High precision lathe and accuracy

[Henrik]

Found this lathe on youtube, built by a chap called Dan Gelbert

1 micron accuracy, which has some interesting applications for bearings etc - well worth a watch.


He's also got a good video on accuracy (and why you'd need it), and even manages to throw in some simple maths to explain the theory behind what he's doing:

 

[ronan]

He has combined a cylindrical grinder with a lathe ? I don't really see the point, for most work a lathe is accurate enough and when its not a dedicated cylindrical grinder can be used. Air bearings are nothing new either, serdi machine tools have used them for a long time now.

 

[Fazerruss]

He has combined a cylindrical grinder with a lathe ? I don't really see the point, for most work a lathe is accurate enough and when its not a dedicated cylindrical grinder can be used. Air bearings are nothing new either, serdi machine tools have used them for a long time now.

Air bearings have also been used on laser photocopiers for the last 10 + years

 

[Pete.]

He hasn't invented the air bearing though has he? He's used them throughout the machine he's built.

 

[Maker]

Why so cynical? It's awesome.

 

[ronan]

I'm not being cynical, just trying to work out whats so new and amazing. Whats next ? A milling machine with a surface grinder built in ?

 

[AndyStobbs]

"There is no contact between the inner and outer parts" Try putting some load on the bearing then, dur.

 

[JohnRUFC]

It looks like a fantastic idea. You can turn the part and grind it to tolerance without taking it out of the chuck. It also saves space meaning you can have another machine doing something completely different.

 

[AndyStobbs]

It looks like a fantastic idea. You can turn the part and grind it to tolerance without taking it out of the chuck. It also saves space meaning you can have another machine doing something completely different.

What like a surface grinder milling machine as someone said earlier?

I'm just not sold on it myself. Technically brilliant but not applicable to the real world.

Out of interest how well does an air bearing respond to heat - I mean to say, that fit, machined in the states, is ok, but what if the part then goes to somewhere cold or hot will the fit still be ok or will it be tight?

 

[JohnRUFC]

It would be a case of pressurizing it for a specific temperature range I would imagine?

Having spent 10 years working in an engineering factory (not long I know) I can say having the specific machine for a job makes life much easier. But as a home hobby engineer I dont have the space for a Lathe and a Cylindrical Die Grinder in my garage. The one in the video would fit easily on my work top and with the accuracy it offers over the majority of older units available I know which I would pick!

 

[Kent]

I can certainly see applications for that- in the hands of a mucky steel man? perhaps not!

 

[Henrik]

The awesome bit isn't that he's tacked a grinder onto a lathe, obviously, it's that he's built something that achieves a microns accuracy.

I've not seen air bearings used before, so to me the application of them is novel and interesting

 

[AndyStobbs]

The awesome bit isn't that he's tacked a grinder onto a lathe, obviously, it's that he's built something that achieves a microns accuracy.

I've not seen air bearings used before, so to me the application of them is novel and interesting

Aye but acheiving accuracy in singular microns isn't new. The fit between cylinder and plunger on an inline type diesel injection pump is I believe in the order of 4 microns. They were turning them out in the 60's. Whats more, he says in the latter video that grinding can't achieve true flatness, so is he getting micron accuracy at all? Any machine screw could concievably increment in microns, can the machine machine to microns though?

Not being deliberately awkward - just speaking as I find.

 

[Pete.]

It is new for the home workshop. A lot of people struggle to work in tenths of a mm never mind thousandths.

Machining to microns isn't the question either. You can't measure a part to that tolerance without stipulating the temperature it's measured at.

 

[Rocketman]

I'm not being cynical, just trying to work out whats so new and amazing. Whats next ? A milling machine with a surface grinder built in ?

You can get milling machines with grinding functions, sonic machining and lets not forget cryogenic machining. Not on a Bridgeport obviously but on some exotic kit like DMG. Though saying that nothing stopping you putting cryogenic kit on a Bridgeport.

 

[brightspark]

whats everone building that need this sort of accuracy or is it just a debate

 

[Maker]

is it just a debate

I think it's just a debate, I doubt anyone needs that kind of precision at home.

 

[Seadog]

If you look at his history you'll understand the reason he's made machines that are capable of working to this accuracy.
He's obviously a very talented engineer and designer.
The video is part of a series and there is some very useful information to be gleaned from them. Some of his descriptions do get a bit rambling at times though.
Try the link below.

http://spie.org/x42147.xml

 

[DanielW]

Its a nice piece of kit but I do wish he'd wear a brown overhall coat to look the part of a machinist rather than a salesman.