Porter-Cable 390K Random-Orbit Sander

WOOD magazine rating
Average reader rating
4.5
out of 5
Brand:
Porter-Cable
Model:
390K
Price:
$130

Description

• 3.5 Amp EnduraTech Motor for increased performance and durability.
• Electronic Load Control for 42% faster material removal.
• EnduraTech Motor Technology has 71% fewer wear components for 5-10 times longer motor life.
• Electronic motor brake reduces spin-down time by 73% for increased productivity.
• Mechanical pad brake reduces free-spin to virtually eliminate gouging.
• Low profile design reduces sander height by 31% for better control and finish.
• Variable speed dial, 7,500-12,000 opm, optimizes removal rate on a variety of materials.
• Optimized ergonomics with rubber grip for comfort and control.
• Integral dust port accepts 1" and 1-1/2" vacuum hoses for optimal dust collection.
• 3/32" Orbit Diameter.

• Amps: 3.5
• Orbits/Min: 7,000-12,000
• Pad: 5", 8 hole
• Abrasive Type: Hook & Loop
• Height: 4 "
• Weight: 3 lbs

WOOD magazine review

Low profile, aggressive, fine-finishing

Review Summary

With its low-profile body and brushless motor, the 390K excelled in every test we threw at it. It’s aggressive without being difficult to control, and produced a flawless, finished work surface with 220-grit abrasives. One minor quibble: Its large grip could be tough for small hands, particularly because there’s no neck for side-gripping.

Detailed Ratings

4.8
out of 5

Performance

5

Features

5

Ease of Use

5

Value

4

Reader Reviews

Porter cable 390 k

Review Summary

I agree with what has already been said but I bought mine a little over a year ago and had to return it three times before i got one that would work. they worked fine at the repair center but after about one half hour, it would quit. the one I have now seems to be fine but man, what a hassle.

Detailed Ratings

4.0
out of 5

Performance

3

Features

5

Ease of Use

4

Value

4

Very happy with it

Review Summary

I agree with the large body size. It could prove annoying to use for people with small hands. If you wear a large size glove this sander will fit you just fine. The dust collection port fit a small size shop vac hose perfectly. Shortly after buying this I had a problem with it starting. It turned out to be dust in the brushless motor. I didn't have to take it apart, just gave it a good cleaning with the air compressor. I highly recommend this sander

Detailed Ratings

4.8
out of 5

Performance

5

Features

5

Ease of Use

5

Value

4

poor performer

Review Summary

I have been putting this sander through the paces for the last few days. I have to say, I am very unimpressed. I get a poor finish with no lots of swirl marks. the dust extraction when hooked up to a vacuum is fantastic, there is almost no dust left behind. The brake is very durable and keeps the sander at just the right speed when not being used. It fits my hand, but I wish the grip was just a bit smaller.

Detailed Ratings

3.3
out of 5

Performance

3

Features

4

Ease of Use

3

Value

3

excellent sander

Review Summary

This is an aggressive beast that does an excellent job with almost no dust. Highly recommend it

Detailed Ratings

5.0
out of 5

Performance

5

Features

5

Ease of Use

5

Value

5

Mine Works Really Well

Review Summary

I got a really good one. This is the one of the two smoothest operating sanders I have, and I've had a dozen different ones. It's easy to control and leaves no swirls or marks at all. The low profile motor makes it very stable, and it's capable of both aggressive stock removal and a smooth finish with just a 100-grit disk. It has a nice, long cord, too. I'm quite pleased.

Detailed Ratings

4.8
out of 5

Performance

5

Features

5

Ease of Use

5

Value

4

Best palm sander to date

Review Summary

I am a professional woodworker and own several different types and styles of sanders and I can honestly say that this one is my most used hand held sander. I purchased it when my Dewalt 5" RO sander suddenly stopped working. It wasn't a bad sander on it's own , but this PC sander seems much more powerful than my previous. It's almost as powerful on the No. 3 setting as my Dewalt was on it's highest setting.
The dust collection is superb when connected to a shop Vac, which is the way you really should be using it at all times, not only for the obvious reasons of maintaining shop cleanliness and health, but also to increase the life of your sand paper and for the ease of switching sanding discs from one grit to another. it's much easier to re-stick the sand paper when your switching grits back and forth, since there is very little dust caught on the pad when attached to the vacuum. I also love the shorter stop time on the orbiting action when turned off. It saves me time. The lower profile is nice as well. The top of the body which you use to hold onto ,is a little bigger than most other 5" RO sanders ,so if you do have small hands, then this may be uncomfortable during long usage for you. Outside of that I believe that this is the nicest random orbit sander I have ever owned and would buy it again.

Detailed Ratings

5.0
out of 5

Performance

5

Features

5

Ease of Use

5

Value

5

Best available to date

Review Summary

In my opinion, this is the best sander on the market today. Its varible speed allows you to adjust to any kind of material. I have been using my daily since the day I purchased it and it has operated with outstanding results.

Detailed Ratings

5.0
out of 5

Performance

5

Features

5

Ease of Use

5

Value

5

Nice sander

Review Summary

Best sander I have used. I am very happy with the performance, this sander is going to replace my other sander.

Detailed Ratings

4.5
out of 5

Performance

5

Features

4

Ease of Use

5

Value

4

I have two

Review Summary

I have toe of these sanders loaded with different grits of paper one of these i have had for 10 years and it is still going strong. Great little sander

Detailed Ratings

4.8
out of 5

Performance

5

Features

4

Ease of Use

5

Value

5

Failed with less than 20 hours of use

Review Summary

This sander works very well and would have rated a higher score, except that mine failed with less than 20 hours of operating time. I don't know if it's a design flaw of the backup pad or someone failed to tighten the three (3) Torx screws which secure the pad to the bearing holder. At any rate, mine failed as the 3 screws worked themselves through the thin aluminum backer plate which is a molded-in part of the backup pad. Personally, I think it should be a steel backer plate.
It also could be that someone forgot to tighten the 3 Torx screws, which allowed them to "work" themselves through the aluminum by vibration. Inspection of the bearing holder, which the three Torx screws screw into, show signs of wear and will need to be replaced as well as the backup pad and plastic pad brake.

Detailed Ratings

4.3
out of 5

Performance

3

Features

5

Ease of Use

5

Value

4

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