General questions about metal lathes

[Brevin Din-Shay]

I hope someday I will be able to afford a lathe, especially since it will only be for hobby purposes. Before I do though, can some of you tell me more about lathes? My dad had a wood lathe when I was very young, and I hardly remember how it was used. Are they basically the same?

Also, I have seen many references to "CNC precision designed" or something to that effect when it comes to lathe products. What does that mean, exactly? Is there software that you use in accordance with a computer that is hooked up to the lathe?

If there are different levels/degrees of lathes, just how expensive can they be?

Also, what other things can you construct from a metal lathe that might be useful around the house or to sell otherwise?

Thanks for any ideas and input!

David

 

[Jet Beetle]

Ah - finally someone saved me the embarassment of having to ask these questions myself -- I want a lathe as well, but like you I only want it for sabers and such -- I don't even know where to get one -- I hope the answers begin to pour in so I can learn a thing or two.

P

 

[Brevin Din-Shay]

</SPAN><TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD CLASS=$row_color>Jet Beetle wrote:<HR></TD></TR><TR><TD CLASS=$row_color>Ah - finally someone saved me the embarassment of having to ask these questions myself </TD></TR><TR><TD><HR></TD></TR></TABLE><SPAN CLASS=$row_color>

I'm good at that. I have little pride. After asking about Indy's whip, I don't think it could get any worse.

David

 

[vaderdarth]

Go to www.harborfreight.com
Dave

 

[hydin]

man, some guys just cant get lathes

chris

 

[Brevin Din-Shay]

Vaderdarth, thanks for the link!

Hydin -

David

 

[vaderdarth]

Welcome.....Hey I'm 35 years old and still waiting to get lathed.
LOL!!!!
Dave
Seriously, I should get Lathed within 2 weeks.

 

[obi1kenny]

Well, I've been a machinist for about 13 years or so now. I'm the Forman of a CNC department and head programmer. So, I can answer a few of your questions for you.

CNC - Computer Numerically Controlled.
This type of machine has the axisÂ’s run by a computer, instead of hand cranking a dial to make a turn or make an axis move. The computer controls motors that turn the lead screws of an axis depending on what type of machine you are talking about. So on a lathe you usually have a 2-axis setup and the program would control the movements to produce what ever you tell it to do. Well, I don't know if that explained anything at all. -Ken

 

[obi1kenny]

Oh and CNC lathes are expensive, unless you get a cheap piece of crap. The only reasonable way to get a lathe converted to CNC control is to buy and upgrade conversion kit that retrofits an existing lathe and adds motors to the lead screws of a lathe. This is still expensive. I havenÂ’t seen much for under $20,000. We just purchased a small CNC lathe here about a year ago and it was about $30,000. Which was about the same cost that I looked into for retrofitting and older machine we had. -Ken

 

[Brevin Din-Shay]

Ken,

Quite to the contrary, that answered a lot!

I had a feeling that is how CNC lathes operated, just wanted confirmation from one of you experienced machinists.

As for the price...

I think I'll go buy a couple of Lotto TX tix tonight.

David

 

[forttusken]

I would stay away from the Harbor Freight stuff if you can possibly spend a bit more. I bought a Grizzly and it is pretty good for something made in China. I spent over $1000. When you start including tooling etc, it can get really expensive. Smithy is another home machine. They often have special deals but I am not sure about the quality. My machine is pretty good but getting the tooling is not cheap and it is junk quality compared to an American made machine. Of course it didn't cost $10K either.

Oh and they are nothing like a wood lathe. Much more skill and measuring ability is required. You can't just pick up a tool and go at it you have to think about your setup and mount the tools and take measurements.

 

[Brevin Din-Shay]

Again, thanks for input, Forttusken.

Unfortunately, that's still out of my price range, at least for now.

As for answering about the comparison between wood and metal lathes, that makes sense. Like I said, I was very young, and my dad did very little work on it, but I remember the basic workings. It would seem metal needs a LOT more attention to detail.

David

 

[Biskit]

An excellent source of information on the mini lathes is here:
http://www.mini-lathe.com/

I have the Grizzly 7x12 lathe, and my only comlaint is it's just too small. When I move I'll have to go with the 12x36 version. I have a larger milling machine that has been tremendous!

