[purple_jeep]

Air pressure for Brake from factory should be set at 80psi.

Cheers

Chris

[Bob La Londe]

Its set at 80 PSI. Not using the stock regulator, but yes using a full FRL. Have also tried pressures upto 125. Still not strong enough to change tools.

[purple_jeep]

If you are interested I can put a Torque wrench on the spindle and see what torque it takes to break loose from the brake here and you can compare it on your machine.

Cheers

Chris

[Bob La Londe]

Well the Hurco may get some changes. I'm a little frustrated with the G320X. They are faulting at lower and lower speed and accell on all axis. Being tnearly the cheapest step direction servo drive on the market they have zero in the way of diagnostics capability. I'm about done fighting with them and want to replace them with something better. I was considering the Viper Drives, but Larken hasn't had any in stock for months.

I probably can't afford self tuning drives, but I would sure like some that allow me to diagnose a fault. Something that has more than a single dumb error output that can be triggered by anything.

[Bob La Londe]

I had spare G320X drives and I swapped them onto the mill a couple weeks ago. It worked great for a couple weeks, then yesterday one of the drives started faulting. I tweaked. I adjusted. I swapped out for another new one. No such luck. Since G320Xs have only one diagnostic output and requests to Gecko for suggestions have gone unanswered I decided to replace them with something else.

I just ordered some Dugong 16035 drives, braking resistance units, and a USB programming adaptor. While they may not fix my issues, I hope they will atleast give me a better grasp of what is going on if I have any problems with them.

[Bob La Londe]

I am always amazed at how hard it is to find some things. On Friday I did a search for local stores that might have Heat Sink compound. Only Radio Shack showed any in -stock and it was the tiniest tube I think I have ever seen. (I've seen it before so I didn't go get it.) Instead I checked Amazon, and found 3oz tubes from Super Lube for about a buck more than the half eyedropper of compound from Radio Shack. Since my wife has an Amazon Prime account I paid for overnight and had it yesterday. Actually I bought two tubes. I should have enough heat sink compound for a lot of projects now instead of having to buy multiple tubes for a single project.

The DuGong drivers are here, but I am debating ordering the C32 breakout board that just connects up with RJ45 patch cables and using my C23 board on something else.

[Bob La Londe]

Wow! I have to say, "FREAKING WOW!"

Yes, you can quote me on that. I just got the first axis working on the new DuGong 16035 drivers. Once I figured out everything I was doing wrong and got it setup right I did testing upto 450 IPM where it faulted. I was testing on X which is not the heaviest axis, but its certainly not the lightest. At 300 IPM (a good speed for a mill) I had it running at acceleration rates upto 80iss. No, that's not a typo. I imagine I could accelerate it even faster. No faults at that acceleration, but all 2 tons of the machine was shaking with a torture testing code file running. I have a feeling my limitation here is that the servos only turn about 2000 RPM reliably under load at the voltage I am running. That would be about 400 IPM. I decided 300 was fast enough. Its fast enough to shake the machine with rapid reversals at even the 30iss I am leaving it at until I get the other two axis going. If I can get 300 and 30 with such a huge safety margin out of Y I'll be thru the roof.

HOLY FREAKING CRAP! Its like a whole different machine.

Of course I only have one axis going, and I have to wait for a new HEDS module to arrive because I broke one of the pins futzing around with the Z axis. I am pretty excited at the moment though.

[purple_jeep]

Damn that's great news! I am finally at the point where I am tuning my servos on the KMB-1 we have been retrofitting. atm we are using the original servo drivers with a Kflop and Kanalog to do the control and I was wondering what speeds I should be targeting.

Cheers

Chris

[skullworks]

I have been saying since day 1 that people who pull off these servos and replace them with steppers or try to run the OEM servos with Gecko's are severely downgrading the machine and not doing them justice.

If I remember correctly Hurco was using the same servos on the BMC20 & BMC30 machines with 400IPM rapids. (not sure what the ballscrew pitch on the BMC is.)

