So I want to calibrate my Maslow

Hello world,

This is a two part inquiry.

This weekend I tried calibrating the machine for the first time, following the instructions from the “Actions/Calibrate” menu. I’m uncertain that I did it right but here are the chain measurements.

I forgot to take an image of the 1-5 cut measurements but I can attach that later this evening. (Sorry). I do remember that the distance from cut 1-2 was smaller than cut 3-4.

Inquiry 1): I’m looking for guidance for qualifying the calibration.

@Dustcloud I was reading your posts about your indepth look at calibrating the machine. I’m new to this part of the machine but wasn’t sure if you had time to support a fellow Maslowian.

Inquiry 2): I’m in the process of trying to trial cut sample designs out of foam and have come across the infamous “Keeping Up” error message. First thing I checked were the motors. I used the “Test Motors/Encoders” function and all motors passed test. Second thing I did was fooled around with the “Position Error Limit”. I change the value from 2.0 to 20 and I was able to consistently make a bad parts (See picture below). The sample is supposed to be a square coaster with “WT” engraved in the center.

What I observe is that the machine has a difficult time machining the overall profile of the coaster…and for some other reason the depth of cut across the engraving is slightly shallow on the ‘T’. I’m not overly concerned about depth yet as I’ve been able to make cuts consistently without an issue. I will address depth later if it is still an issue.

I have attached the coaster nc file to this posting for reference.WT (15.3 KB)

And just for reference this was my first real cut. This cut is what made me realize that the machine needed to be calibrated. The overall profile of this cut is not square, hence the need for calibration.

Thanks for your support.

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If this is a stock malsow with ring kit, the calibration values you show in the screenshot seem off. I would expect a rotation radius in the 130-140 mm area and a chain sag value something maybe around 20-30, but not zero. It would be handy to look at the measurement values, but also what the rotation radius, chain sag, and Y offset were initially… Did you tweak any of those from the default before you tried to calibrate?

No tweaking of values, just entering of measurements. I will try to recal tonight and double check the values. My initial value entered for rotaion radius was 140mm.

Where on the worksurface are you making the cut? Is it near the top-center? The top-center is the most difficult place on the worksurface for the motors.

Hi Joushua,

Slightly off center of the 4x8 sheet. Down and left roughly 4in.

The interesting this is that the rotation radius = 100 and the chain sag correction = 0, both of which are the default values. I think something went amiss in the calibration process. Can you try it again and see if you get the same results?

Here are my new numbers

I think there maybe something wrong with my coaster .nc file The 2D contour of the square is the troublesome area. Would someone be so kind to tell me what I’m doing wrong? I’ve tried changing the feedrate to 20in/min and I see no difference. Here is the file of just the square profile.
New Coaster Square_11-8-18 (20inFR).nc (689 Bytes)

Here is the complete coaster
WT Coaster_11-8-18 (5000).nc (15.3 KB)

So I finally have a bit of sanity following this thread.

This fixed the poorly cut contour of my original .nc file. Now I need to recalibrate…again.