[Ron Thompson]

Not so strange. Nothing is perfect. This is why you fine tune each axis.Good luck!

[Adverse Effects]

this is also why i said to do the testing over as long a distance as possible because any inaccuracy you make over a longer distance is less %

1mm inaccuracy over 500mm is A LOT less than 1mm inaccuracy over 100mm

i already told you how to do it with just a ruler and the wizard yet you are pissing around with doing test cuts with the settings WAY OFF


it would seem you just carnt help some people

[Atomic_Sheep]

There's a couple of reasons why I'm doing test cuts.

1.) I've only got 15cm calipers so my maximum cut that I can measure accurately is 15cm.

2.) I don't have a v bit to be able to somewhat accurately measure over long distances using a crude metal ruler technique. I've only got 3mm drill bits at the moment.

[Ron Thompson]

You don't need a V bit for precise measurements. Use a square end mill and cut a shallow slot. The measurement of the slot will be the length you programmed it to cut plus the diameter of the end mill.

[Adverse Effects]

You don't need a V bit for precise measurements. Use a square end mill and cut a shallow slot. The measurement of the slot will be the length you programmed it to cut plus the diameter of the end mill.

yep

he even said "I don't have an accurate way of measuring distance moved apart from a long steel ruler." so we know he has one

i even explained (WITH A PIC) on how to do it and what you do it more than once

[Atomic_Sheep]

I said I only have a long steel ruler because it was the only way I had of measuring long distances. At that point in time I didn't know you could do test shapes for measuring with calipers. I wanted to measure over the full size of the fable to ensure the most accurate measurement as Adverse Effects suggested, for that I only had a steel ruler.

All good guys, my cuts are now perfect. I got 100.05mm and 40.03mm rectangle. I screwed up my CAM, that's why my measurements were off. The 5mm pitch screw is dead on i.e. 400 steps per unit. If I had to guess... the 0.05 is due to backlash but need to get some DTI to confirm that.

3rd attempts the charm.

[Ron Thompson]

Great! What CAD/CAM are you using? I highly recommend Fusion 360. You can download it and learn it through Youtube videos. The best part is it's free unless you are grossing over $100k in a business. Fusion 360 | Free Software for Students, Educators | Autodesk

[Atomic_Sheep]

Just FreeCAD and PyCAM... thanks for the suggestion, will definitely look into it. Just playing around at this stage but will need some decent software.

[jm82792]

Any thoughts on my old bearing backlash issue?
The thing has a lot of slop due to the bearing and I can't fit in a double bearing to fix it.

[Atomic_Sheep]

Can you post some pictures or video?

[Ron Thompson]

My first thought is to get with your supplier to have them correct the issue. That said, there are some machines the only use two bearings, one on each end of the screw and stretch the screw when tightened.

[jm82792]

My first thought is to get with your supplier to have them correct the issue. That said, there are some machines the only use two bearings, one on each end of the screw and stretch the screw when tightened.

Unfortunately I was busy, the supplier was kind of pathetic and never offered to help.
I could have taken out a Paypal claim but I didn't and I was too busy to put the squeeze plus the supplier admitted they are very cost driven.
I've got three Chinese friends, a few in Indonesia, etc so I know how to work them but I thought I could fix it but I didn't do so.


The unit only has two bearings and does indeed stretch the screw to reduce backlash provided their crappy preload washer thing works which it doesn't.... I only need to do high end woodworking, but since it's only two bearings there's like ,008" slop (due to the crappy way they're tensioning the screw I think) and I can't tolerate that for my 3d work.
Any ideas on how to correct this? I am not that mechanically inclined, however, I'd like to fix this thing up and get it running since past a year or two I'll upgrade. Should or could I bring it into a machine shop and expect/hope $100-$200 USD could perhaps come together a cheap solution?
I was thinking of installing a double bearing by the motor for where the single bearing is, as the screw end is threaded for a nut, and could be "fixed" on one end while the other can move some on one bearing for expansion..

Am I on the right track? I've been paying my way with two little Microcarve CNC routers for years which are great little machines, however, this thing is $100 short of quality and needs help.

