Beginners Way into Power Graving

[Jeff2t]

This is a modification of Shaun Hughes Homemade Engraving Machine to use a flexi-drive drill as a power source. This way you don't need a 12v power supply, speed controller or air-valve footpedal that is required when building Shaun's version.

Just remove the motor on the car tyre compressor, fit a spindle through the bearings to attach your Foredom drill and you are set to go.

Build one of these, practice hard, get good, make some money then go out and buy the professional set-up like the Steve Lyndsay Air Graver - that's what I'm trying to do.

YouTube Video

 

[papart1]

me too!!!!

 

[Doctorslava]

Sergej Waltman, the real inventor of this machine, after first generation with a tire inflator attached the compressor to a flex shaft motor you can buy separately with a pedal. All you need to do is a small plate adapter that mounts on the motor and has threaded holes for attaching a compressor. and you can even hang it with your flex shaft. Loads on the crank of the compressor are not healthy for the flex shaft. Shaun Hughes also mentioned this guy in his videos. You just described my way. I do have a high end handle now, but still using my machine when I need a low speed actuation.

 

[Jeff2t]

Sergej Waltman, the real inventor of this machine, after first generation with a tire inflator attached the compressor to a flex shaft motor you can buy separately with a pedal. All you need to do is a small plate adapter that mounts on the motor and has threaded holes for attaching a compressor. and you can even hang it with your flex shaft. Loads on the crank of the compressor are not healthy for the flex shaft. Shaun Hughes also mentioned this guy in his videos. You just described my way. I do have a high end handle now, but still using my machine when I need a low speed actuation.

Yeah, I saw some advert on Instagram with the motor attached straight to the compressor and instantly thought it makes more sense to connect it with the handpiece then you can still use it as a drill.
Most flex shafts can take a beating as long as you don't put too much of a bend in them as not to permanently kink the inner shaft, Maybe this would benefit from a clip to support the handpiece so it is in-line with the motor shaft.

 

[monk]

this will produce rotation. i'm guessing you need reciprocation to drive conventional style gravers.

 

[Jeff2t]

this will produce rotation. i'm guessing you need reciprocation to drive conventional style gravers.

This produces pulsed air - the piston has it's reed valve removed and the hole blocked up, so on the up stroke it forces air and the down stroke sucks air. You can see it in action if you follow the YouTube link in the original post.

 

[oniemarc]

When I made my SH machine, I hooked the compressor up to a sewing machine motor with the pedal. I could never get to it to work properly, cause of the higher speeds the compressor turns over at. This meant the piston would not move at all in my case when pressed the pedal too far in. Keeping it constant proved to be very difficult to say the least. With the normal setup he used(with the power controller/speed controller) you can set a certain speed you like. Made a world of difference. If you buy the parts on the wellknown chinese "marketplace", you can set it up for less than $50 or so.

 

[Jeff2t]

When I made my SH machine, I hooked the compressor up to a sewing machine motor with the pedal. I could never get to it to work properly, cause of the higher speeds the compressor turns over at. This meant the piston would not move at all in my case when pressed the pedal too far in. Keeping it constant proved to be very difficult to say the least. With the normal setup he used(with the power controller/speed controller) you can set a certain speed you like. Made a world of difference. If you buy the parts on the wellknown chinese "marketplace", you can set it up for less than $50 or so.

This flexi-drive way works quite well. If you press the pedal past about halfway you get the thing that all handpieces containing a spring suffer from where the piston in the handpiece moves faster than the spring can react, but it is perfectly useable having to limit the pedal to halfway pressed.
I Made Shaun's version too, but found the constant noise of the compressor running drove me mad and also you have to make a foot pedal that can give you variable air control.

Check out the YouTube video in the first post to see it working.

 

[oniemarc]

This flexi-drive way works quite well. If you press the pedal past about halfway you get the thing that all handpieces containing a spring suffer from where the piston in the handpiece moves faster than the spring can react, but it is perfectly useable having to limit the pedal to halfway pressed.
I Made Shaun's version too, but found the constant noise of the compressor running drove me mad and also you have to make a foot pedal that can give you variable air control.

Check out the YouTube video in the first post to see it working.

