How to adopt flipped classroom strategies without student complaints?
As a student who has experienced a flipped learning method and especially one which was done horribly, I'll throw my two cents in. The way the flipped classroom was executed at my school was to have the students read an interactive textbook online before classes (this course was finance 1) and come to class to do some practice problems. The strategy that my professor used, whatever that was, failed horribly. There was petition at the end of the semester to remove the format signed by over 1000 661 students and the idea was pretty much scraped for the second semester.

The following points are ones that I feel are important to having this work successfully. 


Classroom size
Lecture material
Difficulty of quizzes and tests related to the amount of lecture material
Make it worth their money


Firstly, it is incredibly important that you are present at all times especially if the classroom size is big. The students are hoping to come to your lecture to learn from you and to learn from your experiences in the subject. Therefore, being there and always lending a hand is very important. Furthermore, if the size of the classroom is too big then consider getting many  TAs. The consequence of not always being present or not being helpful usually means that students stop coming to class because they feel it is not worth their time. I believe the classroom attendance steadily dropped to less than 15 - 20 people per class out of 100+ students across all sections.

Secondly, if you don't want students to object to this teaching style then make sure the teaching material provided to students is sufficient to study from. If the course is technical then a couple of handouts will not be enough. Students need a concept to be explained a number of times in numerous ways using multiple examples. This is how they will study for quizzes, tests and exams. Furthermore, embed your personal experiences and neat tricks/tips into handouts. If you are going to ask students to learn from just Khan Academy videos or something similar then I can guarantee that students will hate it. 

A follow up point to this is the difficulty of the quizzes, tests and exams. If you don't want your students to grovel over the course then make sure your quizzes, tests and exams are representative of the material that you have handed out. One of the main reasons a petition was signed at our school was because of the results. Whether the fault was with the teaching style or the students, that is difficult to say. However, most if not all of the students blamed the teaching method. At the end of the day, most students care about their grades and they will blame the most recent change which in our case was the change in teaching style. 

Lastly, make it worth their money (time). It is important that you explain to students either via hardcore stats or some other method that this is worth the money they have paid for the course. In our case, most students felt that the professor was being simply lazy by not teaching and felt they were losing their money. 

I hope this was helpful! Good luck!

EDIT: 

@JessicaB suggested that I didn't say explicitly where the professor went wrong so I would like to elaborate here.


The professor did not provide adequate learning materials. Finance 1 is heavily quantitative and therefore, most students require lots of examples and in-depth reasoning as to why things work. The strictly online textbook the professor used was not thorough enough to explain some of the problems students were having. Furthermore, the practice problems were not at all indicative of the midterm which was given. To draw an analogy, picture learning only how to solve equations of the form ax+b and then being on the midterm to solve equations of the form ax^2 + bx + c. 
The professor made no effort to provide students assistance even in class (which is the entire point to the flipped classroom concept). The professor usually had one TA which he would, literally, point to whenever we had a question. He made no effort to help students and would simply stand in front of the class. This pretty much made most people believe (and no evidence to the contrary was seen) that he was lazy.
He did not have office hours. If the student was not comfortable asking questions during class then tough luck. He refused to answer questions via email or during office hours.


Hopefully that is explicit enough on top of the points already provided before.