30 March 2008

Single-serving tools

Every so often, you find yourself in need of a unique tool to fit the situation. Most of the time, such a tool can be bought. Though, because of their limited need, stores must sell these for a higher price to average out the lesser demand. Compounding this fact, no one wants to pay a lot for a tool they'll only use once.

I've collected a list of all the one-time, single-serving tools from recent memory. If you have similar single-serving tools, I'd like to see them.

Improvised Headset Press(1) An improvised headset press.

I needed to install the bearing cups to a 1-1/8" threadless headset on the bicycle I was building. But, I was only going to do this one time, so I didn't feel like buying a tool, even if it only cost $20.

My solution was this. A 1/2" screw is used to push two soft plastic plates together. These, in turn, push the cups into the headset. The plates were made out of some plastic from an old cutting board.

For best results, stick the cups in the freezer for half an hour--they will contract slightly and fit more easily.

Have you ever needed a really long allen wrench? [1/2](2) An exceptionally long allen wrench.

Have you ever needed a really long allen wrench? Well, I did when I was constructing the drawer set for my new lathe. Local hardware stores didn't sell allen wrenches this long--at least not in metric--so I built my own.

Take a normal allen wrench and hacksaw-off the bend. It's hardened steel, so it will mess up your blade--use a worn-out blade. Take a length of 3/8 round steel, bore a 1/4" hole at one end, at least 1/2" deep. Insert the hex bit, and then weld it on to the rod.

Have you ever needed a really long allen wrench? [2/2]Also, bend the far end of the rod, or weld on some sort of handle. I used my lathe to turn the rod down a bit, making it easier to bend.

Ultimately, this 5mm wrench will reach more than nine inches deep into a 1/2" hole.

Need a way to measure angles?(3) An easy way to measure angles.

When I moved into my apartment, I immediately devised a plan to build an long shelf above head level in the hallway. Because this apartment had been sliced off of a single family residence, it had an awkward hallway in the wrong place. The hallway space seems like a significant fraction of my apartment, and without the shelf it would all be lost.

The problem was that the walls in this hallway didn't meet at right angles. It's very ad-hoc, with three turns at angles around 13-31 degrees. I needed to measure these angles or the wood wouldn't meet right.

Sure, protractors are cheap, but one wasn't available when I had my inspiration.

I built this out of some 1" extruded aluminum angle-stock and a small machine screw, nut an washers. The trick? A hole is drilled on each bar, 3.5" from the pivot point. For any angle, the two holes and the pivot point make an isosceles triangle. Then, if I measure the distance "h" between those two holes, I can calculate the angle between those bars as 2 * sin ( h / 7 ).

The shelves, by the way, look great and line up perfectly.

So, anyone else have single-serving tools to share?


Dennis Ferron said...

Great blog! Great post!

You end up making a lot of single-serving tools working on cars, especially old ones.

- My fiance's 96 Eclipse had bolts on the side of the engine that were so hard to get to, you could just barely fit a wrench, but not your hand! So I cut one end off a 15 mm wrench and jammed the cut handle into a 1/2 in pipe, to make a cheater bar.

- Changing the clutch on a 71 VW Super Beetle engine requires holding the flywheel while turning the gland nut with 350 ft-lbs of torque. (Action-reaction - that means whatever holds the flywheel must resist 350 ft-lbs too.) There's a tool for it - I didn't want to buy it. So I used a T-post from an old electric fence (plentiful in Oklahoma) and hooked it under two flywheel bolts. It worked, but we bent the end of the T-post around in a complete J-shape in the process!

Sometimes a simple steel nail-set (punch) and a hammer can replace expensive specialty tools. You place the tip of the punch on the thing you want to unscrew, and use the hammer to beat it around the circle. Sounds awful but it works better and damages less than you'd think. I used it to remove a stuck freewheel hub on my bicycle recently - without damaging it. Also works on hex-head bolts and nuts, if they're large diameter.

Nick Johnson said...


Thanks for sharing your single-serving tools.

I know just enough auto repair as was required from growing up in Virginia. One thing I've realized in NYC is that most people don't understand the machines they use everyday, especially their cars. It's sort of embarrasing to tell people how to fix their cars when I ride a bike everywhere.

Funny you should mention removing a freewheel hub with a punch. I've used the same trick to remove bottom-bracket cups at some of the community bike shops I've volunteered at. Works great when you don't have the right tool.

And... as... soon... as.... I... can... pry... myself... from... the... office... I'll post more to the blog.