Bearings

[jstone]

Are both flex shaft bearings in the Z truck NSK 6000 DU's? And is the top one pressed in from the top and the bottom one pressed in from the bottom?

[Jeff_Birt]

No they are not both the same, the bottom bearing is larger. The spindle shaft gets pushed out from the top first. Then, you need to make a tool to tap the bearings out from the inside. Install new bearings, then press the spindle shaft in from the bottom. DO NOT use a hydraulic press for this, an arbor press would probably be overkill kill too. A 6" C-clamp would do the trick.

[jstone]

What is the bottom bearing. The top is a NSK 6000 DU.

[upcedar]

MWM A2020 Roller Bearing Adjustable Assembly $21.95 1 $21.95
MWM A2021 Roller Bearing Fixed Assembly $21.95 1 $21.95

is tthis it? :cool:

[jstone]

Are we talking same bearings? I was talking to LHR and they told me the top bearing was a NSK 6000 DU. I did not ask about bottom one, just assumed they were the same. Are these two of a different brand yet compatible?

[jstone]

Sorry. After a little research I found that both bearing assemblys mentioned are for the Z truck itself. I am talking the bearings for the flex shaft inside the Z truck. The top one is a NSK 6000 DU and I am looking to find out what the bottom one is. Thanks.

[Digitalwoodshop]

I still have 2 lower bearings on back order from LHR since before Christmas.

AL

[Dan-Woodman]

Al
You can probably get those bearing at an auto parts store, just cross reference them to the number. might be worth a try.
Thats what I did for my plunge router. Thats was almost a year ago , still working fine.
I think it was O'riely auto parts.
later Daniel

[upcedar]

is it possible to restore the bearings, a guy was vacuum forming his flex-shaft to get the gunk in better and it works good. could this be done with the bearings or are they frozen-tight from heat?

[upcedar]

are these the same bearings as a S/B Pr machine, I got a basket full of them, but were... :confused:

[upcedar]

just bumpin this up, didn't like where it was @ mod's! I got my bearing's figured-out. thanx's Rick

[hotpop]

In reading this thread, no one ever did say what the lower spindle bearing # is.

I need to know because my lower bearing is shot. I plan to replace both while I'm at it.

[oldjoe]

The reason I am assuming is that in the exploded parts view of the CW they do not list one. They only give you a Z truck part number. So its like you have to buy the whole thing or have them rebuild it for you. CW probably has a bearing press for doing that assembly.

[hotpop]

I was using my CW this morning and I noticed the edges of the of the cut were real bumpy. I saw this before and attributed it to a bad chuck and in fact broke a couple of bits at the same time. Still thinking the chuck was the problem I purchased a new chuck and bits.

I ran a test piece and it seemed OK. I thought the problem was corrected. but I didn't test it long enough.

Cutting into Signfoam this morning the same thing occurred. Bumps along the vertical edges. The piece is ruined.

I thought the new bit was loose ot the chuck had loosened but they were tight. That's when I realized the lower spindle was able to wiggle.

So now I figure my lower bearing has gone bad. I called LHR and requested a new bearing. They told me if I did my own repair I would void my warranty. I didn't care. I don't think my shipping box will survive trip number four to TX and besides bearing replacement is no big deal.

I decided to remove the "Z" truck to check out the lower bearing.

After removing the Z truck I found the whole lower bearing was wobbling in the housing. I called LHR again and was told there is a spacer ring of some sort between the bearing and the housing. Upon closer inspection I could see the ring they told me about. I can't describe it exactly because I haven't taken it apart yet. What I can see is the edge of a metal band that appears to have bumps on it. Apparently the bumps are suppose to center the bearing. I guess the bumps have collapsed because the bearing wiggles about 1/32" which translates to about 1/16" at the tip of the carving tool. Half of my projects have been in oak which might account for the collapsing bumps. The upper bearing also has a spacer ring but it seems OK.

Having been a machine designer and builder for almost 40 years. It seems to me that there has been a design error in specifying the correct size bearing bore, so they came up with quick fix. Bearings of this size should only have about .0005" clearance.

I can't imagine why they would engineer in spacer rings when they know there is going to be a constant side load when cutting.

I also found a loose "Z Sensor" pc board inside the truck that wasn't attached to anything. Guess I'll throw it away.

[rjustice]

Hi Guys,
Be warned that changing out the bearings is not for the "faint at heart" I am working on another tool that will fit the "Z" truck perfectly to press out the spindle shaft through the bearings... After rebuilding a spindle, I understand why LHR doesnt recommend the end user replacement of bearings.

