Was wondering if anyone could tell me whether the spindle bearings in a J Head are the same that are used in a BOSS6 rigid ram?
Reason is that my BOSS bearings have a bit of play in them and as I have a couple of clapped out manual mills with decent spindle bearings I thought about swapping them over.
I have the bearings out of the J Head at my workshop but forgot to bring them home, the manual says Fafnir MM207 LU35T but the bearings I have are RHP bearings so the numbers are a bit different. My friend has the interact manual so he should be able to tell me the numbers tomorrow for it.
By OEM number I mean 1119238 or 1119232 or 11771020 some other number of similar construction.
The "fafnir number" merely tells you that is is a 207 style bearing BUT the MM and the LU35ST denotes a custom "factory modification" that involves a special variant of a 207.
Some of the Bridgeport bearings were custom preloaded, specially sized, hand selected 6207's. If you stick in a generic 6207 as some may try to sell you, you'll probably have a sloppy bearing'ed poor performing piece of crap.
Or, you can stick in a 7207CTYDUL or DUM P4 and have a real smooth ABEC 7 replacment. BUT, you may have to do some spindle rework becauses some of the spindles were U/S or O/S and they used selective fit bearings to service them.
There is a Bridgeport spindle rebuild thread that ran in the past 4-6 weeks on the 'ZOne that explains what went on - too much info to repost it here. Please search it out as the service method doesn't change. You won't be disappointed for doing the reasearch either, TRUST ME.
My OEM parts list of over 50 eome part numbers which included all the production and service bearings that were in use as of 1995-1996 time frame.
Sadly, neither bearing number you provided is on the list.
Either they quit servicing the bearings noted prior to the date of my list or another number or numbers superceded them.
Example: the 11771020, the 1119238 and the 1119232 all are based on the "207" bearing. One or several may work. I know that the 11771020 subs for the 1119232 in some applications
Try contacting Fafnir to see if they have any info on the bearing number you have. Perhaps they have something that can/will work. Or, if you can get the technical details of the design, an alternate could be chosed.
BTW, the 7207 number listed previously will service quite a few of the BPT "specials" once you deal with the OS/US spindle/housing issues that might be affecting you.
CHeck for the spindle thread mentioned previously for more details regarding the OS/US spindle phenomenon....
OK no problems, I was just going to swap over the bearings from the J Head if they fitted but I better make sure the OS/US is the same. Did a quick search for that thread but nothing so far, will go try again.
Thanks for the info