kapex second armature in 8 months

[Rick Christopherson]

I have refrained from posting in this thread because there is not enough information present to make definitive comments on.

My greatest concern is actually terminology. To many people, the word "armature" means anything related to a motor, when in fact the armature is a very specific component within the motor. I see the same thing all the time whenever electronics fail, and people say it must have a "short circuit". In either case, short circuits or armature failures are rarely ever the cause of a device failure, but that is what the general public refers to without realizing that the terms actually mean something else. Something very specific.

Even if the repair ticket specifically stated that the armature was replaced, it doesn't mean that the armature windings were at fault, or that it was even an electrical issue at all. Even something like a gear or bearing failure would require the motor's armature to be replaced. The drive pinion is ground into the end of the motor shaft, and the bearings are permanently pressed onto the shaft.

Electrically, the armature is just several coils of wire and the commutator bars, and it is extremely bullet proof. It is the least likely component to fail, especially on a motor with self-protection circuitry. The primary failure-mode of an armature is overheating, but all EC-TEC motors contain a thermistor inserted into the motor to monitor the temperature of the windings. You can see this in the picture below. The pair of small red wires are the leads for the temperature sensing thermistor.

[attachimg=#]

i bought a kapex last March, it worked great until last October when the armature went out. I called Festool service sent it in for repair and it was returned to me quickly. today while using the same saw the armature went out again.

So when the original poster stated that the armature failed so he sent it in for repair, it indicates to me the likely possibility that the word "armature" is being used in a generic sense to indicate any and all motor related troubles. It may not indicate that the actual armature was the root cause of the failure. A failed EC-TEC module would be far more likely, and that can have multiple causes for its failure, including receiving bad electrical power from utility.

 

[AlBeThere]

Just finished some time with my new OF 1400 EQ. Great router!

And great discussion! I enjoy reading all the different perspectives. It seems that most Festool owners are savvy consumers too!

I completely understand Shane's desire to not let this issue get blown out of proportion. After re-reading the first two post, it does seem that use of the word "chronic" wasn't the best choice of words to described the issue. Festool makes very nice tools as we know from our own experiences and all the positive testimony on this forum. Festool backs them up with a great warranty. I would think if a power tool has an isolated defect, the issue would more than likely show itself in the first year.

At the end of the day, I think all potential buyers who read about one of these isolated issues has to put their faith in the exceptional Festool warranty and the personalized customer service. Clearly, Festool does not want anybody to be unhappy.

Interestingly, I've noticed a pattern of posters that like to say in not so many words when talking about perceived or valid issues with Festool, "if you don't like it, then go buy/use another brand." I've come to realize, that for the woodworker that has the resources to buy and appreciation for high end power tools with superior engineering and amazing dust control, there is no other option. That doesn't mean that we can't have a desire for our chosen power tool provider to always strive to be better even though they really have no competition in this market segment.

I've got some cash sitting in my Paypal account. I think a 118" guide rail is in my future. [big grin] I found the perfect storage spot for it!  The Boss is going to demand some explaining when UPS drops that sucker off on the front porch. [wink]

Mike

 

[Jim Green]

Rick, great information. Thank You but not all of us are as well versed in electrical tools and their components, we just buy certain tools with certain expectations. I also believe the majority of people arrive at the doorstep of festool after exhaustive research and frustration with other tool brands. I also believe people that are willing to put out the extra for these tools probably take better care of them and use them properly. I really don't know what is changed at the service department other than the armature. I just want my saw back and would rather not have the same part replaced it would bother me, maybe it will be something else. I just don't know if that would be a better or worse thing? Again I want to stress that I do like the saw and own many, many tools from festool and will not bore you with a list. As for the flowers I don't know Im a carpenter but again good information. Thanks

 

[Rick Christopherson]

Jim, the purpose of my posting was not to belittle you for not knowing the names of the components within a motor. It was to point out the possibility that all three people were reporting the same failure (and a very serious one at that), when it was simply a matter of the wrong terminology used for several unrelated failures. Based on your followup response, this was a correct supposition.

I see the same thing happen in the computer industry all the time too. Many people call the entire computer case "the hard drive". So if you had several people coming forward to say they were having repeated failure of their hard drive, it would make it appear that there was a serious and repetitive problem with the specific hard drive. But in reality, one person was actually talking about the power supply, another person was talking about the video card, and another could even have been discussing a software problem.

So when three people claim they have an armature failure, it makes it sound like a specific and very serious problem, instead of possibly three unrelated failures.

Below is a picture of the motor armature from a TS55 saw, and all of the associated components that are integral to the armature on a Festool product.

The reason why this was such an important topic to many people reading it, is because an armature failure is an extremely serious problem with any tool. When several people reported multiple and repetitive armature failures, it became even more serious.

