A bit of Solar

I got a message a few weeks back to see if I was still looking for old laptop batteries for 18650 harvesting, and of course I said yes. The next day, I got one or two batteries dropped off at my house:

A few crates. There were a couple of other ones too.

A few crates. There were a couple of other ones too.

Wow. Its going to take some time to crack them all open, harvest the cells, and test them all properly. Of course, I’ve got two batteries for R2 now that seem to be in a good shape and last long enough for pretty much any event. So the question is, what do I do with all the cells I’m going to have once I’ve finally gone through all these crates.

I’ve a few projects in mind that will utilise a couple of cells each, including a standby battery for R2’s brain, but a rough calculation shows that once I’m through all these crates I’ll have approx 1200 cells of varying states. So far, I’m through about half a crate and the vast majority seem to be in a good condition and over 2000mAh capacity. That means I’ve got nearly 8kWh of energy storage! Even if I assume half the cells are dead (so far only about 2% seem dead), thats still 4kWh.

The first thing that jumps out for this amount of storage is a form of power wall. Now, I’m not going to do anything grid tied, that is just too much hassle, but doing something off grid for the garage is definitely doable. If I can perhaps do enough to run the computer and other electronics, plus indoor and outdoor lighting, then I will consider it a success.

25W solar panel for testing

25W solar panel for testing

To start the project, I got hold of a few small solar cells, one 25W, and a couple of 50W ones. The 25W one will be used for experimentation and testing theories out, and the two 50W panels will be mounted on the wall of the garage for a more permanent solution. I also purchased an EPSolar MPPT charge controller, to go with a couple of spare 12V SLA batteries I had spare from initial testing of R2. I went for this model as it has a serial out port on it that will allow me to tie it into my OpenHAB home automation system and graph things like battery charge, solar power production, and any load on the system.

Fabricated a couple of brackets to mount the 100W combined solar panel

Fabricated a couple of brackets to mount the panel

Being able to graph those details will allow me to make an estimate of how much energy I can generate on a typical day, and from that calculate how much I can actually run off my system for a given amount of solar panels, and also work out just how many kWh of energy storage I need.

The charge controller however will only work with standard lead acid batteries, whilst I want to make use of the 18650 cells. To this end, I did a lot of reading and it seems that there are very few hobby level solar charge controllers that will work properly with lithium technologies. Some charge controllers can be made to work with them, but it is more of a bodge.

After much searching, I did find one chinese charge controller that said it worked with lithium batteries, and actually seemed to back that up in the details. One of the main things to look for is that it supports the typical CC/CV (constant current/constant voltage) charge methods that are required for all lithium cells. A few clicks, and it was on its way on a slow boat from china.

Solar charge controller mounted

Solar charge controller mounted

For now, I’ve got the EPSolar charge controller mounted on the wall of the garage, connected to the 100W of panels outside.

Next steps are to get some data logging from the serial port, probably using an ESP8266 based device, dumping the data into my MQTT server, which in turn will be monitored by OpenHAB to be dropped into an influxDB store for graphing with Grafana.

Along with this is the slow process of breaking open a lot of laptop batteries and harvesting the cells. Once I have enough for a decent sized test, I will be looking into various ways of mounting them and hopefully adding an individual fuse to each cell for safety. More research into BMS for making sure the battery is properly balanced is required too.

 

 

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Building a battery for R2 with 18650 cells

There are many options for a battery to power an astromech, from the tried and tested Sealed Lead-Acid, to the latest LiFePO4. This article will look at utilising the very common 18650 cells. These are used in power tools, laptops, even Tesla cars.

WARNING, this article will talk about opening old packs, harvesting their cells, soldering cells, spot welding cells, and lots of other things that could be quite dangerous.

Lithium cells of any type can heat up or burst into flames if mistreated. Only attempt the things in this article if you are entirely comfortable with any possible outcomes. Do other research, read other articles, the author accepts no responsibility for any injuries or death from the instructions given.

General theory

18650 refers to the size of the cells, 18mm x 65mm. They generally have a capacity between 1500 and 3500mAh. If you see anything saying 4000mAh or above, chances are its a scam. There are a lot of cells branded ultrafire that claim over 6000mAh capacity which is a total lie. Voltage ranges from 4.2v when full, to 3.2v when empty. These cells use Lithium-Ion technology, which is a lot safer than the Lithium Polymer that is used in many radio control devices. The drawbacks are that it has a much lower discharge rate. LiFePO4 are even safer, but are also more expensive. Li-Ion seems to be a middle ground, which is why it is used in so many places.

