Beauty in The Beast: Webb 5BVK Barn Find/Conversion

[JimDawson]

Only the spindle bearings should be effected, I would guess the bearings in the upper head would not damaged in a crash. Nor should they affect the runout of the spindle.

PS. My MPG is alive again. Replaced the encoder.

 

[Weldingrod1]

Btw, the drawbar pull is carried -only- by the steel rotating part/shaft. No load in the bearings. It's basically a tube... a fancy, annoying tube housed in irritating rattle-y bearings :-(
Here's hoping the rebuild isnt toooo expensive!

Sent from my SM-G892A using Tapatalk

 

[extropic]

I'm saying that the two lower spindle bearings (41) the spacers (42, 43) the spindle (44) and the quill (46) all need to be evaluated.

From the runout data, the upper (small) end of the taper had little runout, so I would guess that the bend in the spindle is not far above top of the taper. I wouldn't expect the journals for the two bearings (38) to be damaged. In other words, I expect the spindle is bent between the top 41 and the lower 38. Maybe the spindle can be straightened to very close to factory. The spindle bearing (41) journals can be built up and reground. And of course, the taper reground.

I also expect, at least the lower quill bearing bore to be deformed. Both bores (for 41) need to be to size, cylindrical and concentric.

The preload spacers (42, 43) may well be damaged.

Setting the proper preload is a nontrivial process and best done by a real professional spindle builder.

All in all, I recommend sending it to a real professional spindle builder.

 

[Charlieman22]

PS. My MPG is alive again. Replaced the encoder.

Think that puts it in the "damn near" indestructible category.
Good news!
(I'll think about you every time I drop mine...)

Btw, the drawbar pull is carried -only- by the steel rotating part/shaft. No load in the bearings. It's basically a tube... a fancy, annoying tube housed in irritating rattle-y bearings :-(
Here's hoping the rebuild isnt toooo expensive!

Weldingrod - thanks for the clarification. Clear now. Also - they should use your description in the parts book: "99. Irratating rattle-y bearings. 2 - Req"...
So true!

All in all, I recommend sending it to a real professional spindle builder.

Ext. I am fully there.
I have some work I want to complete before I tear it down.
I think I can hold a tight enough tolerance to get what I need - but then out comes the quill assembly for refurb by qualified group.
The 10EE has given me a taste of what a high precision machine feels and works like.
Addictive.
I want to be able to hold some tight tolerances - and the job will probably be worth it.

 

[Charlieman22]

Well - it's been a tough road so far on the spindle.
Doing some work with the mill - nothing like trying to find center on a critical tolerance part when you have runout...
Contacted a few places.
The ones that said - oh - just take the nose cone off and bring us the spindle - were taken off the list...
The most knowledgable - by far - guy I spoke with new the mill and was confident he could rebuild to perfection.
His quote: $4500 - $6500...
Then there were the out of state guys who said they could surely get it done for just $8500 (but I should budget $10K just in case).
Am going to need to find a more cost effective solution if I am going to make this work.
Not sure exactly what that is...
I'll keep searching.

 

[JimDawson]

That's crazy. Give these guys a call. They redid mine for <$1K, and I have virtually the same spindle that you do.
Make sure they know it's a Bridgeport clone machine.

C & M Precision Spindle

World-class Spindle Repair Services and Spindle Rebuilding since 1993

www.cm-spindle.com

 

[extropic]

Doing some work with the mill - nothing like trying to find center on a critical tolerance part when you have runout...

I don't quite understand what you're saying there. Taper runout has nothing to do with locating the center of rotation, as witnessed by the very congruent runout data you published earlier. Now, if the bearings/spindle have become so UN-stiff that the center of rotation is noticeably moving around while hand turning a DTI . . . I guess I would call that dead in the water.

 

[extropic]

Those spindle rebuild numbers are tough OK.
Another option, put out feelers for another mill, same model. Doesn't matter if it runs. You already have access to procedures to evaluate the condition of the spindle taper and stiffness.

I still recommend that you do, on your mill, the evaluation I described in reply #256 (Pg. 26). The experience should be educational and show you what you don't want to find in another.

Have you noticed my new signature line? LOL

 

[JimDawson]

A thought just occurred to me. Put a tool holder in the spindle, tighten it up. Put an indicator on it and push & pull side to side. See if it is loose. It is possible that the bearings are just loose. I have actually had this happen before.

 

[extropic]

A thought just occurred to me. Put a tool holder in the spindle, tighten it up. Put an indicator on it and push & pull side to side. See if it is loose. It is possible that the bearings are just loose. I have actually had this happen before.

Apparently you missed my reply #256 (Pg 26). That was PRE-regrind.