Air Scribe (again)

[SONIC]

Hey Guys,
I'm looking to add a scribe to my LDR table and have come up with a design, but it's so simple compared to all the others I see I wonder if I'm missing something?

My hypertherm 65 will run fine at 90psi regulated pressure (it auto regulates pressure internally) I can drop the scribe regulator and just run it off the already 90psi air. I need one solenoid (3 way see attached) to open the air path to put air to the scribe and the regulator for the cylinder. A spring on the cylinder for return and that's it. Maybe an oil fogger for the scribe as well.

What am I missing?

3-way-valve-example-1024x486.jpg

See attached crappy drawing.

[tcaudle]

Hey Guys,
I'm looking to add a scribe to my LDR table and have come up with a design, but it's so simple compared to all the others I see I wonder if I'm missing something?

My hypertherm 65 will run fine at 90psi regulated pressure (it auto regulates pressure internally) I can drop the scribe regulator and just run it off the already 90psi air. I need one solenoid (3 way see attached) to open the air path to put air to the scribe and the regulator for the cylinder. A spring on the cylinder for return and that's it. Maybe an oil fogger for the scribe as well.

What am I missing?

1. You need regulation on the cylinder at 90PSI the down force will be a LOT more than you need to engrave/mark: It will try to drive the tip though the metal.
2. What runs the marker tool? If it's air you may find it too needs less pressure than 90 PSI. You will have no control of either the down force or the marking action .
All it takes over what you have is two regulators after the solenoid. The major complexity is the slide to hold the marker tool rigid controlling the down force as you drag the tip of the marker over a hard surface. While a spring can be used for return a double acting cylindar and a two way valve sure makes it work better.

You don't need fog for marking or even rotary engraving.

[SONIC]

Thanks for the reply.
There's a regulator before the cylinder to 20psi. And the scribe has a build in speed control so no need for a regulator there below 90psi.
You may be right on the 2 way solenoid instead of the spring, I suppose it's just one more 1/4" air line.

[_Ogre]

our scribe uses a single 4 way air solenoid and a single regulator for down pressure on the 2-way air cylinder
i also used flow control valves to regulate the speed up and down to keep things from slamming
similar to your drawing we use full pressure on the scribe by way of a T fitting after the solenoid

[SONIC]

Well all my parts arrived, so we shall see how it goes!

Last question for now, why does everyone mount all the air lines etc up on the gantry? Is it to avoid the time delay when switching on and off? I'd much prefer to mount to the side of the machine and then run air lines through the cable tracks.

[_Ogre]

most use a 4 way valve, easier to run 1 air line and 1 wire vs 5 air lines

[DesertFabworks]

Here is something to think about if you want marking capibilites. I just got back from Fabtech and got to cut with the 45xp and see the marking capabilities live and in person. In the beginning I was disappointed about hypertherm not making the 45xp in a 65xp because I need the power to cut 1/2 and larger plate but I wanted the marking capabilities.

After seeing and learning about the 45xp there is a different set of consumables for marking and you really need to use Argon if you want the really nice marks. So what I'm going to do is set up my machine with a dual torch. leave my powermax 65 and mount a 45xp right next to it. I will keep the 45 xp plumed to Argon all the time with the marking head consumables in. I will set my offset in Sheetcam just like I would set up a scribe for the other torch. That way I can cut and mark at the same time without switching consumables and changing gas back and forth between the shop air and argon.

The marking is much faster and nicer than what you would get with a scribe setup. So something to think about