How can I improve router survival?

[Glenn de Souza]

I just went through my second router in my router table. The first was a Bosch 1617EVS, lasted about 3 years and the latest casualty is a DeWalt 618, lasted about 2.5 years. Both are very good routers, and to be clear, what has been failing is the bearings. I think part of the reason is my enclosed cabinet style router table had dust collection only at the fence (up top) and nothing inside the box. I have recently added dust control and make-up air venting into the router chamber and we'll see if that improves things.

It seems to me that a couple of things are going on. First, the router chamber is a hostile environment with a good deal of dust flying around, not to mention heat. Second, the router is upside down, exposing it to dust infiltration even more.

Is there a reason routers are not TEFC?
Have others had these issues with router life in an enclosed style router table?
Are there steps I could take to lengthen life like maybe blowing out the router with compressed air from time to time?

Is there a particular brand of router that has a better reputation for surviving the rigors of a router table? I use a Rockler Router Lift FX, so I'm limited to the 2 1/4 hp class (Bosch 1617, DeWalt 618, PC 890 and a few others). The most demanding applications for me are routing dovetail drawer boxes with a Keller Jig and some raised panel work. With the exception of the dovetail jig, I generally take my time and take very small bites, partly for the sake of the tool, but mostly for quality of cut.

By the way, I had the Bosch repaired, and kept it as a back-up so it's in the table now. The DeWalt is going to the repair shop for the same surgery.

Any feedback appreciated...

[Mike Henderson]

I have a PC 890 in my table and haven't had any problems. But I don't know if I use mine as much as you use yours.

Mike

[Charles Lent]

The bearing in routers are sealed bearings, meaning that they have side covers to keep the dust and dirt out of the bearing races, and the grease inside them. They should last for a long time if not run hot. Are you working the routers too hard? Heat will thin the grease and it will leak out of the bearings. Heat may also change the hardness of the bearing races. If you are running the routers for long periods with inadequate air flow, this could be causing it. I always blow out my routers after each use.

Charley

[glenn bradley]

What was the diagnosis on the Bosch? This will give you a good idea on what to replace it with. Dust is not a problem because you have good dust collection. If you are cooking them due to heat, get a shaper. I run my Milwaukee 5625 pretty hard and it is going on 8 years but, it is a router in a table, not a shaper and I task it as such. You may be overrunning the design parameters ;-)

[pat warner]

Too much air flow (vacuum) and you can actually suck the lube right out of a bearing! Collection (from the offall) from inside the cabinet would help. But the reason you're blowin' bearings is overload. Routers of the 2hp ilk are not designed for 3+" cutters.
Frankly, in my view, no 110 vac router is made to accept 3-4" D cutters.
Get a 7518, made to work with big cutters in the face of adversity.

[larry senen]

Its the cheap Chinese bearings used in these tools that are the problem. Had the same thing happen to 5 or more bosch routers. Not mounted in tables btw. I too have a porter cable in my table, an older model so i couldn't say if the newer ones will last any longer.

[Jim Dwight]

I've had an old Ryobi R-500 router motor in my router table for around 10 years now. It hasn't been used all that time, however, I was without a shop for a couple years. But it isn't a premium brand or anything and is holding up fine. I think one reason is my suction does not come out of the bottom of the router compartment, it comes from the top, up around the collet. The area the router pushes air to. I had a previous setup where I pulled air out of the bottom and I noticed the motor got hot. So when I made my router table, I did it differently.

My old Ryobi has a 13.3A motor. That's bigger than my old PC690s but not all that much. I think the ones you are using are 12A. The one Pat recommends is 15A which is definitely bigger but I doubt that is the issue. I've used my old PC690s to use large panel raising bits. But I took about 4 bites to cut the edge of the panel. I maybe cut 3 times with the Ryobi. The big 7518 could probably do it in two passes. That would be useful but not enough to get me to buy it, so far anyway. My experience is any of these routers will do the cope and stick cuts that need to be done in one pass.

[Bob Bouis]

I personally am convinced that cleaning out motors with compressed air is more likely to drive out the lubricant from bearings than any dust that may have worked its way in.

But I have no real basis for this suspicion.

[Rick Fisher]

If you read the CNC forums... Folks talk about the bearings in PC 7518 routers and how they don't stand up to CNC use. Makes sense.. They talk about buying SKS bearings and some Japanese brand I don't remember. Apparently the routers life expectancy goes way up ..

So I guess I'm suggesting you buy a new router and ditch the crappy chinese bearings right out of the box ? :)

[Mike Berti]

Routers are relatively cheap tools. Replacing the 3,5" motor is not so expensive compared to other tools and accesories. What I found expensive are good router tables, fences, router lifts, etc.

[Rick Fisher]

Did a quick snoop .. a set of SKS bearings for a PC 3-1/2 hp router is about $30.00 ..

[Glenn de Souza]

Okay, I think I have a diagnosis. I built this router table 17 years ago. Like I mentioned in the orig post, the dust collection port in the lower chamber is new, also the router lift is new. So after I install them the DeWalt starts going south on me a few days later. Too much coincidence.

