Prepurchase VMC Inspection - Need general Tips and Fadal Specifics

Going to drive a few hours to check out two used Fadals in a few days, and I have some questions. I know asking a tech to inspect it is the ideal option, but that's not my decision to make, so, off I go.

I've been using a 1999 Fadal 2016L for a year and have done some maintenance on it in that time, so I'm a little familiar with it and where the components are and how the 88HS control works, but there's a lot I don't know.


Two areas I need insight on:

1. General tips for looking at a used vmc; what should I be analyzing besides out-of-the-ordinary issues, listening to axis movement/spindle noise, checking runtime? Should I take an indicator and check runout or spindle perpendicularity or take a piece for a test cut? What do you usually do?

2. Fadal specific tips. I actually don't know the year but they look older than the 1999 we have. One is a VMC-4020 with a Fadal 4th axis and 10,000rpm spindle, and one is a VMC-15 7,500rpm. Both have the 88HS control.

a. I have the s/n's, how do I check options? Can I do that at the control?

b. What should I be looking for as possible trouble areas/red flags to watch out for?

c. I remember reading about the Baldor spindle drives dying and hearing a lot about the 10,000rpm spindles having issues, is there a way to know if these are on their way out or if they're in good condition or recently replaced?

d. Is the 4th axis probably terrible? I've never used a 4th- what should I look for there in general besides visible backlash?


Thanks for the input

If it's a box way machine jog the table to the limit of travel. If it's a 4020 the end of the Turcite is exposed. If it's worn (there'll be a step you can feel) then you may need to replace Turcite at some point soon. If the Turcite has come unglued then you will need to replace the Turcite on the x-axis. If the x-axis Turcite is worn then the Y and Z axis Turcite probably needs replacing.

if it's a linear rail machine check the condition of the guides. If the rails/trucks are trashed it's an easy fix, and not too expensive. If it had bad linear rails, i'd be unconcerned if the price was right.

Check the lube pump is working. I would budget in replacing all the metering valves.

The part no on the cards will tell you the version of the control. If it's a -2 control, then figure upgrading to at least a -4 control. I have 4020 with a -4 control, it's very adequate, a -5 is better.

Check if it's a grease pack or air'oil spindle. The air/oil spindle has multiple lines coming into the spindle housing underneath the casting (can't remember how many) Don't be fooled if there's a Bijur air /oil pump above the lube pump. Quite a few air/oil spindles were swapped for grease packed spindles and the pump left on the machine. like mine.

The air/oil spindle is the better spindle, you can run 10k for ever, the 10k grease pack spindle shouldn't be run at 10k for more than the time recomended by Fadal (check the manual). I run my grease pack spindle at 8k all day long, and if I forget to turn the chiller pump on it can get quite toasty (the part of the control that turns the spindle chiller on doesn't work on my mc)

Check spindle runout. Check spindle taper condition. If you have a drawbar tension gage it should be 1650-2000#. Assume that you'll need to change the bellevilles and floater any way. Check the toolholders, if a few have what appears to be rust on the holder then it's fretting, which means the taper isn't in the best condition.

Regardless of the year check if it's a DC or AC machine. I have a DC machine, I wish it was an AC machine for faster cutting feedrates and rapids.

Check backlash. Put an indicator on the table and measure backlash in x y and z. Put the indicator on the end of the ball screw and check backlash. This way you can tell if the backlash is leadscrew,thrust bearings, or both. Thrust bearings are cheap and relitevily easy to change.

Typing BL will bring up backlash values, anything above 20 would have me concerned. the backlash values on mine are larger than I would like. The diameters it cuts are very clean, no steps at any of the quadrant corners. But there not very round. If I want round (enough for a bearing) the part goes on my Makino

Push the table side to side to check the x-axis gibs free play, push and pull the table at the end to determine y-axis gib play. Put the indicator in the appropriate places to check play.

