Spindle For Shark Available

[Rando]

Thanks for sparking my interest, pushing me over the edge to one of the 2.2kw spindles. I went with the air cooled one, just because. I used the platform template provided on this forum, modified for an 80mm cutout. I'll make two plastic ones first, then when the spindle comes I'll make some aluminum ones. Way too much fun!

I believe it will be arriving sometime next week, I assume....

In the meantime, I've been following the trail of making the spindle obey the controller better. My findings so far:

First, several have mentioned just wishing for an on-off from the controller. This should be possible, almost easy. At least on the VFD that's coming for mine, there's a configuration setting that determines how three inputs (X1,2,3?) function. I think there's some configuration there that could be used to connect to the "spindle" wiring inside the controller. Following that thinking, if it was just on-off I wanted, I'd get a cheap low-current reed-relay that will work with the 3/5V spindle output from the controller board. Drive the relay with the same output that goes to the solid-state relay currently, and then connect those two to the controller's X inputs like they were a switch. It might work, but biasing a mechanical relay on the same circuit as a solid-state relay....why do I get the feeling problems will occur?

On further research, and especially reading the VFD's manual, It appears the "normal" way to connect a spindle like this is to have the controller output three signals. First, a 0~10V DC (analog) signal that goes to the 10V input on the VFD controller, which sets the spindle RPM. Your controller might have one; they seem common what with the whole thing being insanely generic.

I we can get the software to output the S### values, and if the controller's firmware supports that command, and it will output that analog voltage, we should be golden. That's the main signal we don't currently have. For complete control, there also needs to be a digital fwd-rev signal, controlled by the M03 and M04 commands (turn on CW, turn on CCW). And, of course, the whole enable-disable signal is needed as well, but that can be mocked up a gazillion ways.

One other "normal" way to control the speed is to take a 10K ohm potentiometer (variable resistor, volume control, etc.) and connect that to the properly-configured X1-3 signals. That will give you a "remote" speed knob, so you at least don't have to always be poking your fingers so close to a 220VAC circuit.

I decided to walk down that path and figure out what's missing. For me, I always wondered just what good the spindle RPM values did in the tool databases. Well, I poked around a little, and figured out how to change the post-processor files to correctly output the spindle speed for the toolpath into the tap file. Yeah, it even works . There are two places the changes need to be made.

(BTW, in case you hadn't figured it out yet, start- and stop- actions and custom gcode go in there, since Vectric doesn't give us features for that directly)

To make the FIRST change, just go into each of the four CNC Shark Post files and make the following change, around line 98:

Change this: "S 2000"
To this: "[S]"

To make the SECOND change, in the post files, go to the end of the file in the NEW_SEGMENT section (around line 183), and: as the last line in that section, add this line: "[S]"

The double-quotes and the square brackets are required. At first I thought it would be "S [S]", based on the variable definitions a bit above there. But, that produced "S S14000", and that just looks wrong.

With those tiny changes, the RPM values you put into the tool data form (including the one-off "Edit" changes), correctly show up in the GCODE files output by the system, with the values set at the same time the normal motor is turned on. Probably want to leave the "spindle ON" mWell, granted I only really tried a short Pocket tool path. It will also output updated spindle speed values for each toolpath.

IMPORTANT: the downside to this is that you're (eventually) going to have to start paying a lot more attention to those values! Now if only we get the CNCCookbook's Feeds & Speeds calculators ("cut knowledge base" to feed directly into the Vectric tool database, eh?

Okay, so the part that goes from the tool F&S gets into the toolpath (with those post changes) properly. The next step is to see if the spindle plug and/or other outputs will create the 0~10V to go the VFD to directly control the speed, and the two on-off and fwd-rev signals. I suspect there's gotta be a way

One more step closer!

Regards to all,

Thom

[rungemach]

Hello Thom

Yes, you are correct in that the on-off control via the Shark controller should be easy. I would suggest using a 110 volt relay driven by the internal solid state relay in the controller. This would be a "non-invasive" way of getting your run signal for the spindle VFD controller. That should not void the warranty and be easily removable as it just plugs into the router power outlet on the controller. Using an external VFD for the spindle using a separate power source also has the advantage of not taking the spindle current through the controller, (and the controller power fuse).

I have been using a water cooled 2.2 spindle for quite some time. The modifications I made were:

1) Add the front panel potentiometer for manual speed control. If your controller does not have this already, (most do not) you can buy a potentiometer that will fit onto the front face of the controller and look just like the factory version, or you can have an external potentiometer and mount it where you want it.