Generally, these cells are arranged in series/parallel to get the desired voltage and capacity. For example, a 24V battery is made of 6 cells in series. Extra capacity is added by putting more cells in parallel, so that if you use cells with 2500mAh capacity and want a 24V battery with 10Ah capacity, then you will use 4 rows of 6 cells, commonly written as 6s4p.

The current drain allowed on a battery is usually 1C, or 1*<capacity>, so in the same example 6s4p battery, you can have a maximum drain current of 10A. Doubling the battery up to be a 6s8p will give you 20Ah and a 20A potential drain. 1C is the safe limit using recycled cells. If you are using brand new cells then you may be able to get a higher current draw by checking the datasheet. For example a NCR18650B can draw 2C and a NCR18650PF can go up to 3C.

Sources

Cells

As mentioned above, 18650 cells are used in many places, and can generally be recycled. The best place I have found for second hand cells is from laptops or power tools. These battery packs can be cracked open and the cells removed. It is quite a labour intensive task, but saves a lot of money. You can pick up job lots of second hand cells from eBay, tho this is getting more expensive as more people are harvesting cells this way.

You have to force the two halves of the battery case apart, usually with a screwdriver or similar flat sharp object, and then separate the cells from the circuitry and cabling inside. Always wear heavy gloves, and take extra care when using a lot of force. Its easy to slip and damage yourself or the batteries. Also make sure to take care not to use the cells as a fulcrum as this will also damage the cell. Basically, be careful and take your time.

An Opus BT-C3100 18650 charger/tester

The drawback is that each cell is of unknown capacity and life, some cells may even be totally dead. They could already have been through a few thousand cycles. Each cell needs its capacity testing with a charger/tester such as the Opus BT-C3400. Of course, if you can ask friends and family for donations of old laptop batteries, you can save even more money. I managed to get a lot donated for free. Despite the drawbacks and amount of work required, you can end up with a battery for next to nothing that would cost a lot if you bought a ready made one. For example, I built a 24V 25Ah (approx) 6s11p for around £50 of cells, plus a few other bits.

The other option is to buy brand new cells in bulk. Either from Chinese sites such as aliexpress.com, or from other sites closer to home such as eu.nkon.nl. Chinese ones are generally a little cheaper, but you do have a long lead time and the risk they are counterfeit. A typical cell such as the NCR18650B (high capacity/average discharge rate) or NCR18650PF (medium capacity/high discharge rate) can be bought for approx £3 a cell.

Additional

As well as the actual cells, there are a couple of other essentials. These are cell spacers, which clip into various configurations to hold the cells in place, and allow air flow around them. You’ll also need nickel strip to connect all the cells together. Both of these items can be bought from aliexpress.com in bulk. If you are buying brand new batteries from NKON, they also sell nickel strips for a decent price when bought in batches of 10m.

Lastly, you’ll need battery connectors and a balance lead. The battery connector can be anything you wish, as long as it will take the current. The balance lead is a connector so you can make sure that all the series cells are at the same voltage. This is important so you don’t let one cell run down lower than the others, which will potentially damage the cell, and maybe the whole battery. You need one for the correct size of battery (eg, a 6s battery will need a 7 wire balance lead) which can be got again from aliexpress.com or ebay.

Constructing the battery

Once you have enough cells together, and all the other items, time for construction. The general process is:

  1. Sort the batteries into parallel sets with the same total capacity. The idea is to have them well balanced before you even start. You can use a site such as repackr.com to help with that
  2. Clip the cell spacers together in the required layout (eg 6×12 for a 6s12p), then lay the cells out. Each parallel set should be the same orientation (eg, negative to the top), but alternate them as you fill in the series set.
    The start of a 6s12p pack. Can see the parallel sets run down the picture, with the series sets alternating across

    The start of a 6s12p pack. Can see the parallel sets run down the picture, with the series sets alternating across

     

  3. Once you have all the batteries in place, clip the top of the frame into place
    Here is a small 3s5p pack, ready for the nickel strips

    Here is a small 3s5p pack, ready for the nickel strips

     

  4. Now its time to connect the parallel sets up. Using either a soldering iron, or a spot welder, connect strips along all the parallel sets. These are the ones that are all the same way up. What this does is create the capacity for battery pack. Be careful if soldering, don’t allow too much heat to build up on the cell, do it as quick as possible. You can get spot welders from aliexpress.com for around £200 that will do the job a lot better.""

