They would have been available until end of production because of the American marketDoesnt look old enough to be an imperial machine.
I’d much rather have the English measurements. I can’t work in metric, I just can’t get my head round it. I know thou, tenths, and most of the common fractions off the top of my head (or can work it out in my head).Hence the test cuts now spent far too much on it to just throw it together and call it OK.
DRO kit will be ordered tomorrow. I was holding off on it until I at least got it back together. Imperial dials when trying to make metric parts is the worst! 1mm = 39 thou is easy... "need to take off 0.65mm diameter = 0.35mm DOC equals... erm... about 13 thou?" makes my head hurt, and I WILL make mistakes
It even has a sticker that says "ISO metric" on it... But the dials are imperial, the change wheels are for an imperial leadscrew, and when I tested it on a known pitch it followed it so maybe it was converted. Who knows, it's probably older than it looks anyways... they've made the M400 for donkeys years.Doesnt look old enough to be an imperial machine.
I can think in thou for clearance... journal bearings and end float, etc, all from shop fitting. My DTI is imperial for that reason - it makes sense in my head. But that's as far as it goes I work in metric mostly, and my mics are all metric for that reason. I suppose I'll start buying some more instruments soon anyways.I’d much rather have the English measurements. I can’t work in metric, I just can’t get my head round it. I know thou, tenths, and most of the common fractions off the top of my head (or can work it out in my head).
I tend to use a 0.5” micrometer on the carriage or the cross slide now if I need something spot on.
then again most of the stuff I make parts for is old so is going to be imperial.
Digital. Then you can flick between. My quantumike has been a revelationIt even has a sticker that says "ISO metric" on it... But the dials are imperial, the change wheels are for an imperial leadscrew, and when I tested it on a known pitch it followed it so maybe it was converted. Who knows, it's probably older than it looks anyways... they've made the M400 for donkeys years.
I can think in thou for clearance... journal bearings and end float, etc, all from shop fitting. My DTI is imperial for that reason - it makes sense in my head. But that's as far as it goes I work in metric mostly, and my mics are all metric for that reason. I suppose I'll start buying some more instruments soon anyways.
It would be nice... but the price and I'm not sure about cheaper digitals...Digital. Then you can flick between. My quantumike has been a revelation
I fitted Mag strip to the M300 C/slide. You only need a bit. Doesnt go anywhere near the tailstock. Only problen is swarf If not covered. I'll do the same as on the TS and fit it to the underneath later this yr.If you have not yet ordered the DRO, perhaps have a little look at availability of dual dials for the machine. Nobilla Machine Tools might be a good place to start. Another option for long-travel is a Trav-a-dial (but they are not easy to find either).
I am not a big fan of DROs on a lathe: too much compromise on making them fit. The cross-slide one always seems to get in the way of the tailstock and the longitudinal one prevents use of a taper turning attachment or hydraulic copier.
The best I have seen is someone mounting a magnetic one under the cross slide. On a different machine I have seen a slimline Newall sphereosyn (maybe it was microsyn) on the back, co-existing with a taper attachment.
That’s how I do themIf its going to rob too much distance from the tailstock movement. The cross slide scale could be mounted to project into the splash tray, there's plenty of room And well out the way
Run the clock along the test pieceI got an hour or so at it last night.
Changed tools, and took out the centre of the test bar down 5mm or so. Started to get a nicer finish with more speed and bigger DOC.
Now bear in mind, when I went crazy buying used tools and a load of inserts on ebay a while back, I knew nothing about ISO insert codes. I was just looking at the tool shape and making sure I could get replacement inserts,
The CNMG inserts I started with really don't like shallow cuts or low speeds, I understand now that they are a proper roughing insert, but the TNMG inserts seem much better, sharper edge and smaller radius.
Nothing to do with the insert shape code, just luck of the draw that I ended up with roughing CNMGs that hate small cuts
Now I'm starting to see what effect the built-up edge has on carbide at low speed/load... and what sort of inserts are better for what. Learning the ISO insert codes the hard way
I've ordered some CNMG finishing inserts for that tool, it's a general purpose left handed turning/facing tool and I ended up with two of them, so may as well leave one dedicated for light finishing.
It's maybe worth its own thread, the discussion of which carbide inserts are best for light cuts and finishing. I'm not interested in "should use HSS" comments, btw.
I then put my small boring bar in, it has some crazy sharp carbide Taegutec finishing inserts to go with it. Used this for the test shoulders.
500rpm, 2 thou DOC, 2 thou feed. Spring cut after first cut. Using my good mitutoyo mic and estimating the 0.00X.
First few cuts - much the same as before - 0.040mm big at free end.
Jacked up front right corner of lathe.
Next few cuts - 0.018mm big. Goes to show... short and stout lathes still can twist
I'm going to talk to Brian and see what he would suggest, as I don't want twist in the bed. Will involve doing something very minute with the headstock probably. Even slackening the bolts, whacking with a hammer and re-seating it might make enough difference.
Fair playRun the clock along the test piece
If zero deviation then indeed the headstock is out
If the clock agrees with the micrometer readings then maybe some bearing play or chuck is allowing slight movement
Return your bed to levelFair play
My only clock isn't sensitive enough though... it would have to show in tenths and it only shows thous. Might have to buy that lever indicator sooner than later.
Plus it halved my error when I jacked up the corner? Or maybe that's over-compensating for the spindle.
The taper is very consistent, though. It shows pretty much the same on the relieved areas where I took much deeper cuts.