Spindle not up to speed before cutting starts

[chrisQWNYT]

i have a centroid AiO controller on my mill.  it seems that when i request higher rpm's for aluminum the spindle is not up to speed just yet.  i would like to modify the Centroid Mill cps to Always wait say 1 sec per 1,000 rpm's.  i have tried myself with no luck as i am not a computer programmer.  any help would be greatly appreciated.  im am using an unmodified post.  i do not have a spindle encoder. 

i am surprised F360 does not offer this as a parameter next to spindle speed in CAM.

[seth.madore]

The easiest thing to do would be to put a hardcoded dwell before the first cutting move. What is the dwell command for your controller?

Don't be surprised that Fusion doesn't automatically support this. Fusion was built with mainstream commercial CNC's in mind, which don't typically suffer from this, or have encoders that monitor speed and prevent motion until proper RPM is attained.

[chrisQWNYT]

i understand they have bigger customers with deep pockets, but they, probably better than anyone else, market to the diy and small business like myself.  i hope to get to the point that i can get a new machine soon.

anyway, centroid uses G4 for dwell with P before the set time or equation to figure the time.  i just timed it and it takes my spindle almost 20 seconds to get to the max 6,000 rpms. i would like it to dwell 4 seconds per 1000 rpms to play it safe.  

can you help modify my cps?

thx

[chrisQWNYT]

so i just retimed it and really paid attention to the spindle speed.  it takes a solid 47-50 seconds to get to 6000 rpm.  so i would like to get the centroid mill cps modified to either dwell 45 seconds or, preferably if not too difficult, have it wait 8 seconds per 1000 rpms each time the spindle starts.

i manually entered a G4 P45 after the spindle M3/4 command and it worked.  obviously i do not want to have to do that 3 to however many times all day for each program.

thx

[boopathi.sivakumar · Accepted solution]

@chrisQWNYT 

It is very easy to modify the post to get you what you wanted

Edit the post (.cps) in any editor and find for this line

// wcs

then paste the codes like below mentioned

  pVal = (spindleSpeed*8)/1000 ;         // Add this line
  onDwell(pVal);                         // Add this line

  // wcs
  if (insertToolCall) { // force work offset when changing tool

Save the post processor and test it. currently it adds 8 sec per 1000 rpm. you can change 8 to any number as per your requirement

[chrisQWNYT]

sorry i am not a proggramer. do i copy&paste it exactly like you wrote it?

 pVal = (spindleSpeed*8)/1000 ;         // Add this line
  onDwell(pVal);                         // Add this line

  // wcs
  if (insertToolCall) { // force work offset when changing tool

Or, like this?

pVal = (spindleSpeed*8)/1000 ; // 
onDwell(pVal); // 

// wcs
if (insertToolCall) { // force work offset when changing tool

and my last newbie programmer question, does the word tool in the last line need anything after it?

thx

[Stuart-H · Accepted solution]

@chrisQWNYT 
Just as posted will be fine

the // are like the REM in basic they mean anything after is a remark for you ,you can replace the add this line with added to add dwell to spindle or WHY makes it easy to find in the future where you altered the Code but please make a copy of the modded cps so you do not overwrite it 

[engineguy]

@chrisQWNYT 

The length of time for the spindle rpm to "spin up" is usually determined by settings in the Spindle Drive, usually a combination of a "Ramp" and "Current" (Amps) settings that determine how quickly the Spindle Motor accelerates and decelerates from any given rpm.

It may not be possible to change those settings depending on what type of Spindle Motor Drive is on your machine, if you know the Make and Model of the drive and the Make/Model/Horsepower of the Spindle Motor itself then it might be worth getting in touch with the Manufacturer(s) of either/both if you don`t have a Manual for them.

To be waiting nearly a minute for spindle rpms to change doesn`t sound like that is intentional from the Machine Manufacturer to me 😞

As you don`t appear to have an encoder or resolver that feeds the Spindle rpm back to the Main control so the machine doesn`t move in any direction even with the .cps modification for a Dwell the Spindle may still not be fully up to speed then an extra level of safety might be to have an M1 command right after the S*** M3/4 command so it will just sit there until the Cycle Start button is pressed.

