The most beautiful thing that you will see today! #61 - Athens, Greece

[Sergio-k]

Originally Posted by zumergido

i dont have a spindle or a MM yet.. maybe another user can tellyou if is nesecesary that system or a pump and a reservoir its enough..
iam trying to do a desing to avoid all fan coolers. dust and fast moving parts are good friends.!!
maybe replace the plastic cooler for a metal one. plastic coolers gets dirty more often. and you can find 110 or 220v fan coolers that can blow your hat! use a hat for scientific test only.

Fernando you got a nice idea about the metal fan.
i'll reconsider that.
If i see that the spindle is doing ok with just the pump and the tank then the whole fan+radiator set will be kicked off the z-car for sure.

[Kobus_Joubert]

Well done Sergio...looking good.

[KenC]

Lovely blinking MM you built there! You will make some dust very soon! Brilliant job!

[Gerald D]

When do you have to go to sea again? I am just curious when you guys think that you have nice weather.

[Sergio-k]

Originally Posted by Gerald D

When do you have to go to sea again? I am just curious when you guys think that you have nice weather.

Lucky for me it's not the weather but the owner's free time that takes me out to the sea

P.S. LOL x 10 at title

[Surfcnc]

Sergio

Your machine is coming together very well indeed.
I can also see your fix for the router bracket you told me about one one of your pics.

Your spindle cooling system layout looks good, it's very compact.


Regards
Ross

[Sergio-k]

Originally Posted by Surfcnc

I can also see your fix for the router bracket you told me about one one of your pics.

Thx Ross

Actually i tried YOUR idea about the router bracket fix.
http://www.mechmate.com/forums/showt...?t=2398&page=2

[Sergio-k]

OK so i'm on the wiring process of my VFD (Huanyang) , and as i was reading the manual i saw that
they state as a safety precaution this :
( No contactor should be installed between the power supply and the inverter to be used for
starting or stopping of the inverter. Otherwise it will affect the service life of the inverter.)

Since i'm going to control my VFD through the RS485 port with Matty's controller plugin, should i just rely on the soft E-Stop (BOB, Mach3) for stopping the spindle or should i connect the VFD's main power from the E-Stop contactor ?

Is there another reason for not connecting the VFD to the E-Stop contactor ?, cause i really don't give a damn about the service life of the inverter when it comes to an emergency cituation.

Sergio

[danilom]

From the china VFD manual:

Note: Do not use the electromagnetic contactor as the on/off button of power supply for the inverter.

VFD should have a input which can be set to
09: Emergent Stop： Emergent stop. It can receive external emergent stop command or other fault signals.

If you just disconnect the mains power, the spindle shaft wont stop but will continue to spin, when the VFD is commanded to stop due to the fault it starts to brake and it will stop the spindle much faster.

I dont know the settings for Huanyang but look in the manual for this. Also note that there are sometimes requirements for braking resistor in case of larger motors.

[Sergio-k]

Thanks Danilo

I must have skipped this part for the deceleration of spindle.

As for the braking resistor it does not apply to this VFD (for 2.2 kw spindles).
P+ PR terminals in my VFD are not connected anyway.

[Gerald D]

We connect the VFD after the e-stop contactor, and we very, very seldom hit the e-stop. But, on the day that we do have to hit the stop, we know that all power is disconnected. (even if the spindle wants to freewheel a bit.....it will stop much quicker if it is chewing my arm).

The reason for the note in the manual is because some people would retrofit a VFD to their drill press and put the VFD between the on/off switch and motor. That is horrible for the VFD.

[Sergio-k]

Originally Posted by Gerald D

.... (even if the spindle wants to freewheel a bit.....it will stop much quicker if it is chewing my arm).

That's all i need to know. You couldn't have been more clear than that.

I'm on the same side when it comes to an E-Stop. I want ALL power down !!!!

[Gerald D]

If the spindle chews your finger, you pull your finger away before hitting the e-stop, and then probably not hit the stop at all.....so the freewheel effect of the spindle is really no problem. I cannot think of any realistic scenario where the spindle freewheel is a problem after an e-stop. If the spindle is rubbing on something and causing a fire, the friction will stop the freewheel. And yeah, if your one arm is really trapped under the spindle, so badly that you have to use the other arm to press e-stop, then the chew load will also brake the spindle. Our size spindles have very low inertia and it only needs a little resistance to stop them dead.

[KenC]

LOL! you are killing me Gerald!

I understand we can make the spindle stop faster by having a "breaking resistor" on our huanyang VFD, but I could never figure out what resistance & power rating of this resistor...

[Sergio-k]

Originally Posted by KenC

LOL! you are killing me Gerald!