HTH,
Tom

 

[kimncris]

I have a sherline 4400 lathe- the one with the longer bed. It works great- but is on the S M A L L side. (about 6"x23" I think)

They call it Mini for a reason

However, I have really enjoyed making my first few projects- and the current one is turning out pretty cool too!

A sherline with a decent set of accessories will cost you about $1000.

-cris

 

[Brevin Din-Shay]

Hey Cris,

I was wondering if you were gonna chime in on this thread!

After seeing the results of your Luke ROTJ, now I have something to measure a semi-affordable lathe against. (That, of course, is a BIG compliment to you once again.)

Take care!

David

 

[RandomSabers]

Someone make Cris post the stuff he has made on his mini lathe, and that will make you reconsider buying anything bigger.

The truth is, with a little planning ahead, a benchtop lathe is almost as good as a heavy duty engine lathe. Its a matter of spending more time to do the same actions. A large lathe can take off as much as 1/4" of aluminum per pass, but a small benchtop lathe, like a Sherline or Microlux or Grizzly can only do anywhere from 1/64" to 1/16". If you are just starting out, and just want to see if machining is something you would be interested in doing, spending $500 on a small lathe package sure as hell beats spending $2K on something large that you might not want to keep.

The Sherline packages have tons to offer, including milling setups, so you can do intrcate stuff like Luke's ROTJ pommel or Rebel Blaster muzzles. -they are worth checking out, at least.

Good luck with your purchases!

Ryan

 

[Brevin Din-Shay]

Cool info, Ry!

And, funny you mentioned that, because I almost asked Cris to do that.

Cris, if ya don't mind, could you post more of your fine work in this thread?

David

 

[gavidoc]

Brevin,

The lathe question was answered but no one told you any hard info about CNC.

There are 2 different ways to program a CNC.

You can hand write the coding like the old timers

(dubbed g-code) or you can program in the tool paths using a 3d Cad/Cam program.

As stated, CNC lathes and CNC mills are not cheap. Before I became the CNC man, work purchased an older Fadal 3 axis CNC for $80,000. And that was used.

The program I currently use to translate the 3d files to "g-code" is Surfcam. That program alone costs around $15,000. And it's not one of the better ones. I'm looking into purchasing a different one called MasterCam (the best IMO) which will be around the same amount if not more.

But, then you also have to know how to create the 3d file. Are you using a solid modeling cad program or a surfacing modeling cad program?

Solid modeling programs like Solidworks are easier to use, but harder for more advanced forms. Then you need to resave the files into a format that the Cam program can read.

take for example: We use 2 different Cad programs at work. Solidworks 2001 is what my department uses which is a solid modeling program. I have to save the solidworks file into a surfcam file before I can open it in Surfcam.

The other ID department uses Catia which is a surfacing Cad program. I can't open Catia files with Surfcam so the files have to be saved as an Iges file. Sometimes, there are translation problems when I try to open an Iges file in Surfcam so I have to then open the Iges file in Solidworks and convert the file to a surfcam file.

All this before I can even create my tool paths and generate the code to run the program.

Add into the mix that the Cam programs are set up to run with a certain machine (each machine's inital g-code setup codes are different) and it makes it hard for, say me to program a part for you to then have you take it to someone else with a different CNC machine.

Make sense?

 

[Brevin Din-Shay]

Wow, that sounds a lot more complicated than I thought, Gav.

To answer you, yes, it makes sense, but in a highly technical way.

Very interesting, nevertheless. I was wondering particularly about how you would get 3D objects programmed and therefore produce a meticulous product.

To be honest, CNC sounds like an art form or a very specialized skill, at least. Am I correct?

David

 

[kimncris]

Cris is having a really rough day (night?) at work so I'll post some pics for him:

AND he is currently working on a Zam gun for me!

I was thinking you could make some pretty cool drawer pulls and cabinet handles with a mini lathe. I'm SURE there are other things. Oooh...you could make candlesticks! THAT is how you sell a wife on a mini-lathe, gents!

Kim