# Miter Saw no longer "brakes"



## nostrildamus

My 10" Compound Miter Saw used to stop spinning within a second or two after releasing the trigger, now it just keeps going and going for about 10 seconds.
Aside from the obvious problem (having to wait until the blade stops), does anyone think this is a safety issue? And does anyone know how to fix it?
Saw is a Hitachi C10FC2. Long out of Warranty.
Thanks


----------



## bauerbach

They bill as a safety feature for sure. safety issue? Well, dont touch a spinning blade, but Im sure you already figured that out... just means you have to be careful for another 10 seconds.


----------



## Steve Neul

As long as you are aware of it I don't think it's a safety issue. The brake mechanism should be easy to get to it if you choose to fix it. Do you have a manual with an exploded view of he motor?


----------



## nostrildamus

Yeah, I checked out the manual, there weren't any parts labelled "brake." I'm not quite sure what it would look like or how it works. I imagine it applies friction to the arbor somehow?


----------



## Hammer1

Open the trigger housing as well as the motor brushes and blow out the dust. Mark the brushes so you put them back in the same exact way. Make sure the trigger makes full motion when letting go. After cleaning out, run the saw at full speed for a couple minutes.


----------



## woodnthings

*the saw probably has a rectifier*

See post no. 5 here:
http://www.doityourself.com/forum/e...ompound-miter-saw-wont-work-circuit-gfci.html


----------



## maple man

nostrildamus said:


> My 10" Compound Miter Saw used to stop spinning within a second or two after releasing the trigger, now it just keeps going and going for about 10 seconds. Aside from the obvious problem (having to wait until the blade stops), does anyone think this is a safety issue? And does anyone know how to fix it? Saw is a Hitachi C10FC2. Long out of Warranty. Thanks


 sounds like a good excuse to buy a new one


----------



## Oneal-Woodworking

maple man said:


> sounds like a good excuse to buy a new one


Nope. He just needs new brushes and all will be well. 

9 times out of 10 - The brushes are causing that problem.

This has happened to me more than once with both Hitachi (same as this one) and my Makita. New brushes solved the problem instantly...

:yes:


----------



## Ghidrah

The electric brakes went on both my saws within a yr of purchase never stopped me from using them. If I understand it, the electronics reroutes the power in reverse for a sec to kill the rpms.


----------



## Steve Neul

I looked at a schematics too and couldn't find the brake. The only thing I can suggest is to call their parts department and see what they say.


----------



## bauerbach

the brake on most are electronic, not physical. maybe not on older saws though.


----------



## Oneal-Woodworking

Steve Neul said:


> I looked at a schematics too and couldn't find the brake. The only thing I can suggest is to call their parts department and see what they say.


I use that same exact saw and just told him how to fix it. 

To be completely honest here - The one I am using currently is a 'combination' of Hitachi number 3 and spare parts from and the first 2 that got killed and tossed in the 'spare parts box for Hitachi saws' box...

I would not hesitate to buy another Hitachi like this after seeing first hand the kind of daily *abuse* they can tolerate before 'needing' attention for myself. :smile:


----------



## sweet willy

Just recently on my Makita I had a similar problem. So I ordered new brushes as that was the most popular solution. Turns out, and I don't know why, the blade had come loose. Scary.


----------



## esselgee

OnealWoodworking said:


> I use that same exact saw and just told him how to fix it.
> 
> To be completely honest here - The one I am using currently is a 'combination' of Hitachi number 3 and spare parts from and the first 2 that got killed and tossed in the 'spare parts box for Hitachi saws' box...
> 
> I would not hesitate to buy another Hitachi like this after seeing first hand the kind of daily *abuse* they can tolerate before 'needing' attention for myself. :smile:



Oneal woodworking nailed it. Had same issue with my dewalt. New brushes=no more problem


----------



## Oneal-Woodworking

esselgee said:


> Oneal woodworking nailed it. Had same issue with my dewalt. New brushes=no more problem


 
OP can test his brushes in seconds to confirm the problem or rule it out. You can either flip them over or switch sides for a fast answer.