I wouldn't be too concerned about the hours if the machines appear to be in good condition. depending on the age, it may not have the original spindle/leadscrews etc.

get the ownere to machine some parts, intepolate a diameter check for steps in the quadrants would indicate the backlash isn't correct., cut some faces in x and y, cut a face at 45deg. If it's stair stepped you may have issues (mine was a bad resolver) machine a face with a face mill with a large stepover compared to the diameter, maybe 1.5" stepover for a 2" dia face mill. Check that there's no step between passes. a step will indicate a tram issue, maybe worn Z axis Turcite.

Yup I agree totally with previous comments. I purchased a warn out Fadal 4020 machine back when I didn't now shit. Machine ran great. XYZ all seemed good. Put some weight on the table and then found out how bad it really was. Take an indicator with you and a vise and maybe a good chunk of steel for weight. You should be able to see the wear or how much out the gibs are with a little weight.

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I bought an old Fadal as a pig-in-a-poke. I learned about them by tearing it apart.

Mine has a grease pack replacement spindle, there are 2 types: with air fitting/90 deg connection and without, mine is without.

I assume it's either a breather or it's for blowing air into the spindle to keep coolant out.

I wouldn't say that air/oil is better than grease, grease technology is very good and if the spindle housing chiller works properly, grease should be fine for the expected life of the spindle. Air/oil is what HAAS used and it consumes lots of air and doesn't do any better job at cooling the spindle (HAAS machines are famous for tools sticking in the taper). I had a HAAS with air/oil and it stuck tools and the spindle got quite warm, so it's not a panacea.

Mine is an oldy with hardened cast iron ways, no turcite.

The ways didn't look *pretty* when I took it apart, but they were still quite serviceable and cleaned up with a stone. Mine had no lube oil going to the table ways for quite some time, but it survived. Turcite probably wouldn't survive a no-lube situation for long.

triumph406 - thanks for all the info.

So where are these air/oil lines at? How would I find them?

What's better about the -4 control?

Checking the lube lines makes sense... I'm not sure how to do that. If I jog it back and forth a few times and see oil on all the relevant surfaces (ways/ballscrew) would that indicate things are working well?

Perry Harrington said:

I bought an old Fadal as a pig-in-a-poke. I learned about them by tearing it apart.

Mine has a grease pack replacement spindle, there are 2 types: with air fitting/90 deg connection and without, mine is without.

I assume it's either a breather or it's for blowing air into the spindle to keep coolant out.

I wouldn't say that air/oil is better than grease, grease technology is very good and if the spindle housing chiller works properly, grease should be fine for the expected life of the spindle. Air/oil is what HAAS used and it consumes lots of air and doesn't do any better job at cooling the spindle (HAAS machines are famous for tools sticking in the taper). I had a HAAS with air/oil and it stuck tools and the spindle got quite warm, so it's not a panacea.

Mine is an oldy with hardened cast iron ways, no turcite.

The ways didn't look *pretty* when I took it apart, but they were still quite serviceable and cleaned up with a stone. Mine had no lube oil going to the table ways for quite some time, but it survived. Turcite probably wouldn't survive a no-lube situation for long.

Click to expand...

Thanks for the input. Learning about it by tearing it apart is respectable, and sounds like a lot of fun.

I learned today that the 4020 is from 1994 - does that year probably have hardened iron, or turcite? This one has a weird looking Z axis way cover, it looks like it just covers the ballscrew... is that normal? It's not the boxxy Z axis way cover we have on our 2016L, but it looks like it was designed that way.

How much backlash should I be worried about on the rotab?

Jrill said:

I learned today that the 4020 is from 1994 - does that year probably have hardened iron, or turcite? This one has a weird looking Z axis way cover, it looks like it just covers the ballscrew... is that normal? It's not the boxxy Z axis way cover we have on our 2016L, but it looks like it was designed that way.

Click to expand...

That's going to have boxways/turcite. Will also be a DC servo machine, so 150in/min feed and 400in/min rapid feedrates.
If the there's a flap covering the z-axis ball screw, but no z-axis covers that's normal.

