Auto Zero all 3 axis at one time

I just got in from the shop and it appears that adding the G20 at the very beginning of the file made all the difference. It is working perfect every time with Universal G-Code Sender.

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Thank you for creating this, Charley. You rock! :+1:

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Cool Charley. One thing you might think about are conditionals in the script so it can time out. Like you can manually position your router close to the corner and run the code. If any axis seeks more than a few inches, the code times out. Might save some people some rail slamming. You can also use variables up top to allow users to control the probing speed as delicate etching bits my snap off their points with a full speed z probe.

Here is a good tutorial on conditionals in gcode:

I did mine in Mach3’s scripting language to assign the macro to the “Auto Zero” button. But I don’t think it is gcode compliant - looks very close though.

His code as it is above will only go 0.5 inches in the X-Axis, 1 inch in the Y-Axis and 1 inch in the Z-Axis.

I also don’t believe grbl supports conditional statements in g-code.

Oh I see now. What happens if it doesn’t find it? Sets that axis zero whereever it ends up?

It throws an error and stops.

If the bit does not reach the touch plate within the specified distance then the program errors out and ends at that point. This will keep it from traveling all the way across the machine to the limits.

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If it were only true. From what I understand, GRBL does not support scripting like Mach 3 does. The programing language wouldn’t be too difficult to learn. Looks much like the old GW Basic programing language using looping statements and IF THEN ELSE GOTO and Line Number References etc.

With that said, using the g-code I have written so far, before running the program you need to position the bit to within 1/2 inch of the touch plate on the x axis and be less than 3/4 inch from the end of the touch plate in the Y axis. Then you run the code and everything is automatic after that. I think you already knew that though.

I think (my own guess) that Inventables went with the GRBL setup because it kept the cost down over having everyone being forced to purchase another controller package like Mach 3. Just a guess though.

I am having a heck of a time getting a consistent z level using my touch plate. I have been engraving brass so I really need it to be within .001" every time. Right now, I zero the z and cut a .001" deep vector with the engraving bit in a “scrap area” before I engrave. If it just barely engraves, I go with it. If it misses, I futz with it manually until it does. About 50% of the time, touching off in the same exact spot with the same exact bit, will yield different results. I may look at a proximity sensor in the near future to see if I can get more consistency to establish z=0 in the top of my work, and use the depth rings on my engraving bits for their intended purpose. But that will take hours and hours of experimentation.

I will be posting the g-code with a complete description of each part that can be changed by the user to control the probing speed, bit diameters, and operation units such as inch or mm. I will also create g-code files for download that will work in both metric and inch modes for 1/8 inch and 1/4 inch bits. I would be happy to edit files for other sizes on request.

Using just homing switches and 1 switch mounted under the homing location to detect the length of the tool bit. All the rest can be calculated because the machine locations can be calculated. This makes Z-Zero with the tool change is easy.

The hardest part for this is to use the stock bottom as Zero.

i will be doing a step by step video, but it will take a bit of time.

Keep making stuff.

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@CharleyThomas

hey man great video when you where milling that aluminum what speed setting did you have your dewalt router on?

[quote=“WorkinWoods, post:34, topic:20534”]
when you where milling that aluminum what speed setting did you have your dewalt router on?
[/quote]In the Video, I started the cut using a 1/4 inch endmill designed for soft metals like aluminum. A standard bit won’t perform nearly as well.

I actually performed 2 cuts to make this. That was primarily due to the piece coming loose during cutting but that allowed me to make a couple of finishing passes for a better finish. Keep in mind, with the roughing settings below, you won’t be able to do this on a stock X-Carve. It has too much flex in the X and Y axis. Modifying the X and Y axis to stiffen them is the only way you can cut that aggressively with these feeds and speeds with a 1/4 inch bit.

The roughing passes were:
Feed Rate was 50 Inches per minute
Depth of cut was .05 inches
Width of cut or Step Over was .05 inches or 20%
Dewalt Spindle speed started at about 1 1/2 but was increased to 2 during the cut.

To get a clean finish I made 2 final passes with these settings:
Feed Rate was 50 Inches per minute
Depth of cut was .02 inches
Width of cut or Step Over was .02 inches
Dewalt Spindle speed started at about 2

Charley

For anyone interested, I have uploaded the spreadsheet. 3 Axis Touch Plate G-Code Generator.xlsx (96.0 KB) I use it to create the g-code files for auto-zeroing all three axis at one time with my touch plate pictured here.

There is also a video I just completed that explains how to use the spreadsheet and shows some video of zeroing a 1/4 inch straight endmill, a 1/4 inch 60 degree V-Bit and a 1/4 inch shank 3/4 inch straight router bit. This spreadsheet will automatically generate g-code for any size bit and works in both Millimeters and in Inches.

The g-code works with Universal G-Code Sender and Pic Sender. I don’t use Easel because I don’t have a reliable internet connection in the shop where the X-Carve is located so I can’t confirm it’s functionality there.

The spreadsheet is saved in Excel 2007 format. I tried to save it in an earlier version format but it lost functionality so 2007 it is. For anyone who does not have access to it, send me a request with you bit size with touch plate dimensions and I will generate the g-code for you and upload it.

I was planning to just create a few g-code files and upload them but each file is dependent on your touch plate dimensions so if I did that it would just cause problems and wouldn’t work accurately.

This truly in a fast and very accurate way to zero all three axis to your work surface. I know I will be using it on almost every job moving forward. I hope all of you can make use of it.

I was asked if I were selling these. At this time I am not but am looking into the possibility of making a few to see how it goes. If I do, I can promise you it won’t ask $77 like the triple edge finder that was pointed out to me earlier in this thread. I was thinking more like $30 plus shipping which would include the touch plate, wire connector, spreadsheet, and some g-code files for various diameter bits. But that is all just thinking out loud for now.

I’ll be happy to field any questions and take recommendations for changes or corrections.

Charley

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Outstanding!

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Charley strikes back with more awesome!

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I don’t know about the awesome but thanks for say so!

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this looks as if it will fix the question of homing , I have a reg milling machine and use a edge fine to locate the edge and center of a part you subtract one half of the dim: of the edge finer this put you on the edge if you were to write into your code to do that the you could use a signal tool for setting up and size bit from the smallest to a vbit, and they would all fine the dead on edge…

Now that’s food for thought.