----------



## del schisler

nostrildamus said:


> My 10" Compound Miter Saw used to stop spinning within a second or two after releasing the trigger, now it just keeps going and going for about 10 seconds.
> Aside from the obvious problem (having to wait until the blade stops), does anyone think this is a safety issue? And does anyone know how to fix it?
> Saw is a Hitachi C10FC2. Long out of Warranty.
> Thanks


change the brush's , that will fix it, my makita saw does that when brush's need changing , i didn't read any other post so it may have been mention


----------



## nostrildamus

Thank you everyone!
I'll definitely try the brushes, though they look OK on inspection.


----------



## Chamfer

1. Oneal is 110% without a doubt correct on the fix.

2. Brakes are overrated. IMHO none stop fast enough to really prevent an injury and most of all they put unneeded stress on the motors that cause them to wear faster. And most saws of any kind do not have them anyway, with the exception being MS's.


If I had my way none of my saws would have a brake. Keep guards on and use proper technique.


----------



## woodnthings

*It's not meant to "stop" the blade .....*

What is does is keep the blade from spinning for 1 or 2 minutes. It stalls the blade down from high RPMs to a slow stop. It is a safety device in that you don't have to deal with the blade spinning while you are setting up for the next cut..... which can be a bit dangerous.


----------



## Chamfer

None of my saws without brakes spin for 1-2 minutes. More like 6-8 seconds.

The brake does nothing but put wear on the motor.


----------



## woodnthings

*That was an "estimate" ....*



Chamfer said:


> None of my saws without brakes spin for 1-2 minutes. More like 6-8 seconds.
> 
> The brake does nothing but put wear on the motor.


There are electric brakes and electromechanical brakes. Neither wear out the motors I have, some of which are 30 years old. The Craftsman RASs have the electromechanical brakes and slow down gradually, rather than abruptly, at least mine do. My 3 HP Grizzly bandsaw has a "motor" brake which stops the saw in seconds, maybe less. 

From the product description:

We took our rock-solid G0514X 19" Heavy-duty Extreme Series® Bandsaw, added a few more features and came up with a new line of ultimate 19" Bandsaws. This saw features an lightning-fast electronic motor brake, a cast iron table trunnion, rack and pinion table tilt control with extra table support, and an innovative resaw fence. The electronic motor brake stops the blade in approximately 3 seconds—all with the simple push of a switch. Now that's fast and easy! 

A bandsaw will spin "forever" without a foot or motor brake because of the momentum of the spinning wheels. A saw blade does not have the same flywheel effect, but it does have some momentum/inertia. 

A brake on a saw, is a safer saw in my opinion for reasons I stated in my post above. You may have a different experience.


----------



## jschaben

ASFAIK, most "electronic" brakes simply apply a short pulse of direct current to the windings of an AC motor. Really effective providing the quality of the DC is good. Most of the ones I have looked at just put a diode in there someplace that is just basically a half-wave rectifier.... lumpy DC if you will. Since the effective voltage of a half wave rectifier is less than the line voltage worn brushes make sense as the brushes will wear and the commutator on the motor has built up some gunk. I have a Chicago Electric (read Harbor Freight) 12" saw and a Triton 10" saw, both with the alleged brakes and sometimes they shut down quickly and other times not. I find that a quick pull on the trigger during the times they want to slowly spin down will accelerate the process. I have yet to find anyone who employs a full wave rectifier in their "electronic" brake which would shut the thing down in milliseconds instead of minutes but I also haven't the budget to investigate the more esoteric, ie Feestools of the world, either.


----------



## BlackWater

I remember thinking, "electric brake? what's that?" Of course that was 30 years ago or so……….


----------



## Chamfer

woodnthings said:


> There are electric brakes and electromechanical brakes.




I have no experience with hybrid mechanical brakes. Electric brakes will without a doubt wear a motor out, from reasons already listed several times in this thread.


----------



## woodnthings

*I missed those*



Chamfer said:


> I have no experience with hybrid mechanical brakes. Electric brakes will without a doubt wear a motor out, from reasons already listed several times in this thread.


