My DS is 8 months old and I feel embarrassed to admit that he is fed to sleep for every nap and I let him nap in my arms. He has never napped in his cot. I have tried a few times but he just cries and cries and because I'm so desperate for him to sleep I give in to the tears and let him feed and then sleep in my arms.
However, yesterday I confirmed my return to work date as being only 8 weeks away and when I go back to work things will be a lot different for DS (not really relevant to post though).
Anyway - because of this I absolutely know that I have GOT to stop feeding him to sleep and instead be able to put him down in his cot and for him to settle off on his own.
His first nap today was on me and lasted 25 minutes - very poor.
For his second nap I let him feed to sleep (as I was do desperate to get a nap out of him) but he woke up after 25 minutes. He was still clearly very, very tired so I put him in his cot to see if he'd settle back off but he had a complete meltdown. I waited 5-10 minutes to see if he'd settle but he was getting so distressed and frantic that I gave up and bought him downstairs. He was obviously still tired.
I bought him down at about 2pm and I'm thinking that seeing as 1.5 hours have passed I might go and put him back in his cot and see if he sleeps. He looks so tired 
How long should I leave him in his cot before accepting a nap is not going to happen? I can't just leave him there for ages otherwise bedtime will come round.
I'm determined to sort out all the issues I have with DS's sleep because I've allowed him to get into some very bad habits 