Looking for slider mechanism for Air Scribe.

[msimpson99]

I got my air scribe working pretty good. I have it connected to a small educational CNC that I wrote up for Servo Magazine. Its just got a simple tool mount. See it here:
https://youtu.be/9aP2tdZBWEM

Now I want to move it to one of my larger machines and am looking for a Air Slide Mechanism. Just something simple and inexpensive. There are a bunch on ebay and even a couple on Amazon.

I want to write up the air scribe build in detail so I may purchase more than 1.

I have most of what I need now for hookup just need the mechanism. Any suggestions, or links would be appreciated.

[acourtjester]

I would look at a smaller linear slide.
here are a few setup I have build and used, I have not tested the last one but I think the spring pressure is better.
You can setup how much pressure is on the scribe by where you set Z "0" at the start of the series.
It could not be used with a scribe and then cut operation the other type can.

pneumatic scribe assembly (3).JPG

DSCN1481.JPG

DSCN2140.JPG

[msimpson99]

I was thinking of building my own using a couple different methods. A slide that moves down has other advantages as well. The CP9361 does not always start when set to a setting less than 4. A light tap on the tip will always start it. By activating a slide, the scribe will always start when the tip hits the material even at the lowest setting. I could do this with the Z axis if it was spring loaded as well, but need to test it.

I like the first one with the dedicated linear slide. Very small and simple. Do you have a source for a guide that small? Also what cylinder are you using?

[Brand X]

http://www.ebay.com/itm/152382385640?_t ... EBIDX%3AIT

[acourtjester]

Here is the air cylinder
https://www.automationdirect.com/adc/Sh ... n/A17030SN

A17030SN air cylinder.pdf

and the slide BrandX shows will work
thisw one is a little longer
http://www.ebay.com/itm/THK-Model-HSR12 ... Sw65FXq8H2

[Brand X]

I used one of these.. Mine had a bit longer stroke, but this is plenty. I like the dual action myself, but each to their own..

http://www.ebay.com/itm/231586036219?_t ... EBIDX%3AIT

[msimpson99]

Ok, one thing I found was that the air solenoid used is crucial in the engraver firing constantly. I started with a smaller 12v activated unit and while it worked ok, I would still get misfires. It has a couple of issues.

1. It does not allow enough air volume to hit the tool all at once.
2. It had no exhaust so the tool would slowly let out air once deactivated. This, Along with problem 1 would cause the misfires.


Here is what I did. I went with a 5-way 2-position valve (110v). These allow you to fire a two way cylinder and control the exhaust in both directions. (Not using this feature)

The B valve is plugged and the A is connected to the tool. Both exhaust ports are left wide open.

OMG..... The tool fires every single time at any setting.

I will be experimenting with ways of controlling the height of the tool. For now its on a custom made 8mm rod system with 8mm trucks. I will be looking at a two way cylinder, Servo, Stepper to control just the tool. Right now its floating and I use my Z-axis to control its contact with the surface.

[motoguy]

I ordered my rails a couple days ago. Going with a Brandx style, floating setup. Mounting to a plate mounted directly to my Z plate. Do you have a link to the solenoid that's been successful for you?

[msimpson99]

Im using this one:
URL 5Way 2Pos Solenoid

There are other voltage options.

[motoguy]

110 is nice, as I can trigger it from the CandCNC box aux ports. I'm not using them for anything else.

[Brand X]

It's how i did mine, but the older 650 box did not have a plug-in out on it.. I used the Table I/0 cards Relay, and works out the same in the long run.