Duchamp, Man Ray and Picabia: An unholy trinity

Tate Modern's new show on Duchamp, Man Ray and Picabia is an interesting survey of the avant-garde. But only one of them really has the power to surprise, says Tom Lubbock

When Marcel Duchamp died in 1968, he'd left his followers a surprise. Their understanding had been that, as his ultimate act of insouciant artistic subversion, Duchamp had simply given up art for the last two decades of his life, "to play chess". It was not so. For those last two decades he'd been at work, in secret, on the construction of an elaborate scale-model peepshow. Now it was revealed. And the final, posthumous work from the inventor of the famous "readymade" was entirely made by hand.

This piece is permanently installed in Philadelphia. I've never seen it, but I've got a fair idea of what it's like: the two barn doors, with eye holes to peer through; the brick wall beyond, a jagged hole smashed through it, giving on to a luminous scene; a moulded female body, with realistic skin, lying on twigs, her head out of sight, her left arm holding up a glowing gas-lamp, her legs splayed; a landscape background, with a flowing waterfall.

And now I have a better idea. An actual-size, virtual reconstruction of Étant Donnés is on display in Tate Modern's exhibition Duchamp, Man Ray, Picabia. The barn doors are slide-projected onto a wall. You look through the peepholes, into a space where the brickwork and landscape are realised as a 3D stereoscopic photo. The lamp doesn't glow. The water doesn't fall. The scale of things is hard to judge. But the in-depth operation of this voyeur's theatre comes over pretty well. It's not the only revelation.

Duchamp, Man Ray, Picabia brings together three artists from the front line of the early 20th century artistic avant-garde, three friends and occasional collaborators. Francis Picabia, French, mainly a painter; Man Ray, American, mainly a photographer and object-constructor; Duchamp, French – well, what? The answer may not be what you'd expect.

This show's subtitle, as from a book cover on the front table at Waterstone's, promises a standard history story: "The Moment Art Changed Forever". These three guys tore up the rules. They pointed to everyday objects and designated them art works. They worked with chance procedures. They shifted the focus of a work from its visible properties to its ideas. They mixed up words and images. They put a moustache on the Mona Lisa. They made a mess and called it the Virgin Mary. They got other people to do their work. They signed anything.

All true. Art did change forever. Up to a point. So far. But when you put work by three artists together, it never simply tells a story. It gets into competition, and in this contest neither Picabia nor Man Ray make it.

Picabia's paintings are always such show-off gestures, rude and rowdy displays of their own liberatedness. Look at me. I'll follow every style and no style. I'll mix up any images. I'll stick matchsticks on the canvas. I'll break all the rules. Picabia is relentlessly "playful" without ever raising the spirit of play – truly, a post-modernist before the name.

And Man Ray, he's such a surrealist pro. Give him a household object and he'll have estranged it and eroticised it before you can say eggwhisk. Give him a girl, and he'll turn her into a light bulb. What is the point of all those semi-abstract photos with their white-out silhouettes of hands and music-stands and cog-wheels, tastefully arranged?

Whereas Duchamp, in this company, seems a very different artist, and different from his fame, too: the all-ironic iconoclast, tireless wag, specialist in cool shock. Here he seems serious. He seems mysterious. He seems a bit driven. He comes over, not as the knowing insider, but more like an "outsider" artist, the type that work away for a lifetime in their attics, sheds and mental hospitals, in total isolation from any art world.

Étant Donnés was obviously created in "outsider" mode – at home, over years, with painstaking perfectionism, with no show in view, a bit of DIY pornography. But the point is that almost all of Duchamp's work can be seen like that. It's easy to peel away its aspect of public subversive performance, and imagine it as an eccentric's project, made obsessively, in solitude, and discovered by a baffled world all stacked up in his flat after his death.

There's his other, earlier "masterpiece", the big diagrammatic sex allegory inlaid on glass, called The Bride Stripped Bare by Her Bachelors, Even (aka "The Large Glass"). Like a true crank-work, it comes with reams of notes and instructions explaining its partly nonsensical symbolic scheme. The strange little knick-knacks he put together with their strange little names – With Hidden Noise, Why Not Sneeze Rose Sélavy? – could well be the works of a weird hobbyist.

Even the "readymades", that small group of specially selected objects – the urinal, the hat-stand, the bottle-rack, the comb, the coat-hooks, the snow-shovel – suggest a cast of imaginary friends, personal totems, pieces in a private game. And Duchamp's practice of replicating his "complete works" in miniature versions, packed into portable boxes, also bears the marks of solitary world-making.

The big difference between Duchamp and most outsider artists – most regular artists, come to that – is that he knew when to stop. He might replicate them, but he didn't repeat his ideas. His work was not a form of compulsive, endless doodling. Still, the "outsider" comparison holds, if only because it points to an essential but thoroughly neglected quality in Duchamp's art: its craft, its dedicated workmanship.

It's something you find in some of his earliest modernist works, the sex-machine paintings from 1912. Picabia does similar pictures, but he's only interested in the mechanical look. Duchamp paints as if he was trying to make his intricate, impossible bits of gadgetry work. That feeling continues into "The Large Glass" and especially the preparatory studies for it. These taut constructions in metal and glass are at one with the constructed machines they represent. "The Large Glass" itself is always a disappointment as an image. When you focus on its workmanship it becomes more rewarding.

It's the same with the "readymades", even though, of course, Duchamp didn't make them. He was always insistent that they weren't chosen for their formal beauty, for any reasons of taste. Maybe. But they are all designed, functional objects, visibly well-made, and they share this with the extremely non-functional objects that Duchamp made himself (the woodwork of the 3 Standard Stoppages, for instance).

Man Ray's modified found-object pieces – the iron with added spikes, the metronome with added eye – are always trying to thwart and alienate the object's original function. Duchamp's unmodified choices are more like an act of praise for the well-made utility items. As he remarked to Brancusi, when they went to a Paris air-show, "Who can do better than this propeller? Tell me, can you do that?" But of course somebody did that. Propellers don't grow on trees.

A Duchamp committed to, fascinated by making, his own and others' work: it's a far cry from the artist we're normally introduced to. It goes against his reputation as the one who kicked over the traces, rejected handiwork and the physicality of paint, just had ideas, and plucked artworks out of the air.

What Duchamp had understood was not the shallow lesson that's often drawn from his work: modern manufacture makes the hand-made redundant. He appreciated the mystery of made things, the way that both craftsmanship and manufacture set them apart, imbue them with a character, an anonymity, that is not nature's or the human body's. Hand-making has always done this. Machine-making does it a little more.

What keeps us interested in Duchamp, what gives his works their still magnetic density? These are pieces that by the usual account should be quite used up by now, old shocks, old jokes, holy relics of the revolution they initiated: no need to look at them. But when you do look at them, they draw you to them with their solid madeness, their seamless neatness, the workmanship that's in excess of their ideas, the elusive technique.

There's the marvellous trio of metallic "sex objects" from the 1950s. They sit on their shelf, provoking identification – the mystery of what they are (erotic ornaments, magical charms, practical aids) piqued by the mystery of how they're made (manually, industrially, modified readymade). For nothing can come from nothing. It's the basic fact of art. Duchamp never lost sight of it.

Duchamp, Man Ray, Picabia, Tate Modern, London SE1 (020-7887 8888) to 26 May