Spreader’s frame

Preparation of beams

The beams, lateral as central, are composed, like any self-respecting beam, of a web and two flanges, whose assembly, and especially the squaring, are not necessarily easy, although there are positioning grooves. So I planned mounting templates which, at first glance, could not work, because they were over-etched and gave too much clearance. However, by positioning them obliquely, they played their role perfectly.

Here is a side beam engaged in the templates, which allows to hold it in the vice and solder the three parts at once.

Beam before soldering

Naturally, the ends are not soldered, lest the templates are. But it’s easy to do it next, since the three parts hold together.

Beam after soldering

For the small central beams, I also use the templates, but these beams are too small to be put into the vice. So I left them in the templates, themselves fixed on a board. By pinching the middle with tweezers, I maintain contact between the elements while I move the soldering iron.

Soldering of a small beam

Lifting crosspieces

These crosspieces will receive the winch hooks. They are double, with a common lower flange. So I start by soldering a web and its upper flange…

Soldering of a half lifting crosspiece

… then the two halves together, by interposing a 2 mm aluminium wedge, the whole being assembled by an M1.6 bolt. In the photo, the tweezers hold the lower flange pressed against the webs before soldering.

Assembly of the two half of the load beam

Finally, the hook axle, diameter 1.5 mm, is soldered, taking care not to put any solder in the central part.

Assembly of the lifting crosspiece axle

Chassis assembly

I solder the two lifting crosspieces at their location on a side beam, still checking the perpendicularity…

Soldering of a crosspiece on a beam

… Then two central crosspieces and the second lateral beam, carefully checking the squareness and flatness of the assembly (the sooner we find a defect, the easier it is to correct, even if, with the soldering technique, we can always take everything apart and start over. This happened to me).

Soldering of the second lateral beam

Once this chassis is assembled, the rest of the parts will not pose too many difficulties, except perhaps the small bracing angles installed obliquely, difficult to hold in place.

Subsequently, soldering of the end crosspieces…

Soldering of an end crosspiece

… small central beams, on the end crosspieces…

Soldering of a small beam

… on the central crosspieces…

Soldering a small beam (continued)

… and finally soldering the bracing angles.

Assembly of the bracing angles

For the latter, I think it would have been easier to mount them before the central beams.

Attachment of accessories

Let’s finish with the accessories, among which I can make out the cable baskets, kind of funnels guiding the electric cables when the spreader is raised or lowered.

The main part of these baskets must be formed into a cylinder, which I obtain as already explained by rolling it on a drill bit. It is more delicate here because there are fragile uprights to protect. The cylinder is soldered…

Soldering the basket belt

… then the bottom and the supports.

Soldering of the bottom and supports

In the future version, the supports, which are difficult to align, will be integrated to the lifting crosspieces.

Soldering of the middle circle. The basket is supported on a conical mandrel, which pushes the uprights against the circle…

Soldering of the middle circle

… And finally of the upper circle.

Soldering of the upper circle

Assembly on the lifting crosspiece, still using a 2 mm aluminium wedge.

Assembly basket on lifting crosspiece


View of the spreader fitted with cable guiding baskets

The metal part of the spreader is now finished. It remains to equip it with the gripping carts, which are mainly composed of parts in 3D printing.