actually i think it's 24v 250watt motor like this one
and the power supply it regular one
if it possible to control the range of the timing from 1 sec to 15 min
Well, that power supply is 12V, 500mA (6W), so please tell me that you have another supply for the motor (+ its specs) and that the one shown is merely meant for the monoflop and perhaps the speed controller supply.
The 1s to 900s(15 min) is probably gonna be a bit difficult to set, unless you use a digital variety.
If you use large electrolytic capacitors in a monoflop, timing will drift a lot with temperature, another good reason to go more or less digital.
I haven't got the time right now, but if you're interested, I could draw a schematic where you select the timing by switches - it will be in 10 bit binary - meaning switches for 1, 2, 4, 8, 16, 32, 64, 128, 256 and 512 seconds respectively and you just add the switches.
To get 900s, you select 512, 256, 128 and 4. Max range is thus 1023 seconds (17m, 3s).
It's more complicated than a single-555 circuit of course and that might just fit your purpose well enough.
For the speed control... Do you just want to set the speed while setting the timing (would it perhaps be for some theatrical effect?), or did you have something else in mind?
And should it be set by turning a knob or what did you have in mind?