I understand we can make the spindle stop faster by having a "breaking resistor" on our huanyang VFD, but I could never figure out what resistance & power rating of this resistor...

Ken

I wrote a few posts above that the breaking resistor does not apply to this kind of VFD unless yours has the P+ PR terminals allready connected.
So no worries about the breaking resistor.

Check this post :
http://www.woodworkforums.com/f170/t...tml#post973497

[Gerald D]

Even when VFDs have facilities for braking resistors, I suspect that don't come into operation if the supply to the VFD is broken.

[Sergio-k]

Now THAT is a breaking resistor for chinese VFD's

[KenC]

Mine does come with the P+ & PR terminal. will dig further into the thread, thanks.

Gerald, while I was not sleeping in class, I heard the lecturer mentioned all motors has 4 modes of operation one is the regenerative mode... I recon the breaking resistor is for applying a load to the spindle coils to take up the regenerative power. Any induction motor for that matter will go into regenerative mode when they free wheel. It doesn't matter if the main is on or off.

[Sergio-k]

Ken

My VFD has the P+ PR terminals too but if you remove the covering plate then and then only you will see if they are functional or not.

[KenC]

OK, I'll check it out ASAP.

[Gerald D]

Originally Posted by KenC

. . . .all motors has 4 modes of operation one is the regenerative mode... I recon the breaking resistor is for applying a load to the spindle coils to take up the regenerative power. Any induction motor for that matter will go into regenerative mode when they free wheel. It doesn't matter if the main is on or off.

Correct. But I believe that the VFD controls when the resistor is switched into the circuit, and it can only do the control function if it is supplied with power. So, my suspicion is that an un-powered VFD will not connect the resistor.

[KenC]

hmm... very possible.

[bradm]

Actually, judging from the behavior when you shut off the power to a VFD, it has plenty of control power, right? It detects the loss of input power (I.E. DC bus undervoltage), waits a programmed time period to see if the power will restore, then faults, and goes into a controlled shutdown using the residual power in the input capacitors. The motor stops long before the control panel shuts down. Wouldn't that be sufficient to manage the braking resistor? Especially since the problem we're trying to solve is that the motor has become a generator, and is supplying excess power that we need to shed somewhere.

[Sergio-k]

Question :

Can i use these clip on ferrites on the output of my VFD ?



Or should i use these ferrite rings and wind through the output wire several times ?



If the cure of electromagnetic & radio frequency interference is the same on both of them i prefer on using the clips.

Sergio

[Sergio-k]

I forgot to ask another thing too.

Can i power from my PMDX-125 12v output all these things (Prox.Sensors with Relays, Water pump and fan, and Led strip under gantry) or it's better to bring a 12v supply from a transformer ?
The Board's Manual states this : "Screw terminal blocks for isolated status inputs also provide +5V and unregulated +12V to power sensors such as the PMDX-170, PMDX-171 and NPN proximity sensors"

Thanks and sorry for asking too much again

[bradm]

Prox sensors, yes. Water pump and fan, probably not. The manual states a max of 250 to 300ma load on that 12v output (500ma total load across is 12v and 5v). That's not likely to be enough to run a water pump and fan under all possible conditions, and you certainly don't want to burn up the built in supply on the PMDX card.

I would be inclined to wire the prox sensors to the pmdx, and use a separate supply for the water pump, fan, and LED strip.

[Sergio-k]

Thx Brad (again).

I was hoping i could avoid running another cable to the gantry but in the end i prefer doing that than damaging my BOB.

[domino11]

Or you could use another power supply that is capable of doing it all and just run the one cable and not use the one on the pmdx.

[Sergio-k]

Originally Posted by domino11

Or you could use another power supply that is capable of doing it all and just run the one cable and not use the one on the pmdx.

Heath
I allready got a 12 core cable from my PMDX to the gantry
So i thought i could do the job with this cable cause things are getting
really tight in the cable chain , and in the gantry's cable passage (i'm running all the cables through the tube).

[Sergio-k]

I'm finishing my wiring on my MM and i'm curently stuck
on the proximity sensors setup.

I have bought this prox sensors which are NPN, NO, 10-30VDC.


And these relays 12-24 VDC, NO / NC


I have wired them like this :



What i cant figure out is how do i set up them in mach3.
I tried some settings in PORTS & PINS ---> INPUT ---> X++, X--...etc but
no result.

The sensors are lit up (their led) when i start the MM and the led is off (just a small glow of the led) when they are over the hole.
However when the sensor is over the hole the BOB's led of Pin 11 where i have attached them doesn't light up.

And another thing is that my relays when they are energized are making
a very disturbing noise, like a small fan hitting the cover.
Is this normal ?

Thanks