    You can also get a device that will give you a full readout, just from plugging the balance connector in. They are only a few pounds from places like ebay. They will let you view the total voltage, each parallel set voltage, and also the max/min/dif between the cells.

    Balance capacity checker

    For the initial charge you will need to use a decent balance charger, such as an imax B6. These are generally for lipo batteries, used in radio controlled quad copters or planes. The benefit of a charger like this is that it will balance the cells out and has lots of monitoring and protection built in. Follow the instructions in the charger manual closely.

    Testing

    Once charged, leave your pack for a while, even a month, testing the voltages periodically. If you have a dead cell, then it can manifest as one of the parallel sets slowly loosing charge. When this happens, you’ll have to dismantle the battery and retest all the cells.

    If you have the time, you can also do a full discharge test with the charger on the battery to get an accurate reading of its capacity. This will take a long time if you’ve made a big battery, depending on the charger you use. If you aren’t overly bothered about an accurate capacity test, just run the battery in the droid (or whatever other use) and monitor the voltage. Don’t let the voltage go down below 3*<number in series> (eg, a 6s should never be let to dip below 18v). To prolong the life of the battery, don’t even let it go that far. Full charge/discharge cycles are the worst case for wear on them, and will shorten the lifespan. I recommend discharging it to around 40-50%, at least on the first try.

    After the first discharge, check the balance of the cells again. Ideally there should be little difference between them in a fully functional battery pack. If there is significant difference (IMHO, 0.1v between the highest and lowest voltage) then you may have a bad cell somewhere. Do another balanced charge and discharge cycle and see if the same cell has troubles. If it does, rip it apart and try again.

    If the battery remains balanced, then you can actually use a none balance charger (cheaper, and usually higher current for rapid charging) for most charge cycles. Tho make sure it is balanced occasionally and no harm in doing a slow balanced charge once in a while.

    Conclusion/Notes

    Using 18650 cells gives you great flexibility in not only the size (voltage and Ah), but also the shape. This example has shown creating standard blocks, but with some creativity you can make a battery that follows a certain shape (ie, follows the outer curve of an R2 unit’s interior). If you want to make use of recycled cells, then this is a very cheap option to get some very high capacity batteries built. Even buying brand new cells will still save you a lot of money.

    For example, I’m currently building a 6s12p pack using NCR18650B cells. I’m getting these for approx £3 a cell. That makes the total cost of cells £216, which gets me a 24V/40Ah capacity battery in a fairly small form factor that can give out nearly 80A (my droid barely pulls 10A at full speed!). I doubt I could fit enough SLA batteries in my droid to get that, and a similar capacity of LiFePO4 would set me back about £800. Even taking into account the cost of a spot welder (which can be used many times of course) its double the price.

    Further research

    One thing I haven’t covered in this article is a BMS. This is a Battery Management System makes sure nothing is going wrong with it, and will cut off the output when the battery gets too low. I’m still researching these myself, and will possibly mess with them on my next pack. IMHO, if you are keeping an eye on the battery voltage during use and doing periodic balance tests and charges, then a BMS is not necessary.

    Also note that capacity of the cells will drop over time, depending on number of cycles, how deeply they were charged/discharged, and how rapidly they were discharged. Take care of the battery, and it will last longer, drain it constantly at high current and it will be dead within a few hundred cycles.

     

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Another hobby?

Hi, my name is Darren and I’m a serial hobbiest.

Well maybe not that bad, most of my hobbies are pretty much related (electronics, computers, science), and a lot are things I’ve been interested in since I was a kid. Most recently, I’ve invested in a fairly decent telescope and mount to do some visual astronomy, but more for astrophotography. I want to take pretty pictures of things very far away! So after a lot of reading of various blogs and websites (Star Gazers Lounge forum is fantastic), and watching numerous youtube videos, I got a tripod for my camera and a couple of cheap lenses off eBay. That is all that is needed and you can get some half decent shots.

My astrophotography album

But it wasn’t enough. So I dove back into the forums and did even more research, and learnt a few important things.