2) Changed the display to output actual spindle rpm.

3) Drive the spindle 0n-off directly from Mach3 ( as I do not use the Shark controller).

If you do not have a full manual for a Huanyang VFD (the one commonly supplied with these chinese spindles), send me a PM and I will email you a pdf copy. That will show all the internal setup parameters and how to change them.

If you are adding any significant weight to the router assembly, watch out for missed steps, especially in the z up direction. The acceleration parameter of the Shark controller may need tweaking to compensate for added mass.

Good luck with your project.

[Rando]

Rungemach, that's a good idea for the 110V output.

And yes, modifying the box seems to me "normal", since I've been modifying it to "fix" certain design "issues" related to grounding, wiring, noise, cooling,.... More invasive surgery to my controller box seemed like a foregone conclusion. Warranty? Sure...I got my unit in December 2014...and have gone so far as to remove and replace the USB jack on the board, modify the grounding underneath it, and pretty much rewired grounding and shielding throughout. Okay, so no warranty for Thom . The rest of you should do what's right for you.

Rungemach, one thing WRT displaying the RPMs on the display...I am certain they are not a real measurement. When I read through the VFD manual (for example, http://www.automationtechnologiesinc.co ... verter-vfd) and look at the parameter F3.7 (page 34, see attached screenshot from the manual), it's clear that it only really knows the frequency value. And since these spindles aren't servomotors, I don't think the VFD knows the real spindle speed, only the set frequency and the F3.7 multiplier. Depending on whether I end up having an actual need for accurate speed, I'm not (yet) convinced I want to implicitly trust the VFD's accuracy to what...5%? 10%? 2? 0.1? But on the other hand, does the number NEED to be accurate? Dunno. Given that it only takes a single linear parameter, I think we can safely assume that ANY non-linearities in speed are not being compensated for by the VFD, so in 99% of cases, that VFD RPM value should be considered "-ish". And depending on that programmed value, could be way-ish off.

Excellent advice on adjusting the Z-axis acceleration; I'll make sure to do that. Thanks! I've been wondering what would happen if I just replaced the whole router-mount-thing with the alumnimum mounting bracket (http://www.automationtechnologiesinc.co ... ndle-motor) going straight to the Z-axis bearing block (truck? trolley? carriage?), and then just insisting that anything that goes in has to be the 80mm diameter. That might help offset the extra spindle weight? Thoughts?

Thom

Hello Thom

Yes, you are correct in that the on-off control via the Shark controller should be easy. I would suggest using a 110 volt relay driven by the internal solid state relay in the controller. This would be a "non-invasive" way of getting your run signal for the spindle VFD controller. That should not void the warranty and be easily removable as it just plugs into the router power outlet on the controller. Using an external VFD for the spindle using a separate power source also has the advantage of not taking the spindle current through the controller, (and the controller power fuse).

I have been using a water cooled 2.2 spindle for quite some time. The modifications I made were:

1) Add the front panel potentiometer for manual speed control. If your controller does not have this already, (most do not) you can buy a potentiometer that will fit onto the front face of the controller and look just like the factory version, or you can have an external potentiometer and mount it where you want it.

2) Changed the display to output actual spindle rpm.

3) Drive the spindle 0n-off directly from Mach3 ( as I do not use the Shark controller).

If you do not have a full manual for a Huanyang VFD (the one commonly supplied with these chinese spindles), send me a PM and I will email you a pdf copy. That will show all the internal setup parameters and how to change them.

If you are adding any significant weight to the router assembly, watch out for missed steps, especially in the z up direction. The acceleration parameter of the Shark controller may need tweaking to compensate for added mass.

Good luck with your project.

[rungemach]

Hi Thom,

You are correct in the speed readout not being measured directly via feedback signal, but is should be a function of the frequency going in, and the configuration of the motor.
In your case, it is likely that 400hz going in to the spindle produces 400 x 6 = 24,000 rpm. So unless the spindle is losing its "lock" on the rotating magnetic field, the speed should stay locked to the incoming frequency and be pretty accurate. Close enough for me..

I also hated having to input the desired speed on the VFD control panel as a numeric frequency (divide by 6), so I installed the potentiometer. This also helps you "dial in" the sweet spot speed on the fly, while checking the "actual speed" on the VFD panel without the math. The Shark factory unit seems to come with the front panel potentiometer that most of the eBay units do not. Although they are easy to add, in the front panel or mounter externally where most convenient.

Converting parts to aluminum can get out of hand, and before you know it you have redesigned the whole machine.

