milling spindle upgrade

[Swarfing]

If you do go that route then i would recommend a resin mix and not cement. No chance of it rusting out from the inside going forward, a cement mix would allow damp/ water in.

[vtsteam]

I haven't had that particular problem swarfing when filling metal buckets for stands, etc. Also I have a cistern coated inside with portland cement under the house. Portland cement neat is waterproof. Many ferrocement boats built with it, and swimming pools,etc, Pipes run through slabs, not to mention rebar, ----- and how often will this base sit in water anyway?

Just use a rich mix (extra cement). if worried. You could paint the bottom, too, I can't imagine a problem here.

[mattinker]

The problem with cement is more shrinkage than rust, if the block shrinks its vibration damping would be reduce. Resin based concrete would seem to be a better solution.


Regards Matthew

[bertie_bassett]

well while I decide what to do with the old base I decided to drill some hole in the plat iv got and make a start at re-assembly -  got the plate bolted down, but both drills ran out of juice so couldn't mount the actual column today

i did manage to repair the damaged nut though

started with this



first i set the base up in the chuck, and clocked off the internal bore



faced off the damaged section till it was nice and flat then did the same to the nut section

i then found a handy lump of ally from my 'might be handy' bin, think it was an old shaft adaptor for an actuator or something

chucked up on a quickly made mandrel and skimmed the outside down to match the bore, added a few small grooves to aid glueing together



left the internal bore as found, thinking the thicker the better



is now clamped up waiting for the jb weld to dry.  i might drill and tap a few spots for extra strength but will decide on that later


as for the broken base here it is in situ



current thinking is to jb weld it together, along with some internal plates and then build some sort of box/stilts directly under the column to take the majority of the weight and brace directly to the plate underneath.
would weigh less then concrete and should be easier to construct.

[awemawson]

That looks a likely candidate for metal stitching:

http://www.locknstitch.com/metal_stitching.htm

[vtsteam]

The problem with cement is more shrinkage than rust, if the block shrinks its vibration damping would be reduce. Resin based concrete would seem to be a better solution.

Nah, it isn't going to shrink. But if fashion and too much extra cash dictate, fill it with epoxy.....

[Manxmodder]

Steve,really, concrete boat,who ever heard the likes. We all know it would sink like a stone 
.....OZ.

[vtsteam]

Steel is even denser, and we all know steel boats can't float! 

(A 1" hole will make it all to too true,  though, OZ!)

btw. "hydraulic" cement expands on curing. Used to fill cracks, etc. And bolting the base to a solid floor makes the fill irrelevant re. vibration.  Though flilling it with anythling is a lot better than it was as a hollow casting.

[mattinker]

The problem with cement is more shrinkage than rust, if the block shrinks its vibration damping would be reduce. Resin based concrete would seem to be a better solution.

Nah, it isn't going to shrink. But if fashion and too much extra cash dictate, fill it with epoxy.....

Nah,
http://www.cement.org/for-concrete-books-learning/concrete-technology/focus-on-floors/concrete-shrinkage

[vtsteam]

This is a little smaller than a floor. 

I've got cast in place steel containers for stands. They're solid.

Concrete filled steel lolly columns can be bought at local lumberyards. The cores don't fall out, even when cut. We've used sections of them for rollers for boats weighing tons. They don't even have fasteners through the sides as suggested earlier for the mill base repair. Or rebar, etc. Classic case of internet research and theorizing vs reality.

[PekkaNF]

This is a little smaller than a floor. 

I've got cast in place steel containers for stands. They're solid.

Concrete filled steel lolly columns can be bought at local lumberyards. The cores don't fall out, even when cut. We've used sections of them for rollers for boats weighing tons. They don't even have fasteners through the sides as suggested earlier for the mill base repair. Or rebar, etc. Classic case of internet research and theorizing vs reality.

Or maybe manufacturer is smart and adds something on the concrete mix? I have met concrete that has something added to to it to EXPAND it intially to outmanouver further shrinking.

Something like this:
http://www.puumarket.ee/?op=body&id=42&prod=269&sid=2104
That english translation looks funny, but I'm not familiar with the real one.

Anyways, I have tempted to measure real world concrete shrinkage on our machinebuilding application, but been putting it of for years, because can't get any immediate results

Pekka

[bertie_bassett]

Well the concrete casting is still on the maby list, though I don't really fancy the weight of it  a concrete slab with 1/2" cast iron skin sounds rather heavy, and ill have to move it on my own. Also the column is tapped and bolts down from underneath so not sure how id get around that one

There is such a thing as expanding concrete. Usually used to fill in holes in the ground. Just don't use it indoors as it gives off hydrogen. Had a one of my pumping stations explode a few years back, when contractors used the stuff

[NormanV]

On page 75 of the book Stuff Matters by Mark Miodownik he states "But, as luck would have it, steel and concrete have almost identical coefficients of expansion"

[vtsteam]

Apologies to Matt for tone earlier.  It does bring up a topic I have often had to deal with. But no need for criticism.

I do think that theory online, in general often overwhelms what actually happens when tried in real life, and it's one of the reasons I do so much experimenting in my projects, despite what is published. I think there are online justifications for both sides of practically every techncal argument, and they're all true, to some degree.