  • Telescope – Numerous different types, mainly split into reflectors, refractors, and catadioptric. All have their benefits and downsides, but for doing astrophotography the telescope isn’t the most important item surprisingly.
  • Mount – This, for astrophotography, is the most important thing to get right.You need to have a solid mount for doing anything more than a few seconds exposure, and one with tracking in Right Ascension at least, to track the stars. And it really needs to be an equatorial mount to avoid rotation of the starfield as it rotates.
  • Eyepieces – You need eye pieces to view through a telescope, and the shorter the focal length, the greater the magnification. These are generally only used for visual astronomy, as cameras bypass the need.
  • Camera – Most DSLR cameras block out a large part of the infra red by design, but you can get them modified to remove this filter and get much more vibrant images. Its not a necessity, but definitely a nice to have.

Whilst learning all this, I had a thought in my head about some form of computer control (Linux based, of course) and actually stumbled upon a few projects to help with this. The first was AstroEQ which was an opensource ‘Goto’ system (select a star, and the telescope will automatically move to center on it) designed around an arduino. That was a perfect start for me, and I was pretty sure I could get it working from Linux. Thats when I discovered indilib!

Indilib is an open source system for controlling all sorts of astronomical instrumentation, not just goto mounts, but also things like auto focusers, digital camera, filter wheels, and other custom devices you may want. Even better, all this can be run from a Raspberry Pi as the control server and a laptop using the actual astronomy software. This would mean I could set it all up, and retreat to somewhere a little warmer to actually do my observations and photography. I’m sure this is against the amateur astronomers code or something, but damn it gets cold out there.

Along with indilib, there is kstars. This is a planetarium program written for the K Desktop Environment, and with EKOS plugin can control any indilib hardware. Not only that, it can schedule work and sequences, and help you plan your observations.

I’m going to (try to) write more blog posts chronicling my progress on getting all this set up, and some HowTo posts on using indilib on a raspberry pi, with kstars, and any custom hardware I make.

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More power!

11934535_10156061505195316_3190924556943319116_oIts been a long time since an update, but we moved house at the start of the year and things have been hectic. At least, thats my excuse and I’m sticking to it! I have been making progress with R2 in the last couple of months, doing a lot of work on his brain for starters, and painting various parts.

Code wise, there has been a couple of fairly drastic rewrites since my last update. The interface is a REST API, which sends commands to various modules as before. I’ve added a scripting module now, so that scripts or loops can be initiated such as random sounds, or a dance routine. The servo module had to have a major rewrite too as I discovered that I could only control one servo at once and had to wait for that to finish before another command could be sent. That wasn’t much good! I’ve also written the first of the actual controller interfaces (not counting a simple web one for testing), R2 can now be controlled from a PS3 controller. Button combos are read in from a csv file to trigger certain effects or scripts. Lastly, R2 now has a voice, and can play any mp3 stored in a directory, including selecting random ones from a list of types. Next step is to get either the Pi or the A la mode Arduino to control the speed controllers. I don’t want to run them off the Adafruit i2c servo controller for safety, I’d rather drive them directly and have some form of watchdog to make sure R2 doesn’t go on a rampage. All the code is still available on GitHub under my user, dpoulson

The PDU also needed a rethink, not least of all because of the amount of current it needed. The setup now has feeds directly to the speed controllers, with relays on the output from them to the motors so I can break the circuit if needs be. These relays will automatically turn off if the battery is disconnected so that any pushing of R2 will not feedback into the speed controllers and fry them. The relays will also be controlled from GPIO pins on the Raspberry Pi so I can disconnect them via an API call. I’ll also have an input for a kill switch that will have to be permanently on if any of the motors are to be powered, possibly using a transmitter in a replica droid caller or hilt of a light saber. I’ve a base idea for the new relay controls:

Powerswitch The relays I’ve found are Omron G4A-1EA, which have the benefit of the switched load being on spade connectors on the top, rather than through PCB traces, which when I did the calculations would need to be massive to support the potential current running through them. This allows me to make a simple PCB with the controller circuit, and hook the 24V battery up to it to power the coils. If the battery is removed, the coils turn off and the circuits are broken. No fried speed controllers.

The 24V connection will probably go through the fuse box I’ve installed, with a hefty fuse. The makers of the speed controllers don’t actually recommend a fuse but I’ve seen a few comments saying a 60+A fuse can’t be a bad idea, just in case!

