"As soon as you place an order for this chain sharpener go to "O's" ( the other guys) website and download the instruction manual for the 511A; the Northern sharpener is identical but the manual is poorly written and leaves you with more questions than answers.
When I received my Northern sharpener I put it together and got ready to try it out and found the instructions to be dismal. After I downloaded the 511A manual I was able to figure out how to set the vise tilt angle although I was still having difficulties. Then I realized that there was some metal from the casting process on the bottom side of the base that kept the chain vise from rotating properly. After smoothing this out with my grinder it works OK now.
I sharpened my first chain which was old and in horrible shape. I could hardly wait to try it out. When I did, I found that it didn't slice through the tree like hot butter so back to the drawing board I went. After another sharpening, and this time I filed the depth gauge on the chain, I was out to try it again. It was still not like a new chain but it was a major improvement. Remember I started out with a worn out chain (which I recommend for the first time using this new tool). There is definitely a learning curve albeit a short one.
I had two more chains to sharpen and even better results. I'm not a total klutz with tools but the practice did improve the results I got.
The motor runs smooth and I did not have any issues with the motor running out of power (I have a friend who bought a $39 sharpener that runs out of steam).
I haven't had a need to use it after sharpening my three chains but based on my experience so far I am happy with my purchase. I would probably have given it a 4-1/2 star rating because of the fit and finish but that wasn't an option so I rated it a five. I haven't seen the competitors 511A other than pictures so I don't have a hands on comparison. But for the difference in price I am happy with the Northern. I hope I am still happy a year from now since I really hate trying to cut with a dull chain."
What is your level of technical expertise? Home Handyman