One thing to look for is if the machine has an extended Z height. I wouldn't buy a 4020 or any other Fadal that didn't have an extended z. Without the extended z your going to be limited in tool length/part size if using a 4th or 5 axis rotary.

Jrill said:

triumph406 - thanks for all the info.

So where are these air/oil lines at? How would I find them?

Click to expand...

this image shows the plumbing for an air/oil spindle.

Jrill said:

What's better about the -4 control?

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The -4 can contour/process faster than the -2. I'd be surprised if there's many machines with a -2 control. I don't know what a 1994 would have come with. -4 is very adequate, -5 has faster contouring and more memory. In other words the -5 can contour the same geometry faster than a -4 control before it starts to stutter.

Jrill said:

Checking the lube lines makes sense... I'm not sure how to do that. If I jog it back and forth a few times and see oil on all the relevant surfaces (ways/ballscrew) would that indicate things are working well?

Click to expand...

If there's oil on the ways is no gaurentee the machine is lubing correctly. My machine had lube on the ways, and I assumed the metering units were working correctly. The machine had sat for a couple of years, and in that time most of the metering units plugged up. I was decieved in thinking the way oil remaining (on the ways) was an indication everything was ok. It wasn't. That's why I said assume that your going to change all the metering units as a matter of caution. There's a flexible line going to the saddle that should be changed as well.

If it doesn't look like an environmental disaster in the coolant tank, the lube system probably isn't working as intended.

The -2 control is the original MPG pendant CNC88 control, I believe the HS debuted with -3, -4 is a 286 based control and -5 is 386sx.

The -2 was still an 8086 control, like the -1, the -0 only came in the original side-mount toolchanger Fadals AFAIK.

A -4 board set runs about 5 grand.

The way covers on a 2016L are large because the L is linear way, the box ways are exposed with just a telescoping "way cover" between the table and the column.

You only *need* the extended Z if you have a 4th, otherwise it's the same Z height as any old VMC, 40x20x20.

Run a circle-diamond-square test if you can.

From your original post, question 2a:

Open up the control pendant....should see the original options list inside back cover. No guarantee, but gives you the starting point.

Also ask last time the machine was leveled....if you get 'deer in the headlights' look or "when Clinton was president", your various measurements may be questionable.

Fred

Ok, on ours I see the options inside the pendant, great tip, thank you Freds.

I'm just testing on ours. I looked inside the side cabinet and I see a 386 processor and I see a "bridge" type board that connects the CPU and graphics and something together and it says a few digits and then "-4A" as the last digits, is that the right place to look? There are a lot of boards and a lot of numbers, not sure where to look.

Is there a way to check the memory capacity in one of the menus when the machine is on?

Really appreciate the knowledge, this was exactly what I needed

upgrade to 1400-4 $2750

Upgrade 1400-4 to 1400-5C $4910 (reman $3600)

Upgrade 1400-2 to 1400-5C $5500

Upgrade Kits | ItsCnc.com

triumph406 said:

upgrade to 1400-4 $2750

Upgrade 1400-4 to 1400-5C $4910 (reman $3600)

Upgrade 1400-2 to 1400-5C $5500

Upgrade Kits | ItsCnc.com

Click to expand...

At that price just as well put the calmotion control on it
Don


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D Nelson said:

At that price just as well put the calmotion control on it
Don


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Click to expand...

But who knows how to use a Calmotion control and are there posts available for every CAM?

There's something to be said for a "repower" using newer parts from the same OEM.

Say you had a Ford F100 and decided to put the running gear from a Ford Raptor in/under it, you'd be able to get parts at the Ford dealer and serviced by any Ford competent tech.

Contrast that to say, putting a Cummins R2.8 into it or maybe a Rover 4.2L supercharged engine, either are modern, but far from turn-key or mainstream serviceable.

You can spend ~$11k and put a NXGEN control on it, which is kinda like putting a HAAS Next generation control on a 1988 VF-0.

