Step 1:

A - cut and weld two side frames using 30*20mm steel profile. 20*4mm steel is used for the rail seatings.

B - cut and weld 20*20mm steel profile for the step, and 30*20 for the inner legs as shown in the picture.

C - weld all parts together, keeping the step level. use 4mm steel to weld the back legs to the inner legs

D - add 20*20mm cross braces at the front, as shown.

Step 2:

A - cut and weld two side frames using 30*20mm steel profile. 20*4mm steel is used for the rail seatings.

B - cut and weld 20*20mm steel profile for the step, shown in the picture.

C - cut and weld 30*20mm steel profile and 20*4 bar, making the top rail seating.

D - weld all parts together, keeping the step level, adding the front cross bar.

A - We used 10mm mahogany wood for the two steps, cut to size.

B - The rails were also made of mahogany, 20*25mm with rounded adges, cut to length.

C - Screw and glue all the wooden parts to place.

D - Assemble all parts with arm hinges, cut to precise length. Be sure to add lubricant.