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

[JimDawson]

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

Yup, I missed that one.

 

[Charlieman22]

Alright - lemme tackle those one at a time.

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

Thanks. Was hoping my post my elicit a few better options. Learned a lot along the way. Was a helpful process.
May try these guys.

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.

When I use a coaxial indicator - it continues to bounce even if it is inside a baby smith ID bushing.
When I turn the spindle, using an indicator - it turns and then occasionally just jumps 3 tenths - but if I reverse it - it doesn't go back to what it was - which it should - if the feeler point was falling into a hole or popping over a high spot.

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

Yep - spindle numbers are a stopper.
Thought of that - but TBH - I'm not sure the question for a 1980's CNC mill is: "did it crash?" More appropriate would probably be: "How many times did it crash". I would expect any and all to potentially have similar issues.

That said - I would like to improve mine.
I am fairly (but only fairly) sure the inability to get my Blake coaxial indicator to settle down properly is due to the bearings.

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

You guys lost me on this one a bit.
I can get some movement if I put an indicator on a tool and grab the tool and push/pull it.
Did the regrind remove the meaningfulness of this excersize?
It was there before - and remained after the regrind.

I assume the bearing tightness is determined by the nose cone?
Ext - did your post #256 address this in some manner that I am missing?

Oh - and signature line? Must be sniffing too much cutting oil- I don't see any signature at all.

 

[extropic]

When I use a coaxial indicator - it continues to bounce even if it is inside a baby smith ID bushing.

I don't know what a "baby smith ID bushing" is but I'll assume the ID is precisely cylindrical with a fine surface finish. If my assumption is erroneous, please advise.

When I turn the spindle, using an indicator - it turns and then occasionally just jumps 3 tenths - but if I reverse it - it doesn't go back to what it was - which it should - if the feeler point was falling into a hole or popping over a high spot.

The description is indicative of bad bearings. For the purposes of this discussion, "bad bearings" includes bad bearing mountings.

I would expect any and all to potentially have similar issues.

That is a particularly pessimistic view. LA is a huge used machinery market with many dealers. All I suggested was "put out feelers.
Have I impressed you so poorly that Poo-Poo is the default response to my suggestions?

That said - I would like to improve mine.

That's an admirable objective. I suppose it depends on exactly what you mean by "improve".
Given that you declined to do the procedure in reply #256 (pre-regrind), I don't know what to suggest or expect next.

I am fairly (but only fairly) sure the inability to get my Blake coaxial indicator to settle down properly is due to the bearings.

I don't have any experience with a Blake coaxial indicator. I think they are .0005" reading indicators. I would use a .00005" reading indicator to evaluate the bearings and housings.

You guys lost me on this one a bit.
I can get some movement if I put an indicator on a tool and grab the tool and push/pull it.

Not well described so not germane.

Did the regrind remove the meaningfulness of this excersize?
It was there before - and remained after the regrind.

I'm not certain of what the regrind did. Based on your comments, it didn't improve the runout and now you see erratic eccentricity which you attribute to "bad bearings". Cause unknown. On the other hand, the runout data you provided, pre re-grind, seemed to describe relatively smooth circular elements (no erratic readings).

I assume the bearing tightness is determined by the nose cone?

The NOSE-PIECE (48) has nothing to do with mounting the bearings.

Ext - did your post #256 address this in some manner that I am missing?

Address what? Reply #256 said nothing about taking anything apart or making any adjustments. If you read #256 and need additional clarification, please reply with photos illustrating the problem.

Oh - and signature line? Must be sniffing too much cutting oil- I don't see any signature at all.

Step away from the cutting oil.

Your choice of options has exhausted me. Good night.

VVVVVVVV SIGNATURE LINE VVVVVVVVV

 

[Charlieman22]

I don't know what a "baby smith ID bushing" is but I'll assume the ID is precisely cylindrical with a fine surface finish. If my assumption is erroneous, please advise.

Indeed. It would seem spell correct got the best of me - should have read baby SMOOTH.

