Member postings for Joseph Noci 1

The ATC is progressing well - Most major mechanical parts are done - awaiting the Bellville springs from South Africa still, and the toolplate has still to be contemplated..Then still the position encoder and stepper/stepper drive.

A refresher of the ATC innards:

Front view of main Housing with fixed Hirth Coupler (item 2) visible. Threaded main shaft fits to tool plate ( Item 1)

Rear of Main Housing with rear Brass bush (item 7a) amd main shaft (item 1b)

Housing Assembly interior -

Main Shaft assembly with front and rear brass bushes, pre-load and lock nuts ( items 4 and 5) , pneumatic piston, seals and seal retainer ( items 6 and 6a).

Breakdown of piston assembly - left main piston (item 6a) middle the outer and inner seals, right the seal retainer.

Piston assembly together - rear 'O' ring not yet fitted in groove

The Hirth Coupler milling operation was complex - many angles and offsets to be implemented accurately. I decided to tilt the mill head to the 30deg angle on the Hirth wedges, rather than make a special milling cutter. However, that required complicated juggling of mill cutter edge positions and offsets, with much head scratching and reversion to CAD.. In the end it was remarkably successful!

Roughing out the slots:

The cutting the 30deg angles to the sides of the slots:

The results:

And the fit - not too shabby-

The flat plate I needed for the Tool holding wedges in the toolplate, as well as the clamps for the peripheral tooling on the toolplate ( drills, boring bars, etc) was hidden in some really rough, rusted flame cut steel plate - from a local ship-yard...

Extracted from the rusted plate by means of the shaper...

Giving the wedges and clamps:

And the whole thing so far filled two cardboard boxes of 450mmx400mmx350mm, one with Aluminium and one with steel swarf..

Hope I have not bored to many folk...

On with the tool plate now..

Joe

Thanks Michael.

Unfortunately the all-imports specs don't seem to be available anymore..

Joe

Progress on the Tool Changer main body machining.

There was still some considerable bandsaw work after cutting the main body block from that 'round bar'. This led to some modifications on the bandsaw...

The saw has a coolant pump which is filled with a Rocol neat cutting oil - the red stuff seen in the pics of the cutting process. It works, but is real messy - sort of sticky and hard to get of the cut parts by simply wiping. Also, the saw's drainage system is abysmal! there is a sieved hole located in the center of the saw tray, and the tray is flat and the coolant pools everywhere on the tray except at the drain hole..So I made a new hole rear left, and raised the saw above its front wheels, forcing the coolant to run to the rear. I also raised the saw slightly from its right side wheels to force the runoff to the left as well. That now works well. Had to fit some plumbing to take that drain back into the tank. Then while I was making a mess, I replaced the Rocol oil with soluble cutting oil. And that was a big surprise!

With the Rocol oil, cutting a 140 x 100 piece of aluminium took 16 minutes ( 8TPI blade). With Soluble oil it took 11 minutes!

A tip for bandsaw users - cut a 40mm square of 10 or 12mm thick rubber - the canvas re-enforced stuff ( conveyor belting) . Then with a hacksaw cut a slit 2/3 down the center. slip that over the blade at the lower guide and it stops all the swarf from going into the drive wheels, and places where it's hard to clean out..

The onto the ATC main body machining - this was done in the 4-Jaw and was a little daunting. The chuck is 200mm OD. The block is 110x110x130 with 2 'ears' ( mounting feet) protruding 30mm from the base end.

I could not swing it faster than 380-400rpm without the lathe starting to shake..The hole bored is all of 90mm deep, 95mm OD at the mouth with a tapered section as lead in for a pneumatic seal, then reducing to a 90mm hole.

The bore completed.

As the inner diameter grew, the surface speed approached what it should be for my DOC and feed rate, and these long snakes came off ( rather than the initial ugly stringy stuff..) Some of these are nearly 4 meters long! The snake would start and go down tween the lathe bed, out the bottom and down towards the floor, and every now and then one would lathe onto my socks and start twitching and wrapping around my ankle, while I am concentrating on stopping the autofeed just in time...

Now busy with the ATC main shaft, preload nut, pneumatic piston, bushes, etc, etc..

And trying to get up the courage to CNC mill the Hirth coupler...Maybe I will do one in PVC to see how it works.

Joe

Noted Paul - I know Underberg - A beautiful area! Away from all the rest of the nonsense...