The battery will connect directly to the center contacts of a DPDT switch, with the fuse box on one side, and the charger connection on the other. This will allow charging the batteries without taking them out of the droid. Not sure if this is best practice or not, needs more research. Currently they are just a pair of 12V SLA batteries that I had, connected in series to give the full 24V.

I’m hoping to get some time either this weekend or next, to hook up the motors, speed controllers, and battery, to test them out and get an idea of potential current draw. They’ll be controlled with a standard RC transmitter/receiver for now. If I can get the legs onto R2 he may even be drivable by xmas.

Fingers crossed!

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Lasers! Pew Pew Pew!

So, the other day a large crate arrived on my doorstep.

Frickin laser!

Hmm, what could this be?

Yep, I treated myself to a new toy. A 40W CO2 powered lase CNC engraver/cutter (Model K40-III). Now, this isn’t exactly a top of the line model, infact it is probably the cheapest you can get one without going down the DIY route. It is a very cheap device from China, with the most basic of functions. Basically an X/Y axis with a couple of stepper motors, a 40W laser, and a very basic controller board. The main drawback (besides all the instructions being in Chinese) is the fact that it will only work with the rather rubbish software that comes with it, and that will only run on Windows XP. That isn’t going to work for me, especially after finding an old XP laptop and trying the software out. To say that it is buggy and un-userfriendly would be an understatement.

Thankfully, I knew this before purchasing it from eBay. There is a great open hardware project call LaOS, which is designed to replace these cheap and nasty controller boards on these types of lasers. So, armed with a PCB from the project, a bunch of components, lots of pictures of the existing setup, and my trusty multimeter, I am going to set about installing a nice LaOS board. The benefits of this new board is the fact that it adds network capabilities. It becomes effectively a network printer, controllable from a linux machine as a Cups based printer. This way, programs like Inkscape to draw the desired output, and send it to the machine. A much easier way to control it.

An LCD display with local controls is also available as an addon to the main LaOS board. All in all it should turn this cheap basic machine into something fairly usable. It should then be able to compliment my printer for making things, and Joy should also be able to use it for some of her arty stuff.

Testing!

So, first stage was to do a few tests to make sure it had survived the journey and was in a working condition before I break it. The front panel has a handy laser test button to let you fire the laser without having a computer hooked up. Needless to say, after hooking up the water pump to cool the laser, I had a bit of fun burning things! 

Frickin laser!

Seems to be working ok

And with it hooked up to a computer with the rubbish software

Frickin laser!

About the best I could do with the software supplied

All seems good, so time to take it apart! Hopefully the next post will have a nice success story of a much improved machine

Frickin laser!

Unboxing!

Frickin laser!

Unboxed!

Frickin laser!

Thats a 40W Laser

 

 

 

 

 

 

 

Second part is here

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Nearly there! The hotends have arrived!

I got a nice parcel delivered today. Two nicely build hotends for my new Prusa Reprap. After all the issues with the Huxley, the Prusa has been a total doddle. The last piece I needed for it was a hotend, and after having some issues sourcing some of the components, I had a look on eBay for any pre-built ones. I found one guy shipping some from Poland that looked perfect for what I needed, not only did they have all the molex connectors already done in a way that is compatible with my Sanguinololu board, but he was offering a twin pack with one .5mm and one .25mm nozel. Oh, and a pre hobbed bolt too!

Prusa build

So, with the body built and the electronics tested, all I have to do is figure out how to attach the hotend and I can start building. I’ve already posted a video a few days ago of the body moving nicely, which is further than I ever got with the Huxley. Never know, maybe by this weekend I’ll be able to print something! Just have to finish work first.

Here’s the video of the first test of the electronics.

Prusa build

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Replacement electronics are here!

The replacement electronics for my Reprap Huxley arrived today at long last. I’ve had them plugged in for nearly an hour over dinner, and no flames. Good start!

I think this evening and weekend are going to be devoted to trying to get my printer working. I hope nothing else turns out to be faulty with the kit I bought. I’m already very disappointed with the quality of it overall. If I had a better understanding of the whole Reprap process, I would have gone with just ordering the plastic parts from somewhere and building my own. I’m sure I’ll do a full write up on it at some point.

