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Yet another nightmare with the fadal..

andrewkeisler

Aluminum
Joined
Apr 23, 2012
Location
Knoxville TN
Hey guys! I'm having some issues with my fadal and I was wondering if anyone could possibly give me some insight or advice. Hopefully Bob or some of the other fadal gurus will chime in.

1992 402028HT
Owned 6 years.
Since ownership I've replaced the keyboard, CRT monitor with LCD, x axis servo motor, 2 amplifier cards, installed calmotion, turret motor, 1030 card (hoping it would fix my DNC issues), probably 3 resolvers, and last month I added a 128kb expanded memory board.

Machine is properly grounded to fadals spec.

For the last 6 months or so, I would leave the machine at idle for hours to come back to a emergency stop condition. Sometimes it would kick the lowest breaker in the side cabinet (I'm not sure what its proper name is). Typically an amplifier fault on whatever axis was currently activated to jog. This wasn't very common until a couple of days ago when all hell broke loose...

This started with many random emergency stops. Sometimes while jogging, sometimes while running a program, and other times while idling. Axis's were also randomly running away (all 3 tried by the end of it). Yesterday no run away issues, but tons of emergency stops.

C axis controller does not respond to NC
C spindle driver fault
C position limit
X servo amplifier fault
Y servo amplifier fault
Z servo amplier fault

Here of a lists of tests I've preformed:

Checking the J2 resolver feedback cable all 3 axis's show 1.3 VAC. Fadal states 1.7 VAC with a strict +/-

Checking the +12v, -12v, and +5v to ground on the 1220-3a board
-12 supply = -12.1VDC
+12 supply = 12.06 VDC
+5 supply = 5.02 VDC

Fadal states to check for AC ripple on the DC voltages and if any is present to replace the power supply.
-12 supply = 0 VAC
+12 suppy = 25.7 VAC
+5 supply = 10.2 VAC

A fadal tech asked me to check the two figures below which were both within his specs:

Checking resistance from #3 to #4 on the amplifier cards
x = 58.2
y = 56.4
z = 61.6

Checking resistance from brown to white on the amplifer cards
x = 1.0
y = .8
z = .8

I've had flickering issues with the LCD monitor for a couple years along with very frustrating issues drip feeding. Random "error during DNC". I am curious as to if there is a common culprit for all of these problems.

I guess I'm here to ask others opinions on the above information. Would you recommend I check anything else? Is it time for a power supply? Thoughts on whether these issues are related? Could AC ripple cause low VAC feedback on the resolvers? I appreciate any information or thoughts!

Thanks,
Andrew
 
99% of all Fadal issues are related to the power supply. That's a big list of
stuff, and I don't see power supply on there.

Runaway without a shut down says you are losing the -12V.. Some of the other stuff says
you have a fluctuating voltage.

In the past I've been a fan of cheap PC power supplies (like the original) plumbed in, but the
ones you can get now SUCK!!!! on the 12V.)...

Cheap and easy would be a new PC power supply.. I've done it more times than I can count... However
I had one machine that just wouldn't cooperate.. The new fancy supply they have now, fired right
up, no problems, its $250-$300 depending on supplier.. I'll never do another PC power supply again.

Random, oddball, F'D up errors that are all over the map are usually funky voltages coming out of that
power supply. You might not catch it on your multimeter, but it just has to dip for a micro second,
and everything goes to shit.

I would also suggest pulling all your boards and cleaning EVERYTHING... I did that and got back
0.15V on the +12v. Enough to get it to fire up sporadically, but not enough to get it to work consistently.
 
I appreciate the reply, Bob. I can now feel much more comfortable with purchasing a power supply. I've always felt like I had some odd voltage issues with the machine and I would be very happy to see my quirky issues disappear, at least for awhile.

They new fancy supply... something like this?:

https://itscnc.com/ele-1071-p-211.html?osCsid=7c18375938e8e6d7722907939212dfc4

I'm assuming that only replaces the 1220-3a board and not components that reside beside of it. As shown here:

Fadal CNC Control Power Supply | eBay

I'm not too sure what the other items are in the assembly, but would you recommend changing those out as well?

Thanks,
Andrew
 
How are you checking the ripple? You need to check it with an oscilloscope. Typically, you would be looking for 30mV or less.
 
........1992 402028HT
Owned 6 years.
Since ownership I've replaced the keyboard, CRT monitor with LCD, x axis servo motor, 2 amplifier cards, installed calmotion, turret motor, 1030 card (hoping it would fix my DNC issues), probably 3 resolvers, and last month I added a 128kb expanded memory board.

Holy Smokes!!!
 
How are you checking the ripple? You need to check it with an oscilloscope. Typically, you would be looking for 30mV or less.

Don't know how sensitive Fadals are but on other old machines, equally important to ripple is rise time and overshoot. As switch mode power supplies age time period from off to nominal voltage can get longer, often accompanied by excessive overshoot before settling. This also requires an oscilloscope to measure.

Most of my troubleshooting experience of older machines are with Hurcos, and they are very sensitive to all rails coming up in time with each other, within a very small window.
 
99%

Runaway without a shut down says you are losing the -12V.. Some of the other stuff says
you have a fluctuating voltage.

.

Nah, runaway without a shut down means that the machine is improperly designed, VMCs are too powerful to be allowed to do such a thing.

Anyway, power supply issues make sense, due to age of machine and randomness of errors
 
Nah, runaway without a shut down means that the machine is improperly designed, VMCs are too powerful to be allowed to do such a thing.