I'm not sure how the acceleration parameters can be adjusted on the Shark, but there are threads in the forum here that mention a key sequence that gets you into the configuration parameters. I use Mach3 and they are directly adjustable on the users screen. Whenever you add mass, the controller may need to know that the axis can not accelerate as fast as it did when it was lighter. This gets important in the z - up movement as the stepper is working against the weight of the assembly and provide the force required to accelerate it moving up. Losing steps in the z - up direction leads to the bit carving lower with each missed step. So the z zero point creeps lower during the run.

I'm curious to see how your air cooled unit works out. I have only used the water cooled ones.

Bob

[tonydude]

Bob,
The acceleration parameters can be adjusted on the Shark by pressing control + G when you have the 2.0 control screen on. When using version 1.5 or so use control + E.

Here is the thread.

http://cncsharktalk.com/viewtopic.php?f ... +direction

Tony

[Rando]

Well, Joseph Poirier has been a huge help trying to track down what is and isn't there for controlling the spindle SPEED via the GCode.

In summary, "we were SO close! And yet so far."

Roadblocks on the path from Vectric tool to actual spindle rotations

The path from Vectric tool databases into the GCode was pretty easy to do by adding a line to output the spindle speed (SRRRRR) GCode, where R is the RPMs. The line in the post-processor file is "S [S]", right before the M03 (start spindle) command. As long as you're using the same bit/mill, the GCode can contain each of the different speeds for each toolpath. That part is cool and works as you'd expect. So, if nothing else, the spindle speed GCode is there....for future use...yeah, that's it.

The path from the GCode file through the CPanel software, through the drivers, was added graciously by Joseph, and we believe that the correct configuration and controls are being sent through the driver to the controller. Sadly, it appears those commands hit a dead-end somewhere before it gets to the pins on the controller dedicated to generating that PWM output. Those pins are either non-functional, or just plain not programmed/connected.

I have the original long-board style controller, and did some sleuthing online. I located that all-too-easily-found PDF online, that includes connector pinouts and a photo of the "next" generation of ncPod controller cards from OemTech.com. Based on their "blog", it's clear they were operating on a shoestring budget, so I figured it was very likely they used the same integrated circuit. From the picture and connector layout, I was able to determine that the needed set of pins....is the block of completely disconnected pins, right next to a mounting hole. While it's technically feasible to solder a wire to those pins, probing them showed no output signals, even employing a pullup resistor.

So, it looks like Spindle speed control isn't going to happen in any kind of easy way with mostly-software changes. Based on talking with Joseph, it sounds like even the newest model of controller card isn't generating that PWM signal.

But....all is not lost...well, not quite.

If we can't control it, we'll have to take the time to set and measure instead....

The startup-time issue has a whole bunch of variables. Depending on your VFD's oomph (aka drive strength), and the acceleration slope set in the VFD, the actual rotational inertia of the spindle, and how far from zero RPM is has to accelerate, spindle speed ramp-up time can be a a LOT more than a router motor. To avoid overtaxing the VFD, on mine a 0-20K RPM startup takes on the order of 5 seconds. Slowing down in free-spin can take even longer. Don't even get me started on a the recommended 650W braking resistor....$600+ for a resistor? Ouch!

Use the G04 Pmmmm Dwell command to add a delay....times four.

So, clearly some additonal delay is needed after the M03 spindle-start (CW) command, and before it heads out to make the first cut. Thankfully, the ncPod controllers does have the G04 "dwell" command. So, if you edit your post-processor file, in the startup part for each job, add a line like this:

G06 P2500

Add that right after the Motor turn on (M3 or M03) command, and it will add 10000 milliseconds delay before starting with the rest of the job. Add a value appropriate to your spindle starting up. From what I've been able to briefly test with our controller, it only likes the Pxxxxx milliseconds parameter, not integer seconds. Now, I'm SURE you're going to think I'm a fardking idiot for putting P2500 and then claiming it will delay for 10 seconds. Well, somewhere buried in the controller is something that multiplies the number you give it by 4. I don't understand it, all I know is that's what it was doing. So, take your real delay and divide by four, then put that in as milliseconds.

Do you verify the router/spindle speed before you let 'er rip?

In my case, when I used a DeWalt D618 adjustable-speed router motor, I wanted to positively verify the actual spindle speed with a handheld non-contact (laser) tachometer. I did the chart, and sure, "just a smidge past 2 gives 10K RPM" was good for a while, but eventually not knowing for sure irritated me. To accomplish that, I need the spindle to be out of the material, but just sit there and spin until I tell it to go ahead by clicking the Continue button.

