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GTI and other spindle rebuilders

Billy_C

Cast Iron
Joined
Feb 18, 2022
We've had some recent terrible experiences with GTI (the one located near Boston). I'm wondering how much of spindle rebuilding is just gamble and if anyone knows what they are doing. I'd like to hear some experiences on this in general if anyone is willing to share.

3 bad products back to back with warning signs from the very beginning not to mention super slow response from there support. I would have a question, they would say I'd hear back, and nothing for a week or more.


MAM72 15k - grease/air - spindle had about 15k hours on it
They assessed it as a lower bearing failure from contamination

Red flag #1 - I asked what they were going to use for O-ring material and they didn't have any idea. I had to order the O-rings from Matsuura and supply drawings where all of them should go.

Received the spindle, installed exactly the way in came out and everything seemed fine for 1000 or so running hours before the top bearing failed (the ball bearing that supports the shaft, not one of the greased tapers). They told me I installed it wrong causing the failure. This could have been the case so we agreed to meet half way on another rebuild.

Received the spindle the second time.
Red flag #2 - all the ports were plugged in shipping except the grease ports.

Red flag #3 - I checked the female spline on the motor and runout was under .0001 which GTI though would be way worse causing our failure (.0004 or more). Maybe the first failure wasn't my fault??

Red flag #4 - I checked the runout on the male spline of the spindle before even taking it out of the packaging and it was .0004.

Immediately I called them and they told me to send it back. I told them we are just going to give up, install the spindle, and sell the machine because this is way more of a headache than anyone has time to deal with.

Nail in the coffin - I installed the spindle and ran it in. All seemed fine. Turned on flood coolant and it came spewing out of all the gaps under the spindle nose, including the the bearing. Most likely it back-fed the grease packs with coolant as well but haven't fully assessed that. Turns out they forgot an O-ring (even though we sent them o-rings and drawings 2 times). I called them again and they said to remove it and send it back. This was obviously their mistake, who would cover the labor on that? They said they don't ever comp labor.


Haas 30k BT30 spindle - belt drive (OE spindle lasted 5000 hours)
I installed a rebuilt spindle and it was overheating on run-in. I called them and they said to run it with coolant. It was still overheating. I called them and never heard back. We had parts to run so we started running stuff at half speed. The spindle failed in under 300 hours. Oiling system was checked thoroughly before installing the rebuild. Really there isn't much else to it. It's essentially a belt drive router.
 
Most "spindle rebuilders" are basically bearing swappers.

Rebuilding a spindle requires specialized tools, skills, and knowledge of how the specific spindle is assembled. Precise measurements have to be made, spacers have to be ground, the preloads for the roller and angular-contact bearings have to be precisely set...numerous details have to be dead nuts.

It's a miracle to me any company besides the OEM's can do it successfully.

ToolCat
 
Over the years I’ve had C&M do several with excellent results. Including a couple Mori spindles that we asked to have converted from 8k to 10k and the original broken ceramic taper liner replaced with steel.

Another save was a Tsugami spindle that their importer tried to have done a couple times at their rebuilder only to fail early. It was an odd construction and took some trial and error, but C&M got it done and it ran for several years until the machine was replaced.
 
All of my spindle work by C&M was either so so or outright bad, 2 rebuilds and a taper grind between rebuilds partly due to a sub par grind to begin with, after they fixed their fubar grind. It really sucks to get your spindle installed to find out the tool holders only have 20% taper contact including the new one I supplied with the spindle. The last attempts were on my Kitamura's spindle. I asked for a rough quote just to get an idea and was told as he rustled papers that they had just done one and $6k, there are not very many 30 taper Kitamuras around and they don't go through spindles. A year later when I was ready to get it done the same thing but $8k. So I called Setco in Los Angeles and was told around $5,500. So off it went to Setco where they did more work like chroming the taper and it ended up being $4,350 for their charge as I supplied some parts from Kitamura. The difference in the quality of taper grind was phenomenal to say the least. Based on my experience with C&M I don't think they have a master to check BT30 tapers with, or they don't use it.

Setco has since sold that repair facility to some employees there. The last I checked my contact person there is now in charge. My experience with them was stellar whether I wanted a full rebuild or keep it as cheap as possible. They are my go to for spindle work until I experience different. C&M is about 90 miles from me so they would be a lot easier to use as I could just drive it to them.
 
