All things Beaver Mill

[Lex DavisParticipant @lexdavis38817]

Thanks for your reply Peter, there is an oil seal (item 40, Gaco Seal #MIS20) in the deep recess of the casting but it is not doing much in my case, the oil is definitely coming down through the spindle bearings, there is no leakage anywhere else. The sight glass is stained but still readable and until I can find an exact replacement it will have to stay there.

[Peter_HParticipant @peter_h]

You're right I missed that oil seal completely. I'm trying to think how else oil could get to the spindle bearings. The only openings I recall on the whole spindle assembly is the aperture at the top where the shaft comes out. Even with the quill at the lowest point, I can't see how, but it's difficult to think about the internals in 3D. I'll think on.

Just so I'm on the right track, oil emerges from between the spindle and the quill, not from between the quill and the head casting?

[Lex DavisParticipant @lexdavis38817]

Correct, it comes down through the spindle bearings, the outside of the quill is dry.

[Mark RandParticipant @markrand96270]

The good things are that you know the bearings are getting lubricated (even it it's not the grease they'd normally have) and that the last thing you want is a lot of 320 Weight gear oil between the quill and the head if they are still a good fit to each other.

Consolation until you find the time and energy to strip the head and replace the seal!

[Antony HardingParticipant @antonyharding74298]

Hi,

For a Mk2 Beaver Mill is there a such a document that tells you the torque settings for the mill? If not how best to understand how much to tighten up nuts and bolts on the unit. Following my other posts have issues with runout on the spindle and before diving into the worrying task of taking out the spindle to see any issues just want to know I have all info needed to put it back together.

Plus does anyone have a clear manual for a mk2 variable speed head? My one has the disk type breaking unit on the top, not the drum style. I have a couple downloaded from the internal but for the drums type break and can’t hardly read the part numbers.

[Antony HardingParticipant @antonyharding74298]

Hi All,

So, means of an update… with the spindle out I am still trying to find out my issue of the 0.9mm run out. While the spindle is on its side, I measured while rotating it on the outside face (photo AA tool end) and now only get 0.2mm run out. Then I measured at the same point NOT rotating it but trying to move the spine up and down and got no movement at all. Then I moved to the back of the spindle (photo BB nut end with locking washer) and done the same, about 0.3mm run out why rotating it and 0.2mm then moving it up and down. Lastly, I placed the indicator inside the INT40 cone and measured a run out of 0.5mm. Also rotating the spine, the bearings don’t sound the best, and you can see in photo CC the internal face of the INT40 cone is not looking its best.

With my past submitted details on my issue and now the above would people believe my best course of action is:

–          Remove the spindle from the spine to inspect the bearings and possibly replace them.

–          Also, clean and, if anyone knows if you can do this hone /polish the inside of the INT40 cone to hopefully remove any imperfections.

Fingers cross with the above I can have a workable Mill.

[SillyOldDufferModerator @sillyoldduffer]

Not sure setting the DTI up like that helps much.  It assumes the outside of the spindle and the outside of the INT40 are round and concentric, which they may not be.   Run out only matters if it’s between the inside of the spindle and the inside of the INT40.

Replacing the bearings should be safe enough, and they are a likely cause.   I wouldn’t mess with the INT40 unless dead certain it was out of shape. I can’t see any imperfections bad enough to cause 0.3mm run-out.

As that’s huge, the cause must be something fairly gross – like badly worn bearings or a bent spindle.  Shine a torch on the far side of a straight edge laid lengthwise along the spindle and rotate it.  Light escaping under the edge should reveal if it’s bent.

Trouble with pre-loved gear is the history is unknown.  Possibly someone smacked a tool good and hard into something solid, destroying the tool and distorting the taper, spindle, and/or bearings.    In theory, heat and a hammer will fix a bent spindle.  In practice, I’ve never had to try.   Anyone else?

Dave

 

[DiogenesParticipant @diogenes]

Now it’s out, it’d be best if you can snug the quill over some vee blocks on the mill table – this will give you a stable platform to work off and both hands free to manipulate things.

I think if you can establish the axial play (‘end float’) first and then the radial play, you will gain a better insight into where and how much things are moving which will then enable you to check concentricity with a more informed view of how the spindle can be / must not be handled to gain repeatable results that you can have confidence in.

As far as I can see from the pictures, the spindle assembly looks in ‘better than average’ condition for a machine of this size and age.

 

 

[Antony HardingParticipant @antonyharding74298]

Thank Dave,

I will take the quill off to show the spindle and remove the bearings, and like @diogenes nots will set it up on the mill table, then as you suggest use a straight edge to see if the spindle is ok.