Just for interest/information 🙂 🙂 🙂

Stay Safe

Regards

Rob

[tomae]

Many controllers have an M code (or possibly G code) to enforce spindle at speed before a move.  My Emco 365mc (with Siemens 840 controller) uses M103 and M104, in place of M3 and M4 respectively to wait for spindle at speed.

From Manual:

M103 Main Spindle ON clockwise with Waiting Time.  Same code as M3, but:
The following blocks only then will be executed, if the spindlespeed has been reached.

'

M104 Main Spindle ON counter clockwise with Waiting Time.  Same code as M4, but:
The following blocks only then will be executed, if the spindlespeed has been reached.

[engineguy]

@tomae 

Yes, but what is telling the control that the programmed Spindle rpm has been successfully reached, needs an encoder or resolver I would expect or a feedback from the Spindle Drive unit ??

Stay Safe

Regards

Rob

[tomae]

---

@engineguy wrote:

@tomae 

Yes, but what is telling the control that the programmed Spindle rpm has been successfully reached, needs an encoder or resolver I would expect or a feedback from the Spindle Drive unit ??

Stay Safe

Regards

Rob

---

Minimally it needs a VFD (Spindle Drive) indication.  Encoder/Resolver would be even better but he said he didn't have one...

-Tom

[chrisQWNYT]

ok, thank you for the clarification.  i will add why i added the change.

thx!

[chrisQWNYT]

so a bit of background... i just upgraded my centroid M15 controller to their newest All in 1 DC controller with touchscreen.  prior to the upgrade the machine did not have this problem.  i am working with tech support at centroid to fix my plc programing to make the machine wait for the spindle to get to speed before cutting.

while i am fixing the plc programing, i discovered the new VFD i bought is bad.  it is a 10hp drive powering a 5hp motor.  and i agree, 60++ seconds to get to 6,000 rpms is unacceptable.  i actually have the same vfd on my 10 hp 24x120 lathe and it spins that chuck up to speed in 5 seconds flat every time without fail.  the manufacturer is actually sending me a new drive after we tried programing this drive over a 2 day period.  if anyone needs an affordable drive the guys at huayang have been absolutely awesome to work with and in my opinion immediately offered to send me a new vfd.  i  have had 5 of their vfd's and this one was bad.

so i hope that with the new vfd, my plc program sorted out and this added feature in my cps i will be sorted out now.

i am happy that this forum is here to help newbies like me learn how to modify my post.  i am again glad i am a paying customer of F360!

thx

[chrisQWNYT]

i have the analog output from my spindle going to the centroid, but apparently my plc is off.  i am working with centroid to get that fixed.  i have never dreamed of writing any code until last week. 

i appreciate everyone's help!

[chrisQWNYT]

thank you for a solution that works!  

i appreciate everyone's patience and help.

[chrisQWNYT]

so i actually ended up at 5 seconds per 1000 rpm.

THANK YOU!!!

[chrisQWNYT · Accepted solution]

it has been a while since i started this post because i thought that i had fixed the problem.  what i later found out was that my shield wire going from the vfd to the control was not connected on one end.  after connecting the shield wire the machine is like a new machine to me now.  the spindle turns on and off like a cnc machine should, no more intermittent 60+ seconds to get to speed or stop.  i may be crazy, but i think the servos are 1/3 as loud now and so much smoother which was a pleasant surprise.  this was the first CNC control that i installed and wired 100% on my own so i do not feel that bad.  anyway, if your spindle, or servos for that matter, is/are acting strange check all of your grounds and shields.

[jklmdesign]

Seth can you help me modify my centroid post to include a dwell time? I've modified it to include an alphanumeric naming convention but can't figure out where to add/edit the dwell. 

[love.grahn]

.