Search found 11 matches

by ekbiker
Fri Dec 22, 2023 11:39 am
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

Nice list, actually I think I would benefit from some of those on the list. I'll ask one more time, after this I'll shut up. I can help code the individual screw comp on paired axis. I have industry experience on many programing languages, including C, C++, and C#. It's free for you, what have you ...
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by ekbiker
Thu Dec 21, 2023 8:46 am
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

I'm sorry, I think i've hit on a sacred cow. I'm just making a feature request and explaining why it would be needed for my particular situation.
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by ekbiker
Thu Dec 21, 2023 8:42 am
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

To cover the entire x-y area of a large format gantry CNC router, it would take days even if you have a laser or CMM. This makes VC impractical and unsuitable.

Individual screw comp is a simple and elegant solution using just scales.
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by ekbiker
Wed Dec 20, 2023 9:01 pm
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

Yes, but you need scales to tell the machine where the spindle is at vs. what the controller thinks it's at. The problem is on a gantry machine, the X scale is mounted on the gantry itself, so it is moving with the gantry. As I travel down the Y, X scale will absolutely not move. And vice versa, as ...
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by ekbiker
Wed Dec 20, 2023 8:02 pm
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

CNCKeith, I'm using a rotating nut, there is no double nut for that. The methods describe above doesn't actually work for gantry machines. As I explained, volumetric compensation does not work because it needs a perpendicular reference. But for the case of a traveling gantry with paired screws, the ...
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by ekbiker
Wed Dec 20, 2023 4:50 pm
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

I'm buying directly from HiWin, so there's good chance the two Y screws are from the same lot. Which means they should be close (fingers crossed). I'm using the R1 rotating nut in 20/20 2650 mm length. Buying ground screws and scales will blow my budget.

Ideally, there should be individual screw ...
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by ekbiker
Wed Dec 20, 2023 10:42 am
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

Uwe, I watched your youtube video on Volumetric Compensation. It will not work for a gantry machines because the Y scale isn't directly coupled to the spindle. And since Y1 and Y2 screws have different pitch errors, this means the perpendicularity to the X axis varies as it travels down the Y axis ...
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by ekbiker
Tue Dec 19, 2023 6:15 pm
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

I'll try. But I don't have the luxury of picking which screws I like. I get what they send me, that's it. Any pitch error mismatch out-of-sync will be magnified on the side that's not running the scale. But will be somewhat okay on the side with the scale. Large parts will have trouble. Doesn't ...
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by ekbiker
Tue Dec 19, 2023 9:12 am
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Re: Screw comp on master/slave axis

No specific application, I'm just trying to build the most accurate DIY gantry machine possible under $30,000. I'm using rolled C7 ball screws but with linear encoders to compensate. Ground C5 screws cost 4 times as much in the lengths I need.

What would you suggest I do?

What I could do is this ...
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by ekbiker
Sun Dec 17, 2023 10:15 am
Forum: Centroid Acorn CNC Controller
Topic: Screw comp on master/slave axis
Replies: 21
Views: 9592

Screw comp on master/slave axis

Hi, I plan to use AcornSix with gantry style Y axis with software defined master/slave. Is there separate screw comp for Y1 and Y2. And let's say that Y1 is master and I run linear encoders, do I need an encoder on BOTH the master and slave? Or can I calibrate the slave Y2 screw comp using an ...
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