They wear out the brushes...possibly? Brushes wear in normal use. Bearings wear out, dry up etc. Motors don't wear out. The windings don't wear out. The armature may wear slightly, over years of use....

I must have not paid attention to my RAS and tablesaw motors with the "brakes" for the last 35 years, not worn out yet.
I'll go out and see if they still work tomorrow. :blink:


----------



## Chamfer

Yes technically, in this case the brushes. Still, if brushes fail completely motors will eventually stop working. They (brushes) are part of the motor.

Im glad your saws have worked well for you. Fact remains that other folks havent had the same experiences.


----------



## Wendel17

We've got two panel saws where I work.
A Cantek from Akhurst...










And a Griggio. 

The Griggio is the better saw IMO, but it lacks the brake on the Cantek. This thing stops almost instantly. Much safer if you ask me. 

It's also nice to not have to wait to move small off cuts away from the blade.


----------



## Davisjr70

I have 12" dewalt that was doing that. Found out I just needed to replace the brushes


----------



## woodnthings

*here's the reason....*



Chamfer said:


> Yes technically, in this case the brushes. Still, if brushes fail completely motors will eventually stop working. They (brushes) are part of the motor.
> 
> Im glad your saws have worked well for you. Fact remains that other folks havent had the same experiences.



Miter saws are universal AC/DC motors with brushes. My saws are induction start and run, no brushes involved and nothing to wear out. My Bosch and Dewalt sliders have brushes and they may eventually need attention. 

A "replaceable" part like brushes on the motor are not considered a warranty part just like the brakes on your car, they wear with use and would only have a limited warranty if any. Any parts that wear with normal usage are going to wear out long before the hard parts like bearings which can also be replaced rather than trashing the motor. Capacitors are also a replaceable part. The centrifugal switch can get burned contacts and need replacement. In my view motors just don't wear out.

Just ask Warner Construction if motors ever wear out...


----------



## FrankC

Having a brake is a good feature to have, just adds another layer of safety. At least when the brushes wear enough to no longer activate the brake the saw still functions until maintenance is done.


----------



## Chamfer

woodnthings said:


> Miter saws are universal AC/DC motors with brushes. My saws are induction start and run, no brushes involved and nothing to wear out. My Bosch and Dewalt sliders have brushes and they may eventually need attention.
> 
> A "replaceable" part like brushes on the motor are not considered a warranty part just like the brakes on your car, they wear with use and would only have a limited warranty if any. Any parts that wear with normal usage are going to wear out long before the hard parts like bearings which can also be replaced rather than trashing the motor. Capacitors are also a replaceable part. The centrifugal switch can get burned contacts and need replacement. In my view motors just don't wear out.
> 
> Just ask Warner Construction if motors ever wear out...






You obviously want the last word so you can have it. Ill just leave with this (since you made the car analogy), a lot of folks would consider a blown head gasket, cracked cylinder/connecting rod or dropped valve as a 'motor gone bad'. The same can be said for the brushes going on an electrical motor, or any other part of the motor. 

My main point in all this was that motors with eleectric brakes do wear faster, period.


The floor is yours for how ever many pages this nonsense continues....


----------



## woodnthings

*a cost comparison is needed here*

A thrown rod or cracked cylinder head is not even remotely comparable to replacing the brushes in an AC/DC motor which could be done for $10.00 compared to $1000s. 

OK, the brushes may wear out faster in AC/DC motor with a brake, I donno that for a fact. The solution to this problem has been well covered, it's just the ancillary discussion that has provoked the controversy. :smile:


----------



## ryan50hrl

I'm gunna have to say not at all the same thing. Brushes are like the spark plugs....not the cylinder head. So much so, they make them easy to access.


----------



## woodnthings

*A Milwaukee 18 V battery circ saw*

This 18 Volt Milwaukee 6 1/2" circular saw has an electric brake that stops the blade instantly. Tune in at 4:10 to see how fast:
https://www.youtube.com/watch?v=ZfKuUZD5nlw&feature=player_detailpage#t=245

I have one like it and it's a powerful and accurate saw. ...love it.


