Author Topic: Finally getting my Tool & Cutter grinder going.  (Read 3398 times)

Offline arnoldb

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Finally getting my Tool & Cutter grinder going.
« on: August 16, 2014, 09:50:31 PM »
My Whotsit's been languishing unused for more than a year now.  The shop got sorted out, and the Corliss is finished, so it was high time to get this girl in operation.

Last weekend I stripped, cleaned and re-assembled everything on the machine, adding oil and grease where the instruction manual indicated.  Sorry; no photos.  It's collected quite a bit of surface rust while in storage, but it's no biggy; the linear ball bearings on the X axis and the dovetail on the Y axis are pristine - with no discernible wear at all.  From it's manufacturing date, this machine is 20 years old, but it's definitely not seen a lot of use.

This morning I nipped out to the shops.  At one I got a cut-price magnetic base - they had one in stock where "a couple of bits were missing", so nobody wanted to buy it.  Turned out, the missing bit was the DI clamping mount.  That suits me, as I'll anyway make my own; the adjusting bits that come with the cheap magnetic bases are really crap and it's easy to make one's own ones.  The base and a DI will be used to do set-ups on the TCG.  The other shop supplied a handful of M8 Rawl plugs - needed to mount the phase converter box.  A little later, with some holes drilled in the wall, everything was mounted and the machine ready to go:


The TCG came with a nice selection of grinding wheels - most of them good quality Norton brand.  Seeing as I'd never used a machine like this in my life, I didn't fancy stuffing up one of those, so I dug around the selection and found an Asian made aluminium oxide cup wheel to start testing things with.  After a thorough inspection of the wheel - both visually and with a "ring" test, I mounted it.

Next I did the "unthinkable" - I read a manual.  The phase converter's manual.  That hurt my head; it seems to have been (badly) translated from Italian, but eventually I got the gist of it, and went through the settings on the unit.  Everything appeared in order, and the phase converter does one very nice thing; it can employ dynamic braking on the motor.  Without any electrics connected to the motor, a finger-flick of the spindle without a grinding wheel mounted would leave it rotating for quite a while, so I was dreading waiting for it to spin down from 3600RPM to a stop with a largish wheel mounted...  Anyway, as it turned out, the phase converter's manual clearly states that no switching should be done between it and the motor, so the machine's own Forward-Off-Reverse switch was set to "Forward", and from now on I'll use the phase converter's own Fwd-Off-Rev switch to control the TCG.

I started the motor, and was totally surprised - bordering on completely amazed.  I've gotten used to the sound of single phase motors running, and even the variable-speed DC motor on my small lathe hums, but this motor is quiet...  There's a barely audible high-frequency whine; I'm assuming that's caused by the phase converter.  The only other sounds are wind-noise.  One from the fan in the phase converter control box, and the other from the grinder motor producing quite a bit of its own air flow - towards the spindle nose.  This is a very good thing; it means the motor blows grinding dust away from itself while in operation  8)

As my "new girl" appeared ready and willing, I thought I'd proposition with a diamond to dress her wheel up. The method and tactics of proposal required a bit of research, but it appears that a suitably down-looking 85o while proposing appear to yield best results.  So I made up a little welded-together-from-flatbar jig to help with that:


The jig is bolted to the top of the air spindle to dress the grinding wheel with the diamond:


It worked a treat:


Emboldened by that bit, I set about face-sharpening a 16mm 2-flute slot mill that I killed a couple of years ago while milling in the lathe before I even had a milling machine:


Came out OK - for a first go - it's nice and sharp on the face, but the flutes now needs addressing - something to try tomorrow:


All-in-all, if I said I'm happy with things so far, that would be an under-statement.  Actually I'm over the moon - this TCG is a seriously nice bit of kit, and I'm looking forward to get to know her a lot better  ;D

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline steamer

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #1 on: August 16, 2014, 10:06:48 PM »
That looks awesome Arnold!     Gotta get my Gorton going
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Offline arnoldb

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #2 on: August 24, 2014, 08:13:50 PM »
Dave, I'm thoroughly enjoying this machine - I have a hunch I'm going to use it quite a bit!

I've played around a bit more with the TCG - just trying to get its "feel", which is completely different to that of a lathe or mill.  It's important to keep in mind that this machine is intended to remove very small amounts of material at a time, but it's controls are all made to suit that.  Making adjustments down to 0.01mm is very easy, and with a bit of care, it's easy to adjust things down to roughly 0.0025mm - though I have difficulty measuring this as all my measuring instruments go down to just 0.01mm...

One problem I have is that the selection of C5 collets that came with the machine are missing some sizes that I'll often use, and unfortunately some of the ones there at some point picked up quite a bit of rust, so I'm not sure how accurate those will be any more...