Amen! I worked field service for Ellison while they were selling Fadal in the late 80s to mid 90s. They were the only machines that I would NOT work inside the envelope while powered up. After seeing a few runaways, sometimes on a brand new one, you just didn't trust them.
 
I'm not too sure what the other items are in the assembly, but would you recommend changing those out as well?

The new power supply replaces all that stuff... Just be careful and label all your wires really really well.
There are 2 sets of wires, both labeled 8 and 9. The ones at the top right of your current board are 120v AC,
The 8 and 9 on the bottom are 5v DC.. DO NOT fuck that up... SERIOUSLY, DO NOT MAKE THAT MISTAKE!!guess how I know?

I would leave the machine at idle for hours to come back to a emergency stop condition.

Are you leaving the table right at the very end of the travel?? Sometimes if you do that it will push
up against the "crash" springs, and the springs push back and then you can overheat the motor or the
driver board.. I usually leave the table about a 1/2" from the end of the travel, some leave less,
I'm sure some might leave more.
 
Thanks guys.

I appreciate the detailed information, Bob. The more advice on swapping out the power supply, the better off I am.

I rarely leave the machine at idle close to a limit. Typically, on the Y, I just go to about 9 out of the 10 inches for loading and unloading parts.

Could you describe to me what the function of the large blue capacitor is that's located beside the amp cards? I was personally curious if it could be out of working range as the wires go directly the all the amp cards. Probably completely unrelated, but I'm curious and can't seem to find any information in regards..

With having just enough electrical knowledge to get myself in trouble and no understanding or ownership of a oscilloscope, I'm going to get a new power supply on the way. So many quirky issues with the machine that could very well lead back to the power supply as being the culprit, I'll gladly take my chances.
 
Could you describe to me what the function of the large blue capacitor is that's located beside the amp cards? I was personally curious if it could be out of working range as the wires go directly the all the amp cards. Probably completely unrelated, but I'm curious and can't seem to find any information in regards..

The info you need, if I recall correctly, is in the trouble shooting flow charts.

Technical Docs | Manuals & Diagrams | FadalCNC.com

Maintenance manual, section 16, about half way through it... Damn handy flow chart,
it won't always solve your problems, but it can give you a good direction to go..
And notice the FIRST thing you need to check, VOLTAGES...

Anyways, I believe somewhere in that flow chart is how to check that big blue capacitor.
 
......Could you describe to me what the function of the large blue capacitor is that's located beside the amp cards?

Smooths out AC ripple in the DC voltage mainly and potentially helps support DC voltage from sagging as much when rapid moves are commanded creating high current draw on the power supply.
 
Thanks guys. Your information is very useful.

"CHECK BUS VOLTAGE
AT BLUE CAPACITOR
ON AMPLIFIER CHASSIS.
(SHOULD BE APPROX. 130-165VDC
DEPENDING ON MODEL)
CONSULT FACTORY IF DIFFERENT"

"INPUT VOLTAGE SHOULD BE 95 VAC AND CAPACITOR VOLTAGE 133 VDC WITH T816 TRANSFORMER"

I assume this is the same blue capacitor that I am describing? To test this, should I have my leads on the positive and negative side of the capacitor or should I be testing to a common ground source of the machine? I also have no clue where these input voltage leads are?

The reason I asked to begin with:

When measuring across the capacitor, I have 110VDC. My machine has the T816 transformer.

Thanks,
Andrew
 
scadvice,

On the inside of the cabinet door there is a diagram for the 3 phase wiring at the transformer and it states T816. I am running 3 phase via 30hp phase converter. I assume thats the transformer I have, but I am not 100 percent certain. I am assuming this since this diagram is glued to the inside of the door...
 
UPDATE:

I installed the new power supply with no issues the first day. By the second day to present (about a week) I have received these errors:

Spindle driver fault
Axis controller does not respond to NC.... I get this one 9 times out of 10

Spindle driver fault position limit... I've got this one once

No axis run away, no dnc issues, screen still flickers occasionally, but not nearly as bad as it used to.

The machine consistently runs better if it has been powered off for awhile.

I did hear the air valve located above the green cnc on button make some strange popping noises a couple of times over the last month. However, I'm not sure if this valve is related to the spindle anyway.

Possibly a bad hall effect sensor?

Andrew
 
Spindle driver fault
Axis controller does not respond to NC.... I get this one 9 times out of 10

Spindle driver fault position limit... I've got this one once

No axis run away, no dnc issues, screen still flickers occasionally, but not nearly as bad as it used to.

The machine consistently runs better if it has been powered off for awhile.

I did hear the air valve located above the green cnc on button make some strange popping noises a couple of times over the last month. However, I'm not sure if this valve is related to the spindle anyway.

Possibly a bad hall effect sensor?

Andrew

At least now its only one thing, and not EVERY thing...

What spindle drive do you have and what are the voltages going to it??
Also since I'm lazy today (and probably tomorrow too), what does the
manual say about those errors?

What is your voltage going to the spindle drive?

Unfortunately when you get a ton of spindle drive errors, in my experience,
a new spindle drive is not too far off in the future... If the money is
tight, spindle drives aren't just for machine tools, and you can find them
on e-bay, if you know what you are looking for.. I can tell you what I did
if you need that.

Many Many moons ago I did have the tool change piston bridge bow up slightly
and cause a pile of problems with the hall effect sensor, but for the life of
me I don't remember what the errors were, or even what exact machine it was on,
or even which shop it was in. They also do occasionally go bad, I had one
go about a year ago, the one for the tool change piston... I single tooled it
for about a week... Pain in the ass that was.
 








 
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