To accomplish that, I take advantage of the fact that the Shark machines don't (yet?) have an automatic tool changer (ATC). Instead, the response of a machine without a tool changer is to simply pause and wait for the operator to perform the manual tool change, and then when safe, click continue. I put an ATC GCode (G06 T1) right after it turns the motor on, and it works like a champ. If, instead of using the G04 dwell command, you want to make it wait until YOU tell it to go, Add that code into the post-processor files (or directly into the GCode).

One thing to note is that in most all cases I've seen, the GCode insists on absolute coordinates. So, if for some reason you want that tool change to occur in a specific place and GCode, go for it! Add the move commands (using absolute coords!) to move the pointy bits to a known-safe location. (Watch the Z when using long bits!) The running program will go to the tool-change-place you commanded, stop there, and then move back after you click Continue.

Next steps waiting (for now)....

Now back to spindle speed. The next hurdles on this quest are pretty large: digging into the controller firmware to see if there is any way to get it to output a PWM signal, or try and figure out a way to trick the controller into putting out some other useful signal on other lines. I don't have access to the firmware source code, for obvious reasons , so for the time being, I'm going to put that quest aside.

Hope that moves us all forward.

Regards to all

Thom

[rungemach]

Hello Thom

It looks like you have crossed the dessert only to come to the base of a huge mountain....
The ramp up speed of your VFD should be adjustable via front panel setting of that parameter.
The factory default is quite conservative for ramping up an unloaded motor.

Does anyone know if NWA has provided a simple means of on-off control yet?

[Rando]

Hello Thom

It looks like you have crossed the dessert only to come to the base of a huge mountain....
The ramp up speed of your VFD should be adjustable via front panel setting of that parameter.
The factory default is quite conservative for ramping up an unloaded motor.

Does anyone know if NWA has provided a simple means of on-off control yet?

You can get the on-off in a variety of ways, including most-easily by plugging in an old 5V (USB) charger to the router-power on the back of the controller, and then programming the inputs on the VFD.

WRT the VFD parameters, I briefly mentioned that in my post:

The startup-time issue has a whole bunch of variables. Depending on your VFD's oomph (aka drive strength), and the acceleration slope set in the VFD, the actual rotational inertia of the spindle, and how far from zero RPM is has to accelerate, spindle speed ramp-up time can be a a LOT more than a router motor. To avoid overtaxing the VFD, on mine a 0-20K RPM startup takes on the order of 5 seconds....

To me, it doesn't really matter what that slope is, aggressive or not: it needs to be calculated and verified for it to be right. As in many areas, "if it ain't tested, it don't work." I'll bet there's a "spindle at requested speed" output that can be configured for the VFD, that a sufficiently capable controller could use to hold the program until it's up to speed.

In the meantime, I spent yesterday putting 4+ Ga of antifreeze+water into a nearby freezer with an automobile transmission cooler, fed via an RV-style auto-on/off pump that sends the 8-10F fluid over to the CNC, where it can pre-chill the spindle to about 35F in under two minutes. First cuts at quite low load showed it getting to about 40F. Hmmmm....is that cold enough? They did say "water cooled", didn't they? I'll post a full write-up on that; it's working out amazingly well.

Regards,

Thom

[Father2Sons]

I am new to this and am looking at the HD4. It seems the water cooled spindle is the way to go, if for no other reason than noise in a residential application. $799 seems pricey for the option as I have found them for as low at $299 online such as the following link...

http://www.ebay.com/itm/1-5KW-110V-Wate ... fresh=true

What is the downside of going this route as it appears to be identical to the one offered via Next Wave and Rockler.

[rungemach]

Some downsides would be:

You would need to get a mount for the spindle. ( Dixie billet can make you an aluminum mount that is stronger than the factory plastic mounts.)
You will need to make a cable to the spindle from the drive unit, and a power cable to the drive unit. The spindle connector is usually supplied by the vendor.
The speed control for the spindle would be with buttons on the drive front panel. The NWA unit shows a potentiometer speed control on the drive front panel. A potentiometer can be added to the lower cost unit. (either internally on the front panel or an external unit, mounted where you want it.

I am not sure if any good instructions, or a means to turn the spindle off and on have been developed. This forum thread is a couple of years old and NWA may have developed the promised on-off interface by now, or just forgot about it. If it is still not available, you would need to manually turn the spindle off and on with either of the units.

If you are looking at a single machine, I would consider looking at stronger machines (like the Axiom). A plastic machine is easy to outgrow (if you use it often, or for heavier applications, or need high precision.)