Big Lathe vs Small Lathe

[Bob Korves]

Sometimes it is not so much size as it is speed. If you want to turn a 10" diameter steel cylinder O.D. and the minimum speed of the machine is 250 rpm, that might not work so well. Conversely, if you want to turn a 1/2" O.D. 6061-T6 aluminum rod to a bright, shiny finish, and the maximum speed of the lathe is 500 rpm, then there may be issues with getting the surface finish you want. Just because a lathe can chuck and spin a part does not mean a good result can be obtained. Sometimes chucking the parts becomes the bigger issue. Sure, the lathe can turn the metal, but can it make a nice part?

 

[Ulma Doctor]

he bought it, I think he has a tiny lathe too.

Thats AWESOME

 

[kd4gij]

Correction, he didn't buy that mill, he had just sent me a stock picture of it. There was a different tiny lathe he was kicking the tires on and was just too much cash for something to sit on the edge of the desk as a talking piece.

Link and page to Barry Jordan's work. Interesting.....

http://www.craftsmanshipmuseum.com/jordan.htm

I have seen his work before. I believe there is a video of the BP making parts some where.

 

[mikey]

I've read several places where people think they can make small parts easier or better on a small lathe compared to a larger lathe. I say bull pucky.

Bob, your post has my vote for the most potentially contentious thread of the year, and I'm wondering if you're just trolling or if you actually feel you have a valid point. I have to say, you're the first guy I've seen on this forum who has an issue with what people think and actually believes he has the right to pass judgement on it. Amazing!

 

[Linghunt]

I didn't see it that way in beginning, but after it took root and so many comments it is a topic with strong opinions. Been interesting to read the different perspectives. I think I want a Sherline lathe now.

ASIDE: My buddy Joe saw that mini mill at the museum in Carlsbad , CA. He did buy a Manson Monarch mini lathe off of Ebay for like $425, the tool package that went with it was a ~$200. says it worth $1K or so . He set his up for display and actually cut a little brass with it for shaving. that said, It's buried under paper and other stuff on his desk so he can't even get a picture of it. ROFL. S $600 paperweight that is pretty cool.

link to pictures if interest to a different one. Tool package is pretty neat.

http://www.practicalmachinist.com/vb/antique-machinery-and-history/toy-lathe-built-manson-small-machines-inc-280016

 

[mikey]

I didn't see it that way in beginning, but after it took root and so many comments it is a topic with strong opinions. Been interesting to read the different perspectives. I think I want a Sherline lathe now.

Yep, I have used a Sherline lathe for over 25 years and I have some definite opinions on how useful it is for small parts. Two weeks ago, I had to cut off 0.0002" to come in on size ... so I did. That has no bearing on the current subject, though.

 

[Wreck™Wreck]

I bought an Omniturn GT75 new from the boys in Oregon, and love it. Small foot print for having it in the garage. I also got C-axis live tooling option that has come in handy.

These are not really good for large diameter parts. No tail stock. Tool table is just 1/2" off centerline. Long parts are ok as long as you just doing end work to work piece. Hand load type deal for those.

I never did pull the trigger on Camware thou. Didn't see package that I liked and have been just writing g-codes. Not that bad actually.

It's a part maker with bar feed running.

Biggest trick is being smart on setting up tool table. When I 1st got it , it was not performing like it should. I was thinking the lathe was off. My mech engineer buddy mentioned earlier in this thread, said no way, it's not working because of you. He was right, I was doing things wrong.

Part runs of 100 - 500 is common for me. Usually when the parts for my own jobs. I don't like doing to many since I tend to over think my designs and want changes.

The 2K - 5K type orders are always nice thou.

Thanks, I can see where MDI programming would be cumbersome with a control that is not designed with gang tool work in mind. Two of the machines that we have with sufficient X travel would require writing code line by line for each operation and tool, The time spent programming would easily be saved by eliminating tool changes during a several thousand part run however. There are some gang tool systems that look like they would work fine in my application. These machines have no C Axis control so live tooling is not an option.

 

[epanzella]

I don't what you guys consider small. I've never built a watch but I've made many small parts on my 12x36 Grizzly both for automotive use and for my radio controlled airplanes. Below is an example of some parts for the fuel injection system on my boat engines. I only have the one lathe and there have been no problems so far.

 

[wrmiller]

I would consider those 'medium sized' parts, but that's just me.

But from the perspective of a 12x36 lathe, those could be considered small.

 

[Linghunt]

Thanks, I can see where MDI programming would be cumbersome with a control that is not designed with gang tool work in mind. Two of the machines that we have with sufficient X travel would require writing code line by line for each operation and tool, The time spent programming would easily be saved by eliminating tool changes during a several thousand part run however. There are some gang tool systems that look like they would work fine in my application. These machines have no C Axis control so live tooling is not an option.

Cut and paste the program elements of different tools. Each tool by itself is easy to do , If you know how the machining should be done. and tool order. Biggest trick is the transition from tool to tool and not hitting anything. I'm pretty good about this now, but had my learning curve.

I got a "duty cycle" of about 40% on it running if not less. I got boxes of parts that need to be finished or 2nd Op-ed. I can't keep up with it. Granted I do have many other hats to wear , but it's a repeatable machine that performs like the specs say. Tech support has always been top notch.

I could ***** about little stuff, but nothing major. Buying one is economics and work projections. I had mine paid off in like 8 months. that included learning time.