Day 15 – To Hell with Ball Bearings


I have decided to forget about getting ball bearings online and as I was doing my nightly jog, I came up with an alternative.

The purpose of the 10 mm ball bearing is to act as a piston in the engraving hand piece. In the nutshell, the hand piece is connected to the compressor which alternatively sucks and blows, moving the ball bearing (the piston) forward and backward really fast, acting like a little hammer hitting at the back of the graver attached to the front of the hand piece. The YouTube video about the homemade engraving machine by this gentleman, Shaun Hughes, recommended using ball bearings.

Since these are troubled times and it is almost impossible for me to head out physicall to search for anything, and I cannot deal with more waiting time and potential disappointment of online shopping, I have came up with an idea for the piston of my hand piece.

Like always, I will make use with what I already have on hands and what can easily be obtained in my neighbourhood mall’s tiny home improvement shop. I shall 3D print a “small cylindrical cup” which is definitely going to fit the inside of the barrel (which has a diameter of 11 mm) of my hand piece better than whatever 10 mm ball bearing I can get online.

Not only that, it will be heavier than a 10 mm ball bearing too, since it is vital for the pistons to have a weight to them (a light hammer would not have much impact). I will try to achieved that with a good sized bolt through the resin cylindrical cup with all the extra nuts I can add.

Yeah… I think that will work. Hmmm… Will find out first thing when I wake up. I shall go work on the CAD first.

There are a lot of people who made their own homemade engraving machine based on Shaun Hughes’ video and they themselves made videos of their process and share their little personal modifications. These people have access to huge, proper metal working workshop. Everything they have produced in metal with their lathe and other power tools, I have done, conceptually, the same thing in resin and my 3D Printer in my tiny bedroom.

It is interesting to see if everything works out in the end.

02:23 PM

Got the “casing” of my pistons printed out.

Perhaps I should have created thicker walls (more than 0.6mm), the prints came out looking rather flimsy. Printed two; accidentally chipped one of them when I was removing the supports.

I still believe that theoretically, it should work just fine. Now I need to smooth the inside of my hand piece’s barrel.

Then I take a quick short trip to the home improvement shop and get the bolts and nuts.

05:25 PM – Piston, done!

Went out to the home improvement shop to get the bolts and nuts. Was quite lucky to find something that really fits in the casing.

Used up all the nuts on the single bolt. While I have nothing to compare it with, my homemade piston has quite a good weight to it. The end of the bolt sticking out like that provides a nice striking point, I reckon. Pretty cool. I might even trim the casing down a bit later, if necessary.

I got another delivery today! It is a piano string which I will coil it up into a spring to be used in the hand piece. No complain about the delivery this time.

06:07 PM


Coiled up the piano string into a spring. Ahh… Takes me back to the days as a student in a jewellery workshop. While the spring is usable (and fits inside the barrel of my hand piece), the tension is rather strong. I will need to adjust when I have the final part of my hand piece.

Hand piece progress: 75%

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I design fine jewellery for a living.