Messages

231

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: January 26, 2015, 05:46:57 AM »

I would have thought that a stepper can actually spin pretty fast if programmed correctly though perhaps im wrong there.

*Please anyone feel free to correct me if im wrong here*

I believe, that if you are running Mach at 35,000 mhz kernel speed, that implies that it can make 35,000 pulses per second, meaning 35,000 steps per second, which at a full step would be 175 rotations per second which is 10,500 RPM. Now, the caveat is, that is a 1:1 ratio which obviously wont work, and 10,000 is probably beyond the rated RPM for a stepper. If you throw an 8:1 ration on there, you're looking at 1312 RPM (at the 4th axis) with the stepper running 10,500 RPM. Also, as Simpson mentioned, the faster a stepper turns, the more torque/holding power it loses. So basically, you'd be at the point where it would be pointless not to do a Servo if you are planning to do high speed operations.

That all being said, I still went with a stepper because of cost, ease of setup, and I didnt need to do lathe work on my mill. Its all about what your intended use is for the machine.

Sorry, I missed this port on my last visit.

You invited: *Please anyone feel free to correct me if im wrong here*

Any while you are not wrong at all, there is a feature of most servo drives that you did not mention which (in many cases) negates the step frequency issue that you correctly identified.

There are a variety of names for the feature; 'step multiplier', 'pulse ratio', 'electronic gearing' and so on, but the function is the same: to alter the frequency or number of steps needed to rotate the motor.  The limits and fineness of this adjustment varies greatly from perhaps a few pre-set choices in hobby drives, to being able to separately specify the numerator and denominator of the ration in industrial drives. Some drives it is as easy a specifying how many pulses per revolution of the motor as a single input number.

In the case of MACH running on the PP, typically the drive would have much higher frequency capability than MACH and the ratios for industrial drives can be very high indeed. "High-resolution encoder of 4194304 pulses/rev" taken from the Mitsubishi J4 series manual.

Without a very serious multiplication of the steps available from MACH, this motor would only be useful for moving something the speed of a farm tractor. 

 

232

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: January 26, 2015, 05:20:16 AM »

There are two models of the InTurn™. The new ULTRA has a one piece Forged Chrome Moly Steel (4140) spindle with a D1-6/A6 mount.

The MEGA shown in this thread has a two piece spindle with a D1-4/A4 spindle.

D1 and A are standards with D1 being CamLoc and A being bolt on.

On the MEGA, spindle is two piece with the flange being a heavy press fit, heated to 550F and pressed on with a 20 ton press at that temp. It is exceedingly unlikely that you could dislodge such a press fit with the several times the 2HP available for the MEGA.

In addition to the press fit, the hardened steel cams for the CamLoc system extend thru the flange and into the spindle itself so the absolute maximum the flange could ever move is the .001" - .002"  clearance in the Cam holes in the flange. The very first prototype MEGA was abused by my own hand for a few years before being sold when replaced by the new ULTRA. A few crashes bent the chuck's backing plate, but the spindle nor D1 flange was ever effected. A bent backing plate is easily skimmed to re-true it. Eventually, I made a thick cast iron backing plate which never bent even in severe crashes.

Early on, I spoke with the engineers at SKF about preloading the ball bearings. Deep Groove balls (as opposed to AC) are not specifically designed to be preloaed, but they have a lateral load spec and as long as that is not exceeded, there is no problem with preloading. Because the spindle is hollow, it has a very large OD which results in a huge bearing that will never see the loads it is capable of in this application, so there is plenty of excess load capability, even for drilling 1" dia hole into steel.

The preload is light and intended only to remove lateral play inherent in the bearings. The amount of preload is far less than what the bearings experience in operations like drilling into the center of a workpiece.

The preload is retained by the steel locking collar on the back of the spindle. The force exerted by backing out a stuck drill bit, heavy cuts on the back side of a workpiece, or using the wrong parameters for TPI on a large tap will exert significantly more force on the retaining collar that just holding the light preload.

The maximum predictable force on the locking collar is easily contained by the friction of the collar against the spindle, which is provided by a fine thread clamping screw. For the forces presented by the MEGA, a threaded connection is not needed, nor was there ever a treaded connection on this piece.

Perhaps you are confusing the MEGA with the new ULTRA. The ULTRA build videos clearly show the threaded retaining collar, but that is required by the optional tapered roller bearings, which are adjusted by clearance and not force applied. The 'micrometer' type of accuracy provided by the 20TPI locking collar is needed to provide this fine adjustment. The collar is still clamped in place using a large fine thread bolt.

In both machines, the locking collar doubles at the main pulley mount so there is also torque applied to the joint. Both applications work out fine on paper with 3x the horsepower ratings of the respective machines. There are lots of MEGAs out there and to my knowledge, only one has dislocated the locking collar. Most likely I did not set the collar tight enough from the get-go, but the user was able to re-establish the pre load and lock the collar down.

There are only a few of the new ULTRAs and only one had the tapered roller option, so it is a bit early to declare victory on that scheme.


 




 

233

Brains Development / Re: Running a Script from a Brain in MACH3 - is this fixed?

« on: January 19, 2015, 03:46:52 AM »

is working here in ver .062  ==>  Uled > invert > 301

Thanks for the Info. Starting with a source like Uled, on my development system (64 bit Win7 pro) invert will work sometimes and sometimes not. Pretty random with no obvious cause. I do not know if the behavior is the same on 32 bit.

