Hello! I finally remembered to change my serger’s knives last week so I shot a video and took some pictures to show you how to do it. Changing out your serger knives is one of those things that gets overlooked a lot. You may hear about the importance of oiling your serger, but keeping sharp knives in it is just as important. Think of them like another pair of sewing scissors. They cut your fabric right before it’s sewn, so you don’t want a dull blade causing any shenanigans. You’ll find mixed suggestions on how often you should be changing the blades so I say to change them when they look like they aren’t getting a clean cut anymore. I know, clear as mud right? I don’t tend to be able to stick to schedules and flying by the seat of my pants when it comes to machine maintenance hasn’t caused me any issues yet so I don’t think it’s necessary to be too uptight about it. 😉
Anyway here is a video tut, and if you prefer text, just skip over it and keep on reading.
The absolute hardest part of this whole process for me is finding the new set of knives. I can hardly find any locally, and the shops that do have them want an arm and a leg for them. I can usually find them for a decent price from different places on Ebay though so check there if you are having trouble finding them.
The first thing to do is take apart your machine. I do as little as possible here because, less work. I just take off the foot and the throat plate and take out the thread. I leave the needle(s) in because they don’t get in the way.
Before you take the blades out, note how they are placed so you don’t end up putting them back in backwards or something goofy. Using a screwdriver, unscrew and remove first the upper knife and then the lower knife. Once I have it all apart, I like to brush it with the lint brush real quick to get out any lint the knives have been hiding during regular maintenance.
Then you just put your new knives in. First the lower knife, and then the upper knife. Once you have them screwed in, hand crank your machine to listen for any rubbing. If you don’t here any metal-on-metal noises, and it cranks smoothly, then you are good. If you do hear something concerning, adjust your upper knife. You want the two knives to be as close as you can get them without touching so loosen the screw on the upper knife, readjust it, and then screw it back in. Then hand crank, listen, and repeat the process until you either have a working machine or you need a margarita. No really, I’ve never had to adjust it more than a couple of times, and I usually get it on the first try so it’s not too hard. If for some reason you can’t get the upper knife to sit right, double check that your lower knife is all the way in (ask me how I know 😉 )
Once you are certain the knives are placed correctly, put everything back together, re-thread it, and test it out on some scraps.
If everything looks good then pat yourself on the back b/c your knives are changed!