Don’t know if this will help or hinder. I am new to engraving and because of cost and the difficulty of sourcing/importing equipment from the US, I’ve decided to build or make all my equipment.
My little engraving tool; which on the outside, looks a little like the Lindsay or Gravemax models, runs best on about 2 bar or 28lbs of pressure. At higher pressure, the tool tends to engrave too deep. Any way:
I was running this setup off a large air compressor I have here in the shop, but as I was still learning, decided to take my kit home. (Waste too much time at work ‘playing’) There it would be impossible to install a compressor and a silent one was/is just completely beyond my budget. (I believe that, till my hobby becomes a paying proposition, I will spend the minimum on it.)
I had an old Sprayvit diaphragm medical compressor (1967) lying in the junk pile and decided to try this. Output was about 30lbs of pressure – in fact a little in excess for my needs. So, I fitted a ‘T’ piece to the air line and on the leg of the T piece, a little length of tube with a small plastic C clamp to it. This is my pressure regulator: it works. For full depth engraving, I close the clamp a little and for lighter shadow lines etc, open the clamp a bit.
For start and stop, I fitted a little micro switch in place of the on/off switch and this; properly isolated and on a lead; I hold in my left hand; the same hand that turns my bowling ball engraving vice. I’ve found that the frequent stop/start of the motor has no detrimental effect – it is a brushless AC motor designed for medical use; so the spec’s are quite high.
In fact, our local hospital had 2 x Bird aspirator kits on auction some days ago and I bought both for a combined price of $50.00. The medical part of this equipment was damaged (masks, piping etc.), but the compressors (both 1/10hp 30lb working pressure units) are about brand new and shows very little sign of use. One of these motors is already rigged for engraving and works a charm. The old Sprayvit will now become my airbrush compressor.
Some of the problems I encountered: The air pulses from the diaphragm pumps makes your engraver sound like a Hemi V8 on 5 cylinders. Solution: Either use a longer air line or make a little ‘tank’ from a larger diameter (2†x 6†plastic) pipe with a baffle fitted lengthwise in the plastic pipe, with some holes drilled into this baffle. Have your air ‘in’ at the top of the baffle in the pipe, and air ‘out’ at the bottom. No more pulses. As for a moisture trap, I just clean out this pipe/baffle contraption.
So far, my total ‘investment’ in equipment is less than $100.00, excluding time and books. I am a machinist (gunsmith), so I had the equipment to make my own tooling.
