Various parts and supplies for class.

[3v0]

I am starting this thread so that I have a single place to ask somewhat lame questions about parts and supplies that I need to stock my classroom with. For most things I need quanity 10.

The question of the hour is wire strippers and side cutters (nippy cutters to some). Most of the stripping will be 22AWG hookup wire for breadboards.
This is a Radio Shack Stripper for $9.
**broken link removed**

Electronic goldimine has a Adjustable Automatic Wire Stripper for $2.
**broken link removed**

The main thing about small side cutters is that the jaws need to line up. Difficult to tell that from a web picture.

 

[gerty]

The Radio Shack strippers are fine. The $2 ones.. well you get what you pay for...

 

[Hero999]

The wire stripper looks pretty crappy.

My advice is don't buy the cheapest tools as they probably won't last as long.

As far as components are concerned, it depends on what sort of class this is but I'd recommend buying:

A packet of E12 carbon flim resistors plus extra E3 values from 10Ω to 1M.

A packet of 25V capacitors E3 values from 10pF to 10,000µF with extra 100nF ceramics.

Some NPN & PNP low power BTJs e.g. BC337, BC327.

Some MOSFETs, IRL540 is good.

General purpose op-amps: TL072, TL074 & LM358, LM324.

Comparators: LM311 (good as it can directly drive small relays), LM339, LM393.

Linear regulators: LM7805, LM7808 & LM317, LM327.

1A bridge rectifiers.

1N4001s.

12V 1A wallwarts - you might want to consider AC output types so they can build their own power supplies and they make it easy to produce bipolar PSUs.

Some connectors for the wallwarts.

CMOS glue logic, e.g NANDs and Schmitt triggers.

Microcontrollers like 12F509 (cheap and chearful) & 16F687.

Assorted LEDs.

Audio amplifier ICs - start with the LM386.

Cheap 8Ω speakers, easilly salvaged from old radios. If you have a choice choose mylar coned types as they're less easilly damaged or you can buy cheap cased units for a walkman from a thrift store.

A PIC programmer or you could do a build your own programmer project.

 

[ecerfoglio]

Electronic goldimine has a Adjustable Automatic Wire Stripper for $2.

I don't think it is from the same manufacturer, but some years ago, where I used to work, we used a similar stripper (made locally in Argentina) in a small production enviroment. It gave very good results.

This type of wire stripper is very easy to use, as it cuts and strips the wire in a single operation.

It also has (at least the one we used had) a very handy "ruler" (graduated in inches and/or milimeters) that lets the user measure the strip length.

Of course, it may be a "cheap copy" of the model, with a shorter life span - But then at 2$ each, you can replace them up to four times and still spend less than 9$

 

[Krumlink]

I prefer non automatic strippers. You can feel them bite through the insulation and after you get good enough it becomes a very fast process.

 

[3v0]

@Hero999

Thanks for the suggestions. In the first term I will only teach enough analog to make basic interfacing possible. Transistors as switches mostly. Ohms law, resistor networks, resistorstors to limit current etc.

Where we go the 2nd term depends on what the students want. Could be more uC's, CS, or analog.

 

[Torben]

I prefer non automatic strippers. You can feel them bite through the insulation and after you get good enough it becomes a very fast process.

I agree. Perhaps there are some top-dollar ones which work better but I have an automatic and it was always nicking solid core wire and clipping a few strands of stranded.

I went to an electronics store in Vancouver (Main Electronics) and asked one of the older gentlemen about what he would recommend and he plopped down a $10 manual wire stripper in front of me, saying "You'll screw up the first few you do but once you get the feel of it you can always trust it". He was right.

Given that I spent years stripping wire by rolling it between my thumb and the small blade on my jackknife, it didn't take long to get the hang of it. And I don't miss the network of fine slice marks I always used to have on my thumb.


Torben

 

[kchriste]

I prefer non automatic strippers. You can feel them bite through the insulation and after you get good enough it becomes a very fast process.

I agree. Those "auto" strippers are usually more of a pain in the butt than not. The wire will slip on the cheap jaws and the cutter tension is never perfect so it either nicks the wire or just stretches the insulation. When I'm in a hurry and it's just hobby stuff, I use nippy cutters as strippers. The one from RS with the wire gauge holes is the better choice.

