DDSCV1.1 3 and 4 axis offline motion controller

[Clive S]

And a GUI that doesn't look like Etch-a-Sketch on acid

Is this better https://forum.linuxcnc.org/show-your...lathe-retrofit

[Merlin201314]

Small update with video to follow:

Controller is mounted in my enclosure and after i spend yesterday all day playing with it, i could say- I like it and i am very happy with it.

Machines moves smoothly as ever at 10000/min and 3000 acceleration. Spindle speed is stable. Program time execution- same as using Mach3 or 4.


Manual has some confusing Chinglish elements as to be expected.




Probing works very well but needs some clarification:

First of all there are 2 types of probing:
Where tool position is at the moment or in Machine Coordinates the probes place on the machine could be predefined and probe or another probe mounted there.

Now the trick. It should be done once only.
Put a tool in collet, tighten it at hand but leave it a bit untightened so that if machine pushes it towards bed it will move inside the collet but at same time is not loose.
One must go to probing settings and make sure probe thickness is set to 0.000 and if not set it so and make sure probing is enabled and " at current tool position".
Then go back to control screen and start moving Z towards table. When you hit Z in table, bit will move a bit into collet. So now you are 0 to table in Working coordinates. Use commands and set Z to 0 in Working Coordinates on screen
M0ve Z up more distance than the probe is thick / by the way Z up is + and down is -, toward you Y is - and away from you is +, X left is -, X right is +, the so called right cartesian coordinate system/
Lay probe on table surface / current Z0/ . + of probe is connected to conductive probe material, minus to spindle body or bit, +should be isolated by other material like plastic from below/
hit "MODE2" then "-A" x 2 times and probing starts . When bit touches plate Z goes up depends how much you have predefined in probe settings. If you look now at probe setting you will see a number that may not be your probe thickness. DO NOT CHANGE THAT NUMBER. Its not wrong.

Now you can probe normally, control knows your real probe thickness, even if there is a loss of power.

PRECAUTIONS:
1. When changing G54 with other WCS you lose your probe thickness so you must do that again. Be Careful! Until you figure all out, raise the probe on a sponge.
2. If you program one of the external buttons that could be connected as 0 instead of "start" / when you hit it it zeroes all in WCS / , then when you zero from it, after that you again gave to repeat the probe thickness setting like from the start. I will investigate further but its start to seem that when you probe and 3 axis are zeroed right before that, that means it comprehends it like you want to set probe thickness, not like setting your Z WCS zero.


I will continue later with my findings. Now back to work.

Hi all, new in the forum....

Regarding the DDCSV1.1 chinese controller,

Is not really clear about the mode 1/mode2 of the Zprobe, i realize that if i setup the probe tool in mode2 with the correct height and current position it works
perfectly as i can measure mi tool with a caliper, so why i need to use the mode1?? (maibe i'm too thick to understand)...
And again, as the chinenglish manual is not clear at all, we all have to guess what is what....
Is someone can explain me the concept it would be great, thank you all
Regards

[Boyan Silyavski]

Its very simple. It assumes you have a zero setting gauge. You hit the gauge and move until is Zero there. Knowing that the gauge is 50mm high you zero the machine. When you hit zero Z, you enter 50mm and now machine knows where bed is. Next put whatever isolated probe on bed and hit Probe. Now it figures the probe thickness.

But hit a button that zeroes all 3 axis together and all of the above is lost. Does that make sense to you?


So lets chew it up again:

In order for you to use automated probing without any further hassle like above, one very simple modification should be made to machine. Mount your probe / VDC+/ on the machine directly, so that + does not touch bed in any way. So that probe surface must be actual table zero level. You can do that by pocketing your bed if metal, fit a plate there connected to +, epoxy it, wait to dry and surface it on bed level. You could even tell controller where that is so every time the probe goes there to check tool offset. or just buy 2 of the cheap 3 euro chinese spring probes from ebay and integrate one in bed.

So once you have that probe level with bed, you could either use another probe or use only this probe

edited: dont use the method i said here as i found a serious mistake from my part, in certain scenarios. Use the mechanical method described above or several post below.

