Thursday, July 7, 2011

Getting Comfortable Wrenching on Your Machines: Screwdrivers, Part 1

Worth fixing.

I'd happily spend the weekend tearing a machine down, but that's not everyone's cup of tea. An experienced sewist friend told me "Most sewers don't care or want know anything about the mechanics [of the machine]. They just want to sew." I get that. But I still want to use this blog to illustrate some simple things you can do to keep your machine in top condition.

Experienced wrenchers may find my tutorials too dumbed-down. There's a reason for that. A lot of people tried their best to help me in the beginning, but because they were already experienced, they'd say things like "take your screwdriver," or "get a soldering gun and some solder;" they already knew in their head exactly what kind of screwdriver or tool, and they'd assume I did too. So I'd go to the store to buy a soldering gun and find out there's four different kinds, each of them different wattages. And five types of solder, "lead-free," "rosin core," "60/40," "63/37" and I wouldn't know what to buy. I'd guess anyway and usually buy the wrong thing.

When I'm learning something new I need everything spelled out for me, because I'm a little thick that way. So I'm going to write the exact kind of tutorials I wish I had read when I started out. I also hope to reach the greatest amount of people, including the tool-challenged and the clumsy, so I'll err on the side of overexplaining.

Before we can get to making some common adjustments and fixes for your machines, I'll need to talk tools a bit. I'll start with screwdrivers.

There are two types of screwdriver blades: Wedge-shaped and hollow-ground.

Wedge-shaped / no good

Hollow-ground / good
You want the hollow-ground. Those are the kinds of screwdrivers machinists use, because they fit perfectly in the slot of a machine screw, taking up all of the slot and providing even pressure when you try to turn the screw. The wedge-shaped screwdrivers--even the ones Singer included with their machines--will not fit the slots properly. If you use a wedge-shaped screwdriver, it will only press on the small part of the screw slot it's in contact with, and if the screw is tight there's a good chance you'll strip the screw.

A stripped screw is a real pain and you want to avoid it at all costs. It has to be drilled out to be removed, and then you need to buy a replacement screw. Since Singer used custom screws, you can't just run down to the hardware store to get another one; some companies make replica screws, but if you can't get one of those you'll need to get one off a parts machine. (See bottom of this entry for resources.)

Here's a faceplate screw on a 15-91. See how the slot is pretty square in cross-section?

When you put in the correct-size hollow-ground screwdriver, it fits perfectly and does not jiggle at all.

If you put a wedge-shaped screwdriver in, it does not fit properly. Look at all of the room left between the blade and the slot. This is a recipe for a stripped screw.

If I put in a thinner wedge-shaped screwdriver, it reaches the bottom of the slot okay, but there is still way too much space between the blade and the slot. Not good.

When you select a screwdriver bit, it must fit perfectly in the slot not only in the narrow dimension, but in the wide dimension. If it only fits well in one dimension, you can still strip the screw.

Another thing to watch out for is angles. Whenever you remove a screw, you always want the driver to be going straight into the screw, not off at an angle.

Something you will be doing a lot of, if you have a lot of machines and want to keep them running clean, is removing the needle plate and feed dogs. If you use a straight screwdriver to do this, you can see that the position of the machine's arm prevents you from getting the bit straight into the screw:

Zooming in, we can see that the bit is not seated properly in the screw. Not good.

Please do not try to remove screws from an angle like this, because if you're clumsy, as I can be, there's a good chance you'll strip it.

I'll show you a few different ways to get those tricky screws out in the next entry, and I'll also review several different brands of screwdrivers and bits, as well as cover where you can get them, and what you should or shouldn't buy depending on your needs.

Some Resources for Replacement Screws

There are two places I use myself:

Jenny from Sew-Classic sells replica screws (and more, which I'll cover later) that are commonly missing or damaged on old Singers: Needle plate screws, feed dogs screws, the presser foot knob-type screws, even the set screws that go into the hinges underneath the machine when it's in a case or cabinet. Since Singer's screws were custom I worried about replicas not fitting perfectly, but every type of screw I've ordered from Sew-Classic fit dead-on.

If you need original Singer screws and/or screws that Jenny doesn't have, Duane over at Singer Original Vintage Products has everything. They're more expensive because these are genuine parts; he has a huge collection of Singer parts machines and can find just about anything you need.

Go on to Screwdrivers, Part 2: Removing Your Needle Plate and Feed Dogs


  1. Awesome explanation! Thanks Nick! Some of that slipped over my head during class.

  2. I knew that screwdrivers were the bane of my existence, but I didn't know how badly I needed a screwdriver tutorial until now! Fabulous blog, thanks for all the info.

  3. Your posts are absolutely what someone as mechanically-challenged as I am have needed all this time. Stripped screws are the bane of my existence (tho some machines have arrived here with already stripped screws, so obviously I'm not the only klutz out there). Thanks!

  4. I'm glad that your tutorials are 'dumbed down". They are perfect for us beginners. I'm fairly new to collecting vintage machines and I need to move nice and slowly when I'm working on my machines so I don't mess it up completely. I really appreciate all the work that goes into your pictures and directions!
    ~Cathy in MA~

  5. Thanks for the links. I knew about Jenny, but was glad to find Duane's link. JEC

  6. Wow, just found you via Peter's blog, and I'm so impressed by this resource you're setting up! I love that you're going into the basics like this, and with such excellent photos and clear explanations. I certainly never knew that different sorts of screwdrivers existed, but the difference is obvious now. I'll be reading more!

  7. Fantastic post, so useful, so many of these machines are just collecting dust.

  8. Aaaaaah. I need this blog so badly, you have no idea! I have an old 1970s Singer, which I am constantly taking apart and putting back together again (usually when I realize I'm in over my head). This is exactly the sort of basic help that I need, thank you!