I have been making chains sharp via one means or another for about 40 years. (gee, that makes me sound old) Anyway, I have used a file for all of those years and in recent years have used an electric grinder. I always freehand filed and it worked for me. On the grinders, I have purchased 4. I got a cheapo Harbor Frt one and had pretty good success with it. (certainly worth what I paid for it) I then bought a newer HF grinder and that one had the bicycle brake clamp which I thought was pretty worthless. So I loaned it to Warpig6. hee hee hee. Then I bought an Oregon 511AX which is really nice but expensive. And then I bought a Northern Tools clone of the Oregon 511 (or 510, not sure) and that works pretty well too. If I had to do it all over again, for my purposes, the Oregon clones would probably be sufficient for my needs. (I probably sharpen an average of one chain per week on a grinder) I am using the first HF grinder for small chains (1/4" and picco) I am using the NT grinder to lower rakers I am using the Oregon 511AX on my 3/8 chains I wish I had one more grinder to do .325 chains rather than change wheels... I am keeping my eyes peeled for another NT clone or similar. The Oregon does a great job, the HF does so so and you have to set up both sides of the chain separately. It is handy to fixed a rocked chain though. For the occasional user, my suggestion would be to get some files, a new chain for a sample of what to duplicate and make your used chain's teeth look like the new chain's teeth.