Newbie question

[1Poet]

As a completely new to engraving person, I sure some will think my question ridiculous. However, I have become interested in pneumatic engraving, in large part to studying Shaun Hughes videos. As a silver wire inlay artist, I appreciate his diy methods, as the tools for inlay must be made by the user, in most cases.
To my point and question. I want to begin this journey as I did with wire inlay. That is, see if it is what I want to continue doing. So, I do not see any sense in spending several hundred dollars when a basic learning setup can be made quite affordably, as per Shaun's work.
I have a basic handpiece purchased on ebay and small 12v dc air compressor, which is fine, for now.
The hose or tubing on the hand piece is 3mm OD. The fitting on the compressor is completely too large for this size tubing, so what is the right size tubing for a small hand piece? Can I use a larger size tubing by drilling out the tube entry without ruining the hand piece' performance?
I realize this is a relatively trivial question, but I do nor have the luxury of experience
Your help and patience is appreciated.

 

[gtsport]

an adaptor will work to connect your hose.

 

[monk]

if you cant find an adaptor, it should be easy enough to fashion one using a small wood lathe. no lathe, you can make one of plastic or wood by careful shaping using a drillpress. any well equipped plumbing shop should be able to conjur up an affordable adaptor to do this. you'll need an adjustable dc power supply. this is needed to change the impact speed. i made one that mr hughes showed on his video. it works well. i don't use it. i just made it for the heck of it

 

[Doctorslava]

I built a handpiece and made a barbed connector for a plastic tubing 1/4" OD. I think Shaun Hughes just drilled a hole in his handpiece to accommodate the tube. Anyway you can use either barbed adapters or any other type. Mine has a push-to-connect on one side allowing easy change between handpieces. And I made 1/8" NPT on the compressor side and use a swaging connector there.

 

[John B.]

Most good automotive stores have barbed plastic hose adapters.
They are available in multi sizes of reduction etc.