tabetha

Despite being the worlds worst machinist on my lathe I'm still trying, I want to do more adventurous things with the lathe, so was wondering what other parts to get, would appreciate views on the following please,
revolving centre(already have fixed) why is one used over the other ?
fixed and moving steady, why one over the other ?, assume these are to support long parts.
4 jaw chuck, is it just for different shape parts or is there some other advantage ?
face plate
digital speed display, how critical is the speed, I seem to find a speed at which cutting seems much easier so assume this is correct ?, can you tell anything by the nature of the swarf coming off the part being machined ?
I'm getting a quick change tool post as setting the height is a pita and fiddly.
Have just spent 6-7 hours cleaning the lathe a 7 X 12, every garage should have one so useful.
I normally machine delrin, alloy, brass and mild, try to avoid SS as my cutters don't like it!!
What is the best cutting fluid, currently using the stuff I bought with it at machine mart, it's a CL300M lathe if any use to know.
thanks
tabetha

155lee

iTrader: (10)

my pals old man had a brilliant conversion on his lathe.a yamaha 350 lc gearbox for different speeds and an old ice cream tub cut to shape to cover all the belts.was an awesome fred in the shed bit of kit and he was always knocking up things on it.as for the original question i dont know anything about else lathes!

timster

Tabbs,a revolving centre allows higher speeds i.e. if you're cutting small diameters or certain materials and requires no lubrication to run.A steady is for long parts and to support components a moving one from what i can remember allows the diameter to be turned with the steady following behind.4 jaw chuck allows you to clock things up true,if you have a concentricity tolerance or want a bore to run accurate to the diameter,far superior to a three jaw chuck.Wouldn't bother with a digital speed display might be worth getting a D.R.O.(digital read out).It's so much easier for turning as you can touch on,measure diameter and put this figure into the dro.Material dependant it should come off in curls(aluminium for example) but can usually tell by sound which will come with experience.Speed wise there's a formula you can use which uses cutting speeds of the material which should be available online.I'll have a look around now for you

tabetha

Hi, ace timster thanks for the info, I notice that I can set the auto feed thingy pushing lever down and pull off the swarf on aluminum as it comes off in spirals, can get these up to about 2 feet long before they break, must make a higher bench for the lathe and pillar drill, but today me bloody compressor started knocking, can't moan it's around 16-18 years old SIP, never had a oil change, was Ł130, hope it's something silly to fix, need me money to buy me new gloss black wheels to show off me 6 pot BUBBLE GUM PINK tarox calipers!!
tabetha

tabetha

I thought you were going to say 350 LC motor, be a bit more than my 300watts!!
tabetha

vaughant

iTrader: (1)

Get yourself a "zeuss" book fella,only about Ł3 in book shops,eBay etc,gives you loads of info about speeds and feeds etc,conversions,drill sizes for tapping,machine sizing got die cutting,best investment for any machinist.

Lathes are a bit like welding,practice makes perfect.grab an old miller now and you'll be able to fab near enough anything!!!!

I used to love making gearknobs on the lathe on my apprenticeship then buffing fuck out of them with microfine paper,mirror finish then with brasso!!!!

Get a bollocking then for putting your hand in with a rag on the lathe!!don't leave the chuck key in either,3 strikes and out rule on my apprenticeship for that!!!!

I've got a real of microfibre tape I'm unlikely to use if you want it sent,be about Ł2 postage?

timster

Been looking for a booklet that i had given to me by my old college lecturer,presto cutting tools its got some good info in there which would be valuable to you.Have a look at this link

http://wapedia.mobi/en/Speeds_and_feeds

About halfway down the page there's a chart for cutting speeds,this is how you work it out


Mild Steel(e.g.)

diameter of material(50mm) x pi(3.142)=157.1
Cutting speed of material(100)x1000=100000


So, you then do this 100000 divided by 157.1 and you should get 636RPM this is a good benchmark to start,dependant on insert wear,condition of machine etc.Doesn't have to be that exact speed just some where near.I would personally go a bit faster than that figure.We use a company called braemar in work for coolant think they're from sheffield way,hope thats of some use to you tabetha.Can't remember what the 1000 figure is for think its surface area or distance,been a while since i've done it!

