Category: Miscellaneous

Happy new year!

Posted by on December 31, 2014

Happy new year everyone!

Reviving an old Jacobs chuck – Electrolytic Rust Removal

Posted by on November 24, 2014

I’ve been using electrolytic rust removal for quite a while now, but this method never ceases to amaze me!

Here’s how I found the chuck, it came with a milling machine I acquired a few months ago, the previous owner had left some tooling in a rotten shed and this is the end result.

Jacobs chuck fossil

I was willing to bet this chuck was trash, and I was ready to throw it away. However it turned out to be an older type Jacobs, it was also a size I didn’t have… So I gave it a try, what can we lose right?

It was frozen shut. In theory the electrolysis should not affect the inside portion of the chuck, because it isn’t in the line of sight with the anode — but I had my hopes this could just work by freeing up the rust near the jaws and the collar.

Surprisingly after a few hours the chuck was in working order!

Sadly it's been abused (more than we thought) and it won't center within spec anymore, however it was quite an interesting experiment nonetheless!

Sadly it’s been abused (more than we thought) and it won’t center within spec anymore, however it was quite an interesting experiment nonetheless!

I did remove the arbor later on, not sure how they were using it like that, the inside of that arbor is hollow and threaded, but it has no surface to register with, aside from the flat face on the hexagonal portion — odd, maybe it was meant to be screwed onto a turret tool blank for a capstan lathe?

So there you have it, you CAN turn your archaeological finds into usable tooling, assuming no apes were previously involved.


Android – Debugging through WIFI

Posted by on February 9, 2014

Ever wondered if you could use ADB through WiFi to avoid using the USB connector while debugging on Android all the time?, turns out you can and it’s simpler than you thought!

Of course, the first step is to root your Android device, But don’t worry, it’s also very easy now adays. I recommend you try Framaroot — Yes, in theory there could be some risk involved, but given the current state of Framaroot I’ve never had a problem and it takes about 3 seconds to root your device, you don’t really need to reboot it either although it’s recommended.

Once you’ve got SU (SuperUser), you can proceed to install WiFi ADB — Avoid any other application, specially if it requires a host on your desktop / dev box since really, you’ve rooted your device, no need to go around obstacles that aren’t there anymore.

Now, simply start WiFI ADB and enable it, the final step is to get your ADB to listen to your device through TCP/ip, we simply open ADB via the console and perform the connect command followed by the ip and the port of your device.

For example in my case:

adb connect

ADB should then report “connected”, otherwise make sure your device is listed to begin with using the “devices” command, it should pop the id of your device. Otherwise, make sure WiFI ADB is enabled.

That’s all!

DIY Electro-Etched Name plates and tags on steel

Posted by on September 20, 2013

The story goes…

I’ve been working on a metal project lately and I wanted to have a name / brand plate riveted to the project, after finding out how expensive a custom one can be I decided to try etching my own using very few tools and chemicals.

The process is similar to toner transfer PCB etching, however we’re going to be using sheet metal (mild steel) and we won’t be etching any traces, instead we’ll have our own logo, specs or any other information we want to add to our plate. We will also choose electrolysis over acids.



Personally I’m a huge fan of the “cast iron” look you can get with this technique, pretty neat huh?


Design it, print it, etch it.

Once you’ve got your black and white design ready, go ahead and print a mirror image to the desired dimensions.

  • Trim your sheet metal to size, mine was 1mm thick but you can use whatever you’ve got. Decide whether you want to leave an edge or not.


    This design is actually an inside joke, I used a couple images from deviantart (hopefully they won’t mind?)

  • Clean the sheet metal, use a degreaser or common soap and a brush or pad to remove any oils and dirt it may have on it’s surface. Sorry, no pictures of this step.
  • You could choose whether to score the surface using 220 grit sand paper (or coarser) or just let the original surface be, it’s up to you. Sorry, no pictures of this step.
  • Proceed to toner-transfer as usual using your favorite method (a clothes iron works just fine).