[Ron Thompson]

I don't know what size ball screw you are using, but I think mine is a 1605. Ebay has bolt on ends that I am sure you could mount to your machine. The driven end may protrude a little more and the other end is probably OK with no bearing unless you are running ridiculous speeds.
Zyltech BF12 BK12 end support bearing block for Ball Screw 1605
If your ball screw machining is different, you may need to buy a machined ball screw to fit. Many sellers will machine to length. Good luck.

[fifa]

Your calculation is not correct.
Micro stepping is not accurate & even the steps are not accurate (due to mechanical misalignment).


regards

[jm82792]

I don't know what size ball screw you are using, but I think mine is a 1605. Ebay has bolt on ends that I am sure you could mount to your machine. The driven end may protrude a little more and the other end is probably OK with no bearing unless you are running ridiculous speeds.
Zyltech BF12 BK12 end support bearing block for Ball Screw 1605
If your ball screw machining is different, you may need to buy a machined ball screw to fit. Many sellers will machine to length. Good luck.

Thanks I'll see what can be done here as it's about time I fix this and press on...
If the block is even somewhat compatible I can get it drilled out here, and indeed I've noticed sellers offering made to order ball screws which should work well.

[Atomic_Sheep]

Does anyone have the 6040 in CAD form?

[Ron Thompson]

There is a 3020 on grabcad, but some details are different. What cad program are you using?

[Atomic_Sheep]

There is a 3020 on grabcad, but some details are different. What cad program are you using?

Still using freeCAD, haven't had a moment to check out Fusion 360 but I was trying to figure out a way of preventing plunging drill bits into the table accidentally so I wanted to install a CNC simulator.

[Ron Thompson]

Fusion has a simulator. When Fusion post Gcode, the first few lines of the program list the tools used and the max Z depth. Very handy for not cutting the table. Here is an example and a screen shot of what it's cutting:

Attachment 338522
(SHUT)
(SHUT)
(T102 D=0.125 CR=0. - ZMIN=-0.23 - FLAT END MILL)
G90 G94 G91.1 G40 G49 G17
G20
G28 G91 Z0.
G90

