gcode resetting my surface zero to Z-0.200"

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Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Yes Mechanical!

Yesterday I went to Home Depot and sorter through their 1/2” steel shafts looking for a straight one bu rolling then against each other and looking for gaps as they turned, indicating a crooked one. Found two bought one.

Dissembled the Z axis removing the stepper, it’s mounting plate, and flange bearing. Unbolted the anti backlash nut Backed the acme thread out.

Made an aluminum piece and put it in the hole where the AB nut was. Out the shaft down from the top through the aluminum piece and into the bottom bearing.

Put the flange bearing back on, the flange bearing turned easily and smoothly by hand and at speed). Th three points of contact were in line the shaft could be rotated and raised and lowered smoothly with and friction or binding. So far everything looks good.

I wanted to simulate the stepper like I did the AB nut, so I took some 1/2” aluminum plate and laid out and drilled the stepper bolt pattern and made a 1/2” hole in the center where the 1/2” rod would go through and bolted them together, then bolted the the stepper plate together with the plate I made back to the top of the Z assembly.

Put the test rod down through the above assembly, and it wouldn’t go through the flange bearing 2” below it. Removed the test rod and unbolted the stepper plate with the plate I made still attached, and just let that assembly sit on top of the Z assembly without and bolts.

Slid the rod through the assembly and moved the assembly around until the rod went through the flange bearing, the AB aluminum part I made and into the bottom bearing. Continued to move the assembly around until the test rod could be lifted and lowered without any drag. There is was The plate that the stepper mounts to was 0.100” off in the minus Y direction, the X direction was right on.
How did it happen, drilling and tapping the holes in the Z stepper mounting plate in the wrong location, most likely a mental error in simple math.

The flange bearing has mounting holes that were made for 5/16” or 3/8” bolts, and I used 1/4” button head Allen screws with a larger washer, thinking that extra clearance would allow for alignment.

A couple of weeks ago I had the Z axis out to machine flats on it. And had the flange bearing out and removed the Z stepper and it’s mounting plate as a unit. When reassembled I left the flange bearing loose so things would self align. Put the Z stepper stepper and it’s mounting plate on as a unit then tightened the flange bearing. The spring coupler is made of steel and has two spring sections and a solid harrow section in the center this makes it quite flexible, but still rigid enough to cause the stepper to work harder, I think I got it more misaligned after that teardown than it was before.

The problem, misalignment of the X mounting plate causing more load on the stepper, and loosing steps. And that one start acme screw had to spin a lot more than a five start I will shortly have.

My five start parts will be here soon, and I’ll just elongate the mounting holes on the Z plate when I assemble the five start parts, then cut a new Z axis mounting plate, and I’ll be doing all math using a pencil and paper.

Thank you all in sticking to this “Mystery Saga”. I’ll let you know how the story ends in hopefully a few days.

Hager
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Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Again the wrong photo
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GME
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Re: gcode resetting my surface zero to Z-0.200"

Post by GME »

Hager,

If you are still interested, here is a link to my machine build.

https://www.cnczone.com/forums/diy-cnc- ... ost2286058

Gary

Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Hey Gary,
She’s a beauty I see your going with a dropped bed design, I especially like that type as they are really rigid giving the X axis a very solid mount, and not having it perched up high. Plus is you put some walls on the inside it keeps from spreading Chips all over when you have to cut without vacuum.
Thanks for sharing Gary.
Hager

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wmgeorge
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Re: gcode resetting my surface zero to Z-0.200"

Post by wmgeorge »

So is this all solved? It was a bent Z ball screw?

Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Looks like the problem is solved.
As I said above, upgraded to a 5 start Z acme shaft, new delrin AB nut, stepper coupling and made a new Stepper Mount plate so the stepper was lined up with everything below.

Ran a simple job of 65 pieces cut at 50IPM and a Z of 10 IPM. All went well. Set up the chinese file from hell and it ran just fine at 50 IPM XY and 10 IPM z. So it looks like my problems are solved.

Think the main culprit was the stepper misalignment with the things below and the steel spring coupler causing the stepper to work harder and loosing steps.

I haven’t done any faster runs to see how fast I can go. Would like to get the Auto Z Zero button working. ..

There are two Auto zero routines, one that just sets the Z height for the current tool and if you change tools you need to run it again.

I’ve seen another one where you set the tool to the material and to a fixed Z axis then go to the fixed plate. This would set the Z position of both into memory and if you changed tools the system would go back to the fixed plate and set the height for the new tool.. this is the one I would like to have. Does anyone have the code for this one?

Again thank you all for taking the time and effort to get me out of trouble.

Hager
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TReischl
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Re: gcode resetting my surface zero to Z-0.200"

Post by TReischl »

Happy to hear that you have it working.

What I found to be the easiest way to implement the auto Z zero is to spend $20 over at Ger21's website and get his Screenset 2010. He has that function all built in, all you will need to do is the wiring connections. Works like a champ every time. And then there is another huge plus, his screenset makes way more sense than the one Mach 3 ships with. Has neat abilities like a Park button. When you click the Park button the machine moves to a stored park position you have entered. Best darned $20 I have ever spent on my machine!

http://www.thecncwoodworker.com/2010.html
"If you see a good fight, get in it." Dr. Vernon Jones

Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Thanks TR, I watched his YT videos and it is a very comprehensive utility. I had a couple of questions and posted as comments in one of his videos, as I need to have these answered before I purchase the utility.
Thanks TR
Hager

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TReischl
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Re: gcode resetting my surface zero to Z-0.200"

Post by TReischl »

Mr.Chips wrote:Thanks TR, I watched his YT videos and it is a very comprehensive utility. I had a couple of questions and posted as comments in one of his videos, as I need to have these answered before I purchase the utility.
Thanks TR
Hager
He is Ger21 on this forum, he is also a moderator over on the CNCZone. I don't know about him, but I rarely check any of my YouTube videos for comments so you might be better off pm'ng him here.
"If you see a good fight, get in it." Dr. Vernon Jones

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Re: gcode resetting my surface zero to Z-0.200"

Post by ger21 »

I do get notified when I get comments on my videos.

You do need home switches, and must home the machine each time you turn it on. This allows Mach3 to know where the plate is.
You would wire the probe to any available input on your board. Sorry, but electronics is not my area of expertise.
Gerry - http://www.thecncwoodworker.com

Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Thanks Gerry,
I’m working on adding switches to all the axis. I’ll contact you when I have that done, parts ordered.
Thanks
Hager

GME
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Re: gcode resetting my surface zero to Z-0.200"

Post by GME »

Have you downloaded the instructions for the screenset off the website? Lots of good information.

http://thecncwoodworker.com/downloads/m ... Manual.pdf

Mr.Chips
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Re: gcode resetting my surface zero to Z-0.200"

Post by Mr.Chips »

Thanks, i just downloaded it.
Hager

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