuts
Reply:I have a 14" Makita chop saw and regularly use 1/8" cut-off discs with no trouble. You might be forcing the cut too much; a good abrasive disc should need very little pressure when cutting relatively thin stock like that. With solid material of large size, it is more difficult unless the saw can rock forward/backward so change the point of cutting contact.When there are four pieces which fit together, all the errors are additive so will seem worse than with one joint. Try using some scrap tubing and recheck the tool angles, then check the cut angle of the cut piece with respect to the disc, and then see how the cut angle measures with your square/gauge. Just cut off very short lengths from your test piece and adjust until the saw is set perfectly.You might also find that different brand discs have different flexibility so another brand may work better.I haven't had any discs which have given me problems and have even bought some fairly cheap ones from ENCO.One more thing--with a smaller diameter saw (usable disc) you will rapidly loose capacity to cut thicker material, so will probably be unhappy. Remember that with the hold-down washer, you have something less than half the wheel diameter when the wheel is new, and the 'something' can be significant, maybe 1 to 1.5" (or more?).Bandsaws have their place, but so do chop saws, and this should be one for the latter (chopper).BTW, If I remember correctly, I think that last thread was more about holding the 'L' shaped stock in the correct position to get the right angle, not the wheel angling off the wanted line. With rectangular stock that isn't a problem. It's good to search for a solution though; we often forget to before posting a question.Last edited by Oldiron2; 10-23-2008 at 02:04 AM.Reason: More ideas
Reply:Hey thanks for pointing out that thread, was a good read. Tried a few searches but guess I didn't use the right combo of keywords to bring that one up. Will try more variants next time.The abrasive blade that came with it was rigid brand as well. I bought another spare one, Norton brand. Will have to test its flexibility. I will try going slower as well. If I have to go that slow I may as well get the bandsaw. Either that or I'm just looking for an excuse to get one
Reply:Excuses to buy new equipment are always GOOD.  I remodeled two houses for my daughter over the last several years and used that as several excuses to buy new woodworking tools. Didn't get any flack from the chief financial officer that way. I used a bunch of different brands of cutoff blades over the years and they all will flex to some extent. Some cut better than others, some wear out quicker than others. Usually the faster the cut, the quicker the wear. I even tried some of the Chinee ones. Most of them cut pretty fast and wore out even faster. Not a bargain at all.Getting a straight cut on angle cuts on tubing is kind off a matter of trial and error. The cut seems to want to walk off of straight worse if you are cutting right at the end of the tube than back away from the end.Last edited by Oldtimer; 10-23-2008 at 09:14 AM.
Reply:Makita cut off wheels are very good.  They don't have the reinforcing chords embedded in the abrasive, and give a smoother, chatter free, cut.  They are available in 5 packs from Amazon at a much lower price than just about anywhere else.The blade will want to wander if you use too much down pressure.  Let the wheel do the work, and back off while running once in a while, it helps to true the saw kerf."Any day above ground is a good day"http://www.farmersamm.com/
Reply:One more thing to remember is that on a Chop Saw when you change the angle of Fence for a Mitre Cut, you also may need to reposition the Fence Forward or Backwards so that the blade is coming down directly over the Material.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:I was at the flea market a few years ago and spotted a tall stack of these: Attachment 24521I aksed the seller, "What are those?"He said: "Those are for a floor scrubber"I said: Floor scrubber? What kind of floor scrubber do those fit?He said: "Oh, they're all about the same; if you have a floor scrubber they'll probably fit." "Try one, if it don't fit, bring it back next weekend. We're not here to cheat anyone."So I made an "as is" -if they don't fit the floor scrubber, I take ‘em to the rifle range- deal for the whole stack of floor scrubber discs. The  "scrubbers" are almost gone now, but if you can ever find a deal on floor scrubber discs that fit your chop-saw, get 'em. They really cut nice! Last edited by denrep; 10-19-2010 at 11:38 PM.
