Hello!
I have a problem concerning X-Carve (1000mm).
The things I cut, are not correct in measurements. Everything I cut, is a few mm smaller than specified in Easel? I’ve also tried Fusion 360.
My settings for $100 and $101 (steps/mm) are 40.030 for both, and both X and Y-axes move very accurately when not cutting anything. Do I have a too weak power supply or what?
Acceleration values $120 and $121 are at their default value (500mm/sec^2)
Does anyone have any similar issues?
-Tony
Did you calibrate your XCarve per the videos that Robert Reike made?
No?
Where can I find them? No quick success in Google or Youtube…
Provided your machine return to correct 0/0/0 it isnt loosing steps (= you have enough power)
Provided your machine travel exact 500mm with a 500mm jog command, you have it calibrated
If your machine produce parts with different measurements than design you have a combination of backlash/slack/runout/actual tool size disrepancy. Any machine, commercial or hobby based will have some sort of deviation)
To start, a 3mm bit may be just shy of 3mm, runout may cause a 2.9mm bit cut a 3.2mm slot for instance.
Slack/backlash will allow the machine to “back off” a little when engaged to the material.
Is the discrepancy the same in soft materials and hard materials (or at relaxed / aggresive cuts?
It seems to have been mostly a power issue.
I added a large 2 Farad capacitor parallel to the power supply. That also removed the rattling noise from the stepper motors. Downside is the system powers on and of a bit slower…
I have same issue…i have always used xcarve to do carvings outlines with no measurable dimensions and have turned out fine but today i needed to create a small slot in wood and it was way off
I used,easel,and also,vectric aspire and bot produced same results so it must be a machine or setting issue
I made a slot that was 4 in long in x and .200 wide in y and .5 deep
The length in x seemed ok…the depth seemed ok but the width of slot,was way undersized…it,was .160
I ran again and same result
I then created a 4 in long and .312 wide slot and it Was way off it measurd ok in length but way off in width .250 and was not centered to piece like it should be
Its calibrated ok…moves what it should move and its not losing steps
Whats really odd is the slot is not centered per simulation it sounds like issues with y losing steps but its not losing steps
Oh and i used .125 end mill for both slots
I may rotate the part 90deg so the width of slot will be in x and see how it turns out…when i get time
I would suggest the following test regime:
The Xcarve require fine-tuning (like most other CNC’s) to be able to deliver maximum accuracy and precision.
Hi…yes 100 and 101 same value and are values recommended by several people…ive never had any issues doing elaborate carvings…but this is first time ive ever actually needed to machinemsomething dimensionally and its failing big time…not even close…my xy are calibrated pretty good i moved in each direction 300mm and vosually looked fine
The slot is only 5/16 wide and is machining only 1/4 wide…thats pretty bad
Will do some more investigating today…belts…wheels…etc
Nothing sounds or visually looks wrong when doing the slot…whats even more odd is when i went to run program again overbthe existing machined slot it just did exact same thing…with no tool load since slot was already cut…so its not a bit or flex issue at all and the fact that the slot is not centered on material in y seems to be a y stepper issue but it does return back to proper 0,0,0
Very odd…
I agree cnc machines need fine tuning…however Unlike most other properly designed cnc machines, the xcarve seems to get out of tune too easily…if you sneeze on the machine it will then need hours of tedius adjusting…lol
Fyi…Using 1/4 2flute bit in soft pine
Slot being too small is an issue but bigger issue is why the slot is not centered to the material in y…in easel and vectric the slot is perfectly centered to material
If it was losing steps in y (which its not) causing slot not to be centered to,part…the,slot should still machine,proper,width …so something odd is going on for the,slot not to be in proper location in y and machining slot way too small in y
Before you do anything Ralf, please perform my suggested test.
That data may provide good clues as to where to look.
Yes i will …ill just do a min depth cut at 30ipm …same speed i used to cut slot…and then report back,actual dimensions …also been having issues with easel not connecting to xcarve…very annoying…have no issues with UGS connecting though
ok haldor here are some sample pockets i did today…this is after i tightneed x y belts to 3lb @ 1 inch…they were only about 1.5lbs prior…the machine is not losing steps and has not been losing steps for months now and it returned to 0,0 fine on all of my test pcokets…machine seems to be running ok as far as toolpaths and sounds ok…im thinking its a complicated…combination of many variables such as
z axis flex/deflection / poor design (prob biggest problem)
possible dull cutter
cut depth
feed rate
acceleration (i want to slow down the machine when it starts and stops a start of a new path…)
tool defection after initial plunge and then starting the slot accleration seems fast
i can understand all of those issues however what i can ot explain is if you look at the 3 inch pocket it is so far off vcentered its ridiculous…the 1 and 2 inch are off centered too but not as bad
they should not be off centered at all…the wood is pretty square…and my machine router is square to my table in x and y
the 3 inch square pocket is .125 off centered…thats unacceptable…with a cnc machine
like i said i have never used my xcarve to do any dimensional projects…i have only used it to do carves of images and text…which all have looked fine using various bits
and calibration…i have never calibrated mine other than just visual on a ruler…so being off a bit im ok with until i calibrate the proper way if i ever get time
Hi Ralf. Thank you for providing some numbers 
Here is my take on them:
1" test:
X=0.987 => 0.013" off
Y=0.990 => 0.010" off
2" test:
X=1.985 => 0.015" off
Y=1.996 => 0.004" off
3" test:
X=2.982 => 0.018" off
Y=2.980 => 0.020" off
If a pocket of 2x2" is carved undersized, but the step/mm have been fine calibrated and the real bit diameter is known, then any deviation will be due to mechanical issues such as tool deflection, machine flex and backlash.
Backlash in particular is present in any machine and professional software allow you to enter such values so it can compensate by computer (also issues like tool wear etc ++)
Regaring vertical center alignment, I really dont think your board was laid down parallell to the X-axis.
If you run a ruler along the center of 1" and 2" pocket, is the datum line also centered on the 3"? It looks like that may be the case, but judging by the photo isnt very precise.
Did you carve the 4 shapes in one go? If you did and all were centered in design then something is wrong.
If you didnt carve them in one go, can you share your file in case there is a work flow issue?
Yes the 3 pockets were 1 program and went from left to,right…the 3 inch off centered concerns me…and yes the wood was aligned to x axis via my square i use that is mounted to mybtable and calibrated to my spindle…it is square to the machine…
Yes all were centered in design…and all 3 pockets are off centered but the 3 in is horrible… .125 off vertical,alignment
From my experince,usingbthe same bit for a pocket in wood is always undersized as compared to machining alum or mild steel
Wood,as coompared to,alum or mild steel is not very dimensionally accurate material,especially soft wood like pine…which i use all the time …my concern is the vertical,locations of the pockets being off so much
