Mori Seiki SV500 Spindle Repair
Mori Seiki SV500 Spindle Repair
This Mori Seiki spindle was sent to us from a company in Italy to repair. Their sister plant here in the United States has been a customer of ours for spindle rebuild over 20 years.
The spindle was completely disassembled when we received it. At times this makes it difficult to determine the cause of failure but we are able to determine which parts will need to be reworked or replaced in our initial spindle evaluation. Our evaluation showed that the front spindle bearings failed first and were stressed to the point that the inner races split. The drawbar assembly gripper fingers and Belleville washers were worn beyond tolerance. The shaft drive dogs and front cover were damaged from impact. The rear housing was tapered and worn oversize by 25 microns.
We replaced the gripper fingers and Belleville washers to recondition the drawbar assembly. Our machining department repaired the damaged drive dogs. The rear housing and shaft taper where sent to our grinding department where they were green ground, chrome plated then finish ground on one of our Kellenburger ID/OD universal grinders.
Once the reconditioned parts passed our QC process the spindle was released to our clean room for assembly. The shaft was balanced on our schenk balancer and the bearings were installed. Then shaft was gently slid into the housing and the capture was set. After the rest of the spindle was assembled the spindle was placed on our custom test stand for break in and final trim balance. When this was completed the spindle repair was thoroughly tested by our QC personnel to insure micron tolerances are held and the vibration levels were within our standards. View Our Mori Seiki Spindle Repair Page Here.
Parker Majestic 73A-4 Spindle Repair
6,000 RPM
This Parker Majestic spindle repair is a perfect example of our standard repair.
After receiving the spindle we cleaned and inspected the overall dimensions to determine the cause of failure. We replaced the bearings. We then adjusted the preload, balanced, assembled, broke in and QC tested the spindle.
The spindle then shipped back to the customer with our standard 1 year warranty.
Republic Lagun VMC3516S
8,000 RPM
This spindle came in broken down. It was also missing the drawbar assembly and parts for the shaft tail. Quite often we do not receive all the parts we need for a proper spindle repair. This Republic Lagun spindle also had worn drive dogs. The shaft taper was slightly below the gauge line. The front housing was +50 microns where the 3rd bearing sat.
We ground chrome plated and reground the shaft taper and the front housing in addition to our standard spindle repair.
This was shipped back to the customer before the estimated time we quoted.
Spindle Rebuilding and SNOW
The snow affects even spindle rebuilding. When we get hit with a snowstorm here in the New England area you wouldn’t think that rebuilding a spindle would come to a halt. Well it does. After getting about a foot of snow and heading to work and arriving late we get the announcement that our freight company would not be showing up. This means that certain parts will not be coming in and customers finished spindles will not be shipping out the door. Calling a customer and telling them the spindle rebuild will not ship because we did not receive the parts or because the freight company isn’t coming in is not acceptable. They don’t have the time to understand our problems, they have their own and hearing ours is not what they want. I recently had to tell a customer the rebuilt spindle was on a truck stuck in Indiana on the road. The highway was shut down and their spindle was not moving. They appreciated the update but were not happy about it being “stuck”. When we get a lot of snow we lose power. You cannot build and test run a spindle with out power. Kids are out of school when it snows. We sometimes have to stay home on a “snowday”. As you can see spindle rebuild does come to a halt with the weather. We now wait for the snow to melt and to see grass growing. If you have warm weather send it our way along with your spindle for rebuild.
We recently had a customer inform us that they were trying someone else due to the lead time we quoted them. We understand that from the customer’s point of view that they needed their spindle yesterday, in a manner of speaking. This particular customer did not have a spare and the OEM did not have any in stock. This certainly put the customer in a bind; so they did what they felt they had to in order to minimize downtime. This customer explained to us that they were happy with our quality and prices, and was hesitant to go elsewhere.
