acceptable temp variance for an incubator?

[Genetic Rooster]

Having looked at many of the homemade incubators using hot water thermostats, and deciding on that build.... I am curious at what the temp variance is between cycles....
Presently toying with one such design, with the back drilled out..but am having a temp swing of 3 degree between on and off cycle.
it shuts off at 102 and will cycle back on at 99....if i set it to cycle off at 101 it will not cycle on till 98.....is this common? and is this within acceptable standards to successfully incubate chicken eggs?

 

[aprophet]

this guy has some good ideas about making t-stats work

http://cmfarm.us/stillair.html

 

[Genetic Rooster]

read it...using a power supply fan from an old tower...the thermostat is a standard lowes lower unit thermostat.....when used in close proximity to the bulbs it gets highly sensitive...and is actually so sensitive that it cycles in flashes only.....it holds an exact temp....but am concerned over causing brain damage, or serious psychological issues for my chicks....( not really) actually it concerns me over the flashing, i cant imagine any bulb surviving very long turning on 10 to 20 cycles per minute. so my solution was to move my heat source(light bulb) to the other side of the Incubator( omaha steak cooler) but now my temp variance is about 3 degrees......hoping I can get a solution that i have just over looked.

 

[abritton77]

I wouldn't use a water heater t stat. I believe that when you do the things that make it cycle really fast the temp setting at the t stat is higher than what your eggs see. Thats fine as long as your room temp does not change. If your room temp goes up then your incubator temp will go up and vice versa. I have a digital controller that I got off of ebay that holds the same temp no matter what the outside temp is. You place the temp probe close to the eggs and set it for the temp you want to hold. You can set the differential as low as .3 C which is about .5 degF. It only cost about 15 bucks more than a water heater t stat and is so much better. I tried the water t stat and couldn't make it work like I wanted. I keep my bator in the garage and the temp moves around almost as much as the outside temp. Just my 2 cents worth.

 

[rebelcowboysnb]

Quote:
I think you mean this page http://cmfarm.us/WHTincubator.html

 

[DadandJoJo]

I'm having the same problem guess I'll ask the question a different way. Ok if I had all kinds of extra $ I would have probally went with an egg turner super 5000 but this was just a small project for me and my daughter with the hope for modest success,our bator is fluxing about 3 degrees also. Are we just spinning our wheels with no hope of succcess? we are in about 5 days but are holding off candling till 10 days.. Its pretty much too late to try and adjust or fix this late into it. So if the stars all line up did we kill the batch or is there still hope?

 

[rebelcowboysnb]

3 degrees probably is equal to .5 to 1 degree in the egg. The should be fine.

 

[aprophet]

Quote:
I think you mean this page http://cmfarm.us/WHTincubator.html

thanks pal

 

[DadandJoJo]

Quote:
thanks thats all we want us newbies just frett or everything don't ya know

at least give us false hope for a minute

 

[aprophet]

Quote:
It is kina funny I may be the luckiest person in the world but I have 2 40 watt bulbs bought from the dollar store about a year and a half ago

they just hatched another 100%er for me

in one of my home built bators