Skil 7 1/4" Magnesium "Mag 77" Wormdrive Saw With Twist Lock Model # SHD77M 72 - Answered Questions & Fixed issues

Might be worn bearings or the electronic brake

Often a collapsed brush spring will cause this - remove the brush caps and inspect the brushes - if the brushes are short >1/4" or the springs are broken or weak you can try just replacing the brushes. With the brushes out you can use a flashlight and look through the tube to inspect the armature. The copper commutator should not look scarred or burnt - if it is you most likely will need an armature.

your problem is you need to change the brushes on the saw very easy and cheap fix

check to see if you have a colapsed brush spring. When they get overloaded it heats the spring and they will colapse and not get good contact with the armature. The brush ce same width aould be hanging up a bit in the holder. Clean the brush holder with a points file and see if the brush travels enough to make good contact with the armature. Or the armature can be bad. It should have a nice even dark ring around it the same width as the brush. If it's pitted between two bars, a bar is missing, or it's discolored above and or below the normal wear line of the brush the armature can be bad.

There was probably a hole in the flange that you discarded that was used to put a pin/ nail/ bolt/ etc in from the body of the saw to hold that flange from turning while you did the nut up. Unless that hole is there you will have no way of holding the shaft to tighten the nut.

Tighten the bolt holding onto saw arbor.

http://www.ereplacementparts.com/skil-hd77-type-worm-drive-saw-parts-parts-c-130_160_1005.html this is a parts break down site

Bearings maybe......I'd also check the armature fan and see if it came loose. Either way it doesn't sound cheap!

Haven't heard anything so I checked the Milwaukee worm drive saw and they recomment about 1/2 oz. Make sure you use an oil for a worm drive that is not foaming. Hope this helps. Also when checking oir level have the shoe set for max depth and on a flat surface remove the oil plug, when filling tip the saw on its side and fill, turn back over and allow excess oil to run out if overfilled.

Disconnect power and spin the blade my hand. Plug it in and see if it works. Often times saw dust will block the brush from making contact and this will work. You could pull the brushes and blow out the brush holders and wipe the brushes off and put them back in. You still could get debris blocking the brush.

Contact Eurton electric. They stock many switches that have been discontinued by the manuffaturer.310-948-4477 or 1-800-423-4789

unplug it. remove the bolt in the center of the blade. the blade will slip off then. a wrench for this should have come with your saw. if not, use any properly sized wrench. if needed, pull back the blade guard, put the blade on a old piece of wood, push down on the saw and use the wrench. the wood and your pressure will stop the blade from turning as you loosen the bolt

Very stupid question and you will be forgiven for getting upset at it, do you have the blade in the right way around?

If you are using tungsten tipped blades. they are extremely sharp and create their own clearance so that the disc proper does not come in contact with the wood being cut and should not cause burning. If you have a conventional blade, the teeth have a set on them - one bent left, the next right etc. This is to once again create the necessary clearance for the disc and reduce loads on it - and to prevent burning.

So there are four possibilities, the first one which I will not repeat. The blades do not have sufficient set on them, the wood you are cutting is extremely hard and the blade is not able to move through quickly enough to prevent burning, or you are using a crosscut blade to rip with - try a combination blade.

This saw requires Skil's heavy-duty, worm-drive oil, part number 80111. If you can find a local vendor that has some great otherwise, type 'skil 8011' in your search engine and shop around for an 8oz tube, they can run from $5 to $10 plus shipping.

I think that you got it right. what I would do is take the armature out and take toa repair shop and ask them to put it on a growler. But after removing look for cut windings and raised commutator bars if either it is bad, also replace the brushes along with the bearings.

Go to www.ereplacementparts.com. They have two SHD77M saws listed but both have a lower guard with part number 1619X01182 for $8.42 (+S&H of course) but a saw worth fixing.

Skil Part # 80111 found at pretty much every Sears store. Here is a link if you want to buy it online.
http://www.sears.com/shc/s/p_10153_12605_SPM197322097P?sid=IDx20101019x00001a&ci_src=14110944&ci_sku=SPM214686306

I hope this helps.

is the commutator (part the brushes push against) all gouged up? What about wire after switch? Also sometimes the plug itself does not make good contact. Pull the switch and move the plug around in the outlet while you have the switch pulled (Watch out it may turn on) Make sure that there is power at the outlet, and try a different outlet.Check all your connections. My guess is the cord.

First, there is no blade lock button on the Skil model 5150. I called the Skil customer service and they emailed me the exact manual for this circular saw. The method I used to loosen a VERY TIGHT blade stud was: spray with WD-40, imbed the blade in scrap wood, set Skil wrench (usually found in back of foot under handle) on so it could be struck going in counter-clockwise direction. Use hammer to strike handle of wrench a couple of times. To replace blade, finger-tighten blade stud, then use wrench to tighten 1/8 turn or (45°).

If you are seeing a lot of spark where the brushes contact the armature that meens that the brushes are low and need to be replaced. If the saw is new though that meens that the brushes have not broken in to the right seat yet.


Good Luck