(BORE2)
M5
M9
T102 M6
S5000 M3
G54
M8
G0 X1.055 Y-2.7547
G43 Z0.6 H102
Z0.0675
G1 Z0. F15.
Y-2.7609
G3 X1.0598 Y-2.7657 R0.0048
Y-2.7467 Z-0.0197 R0.0095
Y-2.7657 Z-0.0394 R0.0095
Y-2.7467 Z-0.0591 R0.0095
Y-2.7657 Z-0.0787 R0.0095
Y-2.7467 Z-0.0984 R0.0095
Y-2.7657 Z-0.1181 R0.0095
Y-2.7467 Z-0.1378 R0.0095
Y-2.7657 Z-0.1575 R0.0095
Y-2.7467 Z-0.1772 R0.0095
Y-2.7657 Z-0.1969 R0.0095
Y-2.7467 Z-0.2165 R0.0095
X1.0518 Y-2.7614 Z-0.23 R0.0095
X1.0677 Y-2.751 R0.0095
X1.0518 Y-2.7614 R0.0095
X1.0584 Y-2.7628 R0.0048
G1 X1.0636 Y-2.7594
G0 Z0.2
X0.6202 Y-1.9954
Z0.0675
G1 Z0. F15.
Y-2.0016
G3 X0.625 Y-2.0064 R0.0048
Y-1.9874 Z-0.0197 R0.0095
Y-2.0064 Z-0.0394 R0.0095
Y-1.9874 Z-0.0591 R0.0095
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Y-1.9874 Z-0.0984 R0.0095
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Y-1.9874 Z-0.1378 R0.0095
Y-2.0064 Z-0.1575 R0.0095
Y-1.9874 Z-0.1772 R0.0095
Y-2.0064 Z-0.1969 R0.0095
Y-1.9874 Z-0.2165 R0.0095
X0.617 Y-2.002 Z-0.23 R0.0095
X0.633 Y-1.9917 R0.0095
X0.617 Y-2.002 R0.0095
X0.6236 Y-2.0034 R0.0047
G1 X0.6289 Y-2.
G0 Z0.2
X1.0605 Y-1.2392
Z0.0675
G1 Z0. F15.
Y-1.2454
G3 X1.0652 Y-1.2502 R0.0047
Y-1.2312 Z-0.0197 R0.0095
Y-1.2502 Z-0.0394 R0.0095
Y-1.2312 Z-0.0591 R0.0095
Y-1.2502 Z-0.0787 R0.0095
Y-1.2312 Z-0.0984 R0.0095
Y-1.2502 Z-0.1181 R0.0095
Y-1.2312 Z-0.1378 R0.0095
Y-1.2502 Z-0.1575 R0.0095
Y-1.2312 Z-0.1772 R0.0095
Y-1.2502 Z-0.1969 R0.0095
Y-1.2312 Z-0.2165 R0.0095
X1.0573 Y-1.2458 Z-0.23 R0.0095
X1.0732 Y-1.2355 R0.0095
X1.0573 Y-1.2458 R0.0095
X1.0638 Y-1.2472 R0.0048
G1 X1.0691 Y-1.2438
G0 Z0.2
X2.43 Y-1.2392
Z0.0675
G1 Z0. F15.
Y-1.2454
G3 X2.4348 Y-1.2502 R0.0047
Y-1.2312 Z-0.0197 R0.0095
Y-1.2502 Z-0.0394 R0.0095
Y-1.2312 Z-0.0591 R0.0095
Y-1.2502 Z-0.0787 R0.0095
Y-1.2312 Z-0.0984 R0.0095
Y-1.2502 Z-0.1181 R0.0095
Y-1.2312 Z-0.1378 R0.0095
Y-1.2502 Z-0.1575 R0.0095
Y-1.2312 Z-0.1772 R0.0095
Y-1.2502 Z-0.1969 R0.0095
Y-1.2312 Z-0.2165 R0.0095
X2.4268 Y-1.2458 Z-0.23 R0.0095
X2.4427 Y-1.2355 R0.0095
X2.4268 Y-1.2458 R0.0095
X2.4334 Y-1.2472 R0.0048
G1 X2.4386 Y-1.2438
G0 Z0.2
X2.8703 Y-1.9954
Z0.0675
G1 Z0. F15.
Y-2.0016
G3 X2.875 Y-2.0064 R0.0048
Y-1.9874 Z-0.0197 R0.0095
Y-2.0064 Z-0.0394 R0.0095
Y-1.9874 Z-0.0591 R0.0095
Y-2.0064 Z-0.0787 R0.0095
Y-1.9874 Z-0.0984 R0.0095
Y-2.0064 Z-0.1181 R0.0095
Y-1.9874 Z-0.1378 R0.0095
Y-2.0064 Z-0.1575 R0.0095
Y-1.9874 Z-0.1772 R0.0095
Y-2.0064 Z-0.1969 R0.0095
Y-1.9874 Z-0.2165 R0.0095
X2.867 Y-2.002 Z-0.23 R0.0095
X2.883 Y-1.9917 R0.0095
X2.867 Y-2.002 R0.0095
X2.8736 Y-2.0034 R0.0048
G1 X2.8789 Y-2.
G0 Z0.2
X2.4355 Y-2.7547
Z0.0675
G1 Z0. F15.
Y-2.7609
G3 X2.4402 Y-2.7657 R0.0048
Y-2.7467 Z-0.0197 R0.0095
Y-2.7657 Z-0.0394 R0.0095
Y-2.7467 Z-0.0591 R0.0095
Y-2.7657 Z-0.0787 R0.0095
Y-2.7467 Z-0.0984 R0.0095
Y-2.7657 Z-0.1181 R0.0095
Y-2.7467 Z-0.1378 R0.0095
Y-2.7657 Z-0.1575 R0.0095
Y-2.7467 Z-0.1772 R0.0095
Y-2.7657 Z-0.1969 R0.0095
Y-2.7467 Z-0.2165 R0.0095
X2.4323 Y-2.7614 Z-0.23 R0.0095
X2.4482 Y-2.751 R0.0095
X2.4323 Y-2.7614 R0.0095
X2.4388 Y-2.7628 R0.0048
G1 X2.4441 Y-2.7594
G0 Z0.6

