No luck with ducks

My first attempt on hatching duck eggs didn’t end well at all.  I mixed them with the chicken eggs in the incubator which I know is not supposed to be done but I did it anyway.  I took a chance because I only had 5 duck eggs to start with and I have a 48-egg capacity incubator and so I didn’t want to ‘waste’ the space.  It takes 28 days for duck eggs to hatch while chicken takes 21 days.  And they have different timing requirements on when to stop turning the eggs.

They were already more than 24 hours delayed before it started pipping.  And just when I thought I’ve hit the rock bottom, the incubator all of a sudden quit working while the first duck egg was pipping and the beak was actually out of the shell moving.  I quickly transferred the 3 duck eggs in a box and placed it under a heat lamp in an attempt to save them.  It didn’t work.  I could not control the humidity and not having a thermometer handy, I couldn’t figure out whether it’s too hot or cold for hatching to complete.

I helped the first 2 ducklings hatch because they were struggling for so long cracking the egg shell and at some point they stopped chirping (pictures below)

The 3rd duckling (not pictured), I didn't help in the hatching process at all but still didn't make it.  

I've contacted the guy who sold me incubator and he will replace the incubator with another one. You definitely get what you pay for when it comes to egg incubators.  This one seems to be a piece of junk.  It quit working at the very crucial hatching time.

I'm not putting all the blame on the incubator because I did manage to hatch several chicken eggs in it.  So next time I incubate duck eggs, I will not mix with chicken eggs anymore.

It's frustrating. I simply wanted at least one duckling.  But I'll try again.