Last place I worked at had a brand new Haas ST-30 CNC lathe. 2 axis with a Haas bar feed. Factory spindle burned up the first year. Replaced under warranty. Second spindle burned up in same amount of time. Ditto 3rd, 4th and 5th spindles. 6th spindle went to GTI for full rebuild. Came back and installed with a independent tech as the owner threw Haas out of the building. Independent Tech noticed the Haas lube pump timers were at factory settings of 1 drop of lube every 4 HOURS! Mind you, Haas factory techs had looked at lube settings repeatedly and said that they were where they were supposed to be. I had a real hard time believing that.
Changed settings so lube gets 30 drops every 10 minutes. Last I heard, spindle 6 was still running solid and quiet.
 
Last place I worked at had a brand new Haas ST-30 CNC lathe. 2 axis with a Haas bar feed. Factory spindle burned up the first year. Replaced under warranty. Second spindle burned up in same amount of time. Ditto 3rd, 4th and 5th spindles. 6th spindle went to GTI for full rebuild. Came back and installed with a independent tech as the owner threw Haas out of the building. Independent Tech noticed the Haas lube pump timers were at factory settings of 1 drop of lube every 4 HOURS! Mind you, Haas factory techs had looked at lube settings repeatedly and said that they were where they were supposed to be. I had a real hard time believing that.
Changed settings so lube gets 30 drops every 10 minutes. Last I heard, spindle 6 was still running solid and quiet.
I’m the last guy to defend Haas machines, but this is another example of shitty techs. That problem goes beyond Haas. I got drug into a situation where a new Mori was about to lose its third spindle in as many months. Dealer tech was writing them off as a bad batch of spindles and just swapping them out. I was at the shop looking at another machine and the owner asked me to have a look at the Mori. About 3 minutes into it, I discovered the chiller was circulating oil but not cooling it. Had an HVAC guy come in and found a cracked copper line had let the freon leak out. He fixed the leak and recharged the system. The next spindle was still going strong over 10 years later.
 
I’m the last guy to defend Haas machines, but this is another example of shitty techs. That problem goes beyond Haas. I got drug into a situation where a new Mori was about to lose its third spindle in as many months. Dealer tech was writing them off as a bad batch of spindles and just swapping them out. I was at the shop looking at another machine and the owner asked me to have a look at the Mori. About 3 minutes into it, I discovered the chiller was circulating oil but not cooling it. Had an HVAC guy come in and found a cracked copper line had let the freon leak out. He fixed the leak and recharged the system. The next spindle was still going strong over 10 years later.
Agreed. I wen to work there just as spindle 5 was croaking its last. The indie tech noticed the timers. We cranked up and now she's still making good parts.
 
Rebuilding a spindle requires specialized tools, skills, and knowledge of how the specific spindle is assembled. Precise measurements have to be made, spacers have to be ground, the preloads for the roller and angular-contact bearings have to be precisely set...numerous details have to be dead nuts.

It's a miracle to me any company besides the OEM's can do it successfully.
Suburban Tool did a video about their spindle rebuilder. It goes into what is required to do it right.

 
Thanks for the feedback everyone. Good to know I'm not alone in my spindle struggles. Obviously when they missed an O-ring (especially one that I sent them), I knew I wasn't going totally crazy.

It's interesting they mentioned synthetic coolant in the video. We are running a synthetic coolant but I would hope the factory FKM o-rings could hold up to that. I definitely knew I didn't want GTI using whatever random crap they had around. I even mentioned to them running synthetic coolant and asked what their plans for the O-rings were, they were clueless. I should have pulled the plug right there.
 
Also interesting to see two different experiences with C&M. GTI got good reviews from the people I talked to in the area, not sure how they ended up being so incompetent for us. Luck of the draw???
 
Also interesting to see two different experiences with C&M. GTI got good reviews from the people I talked to in the area, not sure how they ended up being so incompetent for us. Luck of the draw???
Situations at a company can change at times. New employees, folks gone on vacation, etc. IMO, doing spindle rebuilds is edging toward art. Not every work is a masterpiece.
 








 
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