I now think the issue is not overload but inadequate airflow, namely a vacuum in the chamber which may have been an existing problem which I made far more acute by adding the lower 4" dust port. What little airflow I had is now being robbed and then some by the dust collector, and the router is basically suffocating and probably overheating. The one dinky hole I put in the front door is not nearly enough apparently. I turned the router on and put my hand on the top as inverted, and you can feel just how much air the router's fan is sucking in. So it seems what I did was like putting duct tape over Usain Bolt's mouth and making him sprint the 100m.

For now I'll run it with the door open but I'd like to look for a sweet spot of adequate make up air and effective dust collection. Any guidelines appreciated. Otherwise I'll perforate the door with more holes, perhaps 6-8 and keep adding as necessary until it feels right.

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[Curt Harms]

My router - no longer available Freud FT2000E hangs below a table saw wing router table. I was giving some thought to enclosing it for dust collection purposes. Maybe I won't.:)

[Andrew Pitonyak]

Did a quick snoop .. a set of SKS bearings for a PC 3-1/2 hp router is about $30.00 ..

Yes, but I think that you probably need a puller to remove them and a press to install them. I own neither, which means that I have a set of bearings that I never installed. I figured I should wait until I had no other choice since I then need to go buy a press (or similar).

[Ray Newman]

Trim about 3/4" off the bottom of the router cabinet door to improve the air flow. The door on my router cabinet has a gap and it runs much cooler, dust collection more efficient.

[Kerry Wright]

Glenn,

I'd replace the plexiglass in the door with a filter. That should give you plenty of make up air and keep the dust to a minimum.

[Charles Lent]

To continue my previous post, (had to go to work) don't work the router so hard, or get a bigger router and increase the air flow through it when you are routing. Take smaller / shallower cuts so the motor doesn't heat up. Let it run with no load at all for a minute or two after you have made a heavy cut so it can cool down some. If you use an electronic speed control, either internal or external to the router, remember that the cooling fan is on the same shaft as the motor. When you run the router slower, the fan can't cool it as well as it can at high speed. Industrial variable speed motors usually have a separate fixed speed cooling fan to keep them cool. Your router doesn't have this.

Charley

[Lee Schierer]

Okay, I think I have a diagnosis. I built this router table 17 years ago. Like I mentioned in the orig post, the dust collection port in the lower chamber is new, also the router lift is new. So after I install them the DeWalt starts going south on me a few days later. Too much coincidence.

I now think the issue is not overload but inadequate airflow, namely a vacuum in the chamber which may have been an existing problem which I made far more acute by adding the lower 4" dust port. What little airflow I had is now being robbed and then some by the dust collector, and the router is basically suffocating and probably overheating. The one dinky hole I put in the front door is not nearly enough apparently. I turned the router on and put my hand on the top as inverted, and you can feel just how much air the router's fan is sucking in. So it seems what I did was like putting duct tape over Usain Bolt's mouth and making him sprint the 100m.

For now I'll run it with the door open but I'd like to look for a sweet spot of adequate make up air and effective dust collection. Any guidelines appreciated. Otherwise I'll perforate the door with more holes, perhaps 6-8 and keep adding as necessary until it feels right.

For effective dust control you need at least as may square inches of inlet as you have in your outlet. You can't suck dust out of a closed box, you need air flow. The router also needs air flow for cooling. Since your outlet is 4" in diameter you need at least 12.5 square inches of air inlet.

Once I needed to make one simple cut with my table mounted router. I ran the router for about 3 minutes. I have about twice as many square inches of inlet as I have on the suction outlet. I was surprised at how warm the air in side my enclosure got with no dust collector running.

[Jim Becker]

For effective dust control you need at least as may square inches of inlet as you have in your outlet. You can't suck dust out of a closed box, you need air flow. The router also needs air flow for cooling. Since your outlet is 4" in diameter you need at least 12.5 square inches of air inlet.

Once I needed to make one simple cut with my table mounted router. I ran the router for about 3 minutes. I have about twice as many square inches of inlet as I have on the suction outlet. I was surprised at how warm the air in side my enclosure got with no dust collector running.

This. Spot on.

[Wes Grass]

The 'right' way to do this is to provide an outside source of air for the router. IOW, a duct to the top of the router where it draws it's cooling air in. This would keep the chips and dust from being sucked into it. Ideally, you'd duct the cooling air coming from the bottom of the router away as well, so it doesn't compete with your dust collector. Neither seems particularly easy to do unfortunately.

As for TEFC, great idea. But I don't know how you'd do that with a brush motor. At the least it wouldn't be cost effective for a router. So you wind up with an induction motor and belt drive, or a HF spindle to get the RPM you want. Neither cheap.

Some years ago, just for fun, I looked at an Onsrud pin router to see how easy it might be to convert it to use as a router table. More power, better bearings, less noise.

[Curt Harms]

I've had a thought (dangerous thing, I know) about table router & dust collection. I think cooling air exhaust exits the collet end. Normally air would enter the top and exit the bottom. Hanging in a table cooling air would enter the bottom and exit the top. Many router tables/enclosures have the dust collection at or near the bottom of the enclosure. I wonder if or to what extent having the vacuum inlet near the air intake for the router motor impedes cooling?

[Greg Hines, MD]

You asked initially about routers that are made for router tables, and the Triton has a good reputation for use in router tables.

Doc