Just pulling your leg re tooling Paul. I do find it becoming more and more difficult to get tooling in SA as well - the suppliers are catering more and more for the big CNC guys and not interested in the benchtop machine stuff - There are places like Ardendorfs, etc, but milling cutters made from mild steel are'nt impressive...

Take care Paul, and do post what you are up to!

Joe

Well, I tried that site - read through each of the 8 sections. All I discovered is that you need to be a rocket scientist to understand any of that!

Those that suggested a LM NLGI2 grease have it - I have just packed the bearings and re-fitted them. The bearing showed no signs of heating at all - they just looked ok..so after 17 years with the same grease in them - they did fine!

Joe

Now that the new spindle is 'done', I get to continue with the Toolchanger.

As usual, materials are a problem for me - I needed a big block of aluminium for the toolchanger main body - the body is 120mmx110mmx100mm deep, with mounting feet protruding 30mm either side at the base. The only material I could get was a 200mm diameter x 140mm slice of Aluminium bar!

So, into the bandsaw for the better part of the morning...

First 40mm of the length...

Then the base...

And so on...

Leaving the puzzle...

I cut around 3mm oversize as the saw does not cut that straight when abused this way..and so into the shaper to get the block to final size.

The Final Cut to do...

Next I have to bore out a 90mm diameter hole, 90mm deep in the one side....Hopefully in the lathe with the 4 jaw.

Also machined the blanks for the Hirth coupling - made 3 as I will probably mess one up..These are 100mm OD , 10mm thick EN3

Joe

Edited By Joseph Noci 1 on 19/06/2021 21:50:50

Further progress in the CNC Lathe - New Spindle

As mentioned before, the current headstock/spindle arrangement , although good for rigidity with zero collet chuck overhang, is a problem for the tool changer - boring bars and drills with crash with the headstock when turning conventionally.

So I decided to remake the main spindle, with a backplate to fit a small 4inch 5C collet chuck. The ATC tool plate is now designed to have the long axial tool clear the chuck diameter.

The spindle at bottom is the old short one. The backplate is seen not yet fitted.

Backplate below, before drilling and fitting to spindle.

Backplate drilled , tapped and fitted to spindle. The 4 peripheral M8 holes are for grub screws to adjust the 5C chuck to run true when required. The 3 holes between spindle and backplate are to lock the backplate in place, with 3x M6 grubscrews, and locktite on the spindle/backplate interface and grubscrews.

The 5C chuck - BISON

Spindle assembly done.

Headstock assembled - backplate runout axially and radially is around 0.008 max - will true it up on the lathe itself.

Generally true, but it would depend on the type and size of the milling machine and Shaper... William does not specify which Tom Senior - digging on Google, there seems to be a few variants? - the M1 might move metal faster than most shapers, but I am not even sure of that, if referenced to say an ALBA 2S or Elliot 14M shaper, both types in a number of hobby shops... The Senior E type certainly will not...

My ALBA 2S can take slice a chip of cross section 3x1.5mm in mild steel without burping. And it will do that over a 300mm length in a few seconds- No way I can do that on my bench top mill..I don't agree about it being difficult to find an edge on the workpiece - very easy - use a sliver of the proverbial fag paper and wind the cross slide up to the cutter till the paper is snagged - many folk do that on the mill!

Also, the cutters for the shapers are much easier to make and much cheaper than endmills of big-cut capability. And easy to sharpen. And you can even use them in the lathe..

I would not be without my Shaper if I can help it!  But, I could not do without my benchtop mill either!.

I think there is a balance - if you can afford a big mill with heft capability, you can probably afford the cost of tooling it - collets, cutters ( HSS, Carbide, ) etc then a Shaper is moot. But if you can't, a shaper is an inexpensive solution to hogging metal in preparation for finer work on the small mill.

And since DRO's are mentioned - if you fit a DRO to the shaper, you will be amazed at how accurate you can work.

Joe

Edited By Joseph Noci 1 on 19/06/2021 10:43:54

Thank you.

Both BNS and LM are very common here, in 500gram tubs. It seems very difficult to find definitive usage specifications for these greases though - the Castrol datasheet is so sparse its not worth the two sheets of Epaper its printed on!

The BNS grease has Bentonite in it, which raises it operating temp, but they indicate nothing wrt bearing speeds, etc. All these data sheets refer to wheel bearing use, which is very low speed..Ditto the LM greases.

All the 'Pro' greases relate performance to the bearing DN ratio , or Ndm ratio, normalising bearing speeds, but these Castrol greases glaringly omit any such info.

