Fadal Y Axis Tilt

[Wasatch_Machine]

Hi All,

Long story short, my buddy and I fell into the machining business not too long ago. We would up with some manual machines, a Fadal 6030, and a Fadal 3016L. We are quickly realizing that they have some issues.

The 3016 is out of commission, so everything is currently being run on the 6030. The problem is, we've got some sort of tilt in the table. While loading a piece of stock, I realized that running my Haimer 3D taster resulted in seeing a rake across the stock. After checking the stock and vice, I put a flat piece of material on the table, and unfortunately, it still was present. If I zero out the Haimer, and jog the table toward the back of the machine the dial indicates that the table is lifting about 0.001" per inch of y travel. This seems to be true across any segment of the table. Variance across the X-axis seems normal.

Reading through the forums, I know that releveling the machine is going to be a must.
If that doesn't help, what's our next course of action? Is there a way to inspect the turcite without removing the table? Is this potentially just a gib issue? At what point do you just pitch the machine since its not worth the time?

The machine shop isn't our day job so digging into a problem and DIYing a solution isn't normally an issue. But we now have a six figure contract to figure out how to tackle without a dialed machine. If push really cam to shove, there's a local used equipment dealer with some older Mori Seiki machines that we could bring in, but we're now a little gun shy on 20+ year old machines and would rather not lay out the capital if we don't have to.

 

[pcd]

I realized that running my Haimer 3D taster resulted in seeing a rake across the stock. After checking the stock and vice, I put a flat piece of material on the table, and unfortunately, it still was present. If I zero out the Haimer, and jog the table toward the back of the machine the dial indicates that the table is lifting about 0.001" per inch of y travel. This seems to be true across any segment of the table.

3D tasters aren't meant for sweeping. The reading will change in unpredictable ways depending on the friction between the probe tip and the part. They are meant for finding the location of a single point only.

Use a regular dial indicator instead:

 

[Wasatch_Machine]

Thanks for the response.
We did confirm the problem with a dial indicator after noticing it with the taster. I should have mentioned that part of the reason I was sweeping the stock at all was because I found a taper in a plate that I had decked in the machine.

 

[pcd]

There are 2 possibilities: either the Y-axis isn't square with Z or the top of the table isn't square with Z. I can't imagine the actual axes getting out of square to the tune of .001 per inch.

If you hold an indicator in the spindle and sweep it around in a circle by turning the spindle by hand with stylus riding on the table what do you see? This tests squareness of the spindle axis with the table top.

Is the table top the actual bare cast iron with t-slots, or is it something like an aluminum plate with rows of holes?

 

[Wasatch_Machine]

The table top is bare cast iron with t-slots.

Spinning a dial indicator around in the spindle shows that the table is out of square with the spindle. (operator side reading higher than the back side). Would this indicate that the table itself not square to the z axis? My understanding is that if the axis themselves where out of alignment, turning the indicator in the spindle would show a difference, but sweeping an indicator along the axis should show the same reading.

 

[in2glamisgirl]

Your test indicates the front or back of the table has sunk due to worn x axis Turcite (table underside). Move the table to x axis limits and look for deep gouging or missing Turcite. CNC pros in Idaho should know someone that can reline your table up your way. Normally the final step after new Tercite is to fly-cut (dust cut) the table for best parallelism and squareness.

 

[Mike RzMachine]

find a reliable flat surface like a small granite, prop it up on the table with 2 machinist jacks toward the column, and one in the front. level the top of the granite with the jacks using a test indicator in the spindle while moving x and y axes, don't move Z. you may see the y axis not moving in a straight line, which the above suggestion would apply.

Repeat the spindle tram sweep.
If the tram is off, the spindle assembly may be tilted, nodding down, possibly due to worn way surfaces on Z.
If the tram is good, the table surface is likely not parallel to the Y motion. either re cut the table or put on a sub plate and cut that flat.

If you have an inspection square, you can put that on the leveled granite surface and sweep an indicator up and down in Z to check Z motion perpendicularity to the granite in Y and X. being as far off as you measured, a machinist square would give some insight.

good luck!

 

[Vancbiker]

You really need to find a granite master square to figure out what all is bad. Keep in mind it’s a Fadal so wasn’t all that great to begin with. The fact that moving the Y shows a significant error increase says bad turcite on the X under the table or Y under the saddle or both.

 

[Wasatch_Machine]

Thanks for the suggestions everyone. We'll get up under the table once we get back to the shop and see what we can of the turcite. if it comes down to replacing it, how difficult is it to do on your own vs how much does it cost to have done?

 

[Wasatch_Machine]

find a reliable flat surface like a small granite, prop it up on the table with 2 machinist jacks toward the column, and one in the front. level the top of the granite with the jacks using a test indicator in the spindle while moving x and y axes, don't move Z. you may see the y axis not moving in a straight line, which the above suggestion would apply.

Repeat the spindle tram sweep.
If the tram is off, the spindle assembly may be tilted, nodding down, possibly due to worn way surfaces on Z.
If the tram is good, the table surface is likely not parallel to the Y motion. either re cut the table or put on a sub plate and cut that flat.

If you have an inspection square, you can put that on the leveled granite surface and sweep an indicator up and down in Z to check Z motion perpendicularity to the granite in Y and X. being as far off as you measured, a machinist square would give some insight.

good luck!

By "y-axis not moving in a straight line" do you mean that we will see some wander in the x-axis?

 

[2outof3]

6030's were known to pitch and yaw when they were new. Small base and big travels in a c frame will do that. I can't imagine what it would be like 30 years later.

Start with level and remember she is an old girl with a wobble when new.

 

[Dan from Oakland]

"Normally the final step after new Tercite is to fly-cut (dust cut) the table for best parallelism and squareness."

Really? I'm not sure I would be comfortable with that approach. But..........

 

[Vancbiker]

"Normally the final step after new Tercite is to fly-cut (dust cut) the table for best parallelism and squareness."

Really? I'm not sure I would be comfortable with that approach. But..........

Fly cutting the table top was one of Fadal’s final assembly procedures. Rather than scraping in fits to achieve good geometry they relied of several rather sketchy practices.

After Turcite is bonded to the saddle of a VMC, good machine builders fixture the saddle in a mill and surface the Turcite. Then final fitting is done by scraping to achieve parallelism. This also generates a nice uniform oil holding pattern. The table to saddle is similarly fitted.

Fadal glued strips of emory cloth to the bed ways and then placed the saddle on it. The saddle was cycled back and forth with an air cylinder for multiple strokes to remove high spots. Then a minor oil holding pattern was scraped in. Once cleaned up and bolted together, the table was similarly “fitted”. Since neither if those steps imparts accuracy, a cleanup of the table top was needed to get it parallel to the sanded Turcite.

 

[Speedie]

I never heard that story of the turcite sanding. That is very interesting.

 

[Wasatch_Machine]

Just wanted to post an update on what we decided to do for those that are curious. After pulling the way covers and finding some pitting on one side, realizing that the spindle was in dire need of a rebuild, and our 3016L developing even more issues my business partner and I decided that it was time to pony up and get into something newer. The current plan is to keep the 6030 running as is and transition away from it once the new machine lands. The 3016L will be put in a corner where it will sit until its sold or we decided to gut the electrical cabinet for a full retrofit.