Hi — looking for some help troubleshooting a Maslow 4.1 setup we’re doing with students.
I’m a long-time Maslow user (older model) and have cut hundreds of parts over the years for our high school robotics team. This year we acquired a Maslow 4.1 and got permission to install floor anchors in the school shop.
Current setup & what we’ve tried
Over the last couple weeks the students assembled the machine, installed anchors, and ran calibration.
Firmware at first calibration: 1.15
Calibration performed: 9×9 calibration on a 900×1600 area (units as shown in the UI; happy to confirm if needed)
Right height: ~11’ 0”
So we’re roughly 0.5” out of square in both directions (student-installed anchors).
Calibration on 1.15 passed. To validate, we cut a test square:
File was a : 6" × 6" square
Actual (repeatable) cut: about 6" × 5 3/4"
We cut once on the left side of a 4×8 sheet, then repeated near the center — same result, so it doesn’t seem location-dependent.
When we checked the maslow.yaml (from the calibration), the values for top X / bottom X / left Y / right Y didn’t seem to match our measured anchor spacing (they kind of close but still off by like 60mm in Y direction and 30 in Y). We manually entered our hand-measured values into maslow.yaml and re-ran the 6" square test cut:
Result improved to about 6" × 5 7/8" (still short, but closer)
We then tried small manual tweaks to the X values only (to see if we could “move” that 5 7/8" toward 6"), but eventually hit a center point deviation error and couldn’t recover.
Firmware update issue
We noticed firmware 1.16 was available, so we updated and attempted calibration again. Calibration has now failed repeatedly:
Tried calibration 3 times — it keeps failing, on fitness and exhausting the retries
On the last attempt we entered our measured anchor values into maslow.yaml before running calibration, but it still failed
We ran out of time for the session, and plan to try again Tuesday.
Questions
With a successful calibration on 1.15, why would we see a repeatable ~1/4" error in the cut dimension (especially since it repeats in different locations on the sheet)?
Any recommendations for getting calibration to complete on 1.16?
What logs/file/measurements/ details should I have the students capture and share here to help diagnose this?
Any other sanity checks / test cuts you’d recommend?
Did you keep a copy of your best result from the Find anchors? If so, try entering those values into the maslow.yaml as a starting point. (V1.16 even if they came from V1.15). Running Find Anchors multiple times “should” improve results, it builds on previous results.
In the maslow.yaml file there are two entries:
Maslow_Scale_X: 1.000000
Maslow_Scale_Y: 1.000000
which you can use to adjust for difference in expected and actual results. This is easier in metric (mm) (Mine are X=0.997 and Y=1.008, yours will be unique to your setup).
Be careful if manually editing maslow,yaml as it does not like spaces in the wrong places or tabs at all. Easiest is go to the FluidNC pulldown, then click onConfig Items. Don’t forget to set then save any changes. You should not need to restart FluidNC however.
If you can Save Serial from the Maslow menu and attach it here it will help to see what is going on.
Once you have the Maslow controllable, if you don’t want to waste material testing, move Maslow to one side of your work area and put a mark on the sacrificial board against one side of the sled, jog a known distance sideways (say 1500 mm or 1.5 metres) and put another mark (same corresponding position on sled) measure distance between marks as accurately as possible. Jog Maslow out of the way (up or Down), Divide expected result by actual and put the result in maslow.yaml as the Maslow_Scale_X value. Do similar process for the Y direction. (If it’s worse I got it the wrong way round). Hope this helps.
If you jog back the same distance after entering values in maslow.yaml then it should be close to the correct value
I’ve been working on exactly this issue. If you have a chance to give the beta for 1.17 a try (you can find it here: Interstitial Firmware Releases - #633 by bar) I would love feedback.
What that change does is rank all of the measurements and throws out the worst ones which prevents bad measurements from either throwing off the calibration results or making the calibration fail.
We updated to v1.17 and calibration completed successfully. Initial test cuts were still showing accuracy issues, so we dug deeper.
The root cause seemed to be mechanical damage + flex
We discovered that during an earlier test a few weeks ago, the students accidentally left the button pusher/tool used for inserting the bit in place and then drove the Z down into the sled. That impact damaged multiple components, which explained the inconsistent results we were seeing.
Damage we found:
Both clamp wedges were broken
The bottom clamp was broken
One tower was broken
Later, we also found the Z axis stepper motor had likely been damaged (Z started “clicking” when driving down during cuts)
Fortunately, I had a mostly-assembled Maslow 4.0 kit from earlier (I never got to use as I wanted to upgrade it to 4.1), and we were able to borrow parts from that machine to get the 4.1 back into a workable state. Once we identified the Z clicking as part of the same issue, we replaced the affected stepper motor as well.
Current results
After repairs — with everything tight, clamped correctly, and no longer flexing (I think) — we re-ran calibration on 1.17 a few times and are now getting much better cut accuracy typically with in 1/32
We do have 1 issue still remaining
We still see slightly oblong circles. A common cut for us is 1.13" holes for hex bearings, and they’re coming out a bit oval rather than perfectly round.
If anyone has recommendations for dialing in circle accuracy specifically (tests to run, settings to check, or common mechanical culprits), I’d appreciate it.
@ian_ab last post in this thread talks about x and y scale settings. Look there to compensate for the difference. We are not exactly sure why this is necessary but others have had luck with it.