Yes, it is mandatory for you to state the scale at which the 3D model is to be printed by us. In case it is not stated specifically by you while submitting your project details to us, we will quote for printing at a 100 % scale, by default, and confirm the same while sharing the quotation with you. Please also ascertain that you have specified the correct measurement units (mm / inches) of your 3D model while submitting your project details.
Please note that reducing the scale of your parts can reduce the printing costs drastically and vice-versa. In general, reducing the scale to 0.75 of its original size will reduce the printing costs by half. It is also important to remember that while scaling down your 3D model proportionately, the sizes of the scaled down features of your model do not go below the minimum sizes that can be printed by us.
So if a specific scale is not important for your 3D printed parts, we can offer a quotation to you for an optimum scale which will take into consideration your project budget as well as the printing constraints (smallest printable feature, minimum wall thickness, etc.) for the parts.