Tuesday, September 27, 2011

I Used All Three Lathes

Henry’s teacher from last year had me come in and get her classroom printer hooked up. I noticed a box sitting on her desk.
I asked what it was and she said it was one of the listening stations and the nuts holding some of the audio jacks in had been lost. She was unable to find replacement nuts. Apparently these stations are expensive.
I took it home to fix.
Each of the audio jacks is threaded for the retaining nut.09271155
I measured with calipers. So it’s probably a 6mm thread. A little research and measurement to check and I was left with a 6mm x 0.5mm pitch thread. Unfortunately I did not have a tap that size.
I drilled a piece of brass and gave it a straight knurl on the South Bend (lathe #1).
Set up the largely unused Jet 920 lathe (lathe #2) to cut the metric thread. 09271159
Yes, I single pointed the threads. I did about a 1/4” of thread at a time, then removed the piece and…
Cut off a couple of nuts (on the Taig, lathe #3). I did this four times to make the required nuts and a couple of spares.
I put the jacks in place, I used blue loctite on the threads just in case. The two spares were taped inside the case with a note.
Mine aren’t chrome plated and don’t have a spanner slot, but there you are. I need to find a source for the nuts or just buy a tap. I assume this is a problem that will arise again.
I also had two cap-plugs samples that I squirrelled away years ago to put on the two exposed potentiometer shafts.

Friday, September 23, 2011

Salad Spinner Disassembly

The salad spinner cord broke.
You can see the problem…
There’s a plastic two eared nut on the underside of the top.
I had to drill out the plastic plugs that hid the screws.
And removed the screws.
Then more screws to get at the mechanism.
The gears. The small gear functions as a ratchet.
It slides in that slot. Notice all the fuzz from the frayed cord.
The spindle is removed.
The hub contains a flat spring.
09221110The cord has a knot at the end and another knot to keep you from pulling the cord out too far.
The handle was the only part that I had to destructively disassemble. It was pressed together and seemingly glued.09221112
I decided the easiest thing was to lash the two halves together. I might have a friend print up a replacement on his Makerbot or I may just live with it as is.
By the faint green blur around the periphery you can see that it functions. The replacement cord is the same that we use for our jewelry. It’s pretty tough and we have a ton of it laying around.

Thursday, September 22, 2011

Monthly Miscellany

Just some pictures from the past 30 days…
Henry installed a new toilet seat all by himself (although I did hacksaw off the old seat bolts…)
Hard at work.
Philippe (and Jeff) visited and made us dinner.
I tested the readings from an accelerometer at different angles. (more to come on this later, possibly).
Henry tested Windows 8 (running in Virtualbox) while eating an Oreo.
I needed to mount a hard drive in a hard drive cage that used mounting rails. As it was a used case the rails weren’t included. So I used rubber instead.
Seems to work fine.
Next post will be a tremendously exciting tale about repairing a salad spinner.

Tuesday, September 13, 2011

Interlink SuperMouse

Perusing the junk I don’t need at our local Goodwill I spied this odd mouse.
Being a sucker for vintage computing peripherals I had to buy it ($2.99)
It has two buttons and a pad that seems to function as a joystick.
I began my investigation by unscrewing the bottom.
Which yielded nothing except a rusty weight attached to the bottom plate.
Then I discovered that the mouse was a two piece unit! It just snaps off the base. Note the two channels for the cord in the base, allowing you to orient it with the buttons at the top or bottom.
It’s an Interlink Electronics SuperMouse. There isn’t a whole lot of information available on the internet about this mouse. I found the CDW page that shows it as being discontinued as of Friday, May 16, 2003. Scrolling down, the page has a tiny bit of detail:

On your desk, on the go, in your hand, three mice in one
SuperMouse is a mouse for today's computing realities--long hours on crowded desktops and quick setups on cramped tray tables. Its desktop cradle fits comfortably under your hand, positioning your fingers for hours of effortless pointing with none of the repetitive wrist motion common to desktop mice and trackballs. SuperMouse is also versatile. Use it at your desk, or pop the portable unit out of the cradle and take it on the road with your notebook computer. It can even be used a a hand-held pointing device. SuperMouse is one tough mouse. It has no rolling parts or mechanical assemblies to gum up or wear out and comes with a limited lifetime warranty.
OS Compatibility: Windows 3.1, 95, 98
Keyboard and mouse options
Connector : Serial or PS/2
Ergonomic : Yes
Mouse scrolling device : None
Mouse type : Mouse
Number of buttons : 2-button
Number of keys : 0
Wireless : No
Warranty Information
Warranty Terms: Limited lifetime warranty

I pried the rubber pads off of the bottom and found two screws that hold the unit together. As you can see, it’s fairly simple.
Those two posts actuate little clicky switches on the PCB. The rubber pad bears against the central pointing unit.
The rubber pad does not make electrical contact with the PCB. I'm not sure whether it functions as a simple switch or as I think is more likely is a pressure sensitive device. There are a number of patents referenced on later Interlink products that seem to hint at that, especially the one for a Force Sensing Pointing Device. But I don't know for sure. If you are insane you can look at patents#: 6084572, 4489302, 5296837, 5302936, 5659334, 5828363.

Notice the traces are labelled E,S,W,N and if you follow the traces you can see how each one covers a triangular field overlapping with the adjacent ones.
The underside of the PCB has the connection for the serial cable, resistors, capacitors and a couple of chips.
I assume this is the one that does the grunt work.
I hooked it up to one of my old PCs and found it worked but was somewhat unresponsive. You can scroll up/down/right/left easily but diagonal scrolling was slow. Of course I didn’t have the proper driver and Windows XP just identified it as a generic device. So it’s hard to say how well it worked on a machine running Windows 98 and what extra features the software enabled. In any case a neat little vintage peripheral.