From our stand point this spindle had to have a grind chrome plating and finish grind to bring it back to specs; unfortunately this takes some time. The estimated lead time we quoted them was 5-10 business days. We always do our best to get a customer’s spindle back to them as quickly as we can. We understand how important it is to keep their business running smoothly.
They ended up sending the spindle to another vendor, who quoted them a 5 day lead time. This was their lead time for anything sent in regardless of how much work needed to be done.
We received a call from this customer after the spindle had been repaired by the other vendor. The customer let us know the other vendor took 7 weeks to return the spindle. The customer has since sent us another spindle to be rebuilt.
When it comes to turn around time we try our best to get the customer what they want. If we can’t do this we will tell you the truth. The truth hurts sometimes but it is for the best.
Van Norman Regulating Wheel Repair
This spindle failed as a result of bearing contamination. This is the most common cause of failure for spindles.
We repaired this spindle with our standard repair process. We cleaned and inspected the overall dimensions. The bearings were replaced. We then adjusted the preload, balanced, assembled and broke in the spindle. The final step in our process is a thorough inspection by our quality control technician in our clean room.
Fuji Lathe Head Spindle Repair
4,000 RPM
This spindle had reached its estimated life span and was sent to us for a preventative maintenance check. We test ran the Fuji spindle on our custom test stand and determined through vibration analysis the bearings were near the end of their lifespan.
We cleaned and inspected the overall dimensions of this Fuji Lathe Head. We replaced the bearings, adjusted the preload, balanced, assembled and broke in the spindle. It was then checked by our QC department and shipped back to the customer.
The Fuji machines at this customer location are very important to their process and can have only limited downtime. By repairing their spindles before catastrophic failure they are able to plan downtime and receive much shorter lead times due to a reduced scope of work needed to repair the spindle.
Spindles sent in for preventative maintenance also receive our standard warranty.
Guering Spindle Repair
This Guering spindle came to us as a cartridge-less spindle, meaning only the shaft and bearings. The customer and OEM felt it was best to keep the housing in the machine. This enables them to change the shaft and bearings quickly to minimize downtime. This is not generally the best way to have you spindle properly rebuilt.
In many cases the spindle ages and the bearings start to fail. Fretting and corrosion can damage the bearing bore in the housing. Installing bearings into a damaged, out of tolerance housing will shorten the life of the spindle and generally you will still have the finish problems you had before.
Another issue is when the spindle is installed in the housing. It is difficult for the rebuilder to control what is going on with the customer’s end of the rebuild. Most of the time the bearings are opened to the environment and can get contaminated during the handling of the shaft. It is also very easy to overload the bearing and cause false brinneling of the bearings.
If you do decide to have your spindle repaired without sending in the housing, make sure you confirm your housing bores are within tolerance before you install a fresh set of expensive bearings. This will at least let you know where your problem may be and you can plan ahead for the next spindle failure.
Pibo Multi TRH400-333
3,500 RPM
Our customer has an extensive installation of Pibo Multi spindles. A common cause of failure for this type of spindle is coolant contamination. To protect the spindle from this we evaluate the condition of the labyrinth system on the front end of the shaft systems. The spindle repairs often require a rework or replacement of these parts in order to maximize the contamination prevention properties of this system. Northland Tool & Electronics stocks these parts for many models and we can manufacture them for any repair.
Mazak VTC-16 Spindle Repair
7,000 RPM
This customer wanted a ballpark quote for his spindle repair. He was satisfied with the amount so he sent his spindle in to be thoroughly quoted, which is always a free service. After he received the actual quote he decided to proceed with the repair.
We cleaned and inspected the overall dimensions of the spindle. We discovered that the cause of failure was due to contamination. The taper had 40 microns of runout. The tooling rocked in the taper and the bellevilles were worn.
We replaced the bearings. We also ground, chrome plated and reground the taper. The preload was adjusted. The spindle was balanced, assembled, broke in. It was then checked by our QC department and shipped back to the customer.











