Spindle Bearing Replacement

[HimyKabibble]

I have a Taiwanese BP clone (Birmingham BPS-1649C). Lately, it's
been making intermittent "rattling" noises from the head,
particularly when under load, and when the motor is spinning down
from high RPM (I sometimes run up to 8200 RPM). My guess is it's one
of the (many) bearings in the spindle or the front step pulleys.
I've take the whole top-end apart, including the step pulleys, and
couldn't find anything obviously wrong. I can't tell exactly where
the noise is coming from, so I'm thinking I should just bite the
bullet and replace all the bearings in the spindle and step pulley.

I've found an on-line source selling a complete set of bearings and
belts for what seems like a downright cheap price:

http://www.machinerypartsdepot.com/s...product/RBK-J1

Does this seem like a reasonable deal? Anything I should be
concerned about?

Replacing the bearings looks like a very straight-forward operation,
maybe half a day? Is there more to it than there appears?

Regards,
Ray L.

[HimyKabibble]

OK, that's *not* the right bearing kit - the spindle bearings are in the $300 range.

Any recommended sources for good bearings?

But the other questions still apply....

Regards,
Ray L.

[HimyKabibble]

I *may* have just solved the problem. There were two issues. First, I'm an idiot - no news flash there.... The quill feed (on the top right of the head) was engaged. Second, appears to be alignment. I loosened the Allen screws holding the pulley housing to the head, and whacked the head around. By pushing it as far back as it would go, it is definitely significantly quieter than it was. I can't say yet it's 100% quiet - there was a slight rattle as it was coming down from 8K RPM, but very slight. I'll see how it does on Sunday when I go out to make another big pile of chips.

Regards,
Ray L.

[avtechmachine]

some time the belt make noise and it sound like spindle bearing, you may want to spray some WD40 on the belt during spindle turning, but do not run the RPM too fast, if the rattle noise go away then you just need to replace the belt.

Ahn Vuong

[NC Cams]

Spindle bearing replacement on ANY mill of consequence is not a simple R and R operation.

DO a "bridgeport spindle bearing" search on CNC xone and you'll see a post by me that goes into what one has to do to replace spindle bearings. Do anything but and you'll regret it. It is too complicated and detailed of a procedure to reprise it here.

If you try to oversimplifey the process, you'll grow to regret even having thought of it.

BTW, I used to be a machine tool bearing engineer for a major ball bearing company.

[HimyKabibble]

Originally Posted by NC Cams Spindle bearing replacement on ANY mill of consequence is not a simple R and R operation. DO a "bridgeport spindle bearing" search on CNC xone and you'll see a post by me that goes into what one has to do to replace spindle bearings. Do anything but and you'll regret it. It is too complicated and detailed of a procedure to reprise it here. If you try to oversimplifey the process, you'll grow to regret even having thought of it. BTW, I used to be a machine tool bearing engineer for a major ball bearing company.

God willing, the adjustment I did last night will cure the problem. In case it doesn't, I'd like to read your thread, but can't find it. About when was it? Tons of hits on those search terms, but can't find yours....

Regards,
Ray L.

[NC Cams]

Try "bridgeport spindle bearing". I now I did it - might hve been within the past year or so.

[NC Cams]

Can't seem to find the post - maybe someone can chime in with a link

The "old" search engine would find it - the new google one doesn't have the moxy.

Try going to the Bridgeport/Hardinge mills forum and page back over and over. It should turn up. I"d retype it but my vision is not so good anymore nor is my patience with misspelled typing that ensues

Basically, you first get the right bearings. Many service bearings are not necessarily the same as the OEM pieces. 7207CTYDULP7 for high speed lowers vs 7207CTYDUM97 for hed speed,but stiffer bearing set for less tool deflection. TOp bearings are 6206VVCMAKCS (pregreased with Andok C Grease).

Grease the lowers with Andok C as well. Kluber is cost and complexity in search of a need.

Clean parts with CRC BrakeClean prior to greasing DO NOT BLOW DRY BEARINGS>

THis is a mini version of prior explanation.

measure the spindles as BPT did a lot of selective fit bearings to missized spindle OD.s. Usice spindle OD can be flash chrome plated. OS OD will take a lot of VERY careful 600 grit polishing in a lathe to get standard 7207 size requirements.

THen you install properly, no hammers or presses, use thermal shrink

THen you assemble spindle to quill, again no hammers.

Then you assemble head

Take to shop that does ID spindle grinding.

IF you don't plan to do ID grind, don't bother.

[BobWarfield]

Hi NC Cams! Seems like I missed you on these forums for awhile.

I did the search and found several articles that in total add up to the steps you describe here in more detail.

Those articles and some others are in my delicious bookmark section on spindles here:

http://delicious.com/CNCCookbook/spindles

Cheers,

BW

[HimyKabibble]

The good news is, all my bearings seems to be just fine. I did some flycutting with by 4" diameter flycutter this morning, which REALLY aggravated the noise, finally allowing me to tell where it's coming from - It's the splines between the quill and the spindle. If I set the spindle brake, and turn the spindle back and forth, I can get exactly the noise I'm hearing when it's running. I think the next step is to coat the splines with some nice, thick grease, to act as a damper. Any better suggestions?

Regards,
Ray L.

[NC Cams]

Rykon 3 is an NLGI #3 viscosity chassis grease. Used in ball joints and pivots that see low relavie motin/fiscosity motiong with respect to each other. THick, goey red if I recall. GOt my last tubes at AUtozone.

IF you can find a version of Mo-Lith by Lubriplate in a 3 viscostiy, i'd used that. An alternteive would be any Lithium based, moly fortified NLGI #3 "chassis" grease. Trouble with any moly grease, it is black, dirty and gets into everyting. IT is worse than anti-sieze in some regards.

An option would be to use an open face, "clinging" gear lube. Real tacky stuff that is particularly suited to "stay put' on gears that run in the open.

[NC Cams]

ANy grease one could even went or use cn be found here

http://www.metalworking.com/DropBox/...icants2001.pdf

Yese there are MANY varioandt os "clinging gear lube".