[obrif]

Would like to connect a linear encoder to a syil x4+ does anyone know any
wiring layout and mach3 settings?

Regards

Obrif

[Al_The_Man]

The scale would act the same way as an encoder and go back to the drive as normal for servo control.
Al.

[Ed from NY]

Would an linear encoder feed back into Mach3???

Does that mean your would get position feedback in a stepper setup?

[neilw20]

Adding complexity is not an improvement. What do you wish to achieve.
More accuracy. How will you measure the improvement.

The machine is already an excellent price/performance mix. Get real.

[Ed from NY]

I see your point Neil, but if the guy wants to add it to his machine I think it would be cool. Particularly if it comes with a DRO and he later puts a MPG/jog in it.

I'm also curious to learn what would Mach3 do with that information...

[neilw20]

x4+ already has MPG, but needs Pablo's (peu) second port adaption to be useful.
Only cool if you put it on the spindle for solid tapping.

[Ed from NY]

:LOL:

Complexity!!!

Yeah I agree...

If only I were converting a mill from scratch

Which reminds me...

Have you seen a stepper or servo being used as a spindle motor? Is that very different from what we have today?

[neilw20]

X3/X4 spindle motor is BLDC and really is a servo motor.
Have you got your Y axis rock fixed yet. I just program in the errors as a tweak. I am really lazy, but churn out 100's of hours work on my SX3 every month.
On 15HP CNC lathe (OKUMA LC20), between centers, I held better than 0.0005" parallel all day and never could be bothered adjusting the tail stock which was 0.005" off center. That's why CNC is great. New tools. Easy solutions.

[obrif]

Thanks for the replies,

Since had one linear scale laying around would like to make screw calibration and arrange backlash on the mach pragram.
Till now managed to get 2 raw inputs bits lights flashing when moving linear scale but have not manage to get a reading on dro Can somebody help?

[neilw20]

Read The F*!!@-riendly Manual, Mach3 section 4.5

You have a quadrature signal. Without special electronics, you will be limited in the speed that the encoder moves before getting errors using Mach3.

[Ed from NY]

Have you got your Y axis rock fixed yet.

Not yet. I started to scrape it with varied levels of success, but I would like the reassurance of a flat reference... still, I'm getting better at it and I think I can wing it just with machinist blue.

I have a thread on the main metal working forum, but no suggestions for a cheap reference yet http://www.cnczone.com/forums/showthread.php?t=88112

On 15HP CNC lathe (OKUMA LC20), between centers, I held better than 0.0005" parallel all day and never could be bothered adjusting the tail stock which was 0.005" off center. That's why CNC is great. New tools. Easy solutions.

*sigh* One day I hope to build a machining center from scratch

[obrif]

Managed to get the encoder readings in the screw mapping windows to a micron accuracy at last thanks to the ^%cken helpful SYil Manual and MAch Manual.
Am just playing around with the scale but results are leading to around 0.1 mm HORIZONTAL PLAY in the X4+ head. Is this normal or it can be improved?

[Ed from NY]

Can you be more specific? Do you mean backlash or do you mean you can shake it with your hands? Is the "play" in X in one Y position or across all Y positions?

Out of curiosity, do you have more detail on your set up... as if someone with too much time on their hands could get an idea of what you did and how to do it themselves?

Is the information fed back in Mach3 used in any way other than being displayed?

Thanks

[obrif]

The play is definitely in the X4+ head. i.e. when pushing the head sideways with the hand.

[Ed from NY]

Flex is normal. Play is not.

To minimize play:

• Have you disassembled and cleaned the column like you did for the X and Y axis?
• Try cleaning and lubing the gib.

Sorry if you know these things already, but to minimize flex:

• Inertia is your friend... use higher RPMs (carbide tooling helps)
• Use sharp tooling
• Give preference to tooling and operations that minimize secondary forces in the Z axis (sharp tooling helps a lot more than anything else here)
• All else being equal, use multiple edge cutters
• Try to avoid tooling that is so off balance that they shake the head by themselves
• Finish with a 0.020" pass or smaller, a little flex does not matter when roughing
• Keep the column as low as possible (get rid of vises, chucks and mill holders). If you think that a collet will keep the milling at 1" from the head. A vise or a chuck will add some 3" each. Besides introducing their own flexes they will force you that further up in the column. Think of climbing a ladder, the bigger the ladder the bouncier it gets. Extension ladders are much bouncier than ladders with no fly. All else being equal, stubby wins.
• Use the shortest length tooling that will do the job. All else being equal, stubby wins again.
• When using single edge tooling or off balance tooling watch out for RPMs that cause resonance.
• If the head starts shaking stop and consider how you can improve the load. it will not take you long to come up with something.

Under normal milling operation the flex in the column will not be an issue if you get rid of vises, chucks and mill holders. When it becomes an issue, in my limited experience I have been able to diminish with the above.

If anyone has additions/corrections please jump in, I'm very new at this,

[obrif]

Have managed to get some readings of the x axis movement from the encoder.
After adjusting the steps/unit I found out that the screw/encoder difference was only 0.009mm more in a 260mm ball screw length.
Unfortunatly when trying to set the backlash i found out that the backlash varied along the screw length. I.E if setting bachlash at x=50mm, at x=50 table returned back to an accuracy of 0.002mm but when testing backlash at x=100 (with same backlash value of x=50 ) table returned back with an error of +0.02mm same happened at x=250 but error -0.02mm.
When I took backlash reading at x=250 and set backlash according to x=250 readings table returned to position with an accuracy of 0.002mm.
Does anybody explain why the backlash is not constant along the screw when the screw error is around .009mm and the backlash errors are around 0.02mm ?Doesn't make sense for me!!

[ataxy]

thats why i think the best you can do unless you install double ballnut is to make an average of the backlash and to live with that error as this is the problem with part that arnt 100% precise