Maybe I should cease my pedantism and stuff the grease in and get on with it!

Thanks Chaps!

Joe

I have a Milling head that comprises two taper roller bearings - ID 1.8inch / OD 3.5inch. The spindle was last re-packed with grease some 17 years ago by its then owner. I have used the mill expensively since then and it has behaved well.

Of late it sounds a little noisy, so I stripped the spindle down, and found the grease needs replacing. I have cleaned all and the bearings still look good. Problem is what grease should I use? The head is an old British make, no handbook or manuals, and the previous owner is no more...

The spindle has often worked at speeds up to 3000rpm with mild heating.

I have looked at similar spindles and the grease they seem to use, but most are esoteric and available only in first world places...

Common to me is Castrol greases, but limited varieties - NLGI-2 seems is what is needed, which I can obtains, but BNS - a bentonite clay based grease, an MS grease - a lithium soap grease with Molybdenum Disulphide and and LM grease - a general purpose Lithium soap grease...I suspect these are all typical automotive type greases - for wheel bearings, and bonnet hinges..

Any ideas?

Joe

George, PM me with your email and I will mail it to you - same to anyone interested - If serious though, you would need the schematics, etc as well, which I can provide in an email.

Sure Duncan will help too.

Joe

Absolutely - cooking with gas is just that - cooking with gas - no BBQ involved..And we won't even mention the induction hob - that's just the kitchen outdoors..

And this....! 'Ask an Aussie friend ! N o -one knows more about BBQ,s than they do !!'

They stole the idea from we South Africans! We invented it more than a million years ago!

The First Braai...

( and if you really have no choice - use a COBB..

The COBB Braai.

Edited By Joseph Noci 1 on 17/06/2021 06:57:59

Hello Paul.

I'm in Swakopmund, Namibia - the one and only 'Model Engineer' in the land...Originally from Johannesburg, been here near on 15 years now. Where are you located? - Coastal I presume...Near any tool shops you can get stuff from for me???

Welcome and join in the fray...

Joe

Edited By Joseph Noci 1 on 15/06/2021 21:31:17

Say that quickly, without thinking and somehow the f and t really want to swap...

(sorry..)

Thanks again for your ideas and input. Will spend a bit more time and effort modelling different approaches before committing to cutting I think. The concept is OK but machining capability is a real constraint.

Thank you.

Joe

Thanks Ross.

Not sure what diameter your piston is - mine is 90mm, with 24mm lost in the center bush area, so around 9 square inches which @ 120psi is around 4800N - to mix a few units...

I have no idea how to integrate losses, friction, etc into this, but I am content to go to 120 psi (8.2bar).

I played around extensively with the evaluation tool you linked to - the one you used to create the data sets in your post above. I would have liked to go for 8 springs, maybe more, but the housing length becomes an issue for me to machine - I would really like to machine the housing interior in the lathe with the 4Jaw, rather than on my small mill with the boring head - that is excruciating in focus and concentration, and very slow to get the pneumatic seal finish required..

A lengthened housing in the 4jaw scares me though - the housing is quite large - 140x130x95mm deep -5 more springs adds another 15mm or so to the depth- we will see - need to model a bit more!

I have reduced the Hirth engagement to 4mm, expecting a 4.5 to 5mm extend for the teeth to clear. I kept the tooth angle at 60deg - steeper would allow reduction of preload forces as you say, but I worry as to how steep - when does it become a 'taper-lock' with corresponding big force needed to break the lock?

When you say 8bar is 'safe useable' - what do you mean? I have a 2KW 2 cylinder compressor that seems very comfortable at 10bar. The pneumatic solenoids I have (Festo) for air control give limiting pressures of 15bar. Am I missing something here?

Joe

Edited By Joseph Noci 1 on 10/06/2021 08:36:11

Hellp Ross.

Thanks very much for some very constructive criticism and very good points!

I have adapted the design concept accordingly..

The Bellevilles are 70mm OD, 25.5mm ID, 2mm wall, 4.5mm height Qty - 5. That gives a height of 22.5mm.

At 2000N preload, they are compressed to 20mm ( lower half of image below)

At 4200N they are compressed to 15mm ( upper image half ) with a 5mm extend., ie , a 68% crush.

Use of odd numbers of Belleville spring is OK, if always in series, ie, each one inverted in relation to its mate - if you nest them, they can still be odd numbered, but each must have a nested mate...

