Can You Run a TEFC Motor without the Fan Cover?

[Lance Norris]

I have a Unisaw with a 3HP motor. When I open the motor cover door to inspect things or clean out the dust and chips that my dust collector leaves behind, the fan cover(the opening on the end of the motor where cooling air enters)is always packed with shavings. Can I remove this cover and run the motor without it? The motor is protected inside the saw, and will never catch anyones fingers. I dont want the motor running hot because the air intake is plugged. Whats your opinion on this? Is anyone doing this with a TEFC motor?

[Don Abele]

Lance, are you talking about the hinged cover for access to the inside of the saw? If so, if you remove that you have about an 18" opening in the side of the saw - you'll never get any dust collection with a hole that large.

If you are talking about the end cap on the motor, I'd recommend NOT removing it - it's there for a reason - protection from that spinning blade. Besides, if you remove it, you won't get any air cooling for the motor. The fan works like a centrifugal fan and if you remove the cap there is no shroud to contain the air.

This sounds more like an issue with your dust collection - what are you using?

Be well,

Doc

[David Gunn]

The design of the fan cover aid some in cooling the motor. It help direct the air directly over the motor. Without it, the fan will be less effective. Depending on how long you run the motor though, it may not matter. If you run your saw for long periods of time, I would check to see how hot the motor was if you decide to run it without the cover.

[Eric Haycraft]

I would think that you could safely cut away the grill part of the cover, but the rest of the cover helps direct air over the sides of the motor, so that part is probably necessary. You may want to think about what is causing so much dust to get stuck there anyway. Is there enough airflow into the cabinet?..do you need a bigger DC or port? etc.

[Lance Norris]

This sounds more like an issue with your dust collection - what are you using?

I have a Grizzly G0548. The dust collector is capable, but Im sure my duct configuration isn't. Im running 4" spiral that has 3-90 degree bends in it and a total length of 12'. Id like to run 6" with no turns but this wont be possible. About the best I could do would be to replace the spiral with metal 4" and metal elbows. The saw is stock with none of the air intakes blocked off.
What I was thinking about, would be a blade shroud inside, like the Powermatic 2000.

[Lance Norris]

I would think that you could safely cut away the grill part of the cover, but the rest of the cover helps direct air over the sides of the motor, so that part is probably necessary.

Yes, I think this could be the answer.


You may want to think about what is causing so much dust to get stuck there anyway. Is there enough airflow into the cabinet?..do you need a bigger DC or port? etc.

My ductwork is less than optimal. There isnt much I can do, except replace the 4" spiral I'm using with 4" metal that would be smoother inside. I dont think I will be able to increase the diameter of this run.

[Don Abele]

Lance, without opening a dust collector debate - that's the problem. The most you can get through a 4" opening is about 350 CFM and that's the minimum your saw needs. You have a lot of "stuff" adding up a lot of resistance. The port for your dust collector probably (like my Jet) comes out of the cabinet right under that access door. So it's pulling the dust in that direction, but isn't powerful enough to overcome the suction that the motor fan is generating, so it's getting sucked back up and onto the motor.

A shroud would probably eliminate the problem you are describing, but your CFM's for dust collection is still going to be really low. Besides, is a shroud even available for your saw?

Your best bet is to try and eliminate as much of the spiral and elbows as you can. If you must use elbows, use long radius ones or join two 45's together with a short piece in between to create a long radius.

I just "upgraded" from 4" piping to a single 15' section of 6" spiral with a 4" reducer at the end which I connect to what ever tool I'm using. The improvement was dramatic.

Be well,

Doc

[Lance Norris]

Lance, without opening a dust collector debate - that's the problem.

Don...I completely agree, but there isnt much I'm willing to do, to change the way my saw is ducted. I like the idea of cutting open the grill on the cover as Eric has suggested. For the most part, the inside of my saw stays clean, and I wont argue that larger spiral and less bends will help. If I could fix the clogging of the cover easily, I'd be a happy camper. What do you think about cutting the grill out of the end of the motor cover?

[Lance Norris]

You know... I was think about this, and without the grill to clog and catch the dust and chips from entering the fan, the fan will get dusty and be less efficient. But, if I clean the fan occasionally, whats better, a fan thats dusty and less efficient or one thats clogged and not moving any air over the motor?

[Don Abele]

Lance, I think what will happen is instead of the chips getting stuck on the openings, they are going to get pulled in and bind up inside of the housing. This will not affect the motor - it's sealed. But it will reduce the amount of air that the fan is blowing onto the motor which will lead to excessive heat build-up in the motor. I doubt it would stall the fan as it's attached to the motor shaft and it would take A LOT to stop that shaft. It may cause some smoking if it gets filled with enough dust/chips and the shaft/fan generates enough heat. Will the heat cause motor failure - I don't know...that's outside my scope, but I wouldn't want to be overheating an expensive motor like that.

I wish I had a better recommendation for you, but I just don't. And I can totally understand your situation with the duct. I ran 4" spiral duct for over 6 years before I upgraded to the 6". I still have a single stage 1.5 HP canister DC because I don't have the room or desire to upgrade to a cyclone (yet!).

Be well,

Doc

[Don Abele]

You know... I was think about this, and without the grill to clog and catch the dust and chips from entering the fan, the fan will get dusty and be less efficient. But, if I clean the fan occasionally, whats better, a fan thats dusty and less efficient or one thats clogged and not moving any air over the motor?

Lance, we were thinking along the same lines as I was typing my response. I'd leave the cover as is and just dust it off from time to time.

Personally, I couldn't tell you if I have the same problem, because I don't look in there very often. But I have never seen anything on my saws like you described.

Be well,

Doc

[Lance Norris]

A shroud would probably eliminate the problem you are describing, but your CFM's for dust collection is still going to be really low. Besides, is a shroud even available for your saw?

No shroud is available, but I'm sure I could fab something that would work.

[Bruce Wrenn]

The fan cover not only keeps thing out of the fan, but it directs the flow of air over the motor. Without the cover, this function would be lost, as air would just spill off the end of the blades.