Refurbishing a Beaver VBRP Mill

[penfold]

Easier to just buy a pair of gears and mod them to fit the shafts; you only need a 48 and a 32 as the 60 and 20 are already there. 1/2" per min is pretty slow; you'd be taking a hefty cut to need that.

 

[stormin]

Nice looking piece of kit and another mill that was better than a bridgeport but not as successful in terms of numbers sold.

The knee raising motor looks to be a homebrew addition and probably accounts for the lack of colour coding to the wires and number of starter boxes on the side of the machine. It'll be a good addition once it's all back and working. Hand winding the heavy knee with a heavy casting on soon gets tiresome.

The leadscrew should probably remove from the end with the thrust bearings, usually it's the handle and dial end but looks like it may be the motor end on this one.

Have you checked the table cross feed motors for function, they are notorious for failure on Beavers and Bridgeports.

With all those motors I think you can forget VFD using it's soft start and braking functions, a plug and play inverter or rotary converter outputing 440v three phase is the only way to go. The two speed spindle motor cannot be made to run on 240v three phase without a lot of work.

Look out for a column raising block or maybe get one made whilst it's all stripped down, they are a useful feature even on the bigger mills as space between tool and table always seems to run out.

 

[stormin]

1/2" per min is pretty slow; you'd be taking a hefty cut to need that.

Or you are doing a single point face milling or flycutting operation, say on a cylinder head skim and want a nice fine finish.

 

[mm289]

Thanks Stormin, plug n play inverter or rotary is the way I plan going. When I rewire I want to bring it all back to one 3ph plug (via the necessary contactors etc) so I can just plug it into a 3ph supply and the whole unit is then powered with no messing with rewiring motors etc.

Cylinder head skimming is exactly what I had planned for one of its uses

Any ideas on how the micrometer dials might come off - thats the bit I am stuck on at the moment and don't want to attack them to hard

Cheers,

MM

 

[stormin]

Thanks Stormin, plug n play inverter or rotary is the way I plan going. When I rewire I want to bring it all back to one 3ph plug (via the necessary contactors etc) so I can just plug it into a 3ph supply and the whole unit is then powered with no messing with rewiring motors etc.

Cylinder head skimming is exactly what I had planned for one of its uses

Any ideas on how the micrometer dials might come off - thats the bit I am stuck on at the moment and don't want to attack them to hard

Cheers,

MM

Never had the dials off on the beaver mill my friend had. Weve recently stripped down the feed screws and gear boxes on a TOS mill which appears similar though. The outer settable ring of the dials was seperate and didnt really need to be touched apart from they had seized due to lack of use or dirt ingress much the same as yours.
The method of removing the dials on the TOS was to first remove the handles by removing the central fixing screw. Then on the cross feed dial this revealed a taper pin holding the dial inner and outer onto the leadscrew. Driving out the pin meant the dials could be removed. This then revealed a locknut and thrust bearings securing the screw into a boss. The boss was fixed to the knee with taper pins and four counterbored socket head cap screws.

The logitudinal screw was easier as the handwheel and dial came of as a seperate item complete with the right hand end of the table simply keyed over the lead screw. All the thrust load was taken at the far end of the longitudinal screw in similar manner of thrust bearings, adjsutng nut and lock washer as the cross feed.

Weve done plenty of other work on overhauling this mill and much of it would of been nigh on impossible without the printed manuals I ordered from http://www.machinemanuals.co.uk/

 

[stormin]

Some more photos of a beaver cnc retrofit here.

http://petensneak.com/zenphoto/beaver-milling-machine/

Quite telling is photo 18 which shows lead screw removed with dials still attached.

 

[Pete.]

Easier to just buy a pair of gears and mod them to fit the shafts; you only need a 48 and a 32 as the 60 and 20 are already there.

Yup and since you know the tooth count and can measure the OD (in inches), you can work out the DP of the gears you need.

teeth+2/OD = DP

 

[mm289]

Well, I'm making some progress but its slow!

Had a look at those pics thanks Stormin, I can see what you are saying although the handle and gubbins are missing so it is possible he has taken the lead screw out and just slipped the dial back on.