    Toner applied, ready for etching!

  • Prepare the electrolyte, washing soda and water is preferred but you can get away with salt and water; just do it outside and away from ferrous objects you may wish to remain intact (chlorine gas will rust them).
    • The amount depends on how much water you’re going to use, per liter I use 4 spoons of either chemical, in essence the more conductive your electrolyte is, the more current is allowed to flow and thus the faster the etching process becomes. I’m not entirely sure if the surface finish becomes rough with the increased current, you’ll have to experiment for yourself!
  • Use a battery charger or an ATX power supply, in fact any power supply capable of providing DC at several amps will do.

Your plate to be etched has to become the anode (positive) and the cathode (negative) terminal is connected to some scrap steel. This steel will actually become de-rusted, so maybe choose something you want to restore and kill two birds with one stone — Just try to match the surface area and keep the two parts evenly apart.


Etching… If you think the colour of the electrolyte is nasty, give it a few more minutes… The cathode is indeed too small, but it’s what I had. Plus I wanted to de-rust that part. Notice the steel wire used to contact the anode with the plate to be etched, try not to use copper.


Now it’s all about time…

I often leave the plate to etch for half an hour and I don’t care about the amps going through, I just remove it periodically and touch the surface to get a feeling of how much metal has been etched away.

When to stop is up to you, just keep in mind the resist (the toner) won’t protect the metal from the sides, so you’ll get what’s known as undercutting after a certain point.

There’s also the fact that if your current is high enough, the resist will begin to peel off. This could also happen if your part and electrolyte become overheated, so keep an eye on that matter.


Finally etched, it didn’t come out as I expected but it was a good way to learn, after all this was my first attempt!


Giving it a nicer look

Right now you can go ahead and rinse the plate you just etched. At this point there are several options on the finish…


This is the result after etching another design, no patina yet. So the contrast is low. There’s some undercut and portions where the resist peeled off; the current was too high.

You can leave it as-is for a natural finish, you can sand it with emery cloth or you can apply a layer of black oxide (hot or cold, up to you) and either leave it as-is or brush it to increase the contrast of the letters and to make it look aged.

Other options to create patinas include wood dyes, paint, etc. The work can be sealed with beeswax or a clear coat,

To black-oxide the plate without chemicals you’ll have to heat it red hot, then quench on linseed oil or motoroil. For a higher degree of control over the process you can choose to use a rag soaked in oil instead and apply that to the hot plate, just be careful and do this outside, the fumes are noxious and there’s always the risk of a fire, so keep sand or an ABC extinguisher nearby. This method requires multiple passes and takes a lot longer, but you can get any colour you want from gold to blue.


The end result, pretty good for the money! — All that remains now is a simple cut and a couple holes to be drilled, a countersink wouldn’t hurt either.


If all went well, you’ll have a nice looking plate for your current project, or just some pretty cool piece of art. Don’t get stressed out if it didn’t come out exactly how you wanted it to, it’s still usable and unique.

Get creative and have fun!



DIY Refurbishing your espresso machine

Posted by on May 16, 2013

Leaky head?, Low flow rate?, read on…

Most of mid to low end espresso machines share pretty much the same pump and block assembly with very few differences, there are in fact just a few major designs out there most of which are aluminum/brass based and manufactured in China, however that doesn’t neccesarily make them bad.

In all inexpensive units (and some expensive units sold as “professional” but they’re actually a product of marketing bullcrap) the group head has a spring valve that opens when enough pressure builds on the head, this happens when the pump is turned on and it’s there to prevent water leakage. Some better units will use solenoid valves instead, which also allow to set the flow rate in some cases.

The passive valves used on inexpensive units require a clean surface to sit on, much like an engine valve does. The reason espresso heads can leak is simply because of an uneven mating surface (dirty valve seat or dirty valve) it doesn’t have to be a faulty part so if your machine leaks, don’t assume you’ll need rare / expensive spare parts to fix it. If you’ve taken good care of your unit chances are it needs a slight clean up and polish.