There are a few points to ponder.

1) The spindle shaft is soft.
2) If you beat on the end towards the "Top hat" it will swell or "mushroom" and make it much harder to press out.
3) The bearings have A LOT of press on them (perhaps too much)
4) The "Z" truck is fairly strong but can be broken. There are pictures in another thread where the "Y" axis roller cam was tightened too tight and broke the corner off of the "Z" truck.
4) If you dont support the casting evenly when you are pressing out the bearings, it is not only possible, but probable that you will bend or break it.

With that said, I am very confident that given the right tools most people in the forum COULD change their own bearings. I hope to enable everyone that wishes to do so by creating the these tools.

The bearings are both rubber sealed:

Top - NSK 6000 DU
Bottom - NSK 6002 V

I hope this helps.... Stay Tuned for more to come....

[rjustice]

Hotpop...
There is a spacer around both bearings. I also have a lot of experience with rebuilding machines, engines, CNC equipment, etc... I have never seen these types of spacers. They are corragated stampings that are wrapped around the bearings. The only thing i can think of is that they allow for a slightly imperfect alignment and let the bearings find "squareness" to the shaft and the bore they are pressed into. The bearings still are fairly well pressed into the housing even with the use of the spacers. I think it would take a serious hit and still not loosen up the spacer in the bearing bores.

Ron

[Kenm810]

hotpop
Do these look familiar,
I've had the spacers drop out twice about three or four months apart. http://www.carvewright.com/forum/images/smilies/icon_confused.gif Sorry Ron I really didn't hit them, just my luck I guess

By the way I use corner supports when shipping my machine, they do help -- a little

[Dan-Woodman]

This is interesting info to know, are we talking design error on this bearing spacer?
Kind of sounds like the z-truck may have the wrong size openings for the bearings, or is this a NASA design change?
On one hand it seems to make sence as a shock absorber,
.

RJUSTICE Do you know the thread size of the SEARS QC for the NEWER routers. I know it won't fit the CC or CW spindle , but I'm thinking of making my own spindle for the chuck.
later Daniel

[rjustice]

Ken810.... Sorry to say this but yes, those are the bearing spacers... As hard as my bearings pressed out I would not have believed that they would fall out like that.
Hmmmm... looks like yet another opportunity for improvement. I am going to look into this further... maybe a solid spacer is in order. I really wonder if this was a MFG problem, and they couldnt get the bearings that were required for that size bore, and it was a way to salvage thousands of castings???

Daniel, I dont know what the thread size is on the newer style QC, but i dont see any improvement on it that is worth going after either.

I have lathe time this weekend to get some Chucks made. I have tested a prototype and am ready to release the first style. This style will NOT require replacement of the spindle.

Ron

[Digitalwoodshop]

I bought a spindle and just put it on. My spindle was never sent back from LHR when I wanted to get it rebuilt and found the price the same as a new spindle. I still have some open issues to work out with LHR when I get a chance.

I think for now the best bet is buying a replacement spindle and when RJustice gets his tools ready then do our own.

I see the day when someone makes a replacement spindle built like a Brick Poop House without a QC.....

AL

[rjustice]

AL,
You will see something pretty soon! ;)

Happy Carving,

Ron

[hotpop]

LHR Lower Spindle Bearing numbers:

SKU # P008-00020

Product: Bearing, Deep Groove, 6000-2RS

Price: ?

[DDV]

Hotpop...
There is a spacer around both bearings. I also have a lot of experience with rebuilding machines, engines, CNC equipment, etc... I have never seen these types of spacers. They are corragated stampings that are wrapped around the bearings. The only thing i can think of is that they allow for a slightly imperfect alignment and let the bearings find "squareness" to the shaft and the bore they are pressed into. The bearings still are fairly well pressed into the housing even with the use of the spacers. I think it would take a serious hit and still not loosen up the spacer in the bearing bores.

Ron

Those spacers allow the alum. housing to expand at a different rate then the steel bearing without letting the spindle bearings to become loose and spinning in the housing. I used something very much like that a few years ago to repair an oversize spindle bore.
ddv

[hotpop]

Sounds logical to me.

[jstone]

Hopefully there will be a how-to when rjustice has the tool ready to do the job.

[hotpop]

I tried pressing my bearings out with an arbor press. They were so tight they would not budge. I sent my "Z" truck to LHR. They didn't fix my truck they replaced it with a new one. I could not see spacers in the new truck.

[mister_zed]

Hi,

I know that re-using an old thread is not the best of practices... but starting a new thread for my question would be overkill. ;-)

I have decided to see if I can manage to replace the bearings in my Z-truck (actually two trucks) and see if I can follow the instructions on this forum.

