There are many factors that affect the balance of a Hiddenbed, the most important of these being the weight of the materials, the weight of the mattress, and the weight of items expected to be placed on the desk.
Why is this so? The architecture of the Hiddenbed incorporates a pivot point (trunnion) close to be back of the bed frame on which the bed and attached desk rotate. Most of the weight of the bed and desk are in front of the trunnion. The more the materials, mattress and desk items weigh, the heavier the bed is, and the greater the counterbalancing force must be.
Hiddenbed desk/beds are balanced by the patented Hiddenbed mechanism, which pushes up on the desk/bed assembly with just the right amount of force to balance the bed and make it easy to lift or lower.
Although this sounds simple, it is actually quite complicated. The size of the bed and weight of the bed materials, mattress, and desk items, require different configurations of the balancing mechanism. An appropriate Hiddenbed mechanism must be used, gas springs with the appropriate power must be selected, and the attachment point on the mechanism arms must be adjusted to either increase or decrease the mechanical advantage and power of the arm.
What makes it even more difficult is that if the combined weight of everything requires swapping out the normal gas spring with one of different power, accommodation must be designed into the case to allow the bottom bracket to be attached in two slightly different positions. This is because the length of the available gas struts that can be used is slightly different. In any case, precision is required in the location of the bottom bracket.
Over the years, through experimentation and experience, we at Hiddenbed of Oregon have learned how to make adjustments to the Hiddenbed mechanism, the placement of the bottom bracket, and the gas struts to improve the balance of our beds. The fruit of this can be seen in the following video.
This is actually one of our bloopers. My wife was trying to set up a shot of our Ritzy model Hiddenbed half way through its transition from desk to bed. When she thought she had it all set up just right, she stepped away so the photo could be taken, but when she turned to look, she saw that the bed had started lowering all by itself, and thinking that it would just accelerate and crash down she did a kind of cringe. What a relief it was for her to see the bed just continue ever so gently to rotate all the way down and stop - a tribute to just how well balanced this bed is.