The mounting for the leadscrew is a C shape and it appears that the screw is held in place by an opposite C shaped bracket. You can see the bracket in this pic



There is a socket head screw accesible from this side where arrowed but the remaining screws are reached from the other side i.e. within the gearbox. I suspect when this bracket comes off the leadscrew will slide out sideways.

The leadscrew won't slide out through the gearbox because even if you release the collar and unscrew from the leadscrew, the thrust bearing arrowed will not go over the leadscrew itself.

So I am still flumoxed as to how to get the leadscrew off, the only way I can see is to remove the gearbox.

Have removed all the accessible bolts on the gearbox and no way it is coming off without the top cover sliding off past the dials

Next job, attack the dials again.

Cheers,

MM

 

[Wedg1e]

There's been a Beaver Mk 5 on Ebay for 4 consecutive weeks now, the guy hasn't had a sniff of his start bid at about £670.
Could be because it's in Gt. Yarmouth, so far out of the way even people from Ipswich won't travel that far

I quite like the Beaver, but there never seem to be any for sale up north...

 

[MattF]

Any chance of some photo's which show the whole assembly? Always a bit hard to gauge how things might disassemble from only close-up shots of small sections.

I quite like the Beaver, but there never seem to be any for sale up north...

That's one thing which has always surprised me, machinery wise. Considering that the North has always been more geared towards manufacturing, how come more equipment seems to turn up down South? I'm beginning to think us Northerners must just be too tight to part with owt whatsoever.

 

[mm289]

Here ya go









Cheers

MM

 

[mm289]

Made a bit of progress, got the micrometer dial off after a battle

After trying to turn it incase it was threaded with no success and after studying the exploded diagram in the manual I took the plunge and started trying to drift it off.

Worked a bit of a gap by releasing the nut behind the casing. It is important to keep this nut on though otherwise the leadscrew is pulling just against the "Hoffman bearing" and with break it





Got a couple of small drifts in and applied some heat to the dial and seemed to make a bit of progress so out came the biggest bearing puller I have in the workshop



And it started moving



After a fair bit of working back and forward the dial eventually came off. It is an interference fit that is locked in place by a pin/screw that goes in through the front of the dial. This pin then pushes a ball bearing up to lock the dial in place. (and yes I had removed the pin before trying to get the dial off, reassembled in the picture for clarity )

This then allows you to get to a tapered pin, I am guessing this locks the collar in place that the dial is mounted on.



So thats the good news, bad news is I'm still ******ed if I can see how the leadscrew comes out. I reckon the collar has to come off in the direction of the yellow arrow but that cant get past the flange that holds on the handle engagement collar (in red).



Here is a blow up of the manuals diagram, looks like the end of the shaft is tapered so maybe the flange can be driven off? Difference to the diagram is that it doesn't show the gearbox and powerfeed I have on mine which is the bit stopping me get to the retaining collar around the leadscrew.



So, once again, thinking cap on, open to suggestions

Cheers,

MM

 

[MattF]

So thats the good news, bad news is I'm still ******ed if I can see how the leadscrew comes out. I reckon the collar has to come off in the direction of the yellow arrow but that cant get past the flange that holds on the handle engagement collar (in red).

Is it pulling off as far as the end, to where it's circled in red, then jamming?

 

[mm289]

Is it pulling off as far as the end, to where it's circled in red, then jamming?

The inner collet which is no 93 in the diagram, on mine has the castellated feature cast as part of it. Therefore to slide off the end of the leadscrew it (and the outer castellated feature which is what the handle mounts to) have to slide over the retaining collar circled in red.

The two castellations are seperated by a spring so that in its normal state the outer castellation disengages from the inner.

So the outer castellation does slide as far as the retaining collar and moves freely. The collet and inner castellation don't move (yet) but my supposition is that the collet can be drawn off the leadscrew towards the end now the tapered pin has been removed

Trouble is the retaining collar is wider that the ID of the collet - as you would expect as it is there to stop the handle etc coming off.

So, I am guessing that retaining collar has to come off, but there is no visible securing pin or similar.......

