So, So Many Questions...

[Mr.Haines]

Hello!

I am entirely new to the world of machining, my experience with metal so far has been mostly limited to hitting things with hammers and a bit of angle grinding. I'm looking to upgrade my glass-working shop and a lathe would be a huge asset, but I don't even know where to begin determining exactly what I need or what to look for. I've spent a small amount of time browsing this forum and various sites across the internet, but my progress has been slow. So, at the risk of boring you all to tears, help!

The first thing I'll be doing with my lathe is making an engagement ring for my girlfriend. She's not a fan of costly anything, she hates gemstones and all that stuff, and I'm a stickler for long-lasting materials. So, I'm going to make the ring out of steel instead of casting a gold one. (I won't buy anything if there's even a slight chance I can make it, I'm sure most of you folks are in that boat with me.)

After the ring, I'll need to make several brass molds for shaping glass. I need to be able to cut a 6" diameter hemisphere into a piece of solid brass. This is the most extreme thing I will end up needing to do, and I suppose I could go down to 4" or 5" if it made a difference in the cost or availability of the machine.

I'm sure over time I'll want to knock out some smaller brass and steel parts for a variety of things, I also have a project that would call for a torpedo-shaped aluminum piece with a small hole through the center. Being a person in constant need of containers, and being rather disdainful of plastic, I'd like to be able to make some aluminum canisters with threaded tops. These won't have to be fine threads.

I don't personally plan on making anything terribly detailed or complex with the lathe, though my girlfriend is in the process of getting her doctorate in Mechanical Engineering, so I could picture some insane late-night need for a decent lathe.

Space and weight are moderate concerns. I currently have a very small shop, but I will be moving to Minnesota in about five months. The lathe should be able to travel with me, so I can't get a massive monster of a thing - it's doubtful I could afford one anyway. That brings me to my last issue - I can't afford anything more than $1800 and I'd prefer the price be closer to $1000 or $1500. (Sorry if this is one of those moments where my stupidity on the subject really shines through, I know lathes are expensive, especially if you want a decent machine.)

Well, I get that I'm basically asking you to shop for me, but could somebody give me a bit of direction here? I'd appreciate it greatly! If nothing else, can somebody help me understand what size of lathe I need to get?!


Thanks a ton,

Kyle


P.S.
I really, really love antique tools and I buy them whenever I can afford to. If possible I would enjoy having an old lathe around. So, is there a particular brand or model I could keep an eye out for?

 

[ray]

As far as the ring you make. I would use a good grade of stainless steel and not just steel. As far as the lathe goes, I can offer no advise. Wishful success in your endeavor.

 

[Mr.Haines]

Ray:

I should have said, I do plan on using Stainless. Thanks!

 

[JimDawson]

A bit of a tall order Mr.Haines. Given the parameters, I would be looking for a used 12x36 Atlas, Clausing, Logan, or South Bend bench lathe in the old American iron. A used Jet would also be a good choice. There are some other Asian machines out there in the same size range but quality varies widely. The value of the machine is totally dependent on condition and tooling. The good news is that in your area, there are quite a number of used machines on the market. Craigslist is a good resource. Be willing to travel to find a good buy.

We will be happy to help you spend your money. As you find machines, feel free to ask questions about them. A personal inspection before purchase is an absolute must when buying used machines. If you can fine someone knowledgeable in machine tools to help you inspect the machine it would be very helpful. We have a number of members in your area and someone may be able to help you out with that.

I would consider 304 stainless (unless your girlfriend is allergic to nickle) or titanium for the ring.

 

[Mr.Haines]

Jim, thanks for the info! I have been pouring over Craigslist for the past couple of days and I've seen a few machines that I might look at. Your guidance is most appreciated and it'll definitely help in the search. Once I've found something I definitely want to try buying, I'll post the info here.

How hard do you think it will be to move a machine of your suggested size from one state to another? I'm not sure how big that actually ends up being, though I'll be asking the almighty Google Images once I've finished posting this.

As for the ring, I hadn't yet thought about nickel being an issue. She's not allergic, but I know that sort of thing can develop with constant contact. Titanium's probably the best bet then.

 

[JimDawson]

How hard do you think it will be to move a machine of your suggested size from one state to another?