Reply:I am using a DeWalt 14" abrasive chop saw.  The blade that came with it was a DeWalt 7/64ths.  Since that didn't last until the end of time I have been buying Norton blades because that's what's most readily available at a reasonable price.  They are the same thickness, they seem to work the same.Like Farmersamm noted, don't use too much pressure.  Back off and slow the cut as you near the end to help reduce blade deflection.  A technique I use when cutting miters is to adjust the fence to a position where the blade first contacts about the middle of the piece I am cutting.  If the blade first contacts either edge of the material at the beginning of the cut then it tends to deflect right away mucking up the cut right from the start.  Start slow, let the blade do the work.When cutting at 90° I adjust the fence so the blade starts at an edge of the material.  This makes a faster cut.  But as noted above, for miters this causes deflection, so I adjust it to start at about the middle of the section.Another technique you might use is to cut your piece just a tad bit long then touch it with a grinder to shorten it to length and true up any deviation caused by saw deflection.  You should probably be doing a little grinding anyway to clean the scale off and put a slight chamfer on the cut end where it will get welded to improve penetration.The best cure is to procure a band saw.  That's on my list.  (so are a lathe, verticle mill, two or three more angle grinders, a real anvil, heater for the garage, a bigger garage, a bigger heater for the bigger garage, gantry, electric hoist for the gantry, nuclear reactor,  and a few other items no hobbyist should be without.)-MondoMember, AWSLincoln ProMIG 140Lincoln AC TombstoneCraftsman Lathe 12 x 24 c1935Atlas MFC Horizontal MillCraftsman Commercial Lathe 12 x 36 c1970- - - I'll just keep on keepin' on.
Reply:just a theory, but i believe its in the saw as well or perhaps the design of the pivot.The three phase abrasive saw at work is scary, extremely powerful(5hp) and its on its own stand with table and fences.  It uses HUGE springs to keep in the up position,  It cuts nice and square if the cut being made isnt near the end of the material, and will cut straight if you slow down on the cut.  Going through solid bar i bear down on it pretty hard and it never slows down and the blade doesnt walk.  We run "high quality" radnor wheels on it.My milwaukee abrasive saw at home on the other hand, walks the blade all the time.  I havent even used it enough to need a new blade, damn thing makes a mess.  I suggest a bandsaw, i have a harbor freight 4X6, its decent,  it can be frustrating and its slow. but it cuts good mitres and leaves nice edges.  Eventually im going to get a grizzly swivel head with coolant.Anyways just some food for thought.
Reply:I agree with the above- the saw and pivot itself has some flex and maybe even some "slop" in the pivot itself. Using less pressure will help, but also have a lot at the pivot and see if the is any play that you can remove. A smaller blade will deflect less, too, if you are really having issues. My 12" Makita dry cut is rediculously square. A properly set up band saw will be good as well. I pretty much always expect pieces done in an abrasive chope saw to need a little tuneup during deburring.
Reply:All i use right now is my angle grinder with a cutoff wheel and then i square it up on my 4'' belt/ 6'' disk sander with the miter guage.
Reply:I use a band saw and square it up on a belt grinder.  I use a piece of angle and make sure it is square to the platen or set it to 45.
Reply:those beltsanders are the cats meow, im in the design stage of building my own right now
Reply:Just kind of a passing thought on chop saws, and grinders for that matter.I don't feel all that comfortable with the abrasive dust that's put out by these tools.  If it cuts steel, imagine what it does to your lungs.  Ever get that taste in your mouth when using either tool.  Can't be too good.  And, lets face it, who's gonna stop to put on a mask for one or two cuts."Any day above ground is a good day"http://www.farmersamm.com/
Reply:I don't cut 45s for corners.  I butt square and cap.  Take too much time to adjust the the saw.  Just a thought.
Reply:MJB,Could you post a few more pictures of your Grinder?Thanks!David
Reply:I dislike the abrasive chop saws as they are messy, loud, and dont do a good job. And they wear down. I tried cuttting 4" tubing and after a few cuts the blade wears down enough you cant cut all the way through. Even tried a carbide blade for it. That worked really good on mild steel. Then I  cut some stainless. About 3 cuts and the blade went dull. Thats when I got the bandsaw. What I like is my cheap HF bandsaw with bi metal blades. It cuts pretty dam straight and its pretty quiet. The neighbors like that. Once I set the fence square I try not to move it.  So I made tapered wedges to cut the angles I use. That way the saw always cuts  as square as possible without having to adjust. Just pull the wedge out and you are cutting square again.If needed I square and deburr the material  on a 6x48 Belt sander. The 6"size works well for cleaning up the ends of 4" tubing.  Also buy good belts. They last a lot longer than the standard ones.Blades are critical for the band saw when cutting stainless tube. The Bi-metal from enco are pretty good. They hold up quite well to the stainless.mm135HTP Invertig 201 With water cooler9" Southbend LatheLots of hand tools.