[Bob La Londe]

If I was running the original 88-89 VDC I could easily see it running 400 IPM reliably. As is it doesn't fault until 450.

Its the acceleration that blows me away though. I was testing at 300 IPM and 80iss with no faults. I ran just long enough rapids back and forth to reach full speed. I like the ServoConfig3 software too. The built in graph for tuning is really cool. I noticed for short moves its hard to get really perfect critical damping, but but for any move about 300 steps the graph looks like it came out of a text book. At 100steps it still looks ok, but not perfect. That's a mixed bag for me because I do a lot of 3D machining where short moves are the norm.

[Bob La Londe]

Well, I just hooked up the Y-Axis, and it went so smooth compared to X and Z. When you actually know what you are doing things sure go easier. Out of curiosity I decided to run a short reciprocating program on Y. 3 inches G00. Back and forth. At 400 IPM and 100iss it still didn't fault. I don't know what the acceleration limit is, but the feed limit was right there where the math said it should be. Now if only that darn replacement encoder head would show up so I can raise the quill back up, LOL. Thank goodness I can lower the table. I set it back to 300 and 30 for now. If the Z tests out similarly I'll probably leave the rapid feed at 300, but I'll certainly crank up the acceleration. Y is the heaviest axis having to carry the table and the saddle, but Z has to fight gravity. We shall see...

[skullworks]

On my KM3 - the Z is on the quill.

Now one issue with ballscrews is that when a Z servo is not powered you can have head/spindle drop when the weight is enough to back drive the ballscrew. My Universal Kwik-Switch 200 quill is effectively the same size as a Bridgeport Knee mill but a bit heavier due to the fact that it does not have the rack gear teeth cuts like a manual BP has and it has the U200 locking system vrs just an empty R8 taper plus the spindle is solid all the way up, not hollow for a draw bar. Even with a heavy tool and tool holder in the spindle and no servo brake the drag of the quill seal and motor are enough that I see effectively no power off spindle drop. Inertia wise - the Z axis is by far the lightest axis. I think you will be able to crank those numbers just fine - It really shows on a G83 cycle.

[Bob La Londe]

My Z is also the quill. I've actually had it ALL apart up on top. In fact I put in a new (used) quill and installed new bearings in it. I also had to hone the sleeve for the new quill to fit properly. That was scary. My quill does not fall with everything installed, but with the servo drive belt off it will move with just a little push. Its the reverse that always concerns me. Its so much different of a mechanism than any other axis with the sleeve as "way" and the roller guided elevator. By hand it definitely goes up a lot hard than it goes down. I do pump a lot of oil into that sleeve every 15 minutes though.

FYI: When I hooked up Y I tested it at 100iss and 400ipm. It didn't fault. When I torture test an axis I run back to back reversing rapids just long enough to get upto full speed. In 3 inches it was hitting over 350 in the middle. Its hard to get exact numbers for sure because the readouts can't keep up. I may upgrade the control computer just to have crisper readouts and DROs. LOL. Its still running on a single processor XP box I bought used. My little Syil X4 Speedmaster is running on a W7 Pro64 box, and it definitely has better display management with Mach 3 running. I bought another Win7 Pro64 box for this machine, but if I can keep it running decently on the XP box the new computer is dogeared for a hybrid machine build I am working on.

Its almost anticlimactic to mention this, but its also huge. When the drive settles (which is really really quick after its tuned) its almost silent. No dithering whine. And yes I still have decent high frequency hearing.

[purple_jeep]

Wow those speeds are crazy! Do you know what your position error is over a move? You mentioned the software had the ability to graph for tuning so maybe it has position error?

This is where I am at with the stock servo drives and Kflop/Kanalog 250ipm. Still a fair bit of work to do on the tuning. Error is ~85 counts with 20,000 counts per inch.

Attachment 296774

Cheers

Chris

[Bob La Londe]

I still have my error count set fairly high. After I have all three axis working, I'l start cranking down the error limit for faulting and see what it will really do.

