# DANG! RF-30 PROBLEM!



## Whyemier (Jan 10, 2018)

Was line boring a hole through a tube for a project. Kept getting erroneous readings on the diameter. Near messed it up but believe I can still save it. Why did this happen I asked myself? I started to investigate and found the spindle of my RF-30 was moving .010 - .015. Creating a wobble keeping it out of true. Top seems solid but the bottom is cattywampus. Dang! Now I've got to remove the spindle and check the bearing. I've dismantled it before but admit prob'ly not as fequently as I should. The recommendation is to dismantle and lube about every 90 days.

So now several projects will need to be put on hold until I get it corrected. I believe its just the bearing but it waits to be revealed. 

I guess I've not been paying attention to it's compaints so it decided to get my attention this way.


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## kvt (Jan 10, 2018)

I had never heard that you needed to take the RF-30 apart every 90 days or so. do not remember seeing it in the manual either.    I guess I will have to watch that.


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## 4GSR (Jan 10, 2018)

I think someone is mad....


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## BtoVin83 (Jan 10, 2018)

Damn, I've had my thirty years and never lubed it yet. I'm not letting my mill log on and see this post.


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## Holescreek (Jan 10, 2018)

My RF30 was purchased in 1991 by my uncle. I converted it to CNC around 2005.  AFAIK the bearings have never been out of the spindle for service.  When you dig back onto yours, post the bearing numbers in case I need them in another 90 days.


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## Holescreek (Jan 10, 2018)

I run my RF30 pretty hard a couple times a month with the spindle RPM maxed, driving a carbide 4-flute end mill to cut the contour of a 1/2" tall stack of mild steel.  After my last post tonight I did a little research on this topic.  There is no mention of servicing spindle bearings in the online RF30 PDF manual, but it did give the bearing numbers in the parts list.  I figure some day mine will need replacing and was surprised that all four bearings can be replaced for about $60.

I lubricate the RF30 bearings by squirting spindle oil in the top of the spindle shaft and through the viewing window where I can see the spindle rotating inside the housing (by the taper key slot) about once a month.  This provides flow-through lubrication like my Bridgeports, and leaves oil all over the table mounted fixture.  I'm guessing someone used grease in the OP's spindle bearings.


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## mikey (Jan 11, 2018)

May I suggest you consider changing to sealed angular contact bearings in the spindle and sealed deep groove bearings in the drive sleeve and forgo the bearing maintenance altogether?


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## Whyemier (Jan 11, 2018)

I will check my manaul again. Mayhap I was thinking of another item and got confused about the 90 days


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## Holescreek (Jan 11, 2018)

mikey said:


> May I suggest you consider changing to sealed angular contact bearings in the spindle and sealed deep groove bearings in the drive sleeve and forgo the bearing maintenance altogether?



To be honest, I don't know a whole lot about the pros and cons of sealed bearings.  I do know that when people rebuild their Bridgeports they use the same type of open structure manufacturer spec'd bearings that they took out. I've never seen mentioned that they switched out to sealed bearings.  That leads me to believe that there must be some disadvantage to using sealed bearings in a mill head.  I might be wrong in my thinking, but original mill bearings last an awfully long time.


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## Whyemier (Jan 11, 2018)

Well that's a relief! I dismantled the spindle assembly this morning.   Everything checked out good, there was some slack in the lower bearing cover, so I tightened it, also the nuts and ?tab? washer on the splined shaft were lose. Guess I didn't tighten them as well as I thought last time I disassembled it. Took it's time getting loose.
Regreased the roller bearings and reassembled the spindle assembly...then realized I had parts left over...ACK!    So I re-disassembled the assembly and inserted said extra parts then reassembled again. Runs tight and quieter.


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## mikey (Jan 11, 2018)

Holescreek said:


> To be honest, I don't know a whole lot about the pros and cons of sealed bearings.  I do know that when people rebuild their Bridgeports they use the same type of open structure manufacturer spec'd bearings that they took out. I've never seen mentioned that they switched out to sealed bearings.  That leads me to believe that there must be some disadvantage to using sealed bearings in a mill head.  I might be wrong in my thinking, but original mill bearings last an awfully long time.



Bridgeport bearings run inside a sealed cartridge where debris cannot enter. Not so with an RF-30/31. There are openings in the head that allow dirt, dust and chips to access both upper and lower spindle bearings. In my view, using a sealed bearing is just smart. Moreover, you can install a higher accuracy class of bearing at the same time if you choose and improve the accuracy of your spindle. I don't really see a disadvantage to a sealed for life, permanently lubricated angular contact bearing in this application.


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## Silverbullet (Jan 11, 2018)

Could be the added weight of the boring head with the off set is making a vibration . Any vibrations will really make items self destruct . Just my observations over fifty years of fixing engines and machines.


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