My compressor was built into a wooden box, so virtually no noise at all. Some slight puffing at the most.
Footpedal came from the same "marketplace", so if you add another $15 or so, you'd be there. Sometimes building everything yourself, will cost more...taking into account the failures. Plus the extra time, BUT....it is more fun to do so...hahah

 

[Jeff2t]

My compressor was built into a wooden box, so virtually no noise at all. Some slight puffing at the most.
Footpedal came from the same "marketplace", so if you add another $15 or so, you'd be there. Sometimes building everything yourself, will cost more...taking into account the failures. Plus the extra time, BUT....it is more fun to do so...hahah

Yes mine was in a box, but I had air vents in it and an extra fan for cooling the compressor, so was probably noisier than yours.
I would like to know which foot pedal you used, because I could not find one off the shelf that delivered a variable air supply, they were all either press for on and let go for off, non of them contained a needle valve that you need for variable air.
If you are of a creative mind it is a lot of fun building your own equipment. You learn a lot of stuff and gain an insight that's worth a lot more than any extra money you have spent on the development.

 

[oniemarc]

I agree that building yourself is very rewarding. Most of the time I will try and make something myself. But I feel no shame in admitting to failing alot too. For some things it's not worth the hassle to me...hahaha.

You would have to search for pneumatic pedals. There are different types, but you need the ones with 2 connectors. You could even install a small idler in between the in and out line.

I'll see if I can take a picture of the pedal for you.

 

[oniemarc]

 

[Jeff2t]

View attachment 49776 View attachment 49777

I have one that looks the same, but it doesn't contain a needle valve so you only get full off and full on with a slight variable air flow if you can move your foot slightly between the two, but its not meant to be variable it's just an on/off switch.

 

[oniemarc]

The one in the picture controls the airflow nicely, so I guess there are different types that look the same.

 

[teroon]

Check out Ez graver by Alister Duncan - search it on YT. I have done one acordingly to his schematic and I like the way it works.

 

[Jeff2t]

Check out Ez graver by Alister Duncan - search it on YT. I have done one acordingly to his schematic and I like the way it works.

I started making a solenoid graver, I 3d printed the handpiece and wanted more power than Alistaire's so I used a larger solenoid, but it gets quite hot, it's still a work-in-progress.

 

[teroon]

I doubt that larger solenoid will give you better resoults (I have tried it.). The bigger solenoids require longer time of current flowing into the system, so you will have a graver with heavier piston, but it will be moving slower. And since force=mass*acceleration, the resoult won't be a graver with more power. I used the one from the video but I have change the code in arduino to make it go faster. So I have a piston with 4,5 grams of weight, and device is running with around 2,7k rpm. Not enought to make a heavy engraving like a car parts but for other parts it does well.
Also, I have made a steel sleeve instead of plastic one. The plastic tended to break around the collet fastening..
Anyway. Good luck with your project.

 

[monk]

Yes mine was in a box, but I had air vents in it and an extra fan for cooling the compressor, so was probably noisier than yours.
I would like to know which foot pedal you used, because I could not find one off the shelf that delivered a variable air supply, they were all either press for on and let go for off, non of them contained a needle valve that you need for variable air.
If you are of a creative mind it is a lot of fun building your own equipment. You learn a lot of stuff and gain an insight that's worth a lot more than any extra money you have spent on the development.

i bought a stone sculptors pneumatic hammer years ago. i controlled the thing nicely with an "old style, die cast" pneumatic pencil air blower. it was the type with a lever actuator. very sensitive. such could be mounted on a wood block for use as a nice foot pedal. they usually go now for around 10 t0 14 us bucks in the big box tool stores.

 

[Jeff2t]

I doubt that larger solenoid will give you better resoults (I have tried it.). The bigger solenoids require longer time of current flowing into the system, so you will have a graver with heavier piston, but it will be moving slower. And since force=mass*acceleration, the resoult won't be a graver with more power. I used the one from the video but I have change the code in arduino to make it go faster. So I have a piston with 4,5 grams of weight, and device is running with around 2,7k rpm. Not enought to make a heavy engraving like a car parts but for other parts it does well.
Also, I have made a steel sleeve instead of plastic one. The plastic tended to break around the collet fastening..
Anyway. Good luck with your project

My thinking was heavier piston + more current = harder hit and therefore deeper cut, just seems logical like using a bigger hammer and a stronger arm.

 

[Doctorslava]

Energy is equal to half of a velocity squared times mass. Therefore more mass equal to more heat.