Joe kindly offered to make up a shared package for some stuff he'll be getting from LMS or ArcEuro to split shipping costs to Namibia, but after totaling the collet prices and compensating for international currency exchange rates, my Home Ministry of Finance (HMoF) determined that, even with the potential saving on shipping, sufficient funds are not available in the current financial budget for this capital expense  :rant:

So I decided I'll do what I always do if funds are short - make a plan.  Just over a year-and-a-half ago, I managed to smuggle a set of "closer tolerance" ER25 collets past the HMoF, and I'm quite happy with those.  Not as good as the stuff the guys States-side get, but a lot better than the even cheaper ones I already had.  So, the plan for now consists of making a 5C to ER25 collet adapter for use on the TCG.

A bit of research on the Interwebs turned up the dimensions for the 5C collets - though I must say there are a lot of contradicting sizes and dimensions.  So I "averaged" those to get an approximation.  The ER25 side was less of a challenge; I've made ER25 chucks for both my lathe and mill, and both seem to work OK, so I just used the same dimensions.  With all the information at hand, I took the extraordinary step of drawing the adapter up in CAD - converting all the Imperial sizes on the 5C side to Metric:


I already had a bit of stock to make the adapter from - visible in the photo above - a section of 40mm diameter EN8 steel.  Not ideal - this steel is quite difficult to machine to a good finish, but that's what I have, so it's what I'll use.  It was shortened a bit on the bandsaw to minimise wastage, and clocked up in the 4-jaw chuck:


A bit of green Scotch-Brite worked a treat to clean off the surface rust on the circumference at the outer end and smooth it over , then I used the fixed steady to stabilize the end and faced it off:

This is a fairly long workpiece, so I deemed it necessary to add the steady as additional support.  After the above photo, I also center-drilled the end of the workpiece (this might be needed later).

Then I reversed the workpiece - leaving it sticking out further from the chuck than before, and clocked it up again.  The brightened bit at the end from the last operation on the section where the steady ran made it easy to do it dead-nuts - with barely a flicker showing on the dial indicator.  The rest of the rust on the workpiece was removed with Scotch-Brite, the fixed steady installed again, and the other end center drilled:


With that done, I could remove the steady and bring up tailstock support with the revolving center.  The workpiece was roughly turned down its entire length to the dimension of the C5 head section(36.9mm), then the end turned down to 32mm for 18mm long, and a 4mm wide x 3mm deep thread run-out groove machined in with the rear parting tool:


A section behind where the 5C taper would be was turned down to 31mm - this is not on the plans, but all the 5C collets I have, have the narrower section behind the taper, and would make turning the taper a bit easier.  There's a section next to the threads that forms a register and must be accurate.  Here I've turned down most of the workpiece to the register size:


Rats... that section should have been 31.74mm - I took it a bit far and ended up at about 31.735mm:

I hope that will be OK - only time will tell.

I turned the taper on the nose by setting the Myford's top slide to 10o - I've found it's markings to be very accurate.  Just an overview of progress thus far - that's where my shop session ended for Saturday:


Today's shop session saw one of my favourite lathe operations - single point threading.  For the 5C side of the adapter, I added two run-out grooves - the one closest to the chuck is also where the adapter will be parted off later:


Both the threads needed are 60o form - the 5C end at an outer diameter of 31.54mm x 20 TPI, and the ER side 32mm x 1.5mm.  To thread up to the 5C taper nose on the ER side, I needed to grind up a tool that would give adequate clearance.  Easy-Peasy from a bit of 4.7mm HSS - which I then carefully honed till it was sharp enough to cleanly cut paper:


One of the rules of thumb for good thread-cutting (or turning in general for that matter), is that the toolbit should extend as little as possible from the toolpost - of course this depends on the thickness of the toolbit and other factors.  In this case, I needed to have the toolbit extend quite a way out of the toolpost - simply for the top slide and toolpost to clear the tailstock on the ER side of the workpiece, as well as to clear the 5C "nose" while turning the threads on the 5C side of the workpiece.  And the toolbit I made up is quite thin, so I added another HSS tool blank below it to give additional support - visible here while I was setting the correct height:


Normally one would use the gauge (sometimes called fishtail) shown in the photo just above the last to set the tool square to the workpiece, but this is a bit fiddly sometimes, and as I'm a lazy rotter, it's easier to make sure the toolbit's tip is ground correctly relative to the length of the toolbit, and then it's a simple matter of using a square to set the tool:


On to setting the lathe's leadscrew gearing for 1.5mm pitch.  I paused and snapped a shot showing how I use a bit of paper to set the gear spacing on the banjo - boring, but the photo's there:


I've cut a handful or so of threads - there's one step I never skip, and that's to double-check the pitch after a very thin pass - here I'm checking the 32x1.5mm thread:


From the above operation, I also took the dial reading for the cross-slide - (86 thou), but I'd already used a thou for the pass, so 85 thou.  A quick calculation gave the infeed needed for full depth of cut at 1.299mm - make that 1.3mm - and that is 51 thou, so final depth of cut would be at 137 (well, 37 as I'll pass zero on the handwheel).  After a bunch of passes (lots of cutting fluid) - with decreasing depths of cut toward the end, the magic of the thread appearing happened.  The last pass took just the minutest bit of swarf off visible on the toolbit:

Metric tread on an imperial lathe - so I had to keep the leadscrew engaged...  I found a nice cheat way to reverse things though; I always screw-cut in back gear, and on the Myford it's possible to disengage back gear which leaves the chuck free from the motor drive, but the spindle remains engaged to the leadscrew geartrain.  So it's easy to just turn the chuck by hand to reverse the lot.  My lathe's motor doesn't like to be switched on and off all the time, and with the clutch, I leave it running forward pretty much all of the time while machining.