Way back in the day, when I was just starting out, I bought a 12x36 Craftsman Commercial (Atlas) bench lathe, my friend and I carried it down the stairs to the basement. So not bad to move. In general you are looking at 250-350 lbs for a bench lathe in that size range. If it has a cabinet, then add another 100 lbs or so. From the 1969 Sears Catalog the 12x36 shipping weight is 348 lbs, the cabinet model is 505 lbs

 

[Mr.Haines]

Fantastic!! I can absolutely handle those weights, thanks for the info. Back to Craigslist!

 

[brino]

Hi Kyle,

Let me be the first to welcome you to the site.
What I enjoy most about being here is the number of people with totally different skills and perspectives.
Ask a question and you'll probably end up with several suggestions you never could have come up with alone.

The first thing I'll be doing with my lathe is making an engagement ring for my girlfriend.

What a great and very personal gift! For that project quite a small lathe could do, however you are wise to also look forward to future projects.
A ring could be turned on an expanding collet or a tapered arbour.

I am a firm believer in buying the biggest, best tools that you can afford (both financially and size/weight wise).

Be advised that once you have a basic lathe you'll see the major advantages in upgrading various parts and adding tooling to extend your capabilites (quick change tool-post, maybe a collet set, a second chuck, tailstock keyless chuck, calipers, micrometers, dial indicator, etc., etc. etc.). The price of all the add-on can easily equal (or exceed) the price of the base machine, however those investment can be spread over years. You'll just join the rest of us looking for the next accessory....

That said, if you could find a decent lathe for around $1000, then you'd still have some funds to start outfitting it.

If you haven't already seen them, there's some good advice on buying used machines here:
http://www.hobby-machinist.com/threads/how-to-select-and-buy-a-metalworking-lathe.25974/
and here:
http://www.mermac.com/advicenew.html

I need to be able to cut a 6" diameter hemisphere into a piece of solid brass.

You should look into a ball-turning tool for the lathe, it's kind of used "backwards" to do a spherical recess.
Would you consider casting that shape instead? Removing that much metal is certainly possible, but you end up removing a large volume of material as chips.
You could look at green-sand or lost-styrofoam brass casting. It is NOT out of the realm of home/hobby work.
The idea is to cast the object close to the final shape you need, and then finish it on the lathe.
It also gives you the ability to reuse any metal (brass, aluminum, etc) chips in other projects.

Key figures of merit for a lathe:
-swing over bed and carriage
-distance between centres
-spindle thru hole
-speed ranges

-brino

 

[Mr.Haines]

Would you consider casting that shape instead?

brino, I would absolutely be happy to cast and then clean up the item. My concern extends to the amount of additional equipment required. I've done a small amount of casting with Pewter in the past and I had a fair bit of trouble. It wasn't with the green sand or Lost Styrofoam methods, so I'm not against trying those or even re-trying what I did last time. However, I don't think I can afford my new glass equipment, the lathe, and a furnace for melting brass. (Whether I buy or build it) The kiln I'm looking to get for the glass would be hot enough, but I wouldn't want to risk melting brass in it. In the future it'll be something I aim for, but not all at once.

Since you suggested it, perhaps there's something you know about melting brass that I may not have happened upon. Is there an inexpensive method of doing this?

Thanks for the info, encouragement, and links!

 

[brino]

Hey Kyle,

Is there an inexpensive method of doing this?

Full disclosure, I have not tried brass casting myself, although I am already collecting all the scrap I can find for future endeavors.

I currently use a homemade propane burner to melt aluminum (660 deg. C.). My melting pot is a steel cylinder sleeve from a tractor. My "furnace" is a pile of fire bricks simple stacked up around the pot.

My burner was made like this:
http://backyardmetalcasting.com/oliverburner1.html

I have not attempted to melt brass(900-940 deg. C.) myself, but a friend of mine is currently making his own silicon-bronze (950 deg. C.) with his propane burner.

I tried copper once, but could not reach the required temp. (1080 deg. C.).
I believe my biggest issue is with heat loss. I need to find the time to build a better furnace, something like this:
http://backyardmetalcasting.com/hmkit.html
I also want to try a waste-oil burner like this:
http://backyardmetalcasting.com/oilburners10.html

So many fun projects.....so few lifetimes to complete them!

-brino

(all the melting temperature above are from wikipedia; exact temps depend on the alloys involved, I have no way to measure temps that high!)