So making the distinction of what an armature actually is, is not a matter of negating the importance of a problem. It is just a matter of clarification that they may not be referring to the same thing. As I said above, many people call the whole motor the armature, just the same as some people call the entire computer case the hard drive.

 

[Jim Green]

Rick no offence taken nor do I feel belittled in anyway. A quick check of the fog shows a few people with similar problems. Your post is completely valid and informative and I can see how people can have a similar problem but arrive at it in different ways. I would assume but could be wrong that not all Festool users use the forum so there may be more kapex saws out there with similar things happening to them. I also believe my concerns are valid as I'm sending in a relatively young saw again. In addition I don't feel I need to hide the fact that I have had these problems. I do hold Festool to a higher standard than other brands and do not think I stand alone. My use of the word chronic in retrospect was not fair. Let me rephrase and say it causes me personally concern. Thanks for your responses and when I say thanks I do mean thanks, in no way am I being sarcastic. I think we are all here for information and to share our experiences the fact that we are here shows our commitment to the brand and should include the good and the bad. Again Thanks

 

[PeterK]

Very interesting thread! I have lusted after a Kapex for years and initially this thread got me concerned. As usual, many others added insight into other ways to look at the problem and possible causes. Excellent.

Rick - your posts on this topic are possibly your best yet. Loved how you added other ways to view the issue, possible mechanical problems that could be incorrectly described, and in a way that was not viewed negatively as in discounting the OP. Very tough to do in text on the internet!!

 

[peter halle]

Interestingly, I've noticed a pattern of posters that like to say in not so many words when talking about perceived or valid issues with Festool, "if you don't like it, then go buy/use another brand." I've come to realize, that for the woodworker that has the resources to buy and appreciation for high end power tools with superior engineering and amazing dust control, there is no other option. That doesn't mean that we can't have a desire for our chosen power tool provider to always strive to be better even though they really have no competition in this market segment.

Mike

If this is in reference to my comment, I apologize that it came out that way.  I am a Festool Fan and user.  Frequently I fear that I come across as a cheerleader versus giving sound advice here.  I guess that occasionally when I try to go the other way I mess up.  I have been in the construction industry for 30 years now.  I have come to realize that there is no one perfect tool for all users.  What may work for one might not be the perfect one for another.  I started with a crappy Black and Decker years ago and that lasted two weeks.  Then a Makita, then a couple of Hitachis. I waited and read everything I could about the Kapex and frankly couldn't afford it or justify it.  But I longed for it.  When my Hitachi finally had the fatal breakdown I was lucky enough to have the money in the bank account to get the Kapex.  I only carry the Kapex now and have used it for trim and framing and even wet pressure treated material.  It has handled it all.  But that is not to say that a new Hitachi couldn't have produced the same work.  I know that the dust collection wouldn't have been the same.

The Kapex is a step up in many areas that add to the enjoyment and productivity of using a miter saw - for ME.  But along with the refinements comes the price tag.  For some, as they make the evaluations on cost versus performance / enjoyment / etc the scale will tip in the favor of another brand.  All I was trying to say is that it is ok - even on this forum - to say that because of xxxxx another brand is ok for a user.  The Kapex is a highly engineered tool - but it is not magical.

Sorry for coming across poorly.

Peter

 

[ajones]

I for one understand the frustration when things dont perform as they should, but can we drop this and watching the paint dry on radiators and get back to some wood working

 

[BUTTER]

Like I said, from all of the information that I have, these issues are extremely isolated. I can't give out the number of Kapex units sold, but we're talking an extremely small number of armature/motor issues despite having three reports in this thread.

Here are the recommended extension cord ratings:

Extension Cord Ratings

100 Ft. Not recommended

Shane, are these recommendations for a direct connection to an extension cord, or are they for a connection from dust extractor to outlet?

 

[Rick Christopherson]

Like I said, from all of the information that I have, these issues are extremely isolated. I can't give out the number of Kapex units sold, but we're talking an extremely small number of armature/motor issues despite having three reports in this thread.

Here are the recommended extension cord ratings:

Extension Cord Ratings

100 Ft. Not recommended

Shane, are these recommendations for a direct connection to an extension cord, or are they for a connection from dust extractor to outlet?

Extension cord length on a universal motor is not terribly critical. It will simply reduce the available power to the motor. The better gauge would be to notice whether the saw bogs down frequently and avoid that by using a shorter cord. Anything less than a full bog-down load, and the saw won't care about the cord.

 

[semenza]

I've got some cash sitting in my Paypal account. I think a 118" guide rail is in my future. [big grin] I found the perfect storage spot for it!  The Boss is going to demand some explaining when UPS drops that sucker off on the front porch. [wink]

Mike

That will be arriving via truck freight so you might need to make receiving arrangements. .......................  Just a heads up.

