SMaR: Day 2 Buying Materials


Click on image to see full size.

Let’s make robots lists the items you need. They have some shops where you can buy sets with most of these items, but they are all US based and with import costs, it is impossibly expensive. I’ve compiled the list of things you need with links to the online shops I ended up buying them in here: Shopping List

I can’t promise that the links in the shopping list are the cheapest out there, but I can tell you for 100% sure that they are the correct items. And I wish I’d had that list, because it would’ve saved me a lot of money.
I’ve numbered the items in the image above, because I have useful/bitter/happy comments about all of them.

1.Sharp AERS with cable: hehe.. aers… anyway. I ordered one, I thought it had cables on, it doesn’t. I also thought ‘Well, if it comes without cables I’ll just solder some on’. The Sharp AERS arrived, without cables. This is a problem as it is not the kind of thing where you can solder cables on, you need female headers to go on them. And 3 separate female header cables won’t fit on it. So I’ve had to order the cable separately, which is why it’s not pictured. But I quite like this part because it ‘s quite literally the robot’s face.

2. Male “snap off” header pins: I apprehensively searched for ‘male header’ expecting a horrific result, but it turns out that all of the results on the first page of Google are relevant.. On the order reference of this part the item is called “Single Row Header Strip 36-way- straight” which is probably the filthiest any of the parts is going to sound. I bought loads of these. I bought 3 of the 36 pin strips. This is pointless. 1 of these strips would’ve been enough. Because even with breakage, you’re only going to solder on 6 pins. I ruined about 3 pins, because they are hard as hell to ‘snap off’. So don’t bother buying 108 pins like I did. Even if they’re only 29p per strip.

3. Geared motors + wheels: I think you know by now that I’m not savvy on any of this, so I wanted to get motors that looked identical to the ones in the picture. If you don’t care about that and you know what you’re doing, you can probably get any old motors. I couldn’t, and so I ended up with these. The good thing about these motors is that it tells you which wheels will fit under the tab ‘which wheel?’. I bought the basic black ones, just because I wasn’t a big fan of the coloured wheels.

4.Battery holder: I ended up with 2 of these. Both can hold 3 batteries. I suggest you get the 4 batteries one, it makes it easier to make the body of the bot. I had no idea where the 2nd one came from. Turns out the starter pack comes with one. Seriously, get a starter pack. It saves you a lot of unnecessary costs. I’ll tell you more about it later.

5. Double sided foam tape: This stuff is AMAZING and it literally holds ANYTHING together. I will start using this for anything I’ll ever have to permanently stick to anything else ever. I bought mine off ebay, so just look on ebay or amazon or just go to a shop, you’ll find it somewhere eventually.

6. Picaxe-28 Project Board: This is the bit I was most excited about getting, as it’s the ‘motherboard’ and it looks the most techy and the thing I associate with building robots the most. It is also the most expensive part. Which meant that it took me ages to actually purchase anything because I was worried that all the parts were going to be more than £10, and as you can see you need quite a few parts.
Luckily, most other parts are under £1 to get. And this part is pretty awesome, so it’s worth it. I bought this off the Picaxe website as I would be sure I’d get the right part. I knew I also needed the Picaxe USB download cable, so I bought the starter pack. Turns out the cable supplied with starter pack isn’t USB. So I had to buy the cable separately. The cable in the picture is the wrong one. The starter pack also comes with software, which I’m not using, but I bet will be fun once I’ve got the hang of this thing. But hey, guess what? They’ve realised starters are unlikely to have any downloading abilities outside of USB, so their starter pack now comes with USB. Thanks a lot Picaxe for realising that a month after I spent all that money. Because this bit is the most expensive bit. But at least you’ll save yourself the extra £14.99 I had to spend to get that USB download cable. I could’ve gotten that cable much cheaper somewhere probably, but I wanted to make sure it was compatible with the Picaxe project board, so I decided to play it safe to ensure I wasn’t wasting more money. I haven’t bothered linking to the starter pack I bought with the wrong cable, as I don’t want to confuse you. If you want another cable, have a browse of the Picaxe website and you’ll find it there.