Like I said, this gparticular uide is mostly for inexpensive machines, I don’t have experience with high-end units as I’ve never had the pleasure to work with them.


Alright, bring it on!

To proceed, remove the water reservoir, portafilter and any loose parts such as filters, trays, etc. Tip the unit over, I use bubblewrap on the countertop to prevent scratches. In my case I had to remove the bottom cover (plated steel) which was held in place with 4 security torx screws.

Identify the type of head/block assembly, mine has a 12MM nut which holds the diffuser and forms part of the valve assembly itself. Other heads may use a notched nut or similar assembly allowing for a flat-head screwdriver to be used. Go ahead and remove it.


A view into the brew head before cleaning it, you can clearly see it’s become obstructred. The valve was in even worse shape!

The valve is often spring loaded and has a silicone seal / head. This is where some of the sediment build-up occurs and prevents it from sealing the boiler properly. But most of the build-up occurs on the valve body, which is often (but not always) brass, on more expensive units you may also find stainless steel parts.

Once you’ve removed the nut pull out the spring if it didn’t come out on it’s own, now that the entire valve assembly has been taken apart, use a flashlight to look into the valve body, you’ll probably find the opening to the boiler is slightly (or severely) restricted with build-up.

If there’s no way to remove the bottom of the unit, you’ll need to work with a mirror to look into the boiler.


Valve assembly after clean-up.

To proceed with the clean-up of the valve body you’ll want to use ~300 grit sandpaper (emery cloth) and then 600 to finish off. You could use your Dremel / rotary tool with a fine brush attachment used for polishing brass (don’t use any compounds, just water) but you have to be very careful not to damage the threads or the valve seat, if you increase the original diameter there’s a chance the valve could pop in and float inside the boiler, allowing all of the boiler contents to spew out and it would never seal again forcing you to replace the entire valve head which may end up costing quite a bit of money and may not even be worth it on inexpensive units. Another possibility is for the bulb to catch and get stuck, so beware of the Dremel and abrasive tools.


After cleaning and polishing, it looks brand new!

After cleaning and polishing, it looks brand new!

If you want to make sure all the surfaces are neatly cleaned up and polished, you can use an old lead pencil as a former to wrap a piece of sandpaper around, tapering the top into a cone and then inserting it inside the valve body (with water) you’d proceed by twisting it a few times, removing it, inserting some cloth or paper towel wrapped around to clean up the valve and then take a look inside with a flashlight, repeat until it’s all nice and polished, specially the valve seat.

The silicone valve in my case had a lot of build-up but was easily removed by hand, don’t use any abrasives on it and try not to scratch it in any way.

Now that you’ve cleaned it all up, go ahead and add some water with the unit standing on it’s usual position and give it a few flushes, any loose pieces of build-up should come out, as well as anything you’ve unwillingly introduced while cleaning and polishing the valve body.


This is how the assembly goes, valve bulb/head pointing up.

This is how the assembly goes, valve bulb/head pointing up.

If all looks good, go ahead and assemble the valve back to it’s original state. The silicone valve goes facing up into the valve seat, make sure the spring is nice and clean as well as the silicone valve head. If you see any damage on the silicone it’s time to replace the valve or come up with a makeshift solution…

Once it’s all assembled, torque the nut down making sure your diffuser disc / plate is in the right position and turn the unit on, give it a nice flush.


In my case the diffuser was slightly blocked so I had to clean it up with a needle and lots of patience before I installed it, This procedure made heaps of difference. Basically my espresso was not only leaky but also had low flow rate and it sputtered a lot making it difficult to obtain a straight shot with good crema.


Next in my list would be to access the pump to see if there’s a pressure relief adjustment and go ahead to calibrate it up to 9BAR at the head, that however is going to be a whole ‘notha quest for me. In that event I may probably end up refurbishing the pump as well.


Hopefully this guide has been of use to you!
And as you know, don’t send your machine to the store… A good barista fixes his/her own espresso!


Have a good one,