To recap, I’ve got the frame built with all the stepper motors mounted and the belts in place. So all(?) I have left to do is:

  • Calibrate the electronics
  • Finish the extruder – Just needs the motor mounting I think, and the tube inserting.
  • Finish the hot end – All gunged up, just needs the electronics attaching to the nichrome wire and thermocouple.
  • Mount the hot end
  • Mount the end stops

Once all that is done, I may actually be able to start testing. The testing is going to be a long process I think, I very much doubt I’ll be printing quality objects from the start. Lots and lots of wasted plastic doing test prints, levelling the base, etc. Still, if I can finish this weekend with an actual printed object I’ll be happy. Roll on 5pm when I finish work!

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Hobby electronic links

Since deciding to renew my interest in electronics over the past few months, I’ve tried various websites for supplying components and parts, along with some good sites for learning and ideas. I thought I’d do a quick write up of some of my favourites and put it all in one place.

Firstly, lets start with components. You will always need somewhere to get all your bits from, as well as tools and consumables. Here’s a few sites that I’ve found both handy and reliable. I do like to be able to get everything I need from one place, but I haven’t yet found a one stop shop for everything, but I have managed to narrow it down to just a few that will satisfy most of my needs.

  • Bitsbox – This is a great site to get your basic components from. They are cheap, well stocked, and have a nice simple website to use. You won’t find things like Arduinos, or Sparkfun kits, but you will find just about all the basics you could ever need. Components can be ordered in singles, or bulk, and delivery is pretty rapid. I tend to use Bitsbox to stock up on standard things like resistors, capacitors, common chips, and other non specialist components.
  • Proto-Pic – This is where you go for the more ‘building block’ style components. Things like Arduino, Sparkfun, sensors boards, breakout boards, etc. Great place with a nice easy to use website. I do find that I need to watch my spending here. It is too easy to keep loading up the basket with fun parts, especially shiny things like LEDs. There is a lot going on now in hobby electronics where you buy pre built component modules and link them up for a project, rather than scratch built circuits. Good communication from the staff here, and will part ship your order if they are having trouble with stock, instead of having you wait.
  • Cool Components – Very similar to Proto-Pic. You should be able to find what you want in one of these two stores. I’ve dealt more with Proto-Pic than Cool Components, but more for familiarity than any other reason.
  • Jeelabs – This is a slightly odd case, and is a more specialised shop than the rest. I’ve been working a lot with JeeNodes, and this is the place to source them from. Its a one man shop, but he is designer, builder, and shipper. He also provides a lot of information, not only on how to use his products, but also in general electronics knowledge.
  • Unmanned Tech – Not exactly in the electronics section, but this is where I get my quadcopter autopilot components from. I just wanted to mention it here because the support that is given is great. Very friendly and actually want to help.

Next, lets look information sites. These are places to go for learning more about electronics, techniques, and news.

  • Jeelabs Blog – As mentioned above, Jeelabs provides JeeNodes, along with other modules to go with them. The blog provides a lot of information about how to use their products, how they were designed, and also general information such as circuit design, how to improve your arduino sketches (especially making them low power), and walks you through good ways to measure and bug trace your own circuits. Well worth following.
  • EEVBlog – A great, fun blog by a mad aussie. (Are there any other types?!) He has a regular video blog on a fairly wide range of electronics subjects, including reviews on lab equipment, tear downs of new gadgets, and instructions on circuit design. He’s now making a living from this blog after having many years work experience in electronics. Videos are released on a pretty frequent basis and are well worth a watch just for his enthusiasm!
  • Instructables – This site is just fantastic. People from all over the world with a passion for making things can upload full build instructions to this site for all to read and reproduce. Its not just electronics here either! Anything that involves making things can be found here, from needle work to metal work! The information is free, but it is worth signing up for a full members account which allows you to view the instructables in a single page, rather than multi-page, and also download it as a PDF. Handy for putting onto an e-reader or similar. Great place to look for ideas for projects, or help on something you’re working on.
  • Makezine – Makers are taking over, and this is the place that pretty much summarises the movement.
  • Thingiverse – If you have a 3d printer, laser cutter, or cnc mill (or at least access to one), then you can find many actual objects available to download to be produced. The idea being, if you need something, and design it, you can then upload it to this site for anyone else to produce for themselves. An open source object library.

Thats it for the main part. A few honourable mentions go to RepRap for all your 3d printing needs, and also Youtube. There are many many videos there that are well worth a watch.

 

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3d Roadblocks

Okay, its been a little longer than I hoped for for an update, but it has been Christmas so I’m using that as an excuse.

