Wanting to build an incubator, have questions

[littledel]

I am wanting to build an incubator from a small fridge or freezer, but need help in where to place things. Planning on having three trays that can double as hatching trays. Holding at least 140-175 eggs total for all three trays.
1. Where should the water container go
2. where should the thermostat/hydrometer be placed
3. where to put the fan and is one enough
4. best source of heat and where to locate it.

I plan to have three trays that I can also use as hatchers by turning off the auto turner. (where can I get a egg turner that can turn three trays. Also want to put in a large plexiglass window in the door so I can check on things without opening the door and losing humidity.

Any help would be greatly appreciated. Thanks

 

[bahamas]

the best source of heat would be using a seedling hjeagt lamp at the bottom and mounting a high heat lamp in the middle. One fan should be enough. you can put it neart rthe lamp , but not to close . Put the lamp on the farthest end of the centre and the fan on the oppsite farthest. a container with water shold go on top of the heat pad . thermotres can be set on each tray of eggs to measure the different temps as i am not sure they varry or fluxuate. but i hope this answers ur question

 

[muddstopper]

Quote:
1. The water container can be placed anywhere there is direct airflow, the humidty will depend on surface area of the water level in the container. Since surface area does matter, depending on the size of your water container, you may be able to locate it somewhere other than in the direct airflow. Where it is located is not as important as maintaining the proper humidity levels. Basicly, you will probably have to experiment some ith container size and placement location.

2. I like to place my thermometer as close to or just above the eggs themselfs. This is where the temperature needs to be correct, so why place the thermometer in any other location. Since most Hydrometers donot have an external sensor, and I have not found the humidity to vary to any degree in other areas of the incubator, it can be placed inside the cabinet where it can easily be observed. I Use a Accurite Thermometer/Hydrometer that will read internal and external temp. I Place the accurite in the window of the incubator and just lay the external sensor ( the one on the wire) in the egg tray. The internal temp reading I just switch to the clock so as not to confuse me when I look at the temp reading. I have modified a accurite by removeing the internal humidity sensor off the circuit board and placeing it on a wire so that that sensor too can be placed on the egg tray along side the external temp sensor. This allows me to keep my Accurite outside the incubator cabinet completely. I have found that this greatly extends the useful life of the Accurite by keeping the instrument outside the high temp/humidity enviroment.

3. Fan placement can be anywhere inside the cabinet, but its direct airflow should be across the heat source to help disperse the heat in a more even manner. I place my fan directly behind the nichrome wire I use for a heating element and I place my humidty tray directly in front of the nichrome wire. You donnot want to blow the hot air directly onto your eggs. Doing so will cause the eggs in the direct path of the hot air to become excessively hot, while other eggs will remain too cold. It will also cause excessive evaporation from the internals of the eggs that are in direct contact with the hot air flow.

As to whether one fan is enoungh will dpend on the size of the fan and the internal area of the cabinet itself. As a rule of thumb for my incubator cabinets, I try to size my fans on a 10:1 size ratio. Meaning a Cabinet that has a cubic area of 10 cuft, I would use a fan that blows 100cfms, ( cubic feet per min) This completely circulates the entire air volume 10 times per minute. This is probably way overkill in fan size, but my temps seldom fluctuate more than .1-.2 degrees. I have tried useing a 7:1 ratio, and found that not to be adequant so i guess somewhere between 7:1 and 10:1 would work. Any heat source you use will have a heat retention factor where it is still provideing heat, even after the thermostat has turned the heater off. This residual heat can cause a overshoot in your temperature regulation. I feel the higher airflow using the bigger fan helps reduce any overshoot in temperature.

4. Heat sources can be anything from a lightblub, Nichrome wire (my favorite), to some of the more specialty heaters such as the PTC, ( positive temp control), ceramics, to water heated radiators. I believe in the KISS principle, Keep It Simple Stupid. Light bulbs are probably the simplest to use, if the box gets to hot or overshoots, just get a smaller bulb. Not hot enough, get a large bulb. I dont like them because the take up to much space and are subject to shoot when you least expect them with the constant turning off and on needed to maintain proper temp control. For this reason I use Nichrome wire. This is basicly the same wire you find in your cheap space heaters. It is available in all sizes and the temp range is easily adjusted once you learn the basics of reading a ohm meter. The only thing I find most people have trouble with is reading theresistance of the wire and misinterpeting which way to go to chage its value. I have found that 60ohms of resistance to usually be adequant to maintain proper heat levels inside a cabinet incubator. To increase the heat on your heater, you would shorten the wire which would lower the rsistance. ex, If your nichrome wire is 10ft long and measures 60 ohms, to make the wire run hotter, you would shorten the wire to 9ft which would decrease the resistance, which would make more heat. Lenghtening the wire would increase the resistant and create less heat. As for placement, I prefer to place the heating element directly infront of the fan for the most air flow as possible. This will insure that the heat is quickly dispersed inside the cabinet and help reduce any hot spots or overshoot in temps.

5. Turner motors are nothing more than clock timers or stepper motors. Your cheapest and easiest source would to be to search one of the robotic websites and fine a good low dc voltage gear motor. The speed can be varied by simply reduceing the voltage going to the motor. AC motors are harder to vary the speed without some sort of pluse width modulator. The voltage of the DC motor must remain high enought to maintain the torque needed to turn the trays, and low enought so that the trays dont turn to fast. These motors can be hooked to your turning trays using a windshield wiper design you will have to fabricate yourself, for a constant turning of the trays. If you want the trays to turn a little and then pause before turning further, then you will need t0 use limit switches or electronics to accomplish this. Believe me, the electronics are the simplest way to go. You can contact cbiblis https://www.backyardchickens.com/forum/profile.php?id=41326 and purchase a complete electronic controlboard and gear motor assembly that will allow you to adjust the turning speed down to one turn perhr continuous or on a turn and pause. His control boards are designed to work with his selected gear motors and might or might not work with other low voltage gear motors on the market, so its best to purchase both together. I am currently using his controller and motors in my 3tray incubators ( 144eggs) and they are plenty strong enough for turning several more trays if need be. I had one in a 288 egg incubator and I suspect it could easily double that amount.

 

[bahamas]

yup. Just like i said. Muddstopper also gie a little more insight to the placement and what not hope all of our info helps.

 

[littledel]

Wow, Muddstopper, I really appreciate the info

 

[bahamas]

hey wut about me !!!!!!!!!!!!!!!?????

 

[littledel]

Well, I got me a non-working fridge witha freezer on top. Took off all the junk on the back and am ready to start shortly. I think I will use a light for my heat source, and a small fan mounted near the top to blow across the heat source. I will place the water tray just below that. My biggest issue now is finding an egg turner motor or a motor of sorts that I can use. And figuring out how to connect a thermostat to the heat source. any more suggestions

 

[bahamas]

i have kno knowledge of the motrors as i hand turn my eggs. ( it gives them the love they need ). but jope you get you answers.

 

[littledel]

I am unable due to my job to turn by hand efficiently, so an auto egg turner is a must. I may have to recruit some help I know of.