That's an admirable objective. I suppose it depends on exactly what you mean by "improve".
Given that you declined to do the procedure in reply #256 (pre-regrind), I don't know what to suggest or expect next.

Not sure the disconnect.
I thought the experienced symptoms, and lack of correction through grinding, had left us all agreed that my bearings (and or seats) are likely damaged and at the heart of my runout.
With the decision to have the spindle and quill reworked - my presumption was I was addressing any damaged components.
This is why I did not proceed with further testing.
*I also lack some of the items to do the job currently.

I'm not certain of what the regrind did. Based on your comments, it didn't improve the runout and now you see erratic eccentricity which you attribute to "bad bearings". Cause unknown.

Just to clarify - the erratic conditions were there prior to the taper grinding.

The NOSE-PIECE (48) has nothing to do with mounting the bearings.

Jim mentioned his experience with bearing tension.
The the tech who worked on the machine also mentioned it - and said the nose piece is tightened to tension them.
My comments were based on what I understood to be the method.

As for my lack of enthusiasm around looking for an additional used machine - it's a practical one.
I'm juggling right now - so trying to be as efficient with my time as possible.
I would expect to pay as much or more to acquire a used machine - or parts - as it would take to get the spindle reworked in the end.
So that one got considered - but back burnered for now.
On the other hand, If it turns out that spindle rework is now truly a $5000 operation - then I will rethink that.

My general take was - finding a more reasonably priced spindle repair shop is the most efficient/highest value/lowest risk approach to improving if not perfecting the accuracy/consistency of my machine.

I think this stands - though I can't say I am overjoyed to have to pull down the machine or write the check.
Win some lose some.
Since I didn't see additional data changing that - I thought it best to focus my time on finding a more reasonably priced shop.

 

[JimDawson]

Locknut #39 sets the preload on the bearings. But you can't get to it without dropping the quill out of the head.

To put this in perspective, at $5000 I would fix the thing myself, at about $1000 I would send it to a shop. It's not rocket surgery, but I'm lazy.

 

[Charlieman22]

Locknut #39 sets the preload on the bearings. But you can't get to it without dropping the quill out of the head.

To put this in perspective, at $5000 I would fix the thing myself, at about $1000 I would send it to a shop. It's not rocket surgery, but I'm lazy.

Got it.
That perspective matches mine.

My assumption is - I am going to find a qualified group that want the $1200 range to bring this to tight spec.
It's tempting to add tension to the bearings - mostly just for the R&D - but I am using the mill currently for a project.
Additionally - my suspicion is deformed seats, bent spindle - or both - though I suppose its possible that even with those conditions, a bit of snugging might yield improvements - if not cause quicker wear.

BTW - this arrived. Very nice! Did we know we were getting the extra components? Off to give high rating on Ebay.
Am sure others have found themselves in this position: Want to get my project done - then will make the mill my project.
Wish it was the other way around - but time demands on the first project mean I need to work with what I have.

 

[JimDawson]

Did we know we were getting the extra components?

Cool!

Yes, those were listed in the ad. You got a couple hundred $ in cables and breakouts there. All you need is the power cable.

QTY 1 Power cable for above
https://www.digikey.com/en/products/detail/molex/2451350220/6564767
2 Position Cable Assembly Rectangular Socket to Socket 6.56' (2.00m)
Mini-Fit Jr 245135

 

[Charlieman22]

certainly was a good (and very generous) find.
thanks Jim.

 

[JimDawson]

certainly was a good (and very generous) find.
thanks Jim.

If you hadn't needed it, I would have instantly hit the Buy Now button. I would have bought it just for my stock. That was the best deal on one I have ever seen.

My pleasure to help out.

 

[extropic]

Just to clarify - the erratic conditions were there prior to the taper grinding.

I don't recall you reporting erratic indications earlier. The runout data table was the most definitive spindle condition information published here and certainly didn't demonstrate erratic readings.
Erratic readings was important information to disclose in no uncertain terms.

The the tech who worked on the machine also mentioned it - and said the nose piece is tightened to tension them.
My comments were based on what I understood to be the method.

I don't know what to recommend or expect next.