One of the main reasons that is possible is that the devil is in the details, and online theories often generalize (or get generalized by repetition or expansion) to the point that they are meaningless to many specific cases. Generalizations are common. Specifics, and expressed theoretical limitations, rare. And that stifles experimetation and discovery. Specifics, accident, and even failure are essential to the realization of many projects, and innovation. And much learning about the world.

I ought to be from Missouri, though Vermont is considered a fairly independent minded state, too. I like to do things and find out what happens for myself, or if I can overcome conventionally perceived limitations. Anyway, sorry about the exasperation level expressed, but it's not personally directed -- it's the internet "knowlege base". Taken as an approximation of reality it's helpful, otherwise, I find it frustrating at times. 

[mattinker]

Apologies to Matt for tone earlier.  It does bring up a topic I have often had to deal with. But no need for criticism.

I do think that theory online, in general often overwhelms what actually happens when tried in real life, and it's one of the reasons I do so much experimenting in my projects, despite what is published. I think there are online justifications for both sides of practically every techncal argument, and they're all true, to some degree.

One of the main reasons that is possible is that the devil is in the details, and online theories often generalize (or get generalized by repetition or expansion) to the point that they are meaningless to many specific cases. Generalizations are common. Specifics, and expressed theoretical limitations, rare. And that stifles experimetation and discovery. Specifics, accident, and even failure are essential to the realization of many projects, and innovation. And much learning about the world.

I ought to be from Missouri, though Vermont is considered a fairly independent minded state, too. I like to do things and find out what happens for myself, or if I can overcome conventionally perceived limitations. Anyway, sorry about the exasperation level expressed, but it's not personally directed -- it's the internet "knowlege base". Taken as an approximation of reality it's helpful, otherwise, I find it frustrating at times. 

Apology accepted! I am well aware of how you function, we've both been contributors to this group for some time now. My feeling is that I have a certain amount of knowledge that I can share. Take it or leave it, but know that intentions are good!

Regards, Matthew

[vtsteam]

Well the concrete casting is still on the maby list, though I don't really fancy the weight of it  a concrete slab with 1/2" cast iron skin sounds rather heavy, and ill have to move it on my own. Also the column is tapped and bolts down from underneath so not sure how id get around that one.

Bertie, if it's too heavy, that's that. But if not, you can screw waxed dowels over the holes on the inside as cores to prevent the fill from coverng the tapped hole. You can knock those out after cure. Taper them to make it easier.

[Swarfing]

Guys the only reason my thumb up for a resin solution is that you get a natural adhesion to boot so no need for extra bracing and fixings. I worked in the flooring industry many years ago dealing with all types of concretes, resins and aggregates. Like all mixes it all depends on how much air is excluded to decide how porous the material is. The filler material will really be the deciding factor plus any reinforcing if required like a square of welded mesh, cost wise (UK) two pack resin vs cement would be very little in it.

The piece that is missing you could just box in so the resin mix fills that. A bit of bondo afterwards and a sand/ paint and your done.

[bertie_bassett]

well iv got it bolted down on the flat plate and started re-assembly.

actually quite like it at the lower height, only issue so far is that the knee handle hits the lower tray when the knee is at the lower 2 inches or so, can live with that for now as I doubt ill need it that low down often.

the straightened screw seems to be working well, is a little tight in the middle but not excessive.  and will do for now

[bertie_bassett]

and its alive!!


spent some more time today putting the table on then reassembling the head.





wired up a temp lead direct to the motor as I didn't like the standard wiring, luckily it spun the right way first time! 





that's about all I can do for now, don't have any tooling or a proper vice.

[philf]

Looking good!

How thick is the base plate?

If it's at all flexible you may have problems in that the table might move relative to the cutter when actually cutting metal! If you're not going to reinstate the original base a piece of 20 or 25mm plate (or a piece of substantial channel section) under the column and extending to the nut would help.

Cheers.

Phil.

[bertie_bassett]

plate is about 9mm thick and bolted down to all 4 corners of the angle frame of the cabinet, ill have to see how it goes when I get some tooling, can always be braced from below if required. or the base repaired.  though I quite like the height its at now belts are about on my eye line

[vtsteam]

Well that was quick! It does look nice! 

[bertie_bassett]

Well that was quick! It does look nice! 

Wasn't all that much to fix really, just the screw and nut.

Managed to find a small precision vice I made as an apprentice and a t slot slot clamp which fits perfectly so thats a start on tooling   will probably build my own vice for it along with everything else I need.
Collets and cutters are first on the list though!

Best I start on the other jobs, and many finish off the lathe milling spindle

[bertie_bassett]

not made any real progress since last week, was going to do some today, but after working 23 hours solid I decided to go to bed!

have orderd up a collet set  from arc got 6 10 12 and 16mm.  as thought that would be a reasonable start. also order up a range of 4 flute hss mill from richon to play with, so now just waiting on bits to arrive.

I did start making some adjustments and measuring of backlash, looks like I might need new gib strips as they go in further then I think they should also need to look at the slipt nuts on the x+y as they have been drilled but not tapped?? so plenty to keep me occupied.

oh and got to build a starter panel for it. original had reverse, but I cant see any reall reason to have reverse on a mill?

[PekkaNF]

..... original had reverse, but I cant see any reall reason to have reverse on a mill?

I can imagine reverse used on threading, but don't the new ones have button on the down feed lever?

Pekka