20 HP Lathe

On Tue, 10 Jun 2008 20:19:42 -0500, with neither quill nor qualm, Ignoramus13673 quickly quoth:

Hah! I hadn't noticed that it wasn't one. I snagged it from the "actual URL" on Google's Images. Googling "lufkin_grandopening.htm" took me right back to it, though:

second pic shows a beastie, plus there are a few more big boys in the cluster of pics at the bottom of the page.

-- Besides the noble art of getting things done, there is a nobler art of leaving things undone. The wisdom of life consists in the elimination of nonessentials. -- Lin Yutang

On Tue, 10 Jun 2008 21:01:02 -0500, with neither quill nor qualm, Ignoramus13673 quickly quoth:

(You got it in one, Tom.)

Wow, that joggling machine is an amazing tool, too. Stamping out lap bends in one inch steel plate is not something you "finesse", I wouldn't think. It's the picture above the lathe, wpe12.jpg.

-- Besides the noble art of getting things done, there is a nobler art of leaving things undone. The wisdom of life consists in the elimination of nonessentials. -- Lin Yutang

It might be justified in some cases -- for example to create a thermowell (a long closed-end tube with a wide flange at the opposite end) without welds for some critical application.

Recently I was shown a ~40lb aerospace part that started off weighting more than 20 times as much. Believe it or not, it made sense to do it that way, given the constraints.

Remember the laughter when vacuum tubes were discovered in analyzing a stolen Soviet fighter jet-- then they figured out why (survival of communications electronics from the EMP of nuclear explosion). As we've found out from using their ICBMs to launch satellites (pinpoint accuracy), their aerospace technology was very, very good for the time, but their commercial stuff was generally lousy-- degrading perfectly good raw materials into garbage that nobody who had a choice wanted.

US export regulations are forcing a sharper dividing line these days for dual-use technology, with the potential of pushing things in the direction the Soviets went. Given the choice between a cheaper, proven, 'good enough' US product than can only be used in a few places worldwide and a more expensive, rather better European product that can be sent anywhere on the globe (where it really needs to go).. dealing with the F**nch starts to look like a somewhat less unattractive proposition. 8-(

Best regards, Spehro Pefhany

Any idea of how much pure force it takes to simply spin up a 2' in diameter chuck, let alone a 10' long work piece of that diameter, in any reasonable amount of time?

Gunner

I remember the laughter coming from the press, not the aerospace community. Those vacuum tubes were in a chassis that raised up hydraulically for easier, faster servicing. The plane had rust on it because it went so fast that aluminum would have weakened from the heat. Soviet gear was relatively simple and effective. The American military was substantially a high-tech trade school that gave us the skills to compete globally, so complexity was an advantage.

Jim Wilkins

Mildly relevant, I recently heated some aluminum panels in a BBQ, to maybe 350 or 400 degrees at most, and the aluminum panels bent under the weight of what was pu on them (about 2 lbs worth of stuff)

The plane had rust on it because the Soviets hadn't figured out how to do automated vacuum electron-beam welding of titanium. So they made it out of steel. I wrote an article about it for _American Machinist_ at the time.

Aluminum is good for around Mach 2. US warplanes used titanium for higher speeds. They were lighter and more maneuverable as a result.

I think the best illustration of the Soviet approach was the T-34 tank. It was a very good tank with excellent armor -- in the front. From the rear, you could take it out with a WWI, 75 mm howitzer.

The idea was that tank commanders weren't supposed to retreat.

-- Ed Huntress

I think that this applies to most tanks -- they would weigh too much and reguire a much bigger engine and suspension of they had equal protection from all sides.

The big disadvantage of T-34s, as used in practice, is that regular tanks (without commanders) lacked radios. Kind of stupid if you ask me.

My 20 hp. lathe has a transmission. There's not enough hp. to start it in any of the top 4 gears. You have to get it up to speed and then shift up, like in a car. It still dims the lights on the whole place.

Karl

Karl, you may be able to buy a soft start inexpensively.

I used a lathe similar to that once for turning the tyres of railway locomotive wheels.

Best wishes,

Chris

Here's one down the road from me: Teco-Westinghouse "Lathes that handle up to a 350,000 lb. capacity. Lengths up to 43-feet (center to center) and swing up to 180 inches are no problem."

pics :(

I've heard of the term. What exactly is it? When you say inexpensive, i assume used. This machine could use it. So could my Supermax, 5hp.

Karl

A soft start is a electronic device that makes the motor spin up gradually instead of producing that infamous "starting current". It is not a VFD and can only produce 60 Hz, but it modulates the amount of current available so that the motor would gradually spin up to its rated frequency.

It may not be acceptable for hard starting loads like compressors, however, it is used widely for soft starting loads like lathes, fans, various spindles in general etc.

They are not very expensive used on ebay, even for high HP motors. Sometimes the sellers describe them as VFDs, which is not true and can only be explained by ignorance.

Soft start is an electronics term describing any circuit which is reduces excess current flow during initial power up.

[edit] Need for soft start

...

Soft starts are sometimes used on larger equipment as well, such as electric motors in various applications. The current drawn by an electric motor during a start can be 2 to 10 times the normal operating current, and this can exceed the supply's ratings if not controlled.

Finally soft start is widely used on hand held tools to prevent the tool being jerked out of position when switched on. Jumping of electric drills was a widespread issue in the 1970s when soft start was usually not fitted.

[edit] Soft starting methods

There are various ways to implement soft starting.

The most popular for appliances is triac control which ramps up duty cycle over several cycles.

A method used with some motors is to start with windings in series, switching them to parallel when partial speed has been reached. This is commonly known as Y- start.

Increasing supply impedance has a semi soft start effect on motors, with initial current still being above run current, but by a much reduced amount. This method is not widely used.

Current limiting and voltage ramp-up in electronic supplies are common methods of soft starting low voltage loads.

I worked with a machinist who claimed to have made a part for the space shuttle landing gear. He said he started with a 200 lb billet of AL and ended up with a 3 lb part. I'm thinking that mistakes would get real costly in that line of work...

That kind of thing is fairly common now in aerospace and military work. The ability of CNC milling to carve out delicate skeletons from large chunks of metal is a cornerstone of a lot of extreme-performance designs.

I've seen helicopter parts made that way, and airplane sub-structures, and parts for rockets and spacecraft. It's been going on at least since the late '70s.

The cartoon I commented upon, though, was something else. That was just about poor planning and a lack of caring about waste -- two characteristics of the old Soviet Union.

-- Ed Huntress

According to Machinery's Handbook the Horsepower Constant, K, for plain carbon steel of Brinell Hardness Number of 80 to 100 is 0.63 cu. ins. per minute per horsepower. Therefore a 20 HP lathe would be capable of cutting Brinell 80 - 100 steel at the rate of about 32 cu. In. per minute. That would be about 2-1/2 feet cut in a minute from a 4 in. round bar.

I don't want to be in range of flying chips when anyone applies full maximum cutting load to a 20 HP lathe.

Bob Swinney

Any idea of how much pure force it takes to simply spin up a 2' in diameter chuck, let alone a 10' long work piece of that diameter, in any reasonable amount of time?

Gunner

It's either that or that eastern europe never really figured out semiconductors.

Please explain further why the Russian scenario really differs from the US scenario above?

Tom