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Topic: COMPLAINT: Starter kit components not fitting (Read 29554 times) previous topic - next topic


I have a starter kit from Mouser bought Jan'13. I'm on Project 5, and...

1) The base of the potentiometer is too wide to fit as per the book diagram. It stretches 5 holes across, in the book the diagram shows it as 2. I cannot make the circuit in the book.
2) The header short end is too short to fit into the servo female end.

Now, I've fixed (2) by using short leads instead, which as a bodgejob looks like it'll work. But I'm wondering how to tackle 1 at the moment, trying to redo the diagram.

This, and all the other QC issues like the wires being the wrong colours in the book (or in the kit?) really isn't helpful. There are QC issues with the kit that need to be addressed.



Yet more issues

3) The potentiometer 'base' just doesn't fit well into the board at all and whilst the circuit I've made works, it's all over the place unless I press down very very hard on the base. Basically the connection is wrong, it needs force to make it work. With force it works exactly as expected.

4) I also discovered that the white leads in this mouser kit actually vary in length, this isn't terribly helpful when you're forced to rely on these because the supplied header pins are too short on the short side to work with the supplied servo

5) oh and the servo isn't like the diagram in the book either. In the book circuit the leads are from the top down black, red, white, but on the supplied servo the order is different, black, white, red. Obviously this has circuit implications, using header pins as instructed would have reversed white and red.

This sort of "complete lack of combined QC" is seriously poor. And considering a whole bunch of further projects depend on these components, what, exactly, am I supposed to do now? Whose responsibility are these kits, Arduino or Mouser?



3) The reason the potentiometer base doesn't fit well is because of the pin shapes. They're metal strips that measure 1.05mm wide and .29mm thick at the breadboard end, but this thin shaft is only 3.9mm long at which point the width broadens to 1.98mm. I do not have a tool to measure the breadboard holes; that wider shaft doesn't fit in the hole but the length of thin shaft isn't long enough to make contact unless you push it down hard.

Presumably I need to solder header pins onto the ends to make it work as intended. I don't have the first clue about soldering, anyone throw me a bone?


A bone regarding soldering?

You will need a soldering iron and some solder at a minimum. The solder is made of a metal that will melt at relatively low temperatures (relatively for metal). To get a good solder joint, make sure that you are heating both surfaces equally and apply the solder to the point where your two surfaces touch. The solder will melt and will flow along the metal. The reason for making sure that both surfaces are fully heated is that solder flows on hot surfaces, but puddles on cold surfaces. So, you would have a weak connection (called a cold solder joint.)

Generally, don't apply more solder than you need and only use solder meant for electronics (not plumbing or 'electrical' solder for eaxmple.)

Obviously the iron will get hot, so either buy a stand or an iron with a stand, and keep your fingers out of the way.

If you have the cash, get a good soldering station that has a temperature control. This is a tool that you will end up using quite often if you are getting into electronics as a hobby.



2) The header short end is too short to fit into the servo female end.

You actually have to resize these yourself. I got a strong pair of pliers with an end good for grabbing and took the plastic part of the headers and pushed the pins until the size was appropriate. It took a bit of work but I eventually found a size that fit the servo on one end and the breadboard on the other perfectly. Your solution is fine too though. Whatever works!


Yes, thanks BranchofLight! I saw this written in a post whilst looking for the reason that #7 doesn't work properly either, and tried it, seems to work. That said the servo's wires are on the plastic block in a different order to the book so even with the header pins it still couldn't have worked :(


Yes, thanks BranchofLight! I saw this written in a post whilst looking for the reason that #7 doesn't work properly either, and tried it, seems to work. That said the servo's wires are on the plastic block in a different order to the book so even with the header pins it still couldn't have worked :(

If you just mean the order of the 3 wires from the servo into the pins then you simply have to wire it on the breadboard to compensate for the change.


Yes and that's what I did, but you know when you buy a book as part of a learning kit it's really not entirely unreasonable to expect them to be as illustrated :).


Yes and that's what I did, but you know when you buy a book as part of a learning kit it's really not entirely unreasonable to expect them to be as illustrated :).

