Don't let fear stop you

Sometimes we come across projects or sub projects that we don't want to take on because we are worried what others might think, if it's safe, if others will think it's safe, if it's too expensive. The problem is that when we let these fears and concerns govern what we allow ourselves to do then we end up not accomplishing anything near what we are capable of.

This is something that I have struggled with on various projects over the years, is it safe? What will others think of me doing it? Whatever the case may be. On the instances when I have put these fears into their place by stopping and working out just what the impact will be, then after putting into place safety controls I have always found these projects to be worthwhile. This one today is one of them. Here was my problem:

The controller for the CNC Lathe runs on 110V not the 240V that comes from the walls here. When I got the machines I had a few cords that would connect them to a transformer box  so they could be used with a 240V wall supply. Unfortunately I have lost said cables and to be able to run the Lathe I need to get 110V to it. Bugger.

This is where fear came into it. From the time I have started playing with electronics there has always been an unspoken rule that you just don't have anything to do with line voltage as a hobbyist. This is a very safe rule. However in this situation it would've stopped me from being able to run the lathe again unless I found the power cord (Unlikely). So after taking stock of the risks (electrocution) and working out controls (unplug and leave for a while to let any charge dissipate, test to make sure nothing is shorted to the case before re-connecting) I realized that this could be fixed safely.

And here's the finished product. I can now use a normal power cord like I would use for a computer to power the lathe with 110V.

That's where the scaryness happens. The transformer is potted in epoxy so that's all quite solid.

Looks like I'm not the only one who chain drills and doesn't fully clean up the edges. I had to take off some of the peaks before the new socket would go on.

Testing all of the connections. I'm using an old analog multimeter on ohm reading to check for shorts. It does still work, certainly well enough to show a short circuit.

That's all for today, the next post will be my 100th post on this blog so I am working on something cool for that so stay tuned.

And remember, don't let your fears tell you that something can't be done. There's always a safe way.

Cheers,
Rex

Nathan's Computer: The conclusion

So the computer I have been building for my younger brother Nathan is now finished. He now has it at his home and is finalising the driver install and starting to set up the games that we actually built this machine for. We managed to save quite a bit of money by finding a case which actually had nearly everything we need inside it.

It was a little grotty but we needed a case and DVD drive. While we also didn't need anything else that was in the case we made good use of it because it brought the total system cost down for Nathan. In the end we had ordered RAM, a Power Supply Unit and a graphics card that we ended up using from this machine because the ones in here were better than what had been ordered.

Unfortunately it was very dirty and dusty. We tipped it up on end and all this fell out onto my nice, clean(ish) carpet. Luckily I had Nathan there to help me, so after removing everything from the case he cleaned it all with the vacuum cleaner and did a fairly good job of it I must say.

We were very, very excited when we found this. There was a total of 16GB of RAM in the case. Somewhat more than we had expected to be putting in there right away. So right off the bat Nathan got a RAM upgrade. Also a PSU upgrade as the one in the case was about 100W bigger and had other comparable specs. Also a massive graphics card upgrade. Comparing the GT730 we had bought and the GTX550 that we found there was just about an exact doubling of the Cinebench OpenGL test. From 30 FPS to 60 FPS. It was a huge improvement.

This is how we tested the system initially. If my experience building computer has taught me anything, is that test at every possible point. In this case we tested with the absolute minimum of parts in the machine. RAM, PSU, CPU, CPU Cooler and Graphics card.

Unfortunately I got a bit excited and forgot to take a picture of the first POST screen. Suffice to say that it POSTed and I was very happy and there was much rejoicing.

After that we put everything in and got windows installed. Another very happy moment.

You may have noticed a funny circle in the front of the case:

This is actually a fan controller/temperature monitor that runs from 12V pulled from a molex connector on the power supply and (we guessed) 5V from a funny shaped connector neither of us recognise, let alone have attached to the PSU. So I did what I'm good at and came up with a solution. I cut the funny plug off then soldered the wires onto the 5V going to the power light. I checked the current draw on this when we tested that it was actually 5V using my benchtop power supply and the current draw was not registering on the scale, so less than 0.5 mA which I was quite happy to pull from just about anywhere.

The astute amongst you will notice that the above picture is showing an adapter for 20pin ATX power supplies to drive 24pin ATX motherboards. I had this lying around from another project that I ended up doing the right thing and buying a new PSU for.

The tricky thing about buying parts off ebay is that they may not always work together. The motherboard is from a HP Z400 workstation which looked fine on paper. However initially it wouldn't POST. This is because HP decided to use +12V on some of the pins of the 24pin plug where the ATX standard that everyone else uses at +5V and +3.3V. Not very useful. So I had to splice in this adapter that I already had to a molex Y-splitter so we can get the extra +12V power.

This is what it looked like before installation.

And here we see it in situ.

So there you have it, the build is finished and tested. In the next few days I will do another post detailing the parts list, final cost and some benchmarks (also some thoughts on that parts I used) so keep an eye out for those if you are interested.

If you want more detail on how to build a computer let me know. I have another build coming up in the next few weeks that won't be as crazy as this one but will still give me an opportunity to show how it's done in great detail.

Cheers,
Rex