Seth

 

[jmbfestool]

I know mine might not be a direct armature failer like Rick has said it could be other related problems!  but I had to have mine replaced/fixed last week because my Kapex started to make a funny noise all of the sudden and then a burning smell and then it stopped working tottally! 

Cost me like £270 or so for repair  [crying] 

 

[AlBeThere]

I've got some cash sitting in my Paypal account. I think a 118" guide rail is in my future. [big grin] I found the perfect storage spot for it!  The Boss is going to demand some explaining when UPS drops that sucker off on the front porch. [wink]

Mike

That will be arriving via truck freight so you might need to make receiving arrangements. .......................   Just a heads up.

Seth

Seth,

Thanks for the heads up. It never crossed my mind that it would be a truck freight item but I guess it makes sense with the length being outside the UPS norm.

I'll have to make arrangement for a Friday delivery when I'm working from home.

Mike

 

[Jim Green]

Hello, just to let you know I received my Kapex back and it took a little longer than one would expect. Unfortunately and not all that much of a surprise it was the armature again. There was no obvious reasons for the failure it just needed to be replaced again. I guess it must just be bad luck??

 

[Jim Green]

Hello again, a little surprised at the lack of response. I would still like to get information or ideas as to why there seems to be armature issues with the kapex? Could I have unrealistic expectations for the saw as a daily driver? Shane had also mentioned something about  the recommendations in the manual pertain to operating the Kapex only, not the Kapex and CT. So does this mean I am doing something wrong by using my ct's? If there was something I was doing to cause the failure I would really like to know as it is not convenient to be without the saw. Anyone? Thanks

 

[Administrator_JSVN]

Jim,

I'm no electrical expert by any stretch, but burning up an armature is probably the result of not enough current (which causes heat) or working the saw too hard (pushing through dense material or using a dull or dirty blade).

Do you think the scenarios I listed before might exist in your environment? Did you get back your original blade or was it replaced by service? If original, could you post some photos so we can see its condition?

What type of material(s) do you cut? PT or lumber that's not properly dried and cured can be rough on a saw, as could really dense woods like Ipe.

Just trying to help determine what's going on as it's unusual.

That said, the Kapex is certainly made to be a "daily driver".

Shane

 

[Jim Green]

Thanks for responding Shane. It came back with the original blade. I only cut mdf/ultralite and the odd time spruce 2x4. I do interior finishing. The saw is kept dry and only used inside by me alone. I have used sliders for many years. I don't use a blade till it smokes, the blades are replaced or sharpened on a regular basis. The saw never bogs down because of the materials I cut. When i need to cut somthing like pt or facia I use one of my other saws as I feel the kapex is a little under powered for anything like that. Thanks

 

[Administrator_JSVN]

Jim,

Have you spoken with Claude or anyone in the repair center? Since they are the ones performing the work, they would be in the best position to offer a hypothesis on the cause of the failure.

And apologies for the trouble.

Shane

 

[ccarrolladams]

Two of my Kapex were delivered the first day they could be sold in North America. Both have been used daily cutting all sorts of hardwoods used in making custom cabinets. It has always been my policy and that of the specialist in making face frames, cabinet doors and drawer fronts to use sharp blades appropriate to the species of wood and thickness.

Neither of those Kapex has ever required service by Festool. We do common sense preventive maintenance. Each of those Kapex has had a typical miter saw shroud behind and below hooked to my plant DC system since 2010, as well as a CT22 using a 36mm AS hose connected to the Kapex dust port. We do accurate work but at a pace allowing us to make money. We hand feed the saw through the work using steady pressure, feeling as we go. This is more to protect the blade than the saw, For what we cut the Kapex are more than powerful enough.

For thicker and rougher cross cuts I own a large radial arm saw with a 550mm blade with a 5mm kerf driven by a 7.5hp motor. Those cuts are clean and glue ready but hardly as precise as the Kapex. We have not burned out a motor on the radial arm saw either.

 

[Jim Green]

Hi ccarrolladams, I'm glad to hear that you have had no problems. Unfortunately my experiences are not the same. I too use good sharp blades(Festool at least I think they are good) and cut material that is pretty easy to cut, but yet have now had the armature replaced twice. I do make a lot of cuts a day and by the sounds of it you do too but then again that is what a saw is meant to do. I may not have your experience cutting but I think I am probably close. I also "hand feed?" and don't force the saw through the material as it is sort of the natural way to make a cut I think. Also I too do not use the saw for thicker or rougher cross cuts as I think it it is too delicate for this. So I would guess are usage is very similar but I don't cut hardwoods often so it seems my saw should not have any problems. In addition why would you use a radial arm saw and not the kapex to cut thicker, rougher material if the kapex is more than powerful enough. Thanks