----------



## TimPa

back to the op - 
After the cut, I do not lift the saw until the blade stops, as i've discovered that it tends to cause moare splintering in the cut area (blade wobble seems increased in a slowing blade) plus it can sometimes throw the cut-off as you lift, causing a safety event.

in my opinion, the brake will stop the blade faster allowing me to get moving faster after the cut. if i were not in production, different story maybe....


----------



## bauerbach

the motor spins with the blade, there is no clutch on any that Im aware of. so if the blade is spinning, the brushes are rubbing.

Not sure if the brush wears faster when its transmitting electricity? but otherwise, it seems like the brake saves it some "mileage" and would be a good thing for the lifespan of the brushes.


----------



## Rebelwork

I don't think it matters whether it wears a saw out faster with the brake. If its not working correctly it should be repaired. I have an open blade on my older Makita. Its not safe but I understand the danger,. It currently has partial brake failure. When cutting cabinet parts you may be using it for 1000 parts at one time. You definetly want that brake working regardless of wear or not on the saw.....

Thanks nostrildamus for bringing up the topic. This reminds me to get the saw fixed. So easy to forget these thing when your away from the shop....


----------



## OldEd

Okay... If it is at all like my electric lawn-mower, it's all in the switch. There IS no "brake", per se. What happens is that the trigger switch reverses the power to the motor so that the spinning of the motor causes current to flow IN REVERSE, thus forcing the motor into reverse, which, of course, reduces the speed to zero (or close to it) very fast.

Check the ELECTRICAL schematic: look especially for the trigger switch: it may be in two separate pieces electrically, but in one piece physically.

Then call Hitachi: they should have a compatible switch available. They aren't the sort of thing that undergo major design changes at the whim of some idiot vice-president, in as much as they have to pass Underwriters Lab inspection.:icon_rolleyes:


----------



## phoenixbound

replace brushes to fix your problem. it's the common solution to poor braking.


----------



## OldEd

I finally had nothing to do: my wife objects to my running my table saw after midnight - says she needs her sleep, for some reason...

So I went looking for whatever I could find for the Hitachi C10FC2, which was not a whole lot. Several places wanted to sell me the manual(s), which I of course, refused. I went to Hitachi and poked around and finally located A manual, but it was a rather primitive thing, mostly talking about using the saw...

So I went back to hunting: googling "hitachi C10FC2 manual" produced what I was looking for as the very first hit. I down-loaded it: it is a pdf.

Yup. Just as I thought, there is no mechanical brake: it uses a separate winding on the motor to do the braking. Specifically, on page 19, at "11-3 Wiring diagram", there is Figure 20, the "Actual Wiring Diagram".

I very clearly shows a "2PDT" (two pole, double throw) switch, which connects the brake winding of the motor in one position - presumably the "trigger switch released" position.

The braking method is called "dynamic braking", which uses the motor sort of in reverse to bring it to a screeching stop when the trigger is released.

THIS IN NO WAY WEARS OUT THE MOTOR: the motor is DESIGNED to be operated this way. I only wish that motors for table saws had this feature built in. Unfortunately, they don't... 

It also has nothing to do with the brushes that doesn't occur when the motor is running normally. If the brushes fail, or get flaky, then the motor won't run properly. Loss of braking can't occur simply because the brushes need to be replaced.

That trigger switch is almost certainly the problem, and Hitachi should be able to supply a repair part, if Tool Parts Direct can't. They, however, seem to be a bit sticky about users repairing their machines, and want you to take it to an authorized Hitachi repair shop. 

Here is the URL for the manual: note that it comes from Tool Parts Direct. I don't know if they stock the part, or if they ever did.

www.toolpartsdirect.com/*manuals*/pdf/repair/*hitachi*/*c10fc2*.pdf

Good luck with your machine. I might be in the market for one some day - if I can find a place to put it in my miniscule shop...


