spindle cross section view

[Ross77]

And now for something completely different!
http://www.youtube.com/watch?v=yln_I...eature=related

Thats one brave or stupid person..how many times do yo think they ran the code before siting on the seat? still beats the hell out of Alton towers eh.....

Interesting point about the die grinder, will free spin up to 24000 rpm, and will take all the loads. I did see one with an extended section, which might get around one of your points.

Noisy and fixed speed tho so might not be good for all uses.

Note that I'm not looking to make one, I posted to lure Ross out with his spindle design progress. . . .

Mission accomplished....................................:w histling:

[Jonathan]

They are FAG B7206C.T.P4S.UL
The info is all on the FAG site if I recall correctly.

[Ross77]

Barry
Is that picture that you posted at full resolution? I saved it but gets a bit grainy when I zoom in, Im trying to see if the front bearings are fixed to the shaft and the spring loading is just on the rear bearings.

Cheers

[routercnc]

Hi Ross,
Sorry, that's it. I've found the original picture - scroll to post #9
http://www.cnczone.com/forums/showthread.php?t=101803

There is a model reference number in the bottom right corner of the picture, maybe search on that?

By the way, I stumbled across Steve Hilton's post from earlier this year where he was making a spindle. I notice you replied - but worth another look?

[Ross77]

Thanks Barry, this spindle thing is driving me around in circles........

Yeah I remember that, Think he already had the cartridge spindle and quality bearings, just remade the spindle for er 11 collet. cheers I will look again tho.

[coredump]

Sure if you are milling in the micron ball park. Anyway once you spindle reach thermal equilibrium you don't care anymore about this.

Edit: to be precise, FP1 have two needle bearing outside the taper and directly behind them, a trust bearing. On the other side of the spindle, a single trust bearing.

[Ross77]

Sure if you are milling in the micron ball park. Anyway once you spindle reach thermal equilibrium you don't care anymore about this.

Fair point and and seems to be the mailn difficulty with building high speed precision spindles is getting the correct clearances at operating temp.

You did only mention axial expansion but the real problem (for a diy spindle) I think would be the radial expansion and the resulting change in bearing clearance

if its preloaded when cold it can cause brinelling problems if not used regularly and if the preload increases during the warm up period then there is the risk of overheating and to much preload binding and associated damage.

Therefore I think needle bearings would be difficult to use if mounted in the front. Btw Did you mean needle bearings or roller? as I dont think needle are suitable for high load and cant have a taper added to change the preload. Are they?

Do you have a diagram and design use for that spindle?

[Jonathan]

Surely you want angular contact bearings? I've got a spare pair FAG 7206 bearings... ABEC7 grade (so intended for spindles)! If you're interested...

You need to work it out such that the spindle temperature remains in a certain range, so etc.

[Ross77]

Cheers, yeah I do I was just trying to clarify what coredump was suggesting with the needle bearings.

I already have a matched pair of Barden precision bearings 109HDL (45mm int.) for the nose, if I can make the spindle accurattly then most of an ER 32 collet will be in side the bearing anyway. I do need some bearings for the rear but they will need to be floating or have end float, allowing them to slide on the shaft or housing just adds more maching headaches.

I intend to do a practice run first so might be intested in the bearings.what size are they,contact angle , clearance etc.

cheers

[coredump]

Hi,

You can find the cross view of FP1 spindle here: http://www.usinages.com/manuels-docu...fp1-t3738.html page 55 of the documentation (sorry in french).

Still in french, if you look at this thread: http://www.usinages.com/conception-f...xy-t15107.html the guy build a spindle very close from Deckel spindle (and he got one FP3, no wonder why).
His spindle is made from 42CD4 (no post treatment), BT40 spindle nose (done on an asian lathe), Needle bearing in front, runing on a bearing ring (NKI bearing), double angular bearing (normal SKF) on top.
The trick to have low radial clearance is to use the fact that needle bearing race is thin, so a very tigh adjustement make the race growing, or shrinking. In fact in his case the adjustement is a little bit on the high side. He explain me that Deckel use a wide range of needle, spaced in micron, to found the correct adjustement when building or refitting a spindle (he used to work a lot with Deckel in his professional life). There is also some growable needle bearing (INA), but more exotic.
Btw, all his epoxy granit mill has been done with pure DIY spirit: no big machines (not even his FP3, which he doesn't have at first), no exotic component. I have seen it IRL and it's pretty impressive.