The build of the huxley was going very nicely until I hit a few snags with the kit I’d ordered. Firstly, there are nowhere near enough nuts, bolts and washers provided to complete the kit. I ran out before I’d even finished the frame, let alone mounted the motors, built the extruder, or made the idlers. Huxley

Secondly, the belt for the X axis was too short, so I couldn’t fit that.

Thirdly, the electronics actually burst into flames on me whilst testing and configuring the motors. This was before I’d actually done anything bar plug the power supply in. To say I wasn’t impressed doesn’t quite cut it! Oh, and the analogue to digital converter for the hotend was missing.

So, considering I got a kit for hassle free construction of my first printer, I’m not overly enamoured with it. The UK company have put me in touch with the manufacturer to get things sorted, and they have said they will send out the replacement/missing parts from the states, so hopefully things will get sorted, but I could’ve had a nice working 3d printer by Christmas had everything been right in the first place. The instructions on the wiki also leave a lot to be desired, especially the hotend page, which were for a totally different design. Only one photo showed the model I’d got.

In the meantime, whilst waiting for the replacement parts, I’ve done some research into the electronics available for the various reprap machines, and have decided to build my own electronics based on the generation 7 schematics on the wiki. These electronics all fit onto a single sided PCB, so nothing complicated, and seem to be relatively simple. In fact, I bought a pre-made board off eBay, and had most of the other electronics already ‘in stock’ in my cellar. The gen 7 boards also use pluggable stepper motor drivers, which mean that if one does burn out, then you can simply plug another one in, unlike the kit electronics where everything is surface mounted and impossible to replace.

With all this, I’m hoping I can get a chance this weekend to finish off the electronics and get the main body of the printer working. I’ve built the extruder, mounted the motors, and got all the belts on, so all that is left is the calibrate and level it all, and build the hotend. I’m hoping the hotend will be fairly straight forward, but as I’ve no real instructions, just one picture to go off, I’m going to be very careful!

Anyway, here’s some pictures!

Huxley

Main frame

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X Axis

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Y Axis

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Y Axis in place

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X and Z Axis in place

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Extruder

 

 

 

 

 

 

 

In other news, I’ve been rather impressed with how easy Google SketchUp is to use. I’ve been messing around with it to design the parts for me printed quadcopter. For a beginner who just wants to make simple parts to be printed on a reprap, it is perfect. Install the plugin for exporting to STL files, and you can both upload these to thingiverse, and import into most of the 3d printer software that is available for the repraps.

Also, slightly related, I’ve actually had a quadcopter flying with the Arducopter controller. It was only a brief test as I managed to crash it and shatter 3 of the blades. Spare blades only arrived on Christmas eve, so not had a chance to do much more with it. Just waiting for some better weather so I can fly it outdoors. I’ve managed to snag myself and OpenPilot Copter Control board too last week which should be arriving any day. This is a halfway house between a simple KK Multicopter controller, and the full blown ArduPilot Mega. I’ve got the APM telemetry kit coming soon too, so I can take my laptop and get live telemetry from my quadcopter. Unfortunately, my laptop battery has developed a fault, so the only way I’ll be able to do that at the moment is if I can fly it somewhere with a power socket nearby!

So, hopefully next week I’ll be reporting that my printer is done, and will at least have done a couple of nice test prints. I think my first actual things to be printed will be brackets and improvements to the printer tho’.

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The construction begins…

Two parcels arrived this morning, one a 2.3kg reel of 3mm ABS filament, the other was a surprisingly small box full of plastic and metal. Otherwise known as a RepRap Huxley 3d printer! A little over 3 weeks past the expected delivery date, but at least its here now.

Unfortunately, work got in the way of me doing much, but an hour of my ADSL being broken over dinner meant I could at least open up and check the contents. I must say, it is smaller than I was expecting, but thats a good thing. This should fit nicely on my desk and not take up too much room. The box contains everything you need to build the printer, bar tools of course. This kit is actually an import from the states, sold through a UK company who I assume buy a load of these and then ship them out locally. It did come with a US power cord on the PSU, but for me that isn’t exactly a show stopper! No instructions are included, instead everything you need is online on a wiki, and in numerous videos supplied by other people who have built them and in true open source fashion, contributed back to the project. In this vein, I’m hopefully going to improve the instructions on the wiki a little. I’ve already spotted a few areas that could be improved.

Wonder how long this is going to take me!?

Huxley

Plastic parts, and metal rods.

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