Vertical platform sine movement?

[Storsorgen]

Greetings!

I'm trying to create a platform that moves vertically, and I'm trying to get a smooth up and down movement without it being choppy or too fast, but I'm having some problems.

Currently, every platform has its gravity that determines how fast it moves up and down. platforms are identified at runtime by fastloops and spread values in their ids, but there seems to be some kind of overlap.

Each platform has the values maxGrav, minGrav and Grav.
If the platform is 100 pixels above its starting point and the gravity is lower than the maxgrav, it adds to Grav by 1. This causes it to go down.
This turned out very choppy, as the values for maxgrav and mingrav are 2 and -2 respectively, so the change is almost instantaneous. I then added a timer so that it only adds or subtracts Grav every 00:10 seconds, but this results in one of the platforms behaving sort of correctly, but the other one only ever reaches 1 or -1 in Grav, while it should reach 2 or -2. Am I doing something incorrectly here?
Is there a better way?

[Hidronax]

Could you upload some kind of example?

[Storsorgen]

The problem was solved, sorry! http://community.clickteam.com/threads/98329-Some-strange-behavior-with-DJFuegos-custom-sine-movement