I'm looking at a used 30" import 3 in 1 sheet metal machines. What's the usual wear or breakage points?
I don't plan to use it much, mostly quick little prototype projects in my home shop. I have access to bigger machines when I need to do anything serious or precision.
Make sure the slip roll gears are lubed and in adjustment (Biggest problem) and either use an appropriate dummy piece in thebrake or put a suitable radius on the brake punch (it's SHARP) They are a lot nicer if you replace all the cheesy adjustment screws with proper knobs, levers etc. Also check for wear at the adjustments where the screws weren't cut off square.
Bob
Mine was second-hand and nothing had worn or broken, but the previous owner hadn't been able to cut [plastic sheet?] with it. I had to fiddle with it a lot to get it to cut 1/16" aluminum the full width without the upper blade twisting back part way through the cut. It works a lot better with 0.050 aluminum, likewise with steel less than the suggested maximum. After a few heavy cuts the shear needs readjusting.
The only good way I found to bend accurately was to redo the back gage with threaded rod and nuts and measure carefully on each end from the gage to the point of the upper die. The clamping tee screws that came on it broke off with finger pressure.
I ran a company model shop once that had a well-made 'Triok' 3-in-1 combo machine, but it wasn't really much easier to use than the Chinese one. The shop also had a Pexto shear and finger brake, which I'd love to own but don't have the space. I tried making things on the separates and the combo and found that there wasn't much difference in what they could do although the combo was slower and more awkward.
Jim Wilkins
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There used to be a nice web site showing how to strengthen the machine, but I have lost the url. It involved bolting a strongback on the back side of the blade in place of the stiffening strap. It was about a 1/2" x 3" bar that went from end to end and prevented the blade from flexing. The owner was able to shear fairly heavy stainless steel after the modification.
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