Clearances have been adjusted all round to eliminate over-constrained contact.

A much larger diameter thrust bearing fitted behind the piston to prevent canting. Piston also impinges on spacer -8- when pressurised, as end limit stop.

The pre-load nut -4- now has a lock nut -5-.

Assembly and operation ( as I see it..)

Toolplate -1- and shaft -1b- are threaded and locktite bonded. Hirth coupler -1a- is then fitted to -1- : it centers snugly on shaft -1b-.

Face -2a- is bolted to housing -7-, then brass bush -2b- and -7a- are locktite'ed in place, using shaft -1b- as alignment guide.

A lathe cutting tool is fitted into the toolplate.

Shaft assy -1,1a,1b- is extracted and Hirth coupling 2 is mated with mate -1a-. Housing -7- then fitted to lathe cross slide, locktite applied to Hirth -2- to housing -2a- face and the shaft assy inserted into the bushes.

The cutting tool is aligned with lathe center height, and the shaft assy slid to mate -2- to -2a- and kept in place till locktite cures. Shaft assy removed, then holes drilled and tapped into -2a- to bolt down Hirth -2- to housing -2a-.

-2a- unbolted from main housing.

Shaft re-inserted, Bellevilles fitted, thrust bearing Y fitted, and lock nut 4 tightened till Bellevilles are compressed to 20mm. Locknut fitted -5-. Piston assy -6a / 6- fitted into housing -7-. Cylindrical spacer -8- fitted in housing -7-.

Thrust bearing X fitted over locknut -5-.

Assy -1,1a,1b- , -2,2a- , -3- , -4,5- and thrust beearings are now slipped into the housing -7-, into bush -7a-.

-2a- then bolted onto housing -7-..

ETC....

Seems such a waste of time, removing all that solid material from the innards of housing -7-, and then refilling it with odd shaped pieces of material again...

Joe

Looks more like a web than a single tube Ron.

Joe

I re-furbished an Alba 14M - same as yours - Arrived at home with it on the back of a Landcruiser LDV - thought I would take it down with my engine hoist...Way to high - the hoist is very unhappy lifting the shaper while on the ground with the hoist arm extended to max, and max would not reach the shaper top while on the LDV...rented a small forklift and driver.

Joe

About 16 years ago I converted my EMCO FB2 to CNC , using MACH2 and a parallel port equipped windows PC - XP then..

XP is no longer viable, and nor are PC's with parallel ports..I still have 2, one running Windows 2000 (!) and one XP, both run MACH2 fine and are used for my CNC router table, but both have 'issues'...

I used The XP PC for the FB2 as well. Since I have another side project - the small CNC Lathe, controlled with Linuxcnc and MESA I/O cards, I though to convert the mill to Linuxcnc as well. However, after the many hoops I jumped through to get the lathe doing small things, I decided to stick with MACH2 and purchased an ethernet controller for the machine.

This proved to be painless, installed very easily, interfaced to MACH2 and comes with the designers Software that is very similar to MACH2 and also works very well.

The Module I settled on is the AXBB-E ( E for ethernet from CNCDrive.com) and it provides a lot o built-in buffered I/O, some isolated discretes, Pot inputs for spindle speed and axis feed override, analogue outputs for VFD spindle speed control, etc.

**LINK**

The manuals are quite decent, and installation was very smooth.

So far it performs as advertised and I am happy..

While doing the upgrade, I also changed the steppers to Clearpath closed loop steppers - the steppers I had on the machine were STEBBON, a British make, and a flop, I fear...The business end bearing OD was about 0.6mm less than the ( very roughly) machine cavity in the motor bell-end, and the bearing was 'glued' in - two of the motors bearings shifted slightly, and the rotors would sieze against the stator...

I also made 'heavy duty' swarf covers for the machine as it has to do a lot of EN1 and EN3 machining on my CNC lathe projects, and It will do so under full pressurised coolant flow - more to keep swarf out of the cutting edges..

And lastly, I added a counterweight for the head - Head is 22kg sans tooling, so I added a 19kg counterweight - which works very nicely!

The AXBB card in the control head

Wiring....

All wired..

Counterweight Pully

Counterweight below the swarf tray.

The X axis Clearpath servo

Swarfguards in place

Front flip away swarf guard in place

Now to find a powerful suds pumps..

Joe

Edited By Joseph Noci 1 on 06/06/2021 17:30:08