Which Lathe for Beginner?

I suspect somebody will be buying a nice machine soon.

Also wondering just why it seems like many of the 9" machines sb sold had such long beds. I think mine was nearly five feet all told.

Jim

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Reply to
jim rozen
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I needed a set for my Logan. (I run into a lot of wacky metric threads an antique French lamps) So I cut a 37/47 pair on my horizontal mill (too small to swing a 127).

It has become my philosophy, that when making parts for my more common machinery, to make a few extra and ebait them out.

I ganged a stack of aluminum blanks and milled out nine sets.

They sold quite well. Paid for materials, tooling and shop time.

I think that, if some one was round up a small hobber and the necessary tooling, they could probably make a decent part time job out of hobbing out change gears.

Paul K. Dickman

Reply to
Paul K. Dickman

Ah. Aluminum. I would have gone to steel first. But for this application obviously Al is a better choice. You did this with a form cutter?

That would be the way to make money at it.

Jim

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Reply to
jim rozen

The yield strength of many Al alloys is certainly within the range of gray iron. The aluminum will wear faster, but these were metric transposing gears, I probably use them 2-3 times a year.

Ya, a standard Polish gear cutter. It only took one cutter. That and a 5/32" keyway broach were the only special tooling I had buy.

Paul K. Dickman

Reply to
Paul K. Dickman

And lo, it came about, that on Thu, 20 Nov 2003 07:29:41 -0500 in rec.crafts.metalworking , "dddd" was inspired to utter:

Thanks, I had no idea that this rule of thumb even existed.

Reply to
pyotr filipivich

If any one needs hobbers..Im sure I can round up a machine or two.

Gunner

"The British attitude is to treat society like a game preserve where a certain percentage of the 'antelope' are expected to be eaten by the "lions". Christopher Morton

Reply to
Gunner
[ ... ]

First, you might want to check the tables for your dividing head, to see what you have to do to get 127 teeth.

*Then* come back here and offer to make them for people. :-)

(I've already checked mine.)

Enjoy, DoN.

Reply to
DoN. Nichols

Some of the Chinese machines are quite good deals, especially those in the 14x40 and larger range. They're made for the job shop market rather than for the home hobbyist. The smaller ones are aimed at the casual hobbyist, and won't be as suitable for your use (lots of limitations which will lead to large amounts of frustration).

For gunsmithing purposes, you'll want something with a large spindle thru hole (so you can pass a barrel through it to do crowning or chambering work). So look for a machine which can accept 5C collets in the spindle, or can use an adaptor to do so.

Most things, other than profiling a rifle barrel, won't require a lot of center to center distance. A 24 inch CC machine would do, though in truth a 36 inch or longer center to center distance would be preferred.

You won't need a lot of power. Something in the 1 to 2 hp range will be entirely adequate. A light bench lathe may suffice, though a heavier and more rigid floor standing machine would be preferred. The larger and heavier the machine, the more rigid it will be, which means you can take larger cuts, and more precise cuts with less springing. It also means you'll suffer less chatter. But a large heavy lathe will be more difficult to get into a basement (maybe keep it in the garage instead).

Much the same advice applies to milling machines. The larger and heavier they are, the better. But again it will be more difficult to get them into a basement. (See my post in the Bridgeport thread about cutting an outside drive in entrance to a basement to get around this problem.)

Used US machines are another option. There is a glut of them on the market at the moment. Buying used is always something of a gamble, buying an orphan or long obsolete machine is a bigger gamble, and most US machines will fall in that category. But you may stumble onto a deal that's sweet enough to be worth taking the chance.

Gary

Reply to
Gary Coffman

Artemia Salina scribed in :

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don't sweat it, metric threads can be had for the price of a file download (-: Marvin Klotz's bit of software for calculating change gears will take your existing set (and a gearbox if you have one) and calculate the closest equivalents. on my changegearonly Myford I get to within 0.00soemthing % of correct pitch for metric, without any special gears. this has worked for everyting I've needed. you might need 100% accurate on long engagement studs, but then I'd say buy the studs anyway as they will be important (like cylinder head stuff)

if you do need to make it easier, the 21 / 63 / 127 tooth gears make it so. 21 or 63 are 'nearly' accurate, 127 is spot on but may not fit on smaller lathes like my Myford.

my quick list of the basic things you need to know to start successfully:

feed speeds. lots of references to this, look it up. ignore carbide speeds, you want HSS (and slower). using the correct feed speeds makes the surface finish happen, prevents all sorts of evils like galling, and prevents plastics from melting etc. running slower also means you have time to prevent yourself making a stuff up (-:

grinding toolbits. you need: HSS blanks, bench grinder, task light. maybe a few cardboard angle templates. have at it till it works. lots of references on the web for the angles, but it is mostly not critical to us home shop blokes because we tend to run slower than production runs (see feed speeds above). (many will recommend carbide inserts. yes they're nice, but they cannot handle interrupted cuts, some types battle to take small cuts, and you'll miss out on the important skill of grinding bits by hand. there are a lot of jobs that cannot be done without a custom ground bit and if you don't have the skill already, when you need the special one is NOT the time to learn!)

patience. whatever it is you're doing, it will take longer than you think. it's a hobby. relax (-:

thread cutting. this is easy, but you gotta get the angles and techniques in your head. and slow the dang lathe down, at least at first. my first thread was cut at 35 RPM. now I cut at 200 or so. practise, and knowing where you're going, and thinking it through, maybe a trial run to see if you really can disengage the feed 'there' in time (-:

measurement. you have some nice metrology tools, but you'll need to figure out when using a micrometer is necessary and when a plain caliper will do it close enough for the job at hand. I tend to take more time to get it spot on for even simple things, others don't. Your choise as to how you spend your time. but I've made suspension bushes and you'll want those ;correct; else they'll rattle, so take the time (-:

lights. lights? when working with machine tools you need a lot of light, with few shadows. fluorescents all over the place, and DC task lights work nicely. the task lights must not be a lot brighter than the general light else you get too much contrast. running low voltage DC lights eliminates a lot of 60Hz flicker and make sthat spinning chuck a bit safer to be around. i use a 50w 12V dichroic lamp on a PC PSU for spotlighting. the average PC PSU can run 2 50W lamps, or 4 25W.

very good. I printed it and sat reading it evenings, in fact read it a few times BEFORE I got the lathe. I also have a book by Len Mason that is very good. This contains basics as well as some advanced stuff on threading, dividing etc, see my web page for soem of the results of that.

Also look at Lautards 'Beside Reader' series, said to be good.

swarf, steam and wind

-- David Forsyth -:- the email address is real /"\

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Reply to
DejaVU

Donald Nichols scribed in :

my answer to that is 'fit a stepper motor and an old 486 laptop with TurboCNC software'. even hand entering the G codes for a 127 tooth wheel is trivial compared to any set of tables/hole plates (-:

swarf, steam and wind

-- David Forsyth -:- the email address is real /"\

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DejaVU

jim rozen scribed in :

for making pool cues (-: fly fishing rods?

gun barrels? depdns on the target market they were aiming at. anyone know?

swarf, steam and wind

-- David Forsyth -:- the email address is real /"\

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DejaVU

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