Homemade pneumatic graver

jkoper

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Joined
Dec 11, 2008
Messages
47
Location
Southeast TN
Thank you sir! now how about a closer view? LOL! oh and a question foot controlled?

I haven't had time to make a proper foot control, for now I have a blow gun held in a wood clamp and I trigger it with my big toe :eek::biggrin:

Jim
 

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hdvoyager

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Jun 2, 2020
Messages
14
Location
Scotch Grove, Iowa
It's loosely based on the airgraver, but the piston doesn't idle. It has a spring that keeps the piston in the forward position until the air flow is triggered. It operates off straight compressed air. The air consumption seams pretty good, I've been running it from a 3 gal portable air tank and get about 30 mins or so between fill ups. I made it with a fixed stroke just to simplify construction.It's not a gravermach or airgraver but I've been pleasantly surprised with the performance so far.
I have been trying to make about the same type air powered Graver. My air consumption is terrible. I tried making the piston fit as perfect as possible by sanding it down to a perfect fit. You mastered the air consumption problem, can you give more details please.
 

hdvoyager

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Joined
Jun 2, 2020
Messages
14
Location
Scotch Grove, Iowa
I just finished building my pneumatic graver.Here is a picture with the first practice plate I've cut with it. It works alot better than I do LOL.
I need your help to understand how your graver uses so little air. I have made several copies of the Lindsay air graver, they run well but drain my sir tank quickly. The piston is a very tight sliding fit. With the piston full forward no air enters the graver. With the piston back so the rear cavity fills with air, the graver draws air. The hole in my piston is .089" as are the cross holes and the two cylinder vent holes. The graver works well at 30#-40# and starts at 15#.
 

Sam

Chief Administrator & Benevolent Dictator
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Nov 6, 2006
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10,489
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Covington, Louisiana
I need your help to understand how your graver uses so little air. I have made several copies of the Lindsay air graver, they run well but drain my sir tank quickly. The piston is a very tight sliding fit. With the piston full forward no air enters the graver. With the piston back so the rear cavity fills with air, the graver draws air. The hole in my piston is .089" as are the cross holes and the two cylinder vent holes. The graver works well at 30#-40# and starts at 15#.

If you're making copies of Lindsay's handpieces and you're in the USA, you're in violation of his patent if it's still current. Even if it's not for sale and for personal use. Sorry.
 

edgrabow15

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Joined
Nov 16, 2018
Messages
192
Location
SHIRLEY, LONG ISLAND . N.Y.
Nice work, there is nothing like working with homemade tools.
Yeah I remember back in the good old days in Attica, making my own tattoo machines from a tape recorder & guitar string, Than you heat up baby oil to make black ink and away we go LOL Just kidding about the Attica part, I did make one when I was 16 though just like I described
 

hdvoyager

Member
Joined
Jun 2, 2020
Messages
14
Location
Scotch Grove, Iowa
Lindsay Patent US6095256A officially "Expired - Lifetime" on 2020-01-19. So, information from this patent is now in the public domain, free to use for everyone for the last 10+ months.

I am trying to find out how the graver made by JKeper used so little air per his comments.

I have worked out a very strong air powered graver design that doesn't use a Lindsay type constrictor Ring and runs off of straight air compressor air, not pulsed air. The Piston operates in a straight tube, 3/8" ID, Palm handle one end and the Bit mounting on the other end. Self starting at <20#, runs at 10#+ and at 30#-40# runs very- very strong. It uses much less air than my previous attempts, but it is still more air than may be necessary.

.
 

hdvoyager

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Joined
Jun 2, 2020
Messages
14
Location
Scotch Grove, Iowa
I take great pleasure in inventing tooling that may possibly work equal or better of best the big guys equipment. After all, in their beginning, they too worked out their designs trial and error, learned from their failures and successes and proceeded to received patents on their designs.

For a budding beginner, the big buck equipment ($2K to over 5K) just doesn't make sense to purchase before determining if engraving my/your passion. As a result, Youtube has many DIY air powered gravers demonstrated that you can choose to build, pulse air or compressed air. I believe that DIY gravers are a good learning tool. As the builder gets some skills and decides engraving is their thing, now, they can make a decision to buy the big guy's equipment.

Before designing a graver, a performance baseline must be established. With a baseline (gold standard) now work on a new graver design can proceed. It must follow Value Engineering process (Better, simpler, easier to use, costs reduced)

Is the big guys equipment over priced, they can answer this question? With the precision of CNC equipment, production manufacturing costs, plus G & A overhead and profit should determine the consumer's pricing. But the field of "Engraving" isn't huge plus as the engravers acquire equipment, the field can reach a degree of equipment saturation.

To summarize, many beginners like my self, are on a budget, and don't know if engraving is for them. Yet they are talented enough to build their own graver and learn how to use the equipment.

The compressor air powered graver shown in the attached file does not work identically to the Patented Airgraver, no constrictor Ring, just a straight Tube & unstable Piston striking the Bit.
 

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hdvoyager

Member
Joined
Jun 2, 2020
Messages
14
Location
Scotch Grove, Iowa
Help Please:
My DIY graver is coming along nicely. It starts with a tap, runs at 20#-60# air pressure with 40# being about the optimum. The Tube Housing is a straight tube, no Constrictor Ring. The Piston is located between two soft springs. Start at 20# give it a tap and it vibrates without the Piston making contact with the Bit Holder. The Bit Holder has about 3/16" movement from fully extended under power and as it is pushed back, the Piston now hits the Bit Holder. At first contact, the hits are hard and as the graver is pushed harder, the hits speed up but are still hard..

I see that many commercial gravers have the Bit Holder as part of the main housing and others can adjust the Bit Holder in or out but the design looks rigid at the desired setting. If the Bit Holder is rigid to the main housing, then the entire graver must shake. In comparison, Jack Hammer body does shake but the Chisel Vibrates with maximum force from the Piston's hit.

My question is: Should the Bit Holder/Bit be fixed to the graver body or should it have the capability to float so the hit from the Piston can transmit full power to the Bit?
 

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