In any case, my application is to use ESTOP (OEMled800), and with this source, it does not work inverted at all and with nop the macro does not run until Estop is released (reset).  The macro seems to get 'qued up', but does not execute until reset, so it is not useable in my application because I want the action to take place ON estop, not after.

Using a macro pump seems to be working fine, but the concern there is that a customer may already have one running. Can more than one Macropump run simultaneously?

234

Brains Development / Re: Running a Script from a Brain in MACH3 - is this fixed?

« on: January 17, 2015, 04:35:25 AM »

I notice 2 things odd about this method and wonder if anyone can confirm this behavior, please.

1) Estop seems to suspend all macros with the exception on the macro pump

2) Using the 301 button as a terminator in a brain only works with nop. If inverted, no dice.

I am trying to use an ESTOP event (captured by the brain) to run a macro to turn off the 4th axis spindle and if the above are ture, it would explain why I had no success.

235

Brains Development / Re: Running a Script from a Brain in MACH3 - is this fixed?

« on: January 16, 2015, 06:04:02 PM »

Thanks Alex,

I'll give that a try. Not sure if I did exactly that or not.

Pretty quiet over here in Brain Town . . . .

236

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: January 12, 2015, 02:47:29 AM »

I just asked them for the curve sheets and data now..will post it when I have them if anyone is interested.

The thread has been read 108,500 times because of the technical content and shared expertise and experience.

Please do not hijack this thread by posting ebay bargains on components you have no experience with. 

 

237

Show"N"Tell ( Your Machines) / Re: Success! Mini Machining Center under Mach3 control - Video link

« on: January 09, 2015, 04:53:01 PM »

You can use any servo motor, really. The difference between Stepper and servo is what makes the difference. Which servo is important, no doubt, but not nearly so much as the fundamental technology of the motor type.

Steppers have great holding power and the torque rating is at zero speed and it drops off quickly as the speed increases. Whether a steppers holding torque is adequate for the task depends on the task. No stepper will hold as well as a spindle lock. If you are not going to use flood cooling, you can rig up an inexpensive spindle lock with a 4" band brake and hub for a mini bike or go-cart.

In considering servo motors, one should look at how they are rated. Hobby motors (Keling, etc) are rated at 'just prior to self destruct' levels whereas industrial servos are rated extremely conservatively. Usually at the power level they can sustain 24/7 at for 20 years without a break. Typically an industrial servo can pump out between 2.5 and 3x the torque rating in an 'intermittent' basis.

So, the numbers tell us that a 400watt rated industrial AC servo is equivalent to a 1,200 watt rated (calculated from the power draw) DC brush hobby servo.

A decent used 400 watt industrial AC servo motor and drive set can be had as cheaply as the equivalent new hobby DC servo setup (if you include a decent encoder for the hobby setup)
http://www.ebay.com/itm/MITSUBISHI-MR-J2S-40B-HC-KFS43B-AC-Servo-Drive-Motor-400W-Brake-Set-a18-/160880697451?pt=LH_DefaultDomain_0&hash=item25753ca06b

http://www.ebay.com/itm/CNC-Machine-YASKAWA-AC-220v-Servo-Motor-Driver-400w-Replace-Step-Motor-Tested/321620537287?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D27675%26meid%3D871f20ebd6ed4b699b2af883250a6825%26pid%3D100005%26prg%3D11378%26rk%3D4%26rkt%3D6%26sd%3D160880697451&rt=nc

I would buy these in a heartbeat over a new hobby setup and never look back.

238

Brains Development / Re: How to run a Brain triggered Macro.........

« on: January 08, 2015, 01:06:38 PM »

The forum software suggested starting a new thread as this one is old.

I did that, but wanted to stick something in here to tickle anyone who might still be subscribed.

239

Brains Development / Running a Script from a Brain in MACH3 - is this fixed?

« on: January 08, 2015, 01:04:54 PM »

I read an old thread here which described using 1034 and/or 301 calls but as with the posters in that thread, I cannot get this to work. I followed the  examples exactly with no success,
so I assume it is broken.

Mach ver .66 or .67 does not run the trigger macro using 1034 call nor can I do the OEM Trigger method described.
What does work is setting the trigger macro and running doOEMbutton301 from VB script. This runs the trigger script, but this choice is not on the list of EOM button choices in the Brain editor.

Using a macropump got the task working, but would prefer to trigger a macro from the Brain (initiated via Modbus register).

I'm hoping the methods described in the old thread have been superseded by something new. Can anyone provide a current, functional way tom accomplish this task?
 

240

Mach4 General Discussion / Re: Ethernet Smooth Stepper.

« on: January 08, 2015, 03:50:37 AM »

You can configure the IP address of the ESS, there is a special 'configurator' program for that. Having a small, isolated network that the ESS and a few other devices is on is OK. What I don't like to see is someone trying to stick it on their home/business network as that just opens the door for a lot problems.

Hi  Jeff,

I ordered the ESS from you and it will be here tomorrow. I purchased MACH4 during the 'pre-buy, but my schedule is slammed so I won't be messing with this stuff for a while and I want to remember to ask about the 'special configurator program' you mentioned.

If 'special' means it is not included in the standard doc pack, then can you please provide the means to acquire that program. I will probably be needing to configure the IPs

Also, I want to subscribe to the most active ESS/Mach4 thread so that I get notices of activity. I'm hoping there is a more active thread than this one that I can monitor.

Thanks!