But while trying to locate a source for bearings I realized that it is not so easy. I have seen semi-ceramic and ceramic ones for $30-60, but that is probably not the kind used by LHR, according to the expertise here. So if I look at the steel type, I see that the types are 6000 DU for top and 6002 VV for bottom. The VV type means that there is some kind of non-contact rubber seal that allows the bearing to run above 20000 RPM.

Now, the fun with digits and letters begins. I have located sources of 6002 LLB and 6000 LLB that are also sealed, supposedly hi-speed rated to 26000 RPM and greased in a similar way as 6002VV. And I wonder, couldn't I use the LLB kind instead of VV for both upper and lower bearing? Why should anybody insist on DU on top when there is LLB? Or is there some characteristic of DU that I didn't understand?

What did you guys use as replacements? Did you use the exactly same bearings? (I am not talking digits but letters, e.g. 2RS which I would not use, V, VV, LLB, DDU, DU etc etc.) What were the results?


Have a nice day /Z

[Digitalwoodshop]

I have never replaced any inner Truck Bearings.

Interested in seeing what develops in this thread.

Does LHR offer the replacement bearings?

LHR might even reply.

Good Luck,

AL

[mister_zed]

I have never replaced any inner Truck Bearings.


Never ever? Given the number of hours you have been running the machines you should have worn out at least a few bearings. ;-)

[Digitalwoodshop]

Never ever? Given the number of hours you have been running the machines you should have worn out at least a few bearings. ;-)

That is a GOOD Question.... How many hours on my trucks... I have had Truck Trouble over the years because I was able to send a few to TIM to keep on hand when he wants to test his Porter Cable Style Shafts.... So true... Never wore out a Spindle Bearing. I also spend 90% of my cutting time just cutting plastic.

ANYONE ELSE ever replaced Spindle Bearings... The Internal Bearings?

I think doing work with a 1/2 inch bit may have contributed to the problem.... I do Light weight work....

AL

[mister_zed]

I think doing work with a 1/2 inch bit may have contributed to the problem.... I do Light weight work....

AL

That is my conclusion, too... The truck was not old, possibly 150 hours, maybe less. Not sure.

I wonder why LHR allows for 1/2" bits in the designer (yes, I know they actually do _NOT_ sell such bits) if they can break the machine. Now that I have taken out both bearings I can see that the 6002 at the bottom was in worse shape than the 6000 at the top.

Well, lesson learned: use no larger bits than 1/4" to do bottom cleaning on paulownia, watch out for bits becoming blunt and do not take more than 1-16" at a time... Or maybe stop carving Paulownia... but now that I know how to find may way around the Z-truck I might be tempted to continue with Paulownia and see how well my carving tools survive. Paulownia is so lightweight and so easy to process: no knots, little chipping.

[Mugsowner]

That is my conclusion, too... The truck was not old, possibly 150 hours, maybe less. Not sure.

I wonder why LHR allows for 1/2" bits in the designer (yes, I know they actually do _NOT_ sell such bits) if they can break the machine. Now that I have taken out both bearings I can see that the 6002 at the bottom was in worse shape than the 6000 at the top.

Well, lesson learned: use no larger bits than 1/4" to do bottom cleaning on paulownia, watch out for bits becoming blunt and do not take more than 1-16" at a time... Or maybe stop carving Paulownia... but now that I know how to find may way around the Z-truck I might be tempted to continue with Paulownia and see how well my carving tools survive. Paulownia is so lightweight and so easy to process: no knots, little chipping.

I feel the 1/2" bit would work with small projects in softer woods. I would not stop working with a species of lumber because it dulls tooling faster than others. I carve on Aniegre, which is very hard on tooling, but carves great fine detail.

[mister_zed]

I feel the 1/2" bit would work with small projects in softer woods. I would not stop working with a species of lumber because it dulls tooling faster than others. I carve on Aniegre, which is very hard on tooling, but carves great fine detail.

Yes, one of the reasons why I tried Paulownia is that it is lighter than pine, gives better details than pine. Maybe comparable to oak as far as details go, but at the fraction of weight and maybe 1/3 of the price. And laminated oak has usually smaller laminate bits than Paulownia.

Btw, how long do your tools last with Aniegre?

What happened to my bearings (probably because of dull 1/2" bits) was maybe after 10 hrs of doing bottom cleaning with 1/2" on a series of projects. Of course, the total carving time was way more than that, but with smaller bits like 1/16 and 1/8.