[Merlin201314]

Thank you so much for the kind reply, but as much as i tried i cannot find the way---
You should make a short video, because mode 1 and mode 2 have two different beheaviour, and even if i setup the fixed probe on the machine bed, still not working.

So for sure i do something wrong!!!!!
If you don't mind to write the steps one by one as in a manual with the setup of the mode and next step to follow that would help a lot.
is not clear in which mode you measure the bed zero, (1 or 2?) as my bed zero is at -140mm from the machine zero(which is positive up)
and every time you hit the zero button, it go up to zero the z axis and start again, but the odd number in the controller is always a strange number, it doesen't make any sense honestly..
In mode 2 when the controller is setup as "current position" and the tool gauge entered manually(caliper measured) i can measure the worktop but thats that :-(( and is the only way i can work

[magicniner]

if you have a nice machine its better to have flat table and take and program Z level in CAM from table level. Not material level. As what you do when in the middle of program machining surface is spoiled and no way to zero again there????t

Work Offsets allow you to have bed level as Machine Z-zero with the top of work as your Work Z-zero, that's what Work Offsets are for. ;-)

The professional CNC machinists I've spoken to tend to use a top of part/stock Z zero,

- Nick

[Boyan Silyavski]

Work Offsets allow you to have bed level as Machine Z-zero with the top of work as your Work Z-zero, that's what Work Offsets are for. ;-)

The professional CNC machinists I've spoken to tend to use a top of part/stock Z zero,

- Nick

Unfortunately DIY cnc machine will be always one step behind due to the lack of absolute encoders or scales that at all time tell the machine the exact position, even if power switched off. To rely on working offsets on a machine equipped with cheap chinese limit switches is ridiculous. As i said somewhere above on a couple of occasions i measured 0.4mm initial imprecision and now while browsing 3D printer stuff i found some reports that temperature also changes the situation..

Now the thing is that you are right in a way, cause on a DIY machine, nothing happens if 0.1-0.4mm things are not right when homed. But you could not continue aluminum job if power is cut or you need to reset steppers, i have tried that to no avail, at least a couple of times

[magicniner]

Unfortunately DIY cnc machine will be always one step behind due to the lack of absolute encoders or scales that at all time tell the machine the exact position, even if power switched off.

That statement is true but is not relevant.

Having your bed as machine Z zero and using a work offset is no more complex than having your bed as work zero and setting the bottom of your stock as your Z zero in CAM, it doesn't require any fancy encoders or switches, it does require a little planning, but no more so than using a bottom of stock zero in CAM.

Having your bed as machine Z zero and using a work offset does have the considerable advantage that if machining or engraving a series of features in a surface you can do this on a variety of thicknesses of stock without having to refer to CAM to see what stock thickness you had set and then calculating a compensating offset ;-)

- Nick

[John S]

Dangerous to use the bed as work zero.

What happens if your machine decides to go to Z 0 without switching the tool offset off ?

Bang cutter all the way though the work.

If the top of the work is Z0.0 then all cutting moves are negative, any positive Z moves are safe.

[Boyan Silyavski]

We are talking different machines here. Who uses tool offsets on non repeatable tool holder, like ER20 on a Chinese spindle????? Me not.

You are talking about mills and i am talking about routers.

In reality i use the work offset that suits me better for each separate job and have the good custom to mark that in my file name. like xxxxx 0vacfixt or xxxx0bed or 0top. I would have told that from the beginning but was just making a point here.

its obvious that i don't work in machine coordinates and use different coordinate systems G54 to G59. What i was saying above is that there is no point making fixtures and each fixture to have a predefined work offset, cause the machine anyway will not find properly the 0 just from homing without manually finding the zero.

or am i not explaining what i want to say?

Let's say it in another way. I use nothing complicated but every separate job i find the zero again and again not only in Z but X and Y also. All else is time wasting time on a DIY machine that every time runs totally different job

[Ger21]

To rely on working offsets on a machine equipped with cheap chinese limit switches is ridiculous.

I use DIY hall effect switches, which are supposedly accurate to .01mm or better. There's a thread on CNC Zone where the designer showed his testing for accuracy. Cost about $15 to make.

I've resumed jobs many times after homing, with no issues at all.