Given that I spent years stripping wire by rolling it between my thumb and the small blade on my jackknife

I still do this with heavy gauge wire. If you score the insulation just enough and then bend your wire at the strip joint , then you can pull the insulation off without nicking the wire at all.

 

[Mikebits]

I see you only mention wire cutters/strippers. Would you be planning to by other tools as well. What's the budget? I was thinking something like these tool kits. $18.99
**broken link removed**

I am sure there are others to choose from, but to give you an idea.

 

[Pommie]

When I'm stripping wires for a breadboard, I initially strip a large section at the end of the wire (4") and then use the strippers (below) to cut and separate the length of insulation I require on the finished wire. The insulation can then be slid along the wire until ¼" of stripped wire remains at the end and then I use side cutters to cut the other end. This way only one stripping action is required and I end up with the correct length wire.

**broken link removed**

Mike.

 

[Torben]

I still do this with heavy gauge wire. If you score the insulation just enough and then bend your wire at the strip joint , then you can pull the insulation off without nicking the wire at all.

Actually, I still do that too for the heavier wire, usually just in the truck--I don't do a lot of messing with high amperages at mains voltage .

I try not to use my teeth anymore. I installed too many car stereos using my teeth as wire strippers and now have little chips out of my incisors to show for it.

And just to get back to the topic a little bit (although I bet 3v0 already has most of this):

I like pin headers and through-hole screw terminals for easy hookup.

Switches are good to have on hand. I like to keep a collection of low-rating NO and NC SPSTs and some heavier-duty DPDTs around.

Battery snaps and AA and AAA holders.

CdS cells can be fun. Many people want to make a beam-break detector or similar at some point. You can get cheap laser diodes by scavenging from El Cheapo dollar-store laser pointers (plus you get a small tactile switch and some 1.5V button cells in the bargain).

Desoldering braid and solder suckers.

"Helping hands". 'nuff said.

Having a rotary tool such as a Dremel in the workshop can be a great help when putting everything together.

First aid kit.


Torben

 

[3v0]

Lots of info, not great ordering.

The budget is mushy. We collected $50 per student as a lab fee. The (my) idea was to use this to buy tools/things students would keep. There is other money for equipment, and consumables.

Each student so far:

On order:
830-point Breadboard (Pololu)                             $4.50x3  $13.50
19 Bin Portable Parts Storage Case (HarborFreight)                  $8.00
looking at:
WIRE,22AWG,SOLID,GREEN,100 (Jameco)                                 $7.00

Total $28.50

I could have gone with 2 breadboards but at this price I would rather have 3. Maybe hand out 2 to start with.

I am going to order 9 100ft spools of wire. 2 Black, 2 Red, and 5 other colors, maybe white, yellow, green, blue, and brown. Students can add wire to their kits as needed.

I could shift the the wire out of the student fee's into my supplies to pay for more or better tools.

1/4 watt 1% resistors are on their way from China via Ebay. I plan to supplment the common values by ordering 100's of the common values 1K, 10K , 330R. I have red, green, yellow: 100ea 3mm LEDs on order from MPJA. Still need to order 100 .1uf bypass caps, 20Mhz resonators. Also plan to get each student 8 red and 8 green LEDs with built in resistors to make breadboarding easier. 1 bi-color each to play with.

I like the case. The plan is that it will hold enough for the student to take his breadboard home and wire a project. The bins pull out. I will be cutting wood blocks to hold junebug and the breadboards that replace existing bins. The Junebug
is an exact match for 1 large and 1 small bin. Students will retain removed bins so they can rearrange as desired.
**broken link removed**

The only tools I want to buy at this point are what they need to do solderless breadboard work. A stripper, a cutter, small philips and straight screwdriver to connect wires to screw blocks. None of the sets I have seen so far have this combo. Most often contain nut drivers etc.

I have 3 temperature controlled soldering stations on order from MPJA. Only the 2 returning students will be soldering the 1st semister.

I have PO's in for the 2 color matrix displays that were used in another thread. At under $1.50 each student will get two. Next term I plan to get them each a character and graphic LCD, also an IR sensor.

For the expensive sensors like gyro's and accel I may order 2 or 3 each once the dust settles and have them stay with the school.

I see you only mention wire cutters/strippers. Would you be planning to by other tools as well. What's the budget? I was thinking something like these tool kits. $18.99
**broken link removed**

I am sure there are others to choose from, but to give you an idea.