I'm curious...

[steve_g]

I'm curious... I just replaced my fourth set of brushes in my PC router... When does the Commutator wear out? Is there any other preventative maintenance that should be done to prolong the life of the Router?

Steve

[billp]

Steve,
A few years ago I was running PC routers on my two machines, and another nearby Shopbotter had similar models running on his. I ran almost every one of my files between 10-12K rpm and didn't have to replace my brushes for years. The other shop ran all of their files at the upper end of the PC range and were changing their brushes every few months. My cut quality was as good (usually better in fact), and when I finally upgraded to a spindle (to eliminate the screaming noise factor) my routers were still in good operating condition even though they were nearing 6 years old. I think many people could benefit by doing a little experimenting with a variety of speeds.....

[steve_g]

Bill...
I'm sure your right on, I know I have been running with too light a chip load most of the time... The article I've been editing about "router bit basics" has been an education for me also! Lately, it seems like 90% of what I do is V-carving where bit diameter is constantly changing. I guess I justify running at full RPM figuring that when the bit is at the minimum diameter I need all the RPM I can get.

The first set of brushes lasted about three years and the next three sets lasted about a year each. I'm wondering if the accelerated wear is due to pitting of the Commutator or the fact that every thing I make I now figure out a way to make it on the bot!

Does anyone pull and polish the Commutator when changing brushes?


Steve

[kartracer63]

Speaking of PC router brushes... where is a good place to purchase the PC router brushes? And... is there anything else I should have on hand for router maintenance?

[steve_g]

Eric

There's a Dewalt service center just around the corner from me... they stock parts for every thing imaginable. Whenever I get a set I'm surprised at how cheap they are. All you need is a Philips screwdriver (#1 I think)...I stick a rare earth magnet on the shaft of the screwdriver to help control the screws. It would be possible to loose a screw in the bowels of the router requiring removal of the router to turn it over and shake it out. This last time I changed the brushes without loosing my Z position and resumed without issue. I'm running a Alpha PRT with a double Z.

Steve

[billp]

Using the search engine produced THIS info;
http://www.talkshopbot.com/forum/showthread.php?t=2787&highlight=porter+cable+brushes

[dana_swift]

Bill P's advice on running the PC routers at midrange or low RPM was posted years ago and I took the advice. I usually run my PC router at 12k and have not needed to change brushes in the roughly 3 years I have been running it. It gets medium duty service, so its clearly an excellent tip.

Thanks Bill for the suggestion!

D

[billp]

Dana,
You're quite welcome. The concept had as much to do with the screaming noise a PC makes at the upper end of it's range as much as anything else, but after hearing "the router bit speech" from a number of Onsrud company reps Camp after Camp it just made more sense to give the flutes a chance to "slice" the material instead of pulverizing it.

[paul_z]

I normally run my PC at the high end of RPM and increase the cut speed as much as possible. I never thought about reducing the howl by reducing the RPM. (Guys, guys, I'm trying to think but nothing happens.)

I going to spend more effort exploring mid and slow range operation of the PC.

Thanks guys!

Paul Z

[steve_g]

Well I V-carved Mesquite and Bois d'ark all afternoon at 16,000 rpm (middle of the choices) down from 21,000. My results certainly were not inferior to the higher speed but I'm not ready to say superior yet... It was nice to not have the high-speed scream that goes through ear plugs like they aren't there! I'll step the speed down incrementally while I have a project that will give me a direct comparison as to cut quality. It's a little disconcerting to hear the router bog down when a deep cut is encountered and then have the electronic speed control immediately juice it back up to speed. it's disconcerting only because it's different.

Steve

[michael_schwartz]

I have been running at the lower range of RPM'S as well. I suspect this is better, for the bearings too. When holding parts with vacuum,the finish is great.

Most of us that get by with a router, can probably live with cut times that are slightly longer. If you have to push the limits of cut speeds, then your probably bringing in enough money to justify the cost of a spindle.

[dana_swift]

Correcting my earlier post its 13k rpm I usually run at. I am just getting the first hint of age from the tool, so I probably best get a set of brushes on order. Good to have this thread and the thread "another one bites the dust".

This one is still producing good dust, but that wont last forever...

D