Well, most of the time its quite hard to deal with both the main and the co-supervisor
As you've said, conflicting ideas (and probably some money matters) can be really cumbersome for the student @____@

Still, I'm sure your main and co-supervisor are literate in specific aspects of your field right? So usually you'll have to consult both of them anyway. For instance, my main supervisor is good at molecular biology; whereas my co is good at conventional morphology and taxonomy. Most of the time their area of expertise won't overlap

my case is different. my main will always invite co during our discussion. they collectively give ideas.

when main is not around, then we'll look for co.

my co during my master is just a name only. never involve in anything, and got his name listed in all my master publications.

For my case, all paperworks need to get his signature and this caused much delay. Also, my opinion is that authors should contribute or add value to the paper, not just because one is co-supervising. But that time, i was just a small fish 

Hehe procedures. When i was about to submit my thesis after viva, it was delayed by 3-4 weeks because need my co-supervisor signature and he was too busy to flip my thesis. Lucky you, some lecturers / researchers are ethical enough to refuse having their names in paper when they have no contribution, while others will go berserk  .

Anyway, back to the topic, i think it is good to keep co-supervisor in the loop so that he or she will know what is happening.

Unfortunately its easier said than done

I really dislike supervisors/ co-supervisors who never contribute anything (apart from asking students to add more unnecessary work into their papers/ thesis); and I even hate those who take credit for themselves or belittle our efforts/work put into the paper/thesis... Its sad that unprofessional supervisors like this (quite a lot summore) exists among the scientific community 

You are lecturer already bro? Or still student? 
If I do that I'll probably just forget about graduating

My main is an expert in the field (OB/HR) I'm writing.

My co is a statistics expert and also an expert in the business field.

Both are helpful so far. Can't say for the future. 

my main supervisor when i am doing master research is a lecturer who is master degree holder, excel in handling administration job, talkative but weak in guiding research candidate. Asking me to write conference paper but the main writer should be his name and also tag along his friend name (free ridesm).  I nearly quit the research field until my researcher frens suggest me to find another co-supervisor. Thank god! my Co-supervisor is an associate professor malay women, quite busy but helpful, knowledgeable and easy to talk with. The lesson i learn when finding supervisor is "don't simple trust the information stated in the CV especially when a lecturer boasted himself as hardworking, resourceful.... but in fact....you know"

My master supervisor also expected the same thing from me, and kept delaying my thesis until i have submitted a certain number of papers with his name as first author. Of course i refused and all hell breaks lose. During viva, i was not afraid of the external examiners but my supervisors instead! Was a very intense and stressful period towards the end of my master.

The graduate office staff assigns me to him as i am not the bachelor degree student in this uni previously. He had well establish networking (so-called cable) with management staff and i found that many academic staff boycott him such as purposely absent to jamuan organized by him.   What is more, that's really hard for me to seek help from other lecturer with the same area of expertise as my main supervisor. Some of them refuse to help me. After struggle for two semester, i decide to talk to dean straight away and assigned with another co-supervisor.  Unfortunately, i cannot change main supervisor as i defense my proposal dy. That's really a nightmare for me to deal with him in the past three years.....
For Lyners who decide to step into research field, don't judge a lecturer by his/her cv. Better try contact graduate students under their supervision to ask for clarification whether he or she is trustable or just a mr/dr/prof kangkung in fact.... 

Oh....good.

Which uni are you in?

The downside is that they tend to add in more ideas and give me more works to be done

If one is hardworking, I don't mind. The fact of the matter is that I am not