7.Standard servo: What the hell is a servo? I wouldn’t know what a non-standard servo does. I’ve never heard of a servo. I may have explained before: I have no clue what most of these parts do, nor do I know what they are supposed to look like. I go by the pictures on the lets make robots website. So I scoured the internet and found one that looked like the picture and didn’t say ‘fancy servo’. Also, there are 2 types of servo on the picaxe website, so I bought the cheapest one, as I noticed the only difference is the price.

8. USB Picaxe cable: *grumble* see notes above. stupidpicaxeandtheirVATandshippingcostsandconfusingproductdescriptionstakingadvantageofbrandnewgeeks…..

9. The following are three chips that I could not keep apart at the time I took the picture. They are the following:
DIL 330 x 8 resistor array: I had no idea what this combination of words meant. I went safe and got it from Picaxe as they had one that fitted the description and was only £0.80. The description raves on about how wonderful this ‘yellow chip’ is. Mine arrived and it was black. And looked identical to all the other chips. And it took me forever to figure out which was which. And I panicked because I thought I was missing this part and I didn’t want to order it again. I found it, and I found that it has some writing on the top, which is difficult to read/decipher, so it’s a good idea to mark this chip in some way if, like me, you receive a black one.
Picaxe-28X1 IC: The starterpack I bought had this chip with it. I mean, right now that starterpack will save you a lot of money. So just get that and you’ll have everything you need that’s from Picaxe.
L239D Motor Driver IC: I had no idea what category this bit would be under. It’s not under motors, it’s not under resistors, there is usually no category called ‘chips’ and so it took a bit of browsing. But you can find it if you click that link. Just scroll down to the one saying L239D

10. 3 Shorting blocks, top closed: Once I found, finding the jumper blocks was easy as they were just under the header pins. Before that, it was impossible to find. I mean, seriously, try finding those just searching ‘shorting blocks’.

11.Heatshrink tube: I bought some tubing with a 4.8mm diameter and it was too big, so I bought some more. I bought both 3.2 and 2.4mm diameters and, like in the Goldilocks tale, the middle one fitted my cables the best.

12. Female-female header jumper cables: You know what? Let’s make robots says this is now available everywhere. Tell you what; they’re wrong. Maybe in the US everyone is female-female header jumper cable crazy, but in the UK it’s difficult. So I ended up buying it from cool components which had 10 cables for £2.89. Which is decent considering I COULDN’T FIND THEM ANYWHERE ELSE. Also, these cables are pretty short, you should buy a bunch of them so you can lengthen them by soldering.

Batteries: just batteries, you know?
A soldering iron and solder: A soldering iron is only like £6! Who knew! Also, I’m aware that in the drawing in the banner above I’m holding what looks like a blowtorch, but a soldering iron doesn’t look very visually pleasing and also, when you draw a soldering iron, it looks weird. So it became fire. Everyone likes fire, especially computer drawn fire.

Lighter & cutter: I got to buy a cutter and had the following conversation:
Me: Will this cut wires?
RD employee: Well, not massively thick ones, it’s only a small cutter, but it’ll do small wires.
Me: Well I’m building a robot, so the wires are pretty small.
RD employee: *mind blown by how awesome I am*
Me: *ego boost from being so awesome for building a robot*

A Wire Stripper: I didn’t have this at the start of my process and I can tell you that it’s going to make your life a whole lot easier if you have this. Especially as the wires are SO SMALL. But you can do it without if you have the patience and precision for that kind of thing.

A computer: I have a MacBook. One of those white ones that they stopped making by now. I thought it was cool to get a white one, but then I made a curry and now there are yellow stains where my hands rest on it and the man in the Apple shop had to write that down when I got it fixed. Embarrassing. If you’re getting a MacBook, get one of the titanium casing ones for all the cool and none of the yellow stain embarrassment. Also, don’t get a computer just for this, that is ridiculous. Also; why don’t you have a computer? Where are you reading this? The library? Your mum’s house? In the latter case; you can probably use her computer for the robot programming. In the former: don’t bring your soldering iron to the library, it’ll be frowned upon and tutted at.

I don’t have the meter and I already owned a screwdriver. If you don’t own a screwdriver: go get one. Not for this project, but for all other DIY things that you might need in your house. You are not a proper adult if you don’t own a screwdriver.


One response to “SMaR: Day 2 Buying Materials

  1. Pingback: Sophie Makes a Robot: Day 2 – Buying Materials | Science Communication Blog Network·

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