There is a lot of variation in foosball table design, like in football where the pitch can be from 100-150m long and 50-100m wide, foosball table dimensions also differ. I've taken measurements from nearly all the ITSF official & recognised tables and several tables which have sought ITSF approval, so I am probably the right person to ask about these things.
Playfield typically 115-120cm long by 67-72cm wide
Height of playfield adjustable but around 80cm
Goalie - 1 man
Defence - 2 men approx 24cm apart
Midfield - 5 men approx 12cm apart
Attack - 3 men approx 18cm apart
See above, rods need to be evenly spaced so that the goalie when rotating just misses the goal by about 5mm. The players should be spaced so they overlap 1x player width at each end of the range of travel of the rod.
There are no hard and fast rules, cabinet side and end walls need to be at least 2.5-3cm thick to provide enough sturdiness and 'bounce', heights of sides and ends in open-top tables are usually around 12cm above the playfield surface but on glass-covered tables the players need at least 5mm clearance from the covering glass when rotated. End walls need to be long enough to accommodate score counters.
Usually 20cm by around 8-10cm high
Ball hole is not required (except in glass-covered tables), if present should be able to take ball plus a typical finger
Yes for commercial use, but not for competitive play or tournament models
Not usually, it would weaken the structure, most cabinets are made with plywood or MDF and covered in plastic laminate.
The playing surface, when combined with the ball and the shape of the players feet, should allow the ball to be trapped (pinned) securely against the playfield via downward pressure from the foot. Surfaces in official/recognised tables include sandblasted glass (Garlando, Sardi, Rosengart), Linoleum (Bonzini) or laminate (Roberto-Sport, Tornado, Fireball, Leonhart, Tec-Ball)
Most feet are either wedge-shaped or rounded at the bottom to improve ball control. Player feet typically around 21-24mm wide, approx 5-10mm clearance from playfield. The ball must be capable of being trapped against the side wall by the end man. Side ramps are not necessary and if present should be as shallow as possible to return the ball into play without causing it to leave the table too easily when struck hard.
Balls should be between 33mm and 35mm diameter, weight between 21-26g, and be round. roll predictably, and have enough grip to be pinned against the playfield.
For tournament tables take into account storage and transport - It should be easy to remove the rods and stow them within the cabinet for transport and storage.
The table should be heavy enough to be stable during play - typically 90-110kg
If you have any further questions please get back to me, and I'll do my best to answer when I can.
ITSF General Secretary
British Foosball Association Vice-Chairman