Your theoretical following error is a little over .004, but I bet in reality your parts come out better than that.

[Bob La Londe]

Now for a dose of reality. With reasonable following error count (100) set and actual error counts ( < +10/-10) much lower I can run at 200ipm and 30 iss. Currently the drivers are set at 2X and I get 10K pulse per inch. Both of those things threw me, because I thought it was a pulse multiplier setting. ( 2x or 4x) That of course didn't make sense because there was another pulse multiplier setting. Once I figured out it was about whether or not the drivers read just the rising edge or the rising edge and the following edge it explained a lot. Like why previously I was using 20K per inch and now I was having to use 10K per inch. LOL. I think I'll switch them to 4X and retune.

As I expected based on experience Z was problematic. It was much harder to tune and had tuning numbers dramatically different than X&Y. Before dropping the error count the fastest Z would travel was about 230-240 IPM, but oddley it would still accelerate at the same high rate as the other axis did while testing. I wonder if the motor is weaker than the other two or is somehow different and doesn't turn as fast at the same voltage level. It looks identical. I suppose at the very least I should check the brushes. Unfortunately that requires dismounting it. Fortunately its the easiest motor to pull of the three.

[bhurts]

Servos are rated at no load for speed. How much weight they carry has a big effect on how fast they can really spin. Assuming you're z is carrying the knee or just the head and gravity is most likely causing the slower speeds. Also does it have the same screw pitch and diameter as the other axis?

Ben

[Bob La Londe]

Servos are rated at no load for speed. How much weight they carry has a big effect on how fast they can really spin. Assuming you're z is carrying the knee or just the head and gravity is most likely causing the slower speeds. Also does it have the same screw pitch and diameter as the other axis?

Ben

Just a quill elevator on Z. No head and no knee. Yep. Same 5TPI ballscrew on all three. Looks like the same motor. Y carries the most weight.

[m_mcgranahan]

Hi,



I know the thread is pretty old, but it seems like I have some slop in my bed. I saw several mentions about adjusting things, but I can't seem to find pics or more info about how to adjust the ball screws, and all the other things that were suggested to cure slop in the machine.


Also, I was thinking about replacing the bearings in my KMB-1 spindle. I talked to Buddy at Accurite machine and he said it uses a fafnir 206PP with either medium of High preload on the bearings. (Makes them more precise he said)

Does anyone know where to get the high precision 206PP? Or is there an updated part number I could try instead?

Thanks

God bless...
Mark

[Bob La Londe]

Hi,



I know the thread is pretty old, but it seems like I have some slop in my bed. I saw several mentions about adjusting things, but I can't seem to find pics or more info about how to adjust the ball screws, and all the other things that were suggested to cure slop in the machine.


Also, I was thinking about replacing the bearings in my KMB-1 spindle. I talked to Buddy at Accurite machine and he said it uses a fafnir 206PP with either medium of High preload on the bearings. (Makes them more precise he said)

Does anyone know where to get the high precision 206PP? Or is there an updated part number I could try instead?

Thanks

God bless...
Mark

I replaced the bearings in a KM1 quill and put it in my KMB1. (I think it was a KM1) I was told they are both the same. My stock quill was badly scored. If I think of it when I am in the shop I'll look to see what I used. I bought two sets and put one inside the control cabinet for the future. I had to make a pin wrench spanner for the spindle nose bearing retainer. So I wouldn't lose it I made the other end into a spanner for the Kwik 200 spindle collar. I found "new old stock" New Departure bearings I think. Anyway, what I did was pull the spindle apart, see what was in the spindle, and replaced them with like bearings. I only run the machine at the factory 3600 RPM so I wasn't to worried about an upgrade. At the time I had an RF45 conversion running so I wasn't to worried about down time. Only took me a week or so to source bearings and get them in. Carefully lubed the new bearings with Kluber grease. Then I did a slow proper breakin over a half a day. Works decently.

Why do you think you need to replace your bearings? Surface finish? Noise? Rattles around when you grab the collar?