Don't for get "just put a Calmotion on it" requires the integration effort, ITS literally sells a board swap set to upgrade any Fadal to the latest hardware/firmware.

For that $5K I could theoretically upgrade my 1985 machine to ~1997 specs. I'd still need a new pendant, but if I had a "parts" machine I could make a new machine out of both that looked like it was new.

I'd like to have the faster block processing capability and bigger memory for my machine, watching it cut is kinda painful and it could be faster.

D Nelson said:

At that price just as well put the calmotion control on it
Don


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Click to expand...

I've looked at the aftermarket controls, they look like a good deal until you add 4th and 5th axis cards. I've got a TR65 4th/5th axis rotary, that adds approx $4500-$5000 on top of the base price of these controls. I was talking to another company at westec that was beginning to offer another Fadal upgrade control, having DC servos added another approx $1000 to the cost of that particular control. (can't remember which one)

Perry Harrington said:

I'd like to have the faster block processing capability and bigger memory for my machine, watching it cut is kinda painful and it could be faster.

Click to expand...

Upgrading to 1400-4 would be the cheapest path to upgrade

So, one machine had 0.003" backlash on the Y axis and I'm not sure if that's with 20+ BL comp or not. Is that probably thrust bearings, or worse? If it's more than thrust bearings, what's the usually repair cost for the Y ballscrew? I don't think I can efficiently work with more than 0.001 backlash even if it's being compensated for.

The other machine wouldn't start the spindle and kept having C axis error #10 and #28 (maybe others) which is noted as motor overload, and also says C axis does not respond to NC. Also while using it the X axis had a fault (#17) which kept up for a few minutes before I could move the axis again. That doesn't sound like a quick fix thing, but i'm throwing it out there in case I'm wrong and it's actually just replacing a wire or sensor or something.

99% of the time, its the thrust bearings.. If the machine has the liquid cooled ball screws, the seals go
and leak directly into the thrust bearings.. My 2 cents, the machine isn't fast enough to warrant liquid
cooled screws.. So the cooling goes in the dumpster.

The other reason they go.. CRASH!!!,, or they weren't set properly.. Guess how I know that? I was in a
hurry and figured I'd just shove a bigger shim in and slap it together instead of taking the time to do it
sort of correctly.. I had to do them again in 3 months.

On the errors.. When you start getting weird errors randomly, and if they come and go.. Good bet your
power supply is about to take a shitter, or it already has. A PC power supply is fairly cheap and easy
to wire in.. That was always my go to.. But the newer power supply that they are selling will fix you
up quick, but its not *cheap*, though its also not expensive.

If you are going back, take a multi meter.. You want 5v and 12v, you start dropping a tenth below that,
and you are most likely going to start having problems.. One other thing they warn about is AC ripple,
I have don't have the equipment to check that, but I can tell you that I've had a PC power supply check
fine ±12v and 5v, but just WOULD NOT run the machine.

The spindle drive errors usually mean that it will need a new drive soon, or now, considering the spindle wouldn't run.
Sometimes its a dirty molex connector, sometimes the spindle orient sensor dies or somehow moves too far away from
the magnet..

Just to check... Because this happened to me last week, Spindle error, it would just jiggle, and then throw an
over load error... I didn't have air going to the machine, and the belt had come slack and pinched somewhere.
Put some air to her, and she was happy.

Its a fricken Fadal, its going to need work, if it was doing everything perfect, they wouldn't be selling it.
The good thing is that parts are dirt cheap compared to most machine tools, and readily available, as is free
tech support.

I'd say that 90% of the Fadals that are sold, are sold because they aren't accurate anymore and can't take a cut.
That's about $300 worth of parts and an afternoon of work to have a machine that is fairly close to factory fresh.
Take another day to set the backlash properly, and all the gibs and straps, and make sure you are oiling properly,
and it'll be pretty damn close to new... And it will stay that way for a long time if you don't abuse it.

I heard my cousin is selling a 5 axis Fadal setup, he's in Idaho.