Of course not, but you could look at these small obstacles as the book giving you a chance to flex your problem solving muscles XD


Nice positive spin there - and generally yes I'm very persistent at problem solving. I think though when you're completely new to something, problem solving, even simple things, is asking quite a lot, that's surely not really the appropriate stage for this. I hadn't even put a circuit together before this time last week.

I'm surprised the book doesn't actually have a decent section in it about problem solving! explaining such things as the cables being the wrong colour, the diagrams being wrong, the components not being as described, the components not fitting. Why is this though? I mean itseems a reallyreLly basic ting to get colours and fittings and wire order right, just a case of QC andspeccing. Are these kits assembled by 3rd party people? How accurate is the spec they're sent? In the drive to minimise cost, has component quality been compromised a bit too much?

One thing I'm starting to wonder a lot about is the breadboard actually, just because another guy said he bought a new one and it worked straight away. And some of myissues could be explained by this too.

Mind you I haveno experience at this whatsoever soI could be talkingcomplete b*llocks. Maybe I'm clutching at straws, we'll see as I progress.


So I'm up to project 10 now, but the story is still the same - dealing with incorrect circuits because of bad fitting components actually takes up more time than the exercise or the sketch. Exercise 10  ended up taking a frustrating 3 hrs because I had to add debug output to see if the items were working, then hunt around for a place that the H bridge would settle properly. On the upside it's made me teach myself to solder in order to fix the motor whose lead came off and add header pins to pots & switches to make them seat properly.


I just completed project #5 and had many of the same problems you've identified.  While I've had some electronics training (undergrad electrical course more than two decades ago), I am by no means an expert. 

The most frustrating part so far is the components not staying in the board (especially the buttons and the potentiometer).  In order to make the project work properly, I had to keep my finger pressed on the potentiometer, pushing it down into the board and ensuring proper contact was made.  I haven't gone down the route of soldering on leads as I would really like it if the pieces sat on the board (like shown in the diagrams). 

I wonder if crimping the rectangular pins into more of a square cross-section would help them fit?  But you'd have to be very careful you don't break them instead. 


Sorry to hear the kits been a little frustrating for you Nass but overcoming these problems, is what proto-typing is all about.  It is fair to say I have a bit of experience with prototyping but it was 20 years ago. 

I was really impressed with the selection of components in the starter kit and the book that came with it.  A little light on detail for me personally but very clear, with instructions which are about as easy to follow as they can be.  There are still some challenges that just have to be accepted though.

  • Components which are made to be soldered into PCBs, won't always fit well in a push down breadboard.

  • Components are manufactured in batches. So when the distributor of the exact part runs low on stock, you sometimes have to find an alternative which is close enough.  If you have already printed a couple thousand books detailing the part, well something has to give.

  • Once you get into a project with more than a few connections and more than a few lines of code, the chances of getting it right first time are pretty low and you will have to debug your work, patiently and methodically.

  • Murphy's law says you will never have all your link wires, the right colour and the right length ;)

But, if you have the patience to negotiate the learning curve, designing and building your own circuits can be a really rewarding pastime.

A couple of tips which may help you;

  • As you progress through the projects, try to get a feel for working from the schematics, rather than just duplicating the project photos.

  • Blu-tack can help seat awkward components on a bread board.

  • Get yourself a few meters of bell-wire (1/06) and start making your own links.

  • Awkward components you use a lot (chips and trim pots), can be soldered permanently into strip board (aka Vero board) with flying leads for connecting to a breadboard.

  • Get yourself a basic (cheap) Digital Multi-Meter.  You want one that measures DC Volts, Ohms and has a continuity buzzer.  Simple to use and about the most useful diagnostic tool you will ever buy.



Overcoming problems and problem solving are definitely part of any learning experience, but in my humble opinion a starter kit isn't the place for that. A decent starter kit should work, full stop - components should fit and illustrations should be accurate. If the instructions are out of date, add a supplementary 'update' booklet!Overlooking this, sure, the starter kit is a good introduction - I've definitely learned a lot.

But spending hours and hours, over about half the projects, wondering why completely correct circuits and sketches didn't work only to discover it was the bad breadboard design didn't add anything whatsoever. Once I bought a new breadboard all the circuits worked very quickly... much more encouraging and exciting to a beginner than stuff that doesn't work!

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