[Andy Fritz]

Hi fellow Fadal fans!

I have a 4020 HT from 93 which I bought used a year ago. The spindle has always been kind of noisy, but never when turning by hand. I asked Fadal about it and as this is a grease packed 10K spindle they said there is not much to do about it as far as oil, maintenance and so fourth. Now I am restocking lube and flipped through the machine maintenance manual and what do I see; A note about using Mobil Heavy Medium oil for the Hi/Low something if the high torque option is installed. There are no pictures and as far as I can tell there is no hydraulic oil tank on the machine. Is "high/low" something about gear change? On the manifold block under the electric cabinet there is one line for High/low, but I think it is hooked to either air or the normal way lube pump.
could it be that it SHOULD have a hydraulic unit to help force lube into the spindle at high rpm's? If that is the case and I nver got the hydraulic unit, no wonder it is noisy! The Fadal manuals are the best, but this topic is not really covered unless it is in another manual I dont have.

Cheers,

Andy

[denmar]

The Hydraulic Reservor is a black box that seats on top of the In/out tool assy.
There are to cylinders (bimbas) on the right side of the pulleys, the top one is for
the low range and botton for the Hi. By typing in MDi S.1 and S.2 you would see the
piston switching. The HI/LO that you see under the cabinet are the air supply valves
to The Hydraulic Actuator.
The 10k rpm sealed spindle has air to keep the bearing cool. NO LUBE.

[Andy Fritz]

The Hydraulic Reservor is a black box that seats on top of the In/out tool assy.
There are to cylinders (bimbas) on the right side of the pulleys, the top one is for
the low range and botton for the Hi. By typing in MDi S.1 and S.2 you would see the
piston switching. The HI/LO that you see under the cabinet are the air supply valves
to The Hydraulic Actuator.
The 10k rpm sealed spindle has air to keep the bearing cool. NO LUBE.

Thanks for the explanation, Denmar. Will have a look at it but it sound like there is not much to do about the noise then.

Cheers,

Andy

[masterfabr]

Check the bearings in the tension rollers of the hi-lo speed.

[alex gitzel]

also check the spindle motor mounts,there are 2 types solid alum. or the most common are steel with a rubber strip in between 2 steel strips and are labeled A on the top and solid are B.if you have the rubber ones see if the rubber is soft and squashed out on the sides(new ones will bee flush with the sides)if they are too soft the pulleys will not be the same hight and cause the belts to rubb on the belt guides,check the belt edges.also see if the guides are full of dirt.the front guide is easy to take off and check.just remove the 6 7/16 bolts on out side edge of the drawbar cylinder,pull it up and off and let it hang to the side.then there are 3-4 5/16 shcs that hold the orientation bridge down.(coolant thru spindle machines are a little different).then you can let it hang and check the guide+belts.

[alex gitzel]

In addition to my last post,as a fadal service tech i have seen many differerent types of after market belts,all i have seen are too tall they just barely fit in the slot in the belt guide,real fadal belts have i good gap maybe .050-.100 when placed in the slot.The after market ones are so close on the fit that they will rub on the guide,also many but not all have labels on the outside of the belt that make noise as the go though the idlers.If you have these type of belts you will notice a big difference if you put real fadal belts in they are worth the extra money.another thing to check is the adjustment wire that goes from the splindle motor plate to the head casting by the z screw it should have some tention on it.The proper setting is to put an indicator on the front of the plate,loosen the wire and set 0 then tighten untill the plate moves .005 then tighten the lock nut,this will not work if you have solid mounts or rubber ones that are too soft.also check the pulley hight they should be the same or close(some times the motor one is set a little high at the factory but should be ok)to check measure from the flats that the front belt guide sits on to the bottom of the large pulley step,and the motor plate to the top of the large pulley step on the motor one.make sure that the hydrolics are full.if there still is noise you will have to pull the belts and check the spindle+motor bearings.

[DareBee]

AND
You may just be due for spindle replacement

[Andy Fritz]

Thanks for all replies to this thread!

I removed the belts, cleaned the pulley grooves and belt grooves which did not help but I have figured out a few things in the process;

I have been running this with absolutely NO oil in the high low gear change system but it still changes fine compressing only air.

The grinding noise seems to be related to the low gear belt rubbing against something and only occurs at forward rotation (M3) in low gear.

The A style spindle motor rubber mounts does have bulging rubber only on the ends near the column, BUT if it would not bulge out the motor mount would not sit horizontal. So it may have been forced to extrude to get the motor plate horizontal.

4. The grinding noise goes away if I force the rear end (near column) of the spindle motor plate upwards, but it also looks weird as the spindle motor is no longer vertical.

As forcing the rear of the motor mount upwards also has a "tensioning" effect on the belts I am thinking maybe the belts just need tensioning. If this is the case does anyone know to what factory spec they SHOULD be tensioned to? I really dont want to put excess radial load on the spindle bearings.

Also when you guys fill up the high/low gear change with oil how do you do it? Do you fill the idler cylinders or the reservoirs? What I did was disconnect the 1/4" line from the reservoir, stick it in a jug of oil and manually extend the idler cylinder to suck the oil in. Still I can see air bubbles in the lines and have a more sluggish operation than before. For example the high low air solenoid typically has to click 2 -3 times instead of only 1 time when I was running on only air.

Can someone clarify a few things from the manual?

"6)The reservoir is full when oil enters the 5/32 line on the actuator."
Which is the ACTUATOR? If it is the square box with the check valve it would suggest to fill that box instead of the cylinder.

"WARNING
DO NOT allow an excessive amount of oil to flow into the separator."
Where is the SEPARATOR?

I am now using Vactra 2 way oil as there is no way to find dte heavy medium here. I do have other hydraulic fluids, but figured as Vactra 2 has the same ISO 68 as DTE Heavy Medium it should work ok. Could the slow respond be due to incorrect oil? Should I try the ISO 32 hydraulic fluid instead?

Andy