----------



## FrankC

OldEd said:


> I finally had nothing to do: my wife objects to my running my table saw after midnight - says she needs her sleep, for some reason...
> 
> So I went looking for whatever I could find for the Hitachi C10FC2, which was not a whole lot. Several places wanted to sell me the manual(s), which I of course, refused. I went to Hitachi and poked around and finally located A manual, but it was a rather primitive thing, mostly talking about using the saw...
> 
> So I went back to hunting: googling "hitachi C10FC2 manual" produced what I was looking for as the very first hit. I down-loaded it: it is a pdf.
> 
> Yup. Just as I thought, there is no mechanical brake: it uses a separate winding on the motor to do the braking. Specifically, on page 19, at "11-3 Wiring diagram", there is Figure 20, the "Actual Wiring Diagram".
> 
> I very clearly shows a "2PDT" (two pole, double throw) switch, which connects the brake winding of the motor in one position - presumably the "trigger switch released" position.
> 
> The braking method is called "dynamic braking", which uses the motor sort of in reverse to bring it to a screeching stop when the trigger is released.
> 
> THIS IN NO WAY WEARS OUT THE MOTOR: the motor is DESIGNED to be operated this way. I only wish that motors for table saws had this feature built in. Unfortunately, they don't...
> 
> It also has nothing to do with the brushes that doesn't occur when the motor is running normally. If the brushes fail, or get flaky, then the motor won't run properly. Loss of braking can't occur simply because the brushes need to be replaced.
> 
> That trigger switch is almost certainly the problem, and Hitachi should be able to supply a repair part, if Tool Parts Direct can't. They, however, seem to be a bit sticky about users repairing their machines, and want you to take it to an authorized Hitachi repair shop.
> 
> Here is the URL for the manual: note that it comes from Tool Parts Direct. I don't know if they stock the part, or if they ever did.
> 
> www.toolpartsdirect.com/*manuals*/pdf/repair/*hitachi*/*c10fc2*.pdf
> 
> Good luck with your machine. I might be in the market for one some day - if I can find a place to put it in my miniscule shop...


This is how to works, but the fix could still be to replace the brushes as suggested by several that have actually done it.
If it is the switch why does the brake work after replacing the brushes?
Could it be that worn brushes, though still good enough to run the motor will not activate the braking action?

Putting on my tinfoil hat, I can see an old common appliance repair scenario, "I replaced the expensive switch for you, oh, and I replaced the cheap brushes while I was at it."


----------



## woodnthings

*always replace the spark plugs first...*

If that doesn't do it, then look for more expensive "fixes".
A brush replacement would be under $10.00 or so. Start there as suggested, then work your way "up" ..... :smile:


----------



## nostrildamus

Wow, thanks everyone for the replies.
I'm waiting for the new brushes to be delivered and will try that first, along with a good clean-out.
BTW I forgot to mention that sometime before my problem started, there were a couple sparks inside the housing and a whiff of electrical-type smell...


----------



## OldEd

FrankC said:


> This is how to works, but the fix could still be to replace the brushes as suggested by several that have actually done it.
> If it is the switch why does the brake work after replacing the brushes?
> Could it be that worn brushes, though still good enough to run the motor will not activate the braking action?
> 
> Putting on my tinfoil hat, I can see an old common appliance repair scenario, "I replaced the expensive switch for you, oh, and I replaced the cheap brushes while I was at it."


I understand your comment, but, in my experience, failing brushes will show up first as problems with _running_ as well as braking. I've never seen a case where only the braking was affected by the brushes going bad, whereas I have replaced several "dynamic braking" switches, my electric lawn-mower being only the first.

This is especially true in this instance, I believe, since the saw has been in use with no braking for an extended period of time. Bad brushes might show up first in bad braking, but should quickly advance to bad running.

However, since brushes are probably much easier to get obtain than the switch, he should go ahead and change them. It certainly can't hurt. And some contact cleaner may fix the switch, if access to the inside is possible. 

