If no continuity verify there is nothing stuck under the brushes and they are making contact, I have never seen a brush base motor With more than a couple fried coils if no continuity through 360 degrees rotation of the com a brush contact wire may have burned off or the wire at the switch since you said there was voltage at the switch. If you have a electrician friend ask to meg the motor, this is a high voltage ohm meter that checks for leakage in the windings to the frame while turning to the different field windings with the trigger pulled these values should be at least 10meg at 250 v higher is better.Ĭhecking the continuity blade to blade on the plug with the trigger pulled is usually less than 10 ohms and on some motors less than 1 ohm. I have to do this to motors that have been sitting on the shelf in an unheated warehouse when they are an open drip frame style. If you don't have any dead spots and the saw was in a damp location you may be able to bake it out in a oven at approx 150 deg F.
#Skilsaw model 77 brushes full#
Using an ohm meter on the power plug with the trigger pulled you should see a low value of resistance, rotate the blade a little at a time you should have a similar resistance value through a full 360 reveloition of the commuminator. If the saw was in a damp location the windings may be saturated causing the higher than normal arcing. I do extensive work on brush based motors there is always arcing but it should be uniform and not very large. So if above diagnostics (posts) are correct, the owner has the option of taking the tool to a trained repairman, or extending the tool's life by some relatively simple means.A properly running brushed motor should have a chocolate brown appearance this is a oxide that forms from moisture and brush wear. We were able to refresh many a starter this way - and "keep them running." So, how does this relate to a circular saw, drill, or any other motor? Because apart from being AC/DC, and unless things have changed, their component parts are similar.
#Skilsaw model 77 brushes manual#
Since we didn't always have the luxury of a metal cutting lathe, we would "cut" the commutator with emery cloth until was bright and shiny.and then we'd lightly cut the segment lines with a broken hacksaw blade. SC 29640 VINTAGE SKILSAW MODEL 77 PROFESSIONAL WORM DRIVE SKIL SAW ONE OWNER 13A MANUAL, Powered by VINTAGE SKILSAW MODEL 77 PROFESSIONAL WORM DRIVE SKIL SAW ONE OWNER 13A MANUAL THIS IS A SKILSAW PRTABLE SAW MODEL 77. Our fix was to replace the brushes if we could, or square them off if we couldn't. (If not, it was usually a shorted out armature.) Anyway, along with the brushes being worn, we'd often notice that the commutator was also worn - and blackened, too. Most of the time, the problem was just as described in the above posts. Worm Drive Saw, HD77M (F012HM7702) 7 1/4 Magnesium Worm Drive Skilsaw, HD77 Type 17 Worm. Unless we could cannabalize, we would remove the starter and break it down. Skil / Bosch 1619X01351 2610320391 2610912980 Carbon Brush. eight pieces of I' abrasive cloth that are backed by replaceable brushes.
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There were times when we had to get a vehicle starter "working" again because spare parts weren't always readily available. Made by Skilsaw, Inc., of Chicago, for Skil Saw models 77, 87, 800, and 825. Rich - your message made me recall something we did on occasion while serving in the military.
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Re: Skil Circular Saw - What is the problem?