Its like being Poiroit down here

Cheers,

MM

 

[MattF]

Trouble is the retaining collar is wider that the ID of the collet - as you would expect as it is there to stop the handle etc coming off.

So, I am guessing that retaining collar has to come off, but there is no visible securing pin or similar.......

I may be misinterpreting the photo, but to me that just looks like a plain shaft with a groove in it for a circlip or such. I'd personally think the end of that shaft is just splayed or damaged, hence why the piece won't slip off. I'd just tickle that end of the leadscrew shaft with a fine file to true it back up, then try slipping that dog clutch off again. I'd think it's as a snug slide fit which is merely catching on a surface imperfection.

Just run your fingertips around the shaft, (why do most terms seem like a double entendre? ), and feel for any gouges, burrs etc. I'm guessing you'll likely note quite a few.

 

[mm289]

Pics aren't making it very clear so have taken a few more. The retaining flange is like a "mushroom head" to stop the castellated collar coming off.



Also included a wider pic of the gearbox and leadscrew assemble for context



Cheers,

MM

 

[mm289]

So after loads of searching to try and find info on dissassembling the lead screw I turned up nothing.

So had to proceed on the basis of logic and a bit of brutality

Loads of pics below as i want to document this just incase someone else wants to do similar and searches the web for some info

First off, ground of the end of the button/mushroom head.



This then allowed me to remove the outer castellated collar. I could then apply some brute force to the remaining inner collet (item 93 in the diag above).

After some battering the ring started to move and revealed a "sleeve".



Turns out the "button" end is actually a sleeve that fits over the end of the lead screw. The inner collet then fits over this.



These were seized together and I doubt would have seperated without the force I applied.

Worth noting is that there is also a HIDDEN grub screw. it is beneath the ball bearing that acts on the mic ring to secure it (item 66 in the diagram).



With the collets removed the gearbox cover will slide off.



Revealing the innards of the gearbox



The gearbox is sitting on locating dowels and to get it to clear these you first have to slacken the shaft nut from behind the box



Then you have to remove a retaining collar held in place with a pin



Once this is done the gearbox will slide forward and drop down



Gearbox removed,



Geartrain can then be slid of the leadscrew



And finally the gearbox mounting plate is revealed

It is held in place by 4 bolts, 3 hidden behind the gearbox and 1 coming through from the opposite side.




With these undone, the gearbox mounting plate will slide off its locating dowels and reveals the circular plate that holds the leadscrew.



With the circular plate removed from the dowels the leadscrew will slide out of the side of the bed.



And finally, the leadscrew is removed

Hoo-haa

Cheers,

MM

 

[MattF]

Glad to hear you finally managed it. What were the chances of figuring out that mushroom sleeve on the handle spindle.

 

[mm289]

Next job was to remove the knee.

The knee is locked onto the column with a gib held in place by some locking plates, shown here. I have punch marked the plates ready for when they come off for cleaning.



The locking plates are held in place with bolts which can be loosened with shortened Allen key, the elevating nut for the knee is held in place by 3 nuts at its base.

With the plates loosened and the elevating nut removed my new cross beam and girder trolley came into play.



The column with knee removed



Cleaned up the face of the column



Top is in very good condition, although there is heavier marking near the bottom, looks like this is where it has spent most of its working life.



Sides of the column looks OK.



Cleaned up the knee



Not sure if it shows in the picture but the "depth" of the mating surface when referenced against the casting of the knee is very different across the length of the
surface. It looks almost like it is worn at one end, especially as it feathers out onto the casting, but looking at the depth of the oil ways they are all pretty consistent.



So question is, is this where the knee would have been ground flat when it was manufactured and the differing depth is due to the original casting being rough?

The top surface of the knee looks to be in pretty good condition



Of more concern is the outside edge of the keyway which has some obvious wear towards the front.



The opposite side is fine but there is a definite groove worn here. Not sure how much impact this will have on the accuracy of the mill. Don't really have the facilities to grind it flat again so open to suggestions on whether this make ths mill viable still?

Cheers,

MM

 

[Rig Pig]

How is the rebuild going?