In case you are wondering, I went to college for electrical engineering, and "fixed things" as a sideline for friends and neighbors for many years. In fact, what stopped my sideline was the advent of the "throw it ALL away" society, in which things (ranging from pencil sharpeners and can openers to automobiles) were built to be thrown away and repurchased rather than repaired.

If you check Wikipedia for the subject Dynamic Braking you will find an article which discusses it's application to traction engines: i.e. railroad locomotives, etc. This is a variant of what we see in small motors such as in a chop saw, almost all of which have dynamic braking as a pretty much mandatory safety feature. I'm not aware of any law which requires it, but I believe that no manufacturer who wishes to remain in business for very long would put one on the market without it.

In my attempts to get the same feature for a table saw, I ran into the little problem of "It costs money, and if we do it everybody will have to do it, and we try to coexist with the other folks in the business, and so we don't want to make waves..." 

There is, in fact, a precedent: an airplane manufacturer made a change in the brakes for it's light aircraft. Subsequent to this, the owner-and-pilot of a plane with the older version of the brakes ran off the end of the runway and died in the resulting crash. The family sued the builder for damages, saying that the builder should have retrofitted all the older aircraft with the new brakes. They won, and the builder went broke.

(The company (which shall remain nameless) that I worked for for many years had a team of liability lawyers on staff - we engineers got lectured to rather more frequently than we thought necessary.)

P.S. Your tinfoil hat, I'm sorry to say, will NOT prevent the people on Planet Gigglepuss from causing you to mess up that critical cut on the most vital part in the most expensive wood that your nearest and dearest absolutely MUST have by yesterday morning for....(fill in the blank with the appropriate event, recipient, etc. I know this for a _*FACT*_ because they have told me so).


----------



## Gary Rutledge

To the original poster, replace brushes. If you cut a lot, order extra set. Or two. The saw will run FINE for quiet a while (like it's probably doing now) without the brake working properly. Don't wait too long or you will pit/scar the commutator. Years ago, I understood this to be a shunt brake (dynamic). I am currently using two miter saws, Hatachi 10" C10SFH compound slider and the 8 1/2" C8FB2compound slider.( I bought both saws used) The 10" is mounted in my shop,about 10 yrs, and has had thousands of cuts. The 8 1/2" slider is mounted on a cart made of 3/4" conduit,with small pull out tables left and right, compressor mounted underneath. This is my job site saw. Have had it for a very long time. It just keeps running. I know I have installed architectural mill work, cabinets and run "MILES" of trim, mostly crown, with this little workhorse. With the 8" I've cut up to a 10"/12" wide crown and 2" mill work at 45*. Thousands of cuts. The brushes do wear out. Cannot remember how many times. Like tires on a car. I always order extra, they're cheap and easy to replace. This has ALWAYS WORKED to get the brake to work. While in the motor once , I Replaced the motor bearings on the motor and the linear bearing on the slider even though they didn't need to yet.
Have been in the trades since the late sixties. Back then we used our table saw with sled to cut trim, later, moved up to radial arm saw, and then finally a Rockwell chop saw when they came out. IT had a button on the handle you pushed to slow down the blade. Wouldn't even last a month of regular work. The worst mitre saw today is really not so bad as compared to a radial/table saw mitering for good safe production work, brake or no brake. There really are some people, regardless of all the safety features we have today on our modern tools and equipment, that have no business in a workshop environment with moving sharp cutting blades........
I'm pretty much a lurker, this is my first post I think on this forum. I noticed several people give the correct solution right away. When you USE your tools a lot, you begin to understand their little quirks like needing regular NORMAL maintenance (oil, brushes,blades, bearings....etc.) I also noticed that some people, regardless of all the evidence, refused to be convinced. (smile...) 
The shunt brake on MY saw is a clever little safety feature that is very important to me for someone doing production work. I cut a lot of very small parts and to save the start and stop of the motor every five seconds, usually tie rap the switch on and use fixed foot air nozzle to remove part, keeping my hand away from blade. 
The brake is a neat feature, but it hasn't prevented an occasional light KISS with the eighty tooth carbide. Gotta be thinking.

Gary


----------

