I have a Milwaukee 6390 circ. saw that blew the motor windings out today.(It’s their new one with the silly tilt loc handle.) I’m not adverse to having it repaired, but I’m wondering if this is a common enough problem with these saws that I should stay away from it. Anybody else have this happen?
Edited 4/21/2002 2:25:49 AM ET by ALANROBERSON
Edited 4/21/2002 2:32:53 AM ET by ALANROBERSON
Replies
Alan; the one time i used a milwalkee tool i was so uinimpressed, i never bought one. My Porter Cable has never stopped since new. I reccomend PC...
Alan,
Just so happens I had the same thing happen to one of our millwakee's recently. I was using the saw myself when it happened and it wasn't under any large load. I am curious about any other responses also. I've never had a saw do this in nearly 30 years of using many brands. I actually kind of liked the saw until this. Luckily, the flying copper windings didn't cause any harm to me.
Bish
I have had the same saw for about a year and it has performed well, even under a heavy load. I like the torque and the smoothness of operation. I have not bothered to use the adjustable handle much on the job site however. I am assuming that you are still covered by the warranty? Send or bring it to the service center and let them deal with it.
If you read the guarantee to all Milwaukee tools you will find that their tools are guaranteed for life on manufacturers defects as long as you don't open up the tool. You will need the receipt to make the authorized repair center honor the guarantee.
By "blew the windings out" do you mean that centrifugal force threw the copper wire off of the armature? If so, that's more likely to happen when the saw is under no load at all. But it shouldn't ever happen to a well designed and well built motor. The only time I've ever seen that was on an old Volvo starter motor, when the solenoid got stuck and the engine drove the starter much faster than electrons ever could.
-- J.S.
It looked like someone stuck a firecracker between the windings at the end of the armature. I think it happened as I was starting a cut.
Wormgear! Used to use a sidewinder, still do sometimes. But if you like the performance, endurance, and yes, weight of a Humvee, get one of them boat anchors. I once cut my way from Lansing, Mi to Portland Or...................
Regards, the monk
Ya I've got a couple of dem too. The milwaukee was nice for weight and precision stuff. Plus it was free. My wormgears are great for framing, just been around the block a time or two.
Edited 4/24/2002 4:14:03 AM ET by ALANROBERSON
Hmmm,
I worked construction over 10 years in Lansing, Okemos, East Lansing, etc.
Been self employed contractor in Portland for 10 years or so.
joe d
Then it's clear that there was more centrifugal force than the windings could handle. No two ways about it, they don't build those motors right. This is a model to avoid.
-- J.S.
This might not be related to this particular case but I have seen carpenters cuss individual saws, the brand, the manufacturer and the lineage of the person who sold them the tool and life in general because the tools keep quitting.
Sometimes its cheap, defective tools. Sometimes it's the carpenters asking too much of the tool. Frequently I suspect that it is an electrical problem. A defective temporary power pole with breaker, buss connection or receptacle problems can cause this problem. More frequently it is the cords that the carpenters are using. I have seen people use 150' of glorified lamp cord to get power to the saw.
Motors are, in simplified terms, constant power devices for any particular load condition. What the motor can't get in voltage it will make up in amperage. This causes the windings to overheat quickly. Combine this with a hot day, a dull blade and a carpenter trying to rush the cuts and you have a recipe for making even the best quality saw into an expensive paperweight.
The longer the cord run. The higher the amperage of the load. The larger the wires must be to avoid too much voltage drop. I made up a cord for a friend who was working jobs pretty far from the temp pole. 8/2 industrial cord with HD 15/20 amp cord caps and made it 150' long. The cord must weigh 50 pounds. He was skeptical of needing it and I must admit that it is slightly overbuilt but he had a long history of burning up power tools. Now, other ones that have been clearly abused, he hasn't burned up any tools. He runs the giant cord to the house and plugs in a splitter. He also claims that people are reluctant to mess with it thinking that something that big must pack more of a kick.
I don't think you need to go to such extremes but so many seem to spend real money on power tools and then purchase cords as an afterthought. $300 tool working at the end of a 100' 16/2 that goes for $10 at a discount store. Most larger tools come with a guide to the recommended cord size for any particular length and load. It's cheap insurance to follow its lead.
The centrifugal amature failure that started this thread certainly wouldn't have been caused by low voltage from going too far with cheap extensions, but it might have been caused by excessively high voltage. Is it possible that the temp power was hooked up wrong, and the saw was hit with 208 or 240? If so, my previous idea was wrong, and it's not the saw maker's fault. But if it's just the utility running a little hot, say 130 or 135, a good motor should be able to handle that.
-- J.S.
John,
At least in my circumstance, The saw failure happened inside my woodshop, on a 25' #12 ext. cord, coming of a 20 amp wall outlet. The saw had a new blade on it, had not seen much use, and failure occured sawing thru 1/2" plywood. I've got to believe it was a defective motor. Home Depot swapped it out, no questions asked. I don't do much buisness with them, but they are good to deal with on portable power tool problems. Usually they will simply exchange tools with no problem.
Bish
Yup, definitely a defective motor. If the voltage had been too high, high enough to kill the motor, then loads of stuff would have been blowing up all over your neighborhood.
-- J.S.
Edited 4/26/2002 2:26:03 PM ET by JOHN_SPRUNG
I agree that this case sounds like a defective motor winding and not any electrical supply problem. I doubt that even running the saw on 240v, not that uncommon a miswire job, would cause the windings to explode as you describe. Most power tools run extremely well on 240 volts but unfortunately they don't ever seem to run very long. In this case the motor tends to start to smoke and then fail not explode.
I didn't mean to imply that you had done anything wrong. I intended to help inform those who may read this thread with an eye towards having tools that will perform well and last a long time. I mentioned the cords only because they are a perennial cause of tool failure, or shortened life, that is regularly blamed on shoddy tools and abusive help. Power tools run stronger, cooler and longer when fed the right voltage and properly sized extension cords are vital in making sure this happens.
Good points on the cords. We use 12 ga. cords on our job sites and I also have a 10 ga. cord we made up for the extra long runs to the generator we seem to run into now and then. Using a good quality generator on the jobsite is also important. Some of the units sold by the DIY stores really aren't meant to work at the level we need, and probably don't do the tools much good in extended use if there is much power fluctuation.
Bish
Well in case you were still curious I left the saw at the service center for the Milwaukee rep to look at the next time he came through town. I don't know what the cause of the problem was, he didn't tell the people at the service center, but they covered it. So I'm happy. BTW - orig. quote to fix - $170. New - $140
I've got a six year old hitachi. It handles better than any
saw I've ever had. Recently was tempted by the new milwaukee
saw, it feels good, cuts great. But don't like the "tilt-lok" handle
thing, so I needed an extra saw, bought Hitachi and paid $ 89. plus tax at "home depot
type" store. Anyway my old hitachi (and a few makitas) has been
through hell and back, motors are incredible, no problems except tables get beat-up and
replaced every few years. Stay away from new saws that burn out within
first week.