 

Yep them bearings are a costly item of £300 but if this is my issue, why painful in cost happy days if this is the issue.

 

Have you ever had to change bearings on a Spindle? what’s the best way to get them off and on? Can believe is a very snug fit.

[Antony HardingParticipant @antonyharding74298]

Hi @diogenes,

Thanks for your message… While on blocks on my workbench, end play of the spindle in the quill (in and out) was 0.0mm on the DTI. But like to say will buy some V Blocks and try this on the mill bed. Following my message above and being new to machining need to find a way to make this bad situation turn into a usable machine. Its a lovely mill as a unit and don’t want to scrap it. Just hope the spindle is straight and maybe its the bearings?

 

As a side note would you know how best to polish off the small amount of dirt/rust i have on the quill and inside the INT40 spindle?

[Antony Harding]

On Antony Harding said

As a side note would you know how best to polish off the small amount of dirt/rust i have on the quill and inside the INT40 spindle?

 

A few of these with the appropriate non-embedding abrasive on them followed by a proper clean:

[Antony HardingParticipant @antonyharding74298]

Afternoon All,

Following my past issues with my spindle I found the courage to breakdown the quill from the spindle to inspect the bearings and was very surprised to see it had only two bearings. The Manuals notes there should be three. Has anyone seen this type of spindle before with only two bearings? The marks on both bearings are (32008c SNR France).

[Antony Harding]

On Antony Harding Said:

The Manuals notes there should be three.

Is the exploded diagram in the manual you have specifically for the 40 taper spindle?

It is true that the 30 taper spindle has three bearings, but the design may have changed for the 40 taper option.

What manuals exist for the Beaver are not comprehensive in the sense that not every option Balding offered made it onto paper.

SNR is now part of NTN, but the bearing designation is a standard taper roller one. If replacing, it would be wise to talk to a bearing specialist to find out what precision level or class they would recommend for a spindle application.

[Antony HardingParticipant @antonyharding74298]

Thanks, below is the diagram that I have (if anyone has a diagram for the 40 taper that would be great).

Could anyone recommend a bearing specialist they have used in the past? Being that the 30 taper uses Hoffmann bearings, would like to see if I can get Hoffmann bearings for my spindle, as I believe from reading, Hoffmann and German precision bearings ???? Plus not sure if the bearings in the spindle now are the original ones anyway.

[SillyOldDuffer]

On SillyOldDuffer Said:

Trouble with pre-loved gear is the history is unknown.  Possibly someone smacked a tool good and hard into something solid, destroying the tool and distorting the taper, spindle, and/or bearings.    In theory, heat and a hammer will fix a bent spindle.  In practice, I’ve never had to try.   Anyone else?

Dave

 

My Mk1 VBRP had obviously had one or more serious crashes in past lives and the spindle was, indeed, bent. More at the top than the bottom. Supporting it on V blocks, U mapped the bend using a DTI, then moved the supports to appropriate locations and straightened it with a block of brass and a soft hammer. No great difficulty.

 

On Antony Harding Said:

Afternoon All,

Following my past issues with my spindle I found the courage to breakdown the quill from the spindle to inspect the bearings and was very surprised to see it had only two bearings. The Manuals notes there should be three. Has anyone seen this type of spindle before with only two bearings? The marks on both bearings are (32008c SNR France).

 

The 40 NMTB spindle arrangement was significantly different from the 30 NMTB one. This was necessary because the quill diameter wasn’t changed and that was sized for the 30 taper spindles. Hence the taper roller bearings, which take less space than angular contact ball bearings.

It’s not easy to tell from your photo, might just be grease on the outer race and rollers. After cleaning, if they aren’t all shiny and spotless, with no flats or grooves, then it’s new bearing time.

[Antony HardingParticipant @antonyharding74298]

Hi All,
Can anyone help me to understand why I can’t pull down the locking pin enough to enable the spindle (turning the handle) to come done? It moves down halfway but no further.

[rorydParticipant @roryd]

Morning All,

I’m trying to get the speed controls working for a Beavermill 5.

The head motor runs fine as well as its hydraulic and pneumatic elements of speed control and mechanically the machine is largely sound.

The X, Y and Z axis on this particular model have electronic control, via a small pair of rotary selectors the the left of the head, along with start button, speed control pot, tuning pot, indicator light, and quick traverse function. The top selector selects between “rev”, “off” and “for” and the bottom selector select “X”, “Y” or “Z” axis.

Control is via a Quinton Crane Electronics Derby speed control board, in the lower LH cabinet on the main machine.

The photo’s show one of the axis motors and the speed control board.

Anyone else with this setup? Any schematics or diagrams for this setup available? Thanks Rory

 

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