(2D CONTOUR1 2)
M8
G0 X1.9962 Y-0.6876
Z0.6
Z0.2
G1 Z0.1019 F15.
Z-0.0625 F13.1
G2 X2. Y-0.6875 R0.0625 F15.
G1 X3.
G2 X3.0625 Y-0.75 R0.0625
G1 Y-3.25
G2 X3. Y-3.3125 R0.0625
G1 X2.
G2 X1.9375 Y-3.25 R0.0625
G1 Y-0.75
G2 X1.9962 Y-0.6876 R0.0625
G1 Z-0.125 F13.1
G2 X2. Y-0.6875 R0.0625 F15.
G1 X2.063
Z-0.11
X2.313
Z-0.125 F13.1
X3. F15.
G2 X3.0625 Y-0.75 R0.0625
G1 Y-1.8751
Z-0.11
Y-2.1251
Z-0.125 F13.1
Y-3.25 F15.
G2 X3. Y-3.3125 R0.0625
G1 X2.3082
Z-0.11
X2.0582
Z-0.125 F13.1
X2. F15.
G2 X1.9375 Y-3.25 R0.0625
G1 Y-0.75
G2 X1.9962 Y-0.6876 R0.0625
G1 Z-0.16 F13.1
G2 X2. Y-0.6875 R0.0625 F15.
G1 X2.063
Z-0.11
X2.313
Z-0.16 F13.1
X3. F15.
G2 X3.0625 Y-0.75 R0.0625
G1 Y-1.8751
Z-0.11
Y-2.1251
Z-0.16 F13.1
Y-3.25 F15.
G2 X3. Y-3.3125 R0.0625
G1 X2.3082
Z-0.11
X2.0582
Z-0.16 F13.1
X2. F15.
G2 X1.9375 Y-3.25 R0.0625
G1 Y-0.75
G2 X1.9962 Y-0.6876 R0.0625
G0 Z0.2
X1.5038
G1 Z0.1019 F15.
Z-0.0625 F13.1
G2 X1.5625 Y-0.75 R0.0625 F15.
G1 Y-3.25
G2 X1.5 Y-3.3125 R0.0625
G1 X0.5
G2 X0.4375 Y-3.25 R0.0625
G1 Y-0.75
G2 X0.5 Y-0.6875 R0.0625
G1 X1.5
G2 X1.5038 Y-0.6876 R0.0625
G1 Z-0.125 F13.1
G2 X1.5625 Y-0.75 R0.0625 F15.
G1 Y-3.25
G2 X1.5098 Y-3.3117 R0.0625
G1 Z-0.11
G2 X1.5 Y-3.3125 R0.0625
G1 X1.2598
Z-0.125 F13.1
X0.5 F15.
G2 X0.4375 Y-3.25 R0.0625
G1 Y-2.0699
Z-0.11
Y-1.8199
Z-0.125 F13.1
Y-0.75 F15.
G2 X0.5 Y-0.6875 R0.0625
G1 X1.2299
Z-0.11
X1.4799
Z-0.125 F13.1
X1.5 F15.
G2 X1.5038 Y-0.6876 R0.0625
G1 Z-0.16 F13.1
G2 X1.5625 Y-0.75 R0.0625 F15.
G1 Y-3.25
G2 X1.5098 Y-3.3117 R0.0625
G1 Z-0.11
G2 X1.5 Y-3.3125 R0.0625
G1 X1.2598
Z-0.16 F13.1
X0.5 F15.
G2 X0.4375 Y-3.25 R0.0625
G1 Y-2.0699
Z-0.11
Y-1.8199
Z-0.16 F13.1
Y-0.75 F15.
G2 X0.5 Y-0.6875 R0.0625
G1 X1.2299
Z-0.11
X1.4799
Z-0.16 F13.1
X1.5 F15.
G2 X1.5038 Y-0.6876 R0.0625
G0 Z0.6

M9
G28 G91 Z0.
G28 X0. Y0.
M30

[Adverse Effects]

there is a little program i use to look at the GCode

GPlot1.3

Attachment 338530