getting started , latency and breakout board questions

Thanks unknown what thinkcenter gave you problems?

thanks tommy light   I will try the LED trick,   that sounds fun,   

I saw a map for the DB25 connector,   but then i saw another one that i thought was different.    AND should i wait for the BOB before i try the LED test,    Doesn't the BOB offer a protection/insulation service so to speak from having a wiring problem burn up the computers motherboard  ???

For tonight i am falling in a hole trying to pick a servo,   I really like the idea of the Technic Clearpath all in one servos.

There are a bunch available on ebay .     I have been looking at the NEMA 23 size for my Z axis .    This is for the Quill z feed, NOT the Knee.

So there are  Step and direction only  the SD series,   and the other is a SC series which have Software API control and Step and direction.
  i only have a tiny understanding of what i think Software API is,    and i am not sure if the C11G BoB will operate as a software API, ( I don't think it will ) 
But would there be any difference in the smoothness?   
     Step and direction seems like i can wrap my head around ok. 

Also am i being  a Backwards techophobe / ludite,   for sticking with the parallel port VS going with MESA cards?    It is not too late to change my system, 

Also another question  since the Clearpath servos seem to have everything But the actual servo power supply,    Could i get away with haveing only one larger power supply?

and a question. on power supply.    Does a step / direction system need a  special power supply;  Clearpath  specs a 75Vdc power supply.     but there is a voltage range of 24 to max 90vdc 

The step and direction signal are low voltage correct?    Then the BOB converts that tooo??  variable voltage?   or variable amps or both??

man i have some gaps in my knowledge but i am reading up,   and the forum is helping a lot

thanks
 

Clearpath are overpriced but have a step/dir interface, their torque curves indicate the are more like a stepper than a servo. If you must use them, use the SD only. Linuxcnc controls that.
For you first machine with a BOB, don't go overboard. Use open loop steppers, or closed loop steppers if you want to wasre a bit of money.
Generally something like Clearpath would be powered by a 60-70 volt toroid power supply rectified to DC but unregulated.

It's M73 tower with a Intel G3 something or other, went straight for an I5, world difference, CPU and cooler was AUD $20 off FB marketplace.
I use it as a dev machine now.

Tested it with software step generation on the lathe, worked fine, but that was just a test.

Big OOPsie,   I just assumed that the Clearpath servos had absolute encoders.    THEY DON'T.
    I thought i wanted absolute encoders....  at least for the end product.   
i have a friend with a Full size WEB mill and he runs steppers,   I don't think he is in love with them,  but he has not changed them out either.

     RodW i think you are correct for a first machine,   unfortunately I only have one CNC mill.   and i dont' really want to buy a learner set of servos or steppers and then have to replace them to get a good accurate part.    That is why i was wanting to start off with ONE used small clearpath servo, and not just buy a whole set without trying one first.
     
For easy and simple the clear path  SD do seem ok.   And i don't know if i agree with you on the overpriced part,   i just looked at some steppers and by the time i get a stepper and a drive they are pretty close to the clearpath price,   It did seem like the steppers may be more powerfull for the size, is that true??
    Also I am not buying NEW NEW clearpath.   There are lots of new open box or slightly used Clearpaths for sale ,   which also makes me  wonder why so many are for sale???  

i read the thread    " some advice and opinion of the Clearpath servos",    now i need to look into that further.

Too much reading tonight  and not much closer to a servo decision 

Good afternoon I have a question,   It is both linuxCnc, and just Linux.
      First   I have been running LinuxCnc from a  Startup Boot thumbdrive.    I had a friend help with the original Linux install, and LinuxCnc install on this computer  Lenovo intel g73.   
     At some point I think  i would like to get rid of the thumbdrive boot ,  and have this computer just run linuxCnc , or if possible Linux Debian 12, and LinuxCnc .     But for now i am pretty happy with the LinuxCnc on the thumbdrive and i have  Linux Debian 12 without the thumbdrive. 

I am still learning both Linux and LinuxCnc for sure.    
     I have a very old robot arm that i can run on a windows terminal .   I ASSUME i should be able to run the arm from a Linux terminal????   

BUT

I can not seem to change the serial port parameters in either Linux, or LinuxCnc.    
I have tried several times to change the serial port parameter with various different terminal  commands? 
    I have tried
             "     stty -F /dev/ttyS0 57600 cs8 -parenb -cstopb   "     i have also tried to add " sudo" in front of the line.
i always get permission denied.
    I believe i have root access,   but maybe not.    i have tried to change my user status to  a  " ALL "   and some other things,  but no luck

I am not sure if this is a problem with my install,  or if i need a more potent permission .

I thought i was the only user on this install and i thought i have    "  ALL access"   but apparently I don't..

Shouldn't i have the same access in linux and LinuxCnc

i did mange a command that listed all my permissions and i am pretty sure i have at least admin level   

how can i get permanent root access

thanks


 

Good afternoon Tommylight thanks, I tried something pretty similar to this with out the < > .

That was several tries back

i just tried it and i added the < > with my username in the middle of the<> and i got a
bash: syntax error near unexpected token 'newline'

next i tried without the < > and i got asked for my password,       that is good correct?

i made a typo next, trying the stty -F /dev/ttyS0

---

and on the 2nd try with the stty i got permission denied again.

if i make a typo do i lose my root access? and need to start over with dialout line ?

i tried the whole process starting with the  " ls " again,  no typos and still permission denied

Since the command line has my name twice that means i am logged in correct?   does that mean  i am logged in a both user and admin?

Logout out then log back in, then you'll be good for your permissions and group membership.