p.cressie

I'm a cnc miller by trade so not the best on a manual lathe. I've just warped my brake discs and I'm going to skim them this week, is it just a case of skimming both faces ( obviously not removing the disc in until I've done both faces) or do I have to skim the face that sits on the hub. Sorry for hijackin your thread

timster

Does it state a minimum thickness on the disc on the outside edge?If it doesn't I personally wouldn't skim them.if it does you ned to make sure the face that sits against the hub is running true.If you're not sure ask someone to skim them for you

dannyblackpool

Ive just bought one of these as need a lathe, wasnt intending buyin one so big, but need one with some grunt and im only paying Ł500 for it including lots of tooling.

Never even turned one on before.................... GOD HELP ME!!

focusv8

There's only one rule to using a lathe if you haven't used one before;











DON'T LEAVE THE F*CKING CHUCK KEY IN THE CHUCK.





IN CASE YOU MISSED THAT;





DON'T LEAVE

THE F*CKING CHUCK KEY

IN THE CHUCK

And when you have done and decide to put the key on a chain,

USE A F*CKING BIG CHAIN

.

wirralphil

Set the feed to a higher speed so the swarf chips off (thats if your using carbide tip tools)

Zeus book is the 1st thing an engineer should buy imo.

alanfordtw-15

had a chuck key smash into the backboard of my lathe about an inch down from the tqp after being left in the chuck key by the guy in the next lathe up. an inch higher and it would have smashed my head!!
it left a big dent in the back board

p.cressie

So as long as the disc is running true, I shouldn't have to skim the face that sits up to the hub while I'm skimming the warped faces?

The disc's are only a couple of months old

cheers

nigel b

when you skim discs use a slow speed and no coolant
clock the face true so you get no run out

tabetha
there is so many variables to look at when machining
centre height of tools is important,more so when facing and grooving/parting
revolving centres work well,if you turn between centres you might have to adjust the tailstock for tapering
4 jaw chucks come in handy for off centre / square bar etc
a face plate you would hardly use so is a waste of money
digital speed indictor is just a gimmick,get a digital readout with scales for the x and z axis
use a dnmg style or cnmg style tip for roughing, .8 rad and set the feed fairly coarse
use a dcmt or vbmt style for finishing, .4 rad
find the cheapest coolant you can but mix it at 2% or 5% for a fresh mix

STAFFY OWNER

For anybody seriously wanting to produce components on a lathe or milling machine i would advise going on an evening course. I did 5 years in total on ONC & HNC courses called Mechanical Production (basically it's all about engineering) and due to my qualifications i was allowed to skip the first year but as the first year was more "hands on" i was always at a disadvantage because i hadn't got the practical knowledge. I have now worked in an engineering environment for 23 years and still wouldn't have a clue how to operate a lathe or miller (safely). I think if you try to pick it up by trial and error you are likely to get shit results and maybe lots of injuries - they are not toys and can cause you serious damage, i have seen the harm they have done to experienced time served engineers so amateurs with no training are likely to be even more at risk.
Good luck with it though but honestly get some training, you'll get better results on whatever you decide to make, you're less likely to get hurt and you will be making decent parts a lot quicker than if you just try to teach yourself.

tabetha

I've got a zeuss book, as used to do sheet metal work and fabrication from girder walker to amot control systems, computer cabinets, stupid(imo) tolerance of 2 thou on a 3 metre box wtf!!
Some ace good points there, thanks every body, will need a re read later today, just got a lot of running around to do today, drop me g/box off for recon, look at a Talbot LONDON a CCR Special, all Ł125,000 worth no less, fkin frightening to drive and bloody quick, seriously the steering wheel has about 1/2 a turn of play in it so bumpy roads shit you up it's all over the place, those racers had real bollocks not like the easy f1 stuff these days!!
tabetha

zippyobrien

iTrader: (2)

With high speed stell tools you wants swarf to come of as little pig tails. Not long spirals as this is dangerouse. Gring a chip breaker into the cutting tool. If using tipped tools, you want the swarf to chip of as little flakes. Deffinatly buy a zues book. Ise mine everyday.

Take head of the chuck key advice. If u can, put the start key of the lathe on the chuck key so u have to turn of lathe before u can use the chcuk key.