about air gravers

[ogarrido]

Hi everyone,
My name is Onofre. I am a Spanish luthier and I am becoming quite interested on engraving since I customized a tunner for one of my guitars by engraving a simple design on it.

I don't know whether this is the correct place to ask about it, but the sections about equipment are read only for my so far.


I am quite confused on the air engraving principle of working for the hand piece. I have seen many people making modifications to car compressor to remove the one-way valve so it produces a positive-negative cycle of pressure to the handpiece. I guess then that the piston just follows that pressure for oscillating and hitting the graver tip.

ON the other hand I have seen people that looks like using a standard compressor, so just positive pressure reach the hand piece and then the handpiece itself implement some kind of oscillating principle ( by using a vent hole y the proper place) to produce the movement of the piston.


Am I wrong?. Are all of them just using positive-negative cycling pressure and there are not any other handpieces designed for just standard compressor.


thanks in advance for your answers, and sorry in case this is a silly question...


kind regards

 

[SamW]

Welcome to the forum Onofre. I cannot answer your technical questions but expect someone will do so. It does sound like you understand the principles fairly well. I use the Lindsey Airgraver. I have built a few guitars and ukuleles just for fun and to experiment with engraved aluminum inlays/rosettes.

 

[Leonardo]

Hola Onofre, bienvenido al foro!

Todas estas inquietudes técnicas suenan como que quisieras fabicarte tu propio sistema de grabado. Hay algunos proyectos hechos con pequeños compresores portátiles para coches, pero no se que resultado han dado a la larga.

Los sistemas de grabado profesionales utilizan un compresor para proveer el aire.

Puedes escribirme si deseas comentar más cosas. También puedo pasarte los datos de Dimas Sánchez que es un excelente grabador profesional de España para que hables con el.

Cordiales saludos,
Leonardo

 

[JOEYS CARVED ART]

The Lindsay airgraver works with a standard compressor as long as you have the regulators for it

 

[monk]

the lindsay operates on lower pressure, or cubic feet of air per minute-- cfm. the other systems use higher pressures/cfm. the 12 volt system uses interrupted pulses of air. in conjunction with a spring. the other systems is basically controlled inside the actual handpiece. i don't advise doing this. the lindsay can actually be cycled by blowing thru the air hose, as it needs fewer cfm/minute.

 

[Doctorslava]

In Lindsay system everything happens in a handle. You have a pressure from line , hollow piston and special geometry. Air comes through the piston in a venting chamber, pushes piston backwards and closes the inlet redirecting the air. Air pushes piston ahead and here is a cycle. Venting works pretty mach as in AK47 .

GRS system has a rotating valve inside enclosure that creates pulses. You supply air from compressor to the box (In Gravimeyster you have a built in compressor and also rotating valve). To return the piston GRS handles use a spring.

So-called Valtman system is a modified compressor with stuck inlet valve. Piston of the compressor and piston inside handle are coupled and inside a hose you have negative and positive pressure.

Newest electronic systems. Pretty much a solenoid with power supply. Either coil or magnet suspended by springs inside a handle and moves by changing a magnetic field.

I think it is more or less answers your question. Thanks
Slava

 

[dogcatcher]

Welcome to the Cafe. Lived 3 years in your beautiful country, 1960 to 1963 courtesy of the US Air Force at Moron AFB, as a high school student, took classical guitar lessons in Sevilla. My son still has my guitar,

The homemade versions by Hughes, work pretty good, better than hand pushing. The others answered how they work. here is another home version to look at. https://www.labellenote.fr/articles.php?lng=en&pg=1118&mnuid=589&tconfig=0