Couldn't resist a test  ;D:


The gearing for the 20TPI thread was much simpler than for the 1.5mm pitch:


I could use the thread indicator and disengage and re-engage the leadscrew for the 20 TPI thread.  Made it double-quick to do  ;D:


Out with the fixed steady again - the section behind the 5C taper was ideal for this - and some deep-hole drilling commenced:


So close, yet so far; I wanted to finish this workpiece this weekend, but had to stop.  There's some more drilling needed, and the 8o ER taper bored before parting off...

Kind regards, Arnold

« Last Edit: August 24, 2014, 08:19:48 PM by arnoldb »
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline arnoldb

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #3 on: August 30, 2014, 07:18:37 PM »
 :) Had some play-time today after a seriously hectic work week.

First I bored the 8o taper for the ER collet:


Then (very messily) parted the adapter off - catching it on a length of brass rod held in the tailstock chuck:


As I'd turned the 5C side threads without being able to test them, the first thing I did was to check that the adapter screws into the 5C drawbar.   :cartwheel: Slightly loose, but a better fit than the actual 5C collets I have:


On to the keyway - I wish I had some proper keyway cutters or a wide enough slitting saw, but no - I had to mill it out with a 3mm mill.  As I didn't have 3mm slot mills, I had to make do with a 3mm end mill - and here's the result of what happens with just a bit too much chip build-up around the end mill - and maybe an over-aggressive feed rate:

 :-\ - Oh well - broken cutters happen to the most experienced machinists in the best of shops - so it's a thousand times more likely to happen to me.  Fortunately I have a couple more 3mm end mills in stock...

Eventually I managed to finish milling the slot - and the adapter was done.  I'm rather pleased with how it turned out:




It fits the air spindle quite well too:


A quick run-out check - maximum:


And minimum:

0.01mm or about half a thou - I'm happy with that.

Had to test it out.  I have a nice 3-flute 20mm end mill that I'd trashed on some unknown steel - so I set about sharpening it up:

After some flute grinding:


That may look good, but does it actually "cut it" ? - I tested on some hot-rolled steel:

 :whoohoo:  Nice big chips and a smooth finish; I couldn't be happier.

As I'd also sharpened the end of the mill, I thought I'd try that out too - a "just-under-20mm" slot 1.5mm deep in one pass at a high feed-rate:

It cut like a dream - though the surface finish at the bottom's not great...  That should improve with a lower feed rate, but I'm satisfied for now.

Enough messing around with tooling now; the TCG's running, and I still have a lot to learn using it, but it's high time I built an engine.  Don't know what yet; I'll sleep on that.

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline Jo

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #4 on: August 30, 2014, 07:22:23 PM »
 8) Good stuff

Now about your next engine, have you ever considered castings  :mischief:

Jo
Usus est optimum magister

Offline Roger B

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #5 on: August 30, 2014, 07:36:18 PM »
That's a nice looking machine and some good results  :ThumbsUp:  :ThumbsUp: All I need is a bit more (about double) the space to add all the good things I see on the forum.
Best regards

Roger

Offline steamer

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #6 on: August 30, 2014, 09:07:21 PM »
Nice!.....Need to make a spindle for my Gorton.....it's on the list!.... :facepalm:
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline arnoldb

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #7 on: August 31, 2014, 12:57:49 PM »
Thanks Jo.  I've been longingly looking at castings, but by the time I can get them delivered here from the small handful of suppliers that are actually prepared to ship to Namibia, the costs double...  One day maybe, but unfortunately not soon  :(

Roger, thanks  :) - I'm fortunate to have a bit of space, and if it were not for some "odd" circumstances, I'd never have gotten hold of this machine...  Then I'd most likely have done what Kim's doing now, and made attachments to use with my bench grinder.  I still need some more tools though - there's a spot pretty much reserved for a larger-than-myford lathe, and if I can get my grubby paws on a shaper I'll be over the moon.

Thanks Dave - I know what you mean about that list...  It never gets shorter  :LittleDevil:

Kind regards, Arnold
Building an engine takes Patience, Planning, Preparation and Machining.
Procrastination is nearly the same, but it precludes machining.
Thus, an engine will only be built once the procrastination stops and the machining begins!

Offline Jo

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Re: Finally getting my Tool & Cutter grinder going.
« Reply #8 on: August 31, 2014, 02:17:11 PM »
I've been longingly looking at castings, but by the time I can get them delivered here from the small handful of suppliers that are actually prepared to ship to Namibia, the costs double...  One day maybe, but unfortunately not soon  :(

 :headscratch: Are they anti Africa as a delivery location? We seem to have no problem getting castings from the other side of the pond. Normally they are cheaper  ;D from over there 

Jo
Usus est optimum magister