My rack is almost done! thermostat+probe questions and general feedback requested.

I read and looked up a lot of racks that were on the web and tried to take what I thought were good things from each of them. I am only trying to to collect a few nice snakes (at least a first) so I didn't need anything high volume or crazy. I ended up making a rack that holds 10 sterlite 32 quarts tubs. 2 Wide and 5 Tall. I made it out of melamine and 2x4s and then painted it and used pegboard to finish up the look. I used heavy dude casters to make it easy to move and left the 2x4s sticking up a little bit to be able to push it around if needed. (scroll down for pics) I am almost done and am at the heating part and had a few questions.

First off, thermostats/dimmers. I think I have decided on a basic herpstat to use in on/off. The room where my snake rack will be is in the 70-80 degree range all year (south florida). I have read a lot of postings saying that no matter how good your thermostat is, that you should use a dimmer as a back up in case it fails to limit that max power that would go straight the the heat tape. For an extra 10 bucks this doesn't sound like a bad idea but what do you guys think?

Secondly, I bought the 11 inch flexwatt that isnt in panels and can be cut any length and was going to cut 10 8x11 inch pieces, one for each tub. The pro to this is that the wires can exit out of the back and keep it a lot cleaner. This would cover about 1/3 of the tubs bottom. Should I make them cover more or less than 1/3?

Lastly my biggest question is where should I attach the probe? I can do it directly to the heat tape but im not sure thats the exact temperature that will translate to the inside of the tub where the pythons will lay. Do i need to measure the actual inside of the tub and adjust from there or do I just set the prob and assume the inside will be the same?

http://img594.imageshack.us/img594/7...1007023741.jpg

http://img403.imageshack.us/img403/2...1007023807.jpg

http://img210.imageshack.us/img210/6...1007023843.jpg

My first and only BP at the moment, my female "Fluffy." She is about 700 grams.

http://img580.imageshack.us/img580/9...1007023949.jpg

Quote:

---

Originally Posted by Billy305

Lastly my biggest question is where should I attach the probe? I can do it directly to the heat tape but im not sure thats the exact temperature that will translate to the inside of the tub where the pythons will lay. Do i need to measure the actual inside of the tub and adjust from there or do I just set the prob and assume the inside will be the same?

---

First, nice DIY rack. :gj:
As far as probe placement you want to attach it directly to the heat tape. You will then have to adjust your thermostat setting to get the correct temps in the tubs. The thermostat temp setting will usually be higher then what the actual hot spot in the tub will be.

nice rack, looks good !!! u could pry get away with two rows of the 11in heat tape on the back and do back heat.. that way u only have two lines of heat tape two sets of connectors and two wires... and by looks of it ur rack is only maybe 4ft high so only 8ft of heattape... just a suggestion

1/3 of the tub is fine. Break off a piece of plastic from another tub. Tape the probe to one side of the plastic, and the other side of the plastic to the flexwatt. This will give you a better idea of the actual temps inside of the tubs. Use a temp gun to dial it in perfectly. With balls, I like to keep temps around 92 on the hot side and 82 on the cool side.

Also, belly heat is much better than back heat, IMO. I have back heat on one of my 28 quart racks, and it runs at 100% constantly. My belly heat racks, on the other hand, usually only run at around 30%.

Thanks for the responses. I should have no problem chaining 5 pieces of 11 inch flex watt cut in to 8 inch long strips on 1 cord right? I was planning on using 2 power cords, one for the left and one for the right.

Wh00h00 thanks for the tip about the broken plastic piece. That's a really good idea.

The bit of tub for the probe is a great method I have used a bit of the lid in the past as my rack is lidless design...

The back heat does need more power to do the same job it does add a bit to ambient air temps but not enough to over come a cool room anyway so it really is a small gain.

no you should not have too many problems doing that assuming you ca cut the flexwatt at 8" sections some versions you can some you can't.

Nice looking job BTW!

wait how would the dimmer be used as a back up? can you explain

you could also do the heat up and down the sides like Animal Plastics does on some of their racks.

Using a dimmer IMO is a not very useful it bypasses the reason why you would use a t-stat. Personally I'd use a second on off t-stat as a back up.

it is easy and requires no wiring.

http://images9.fotki.com/v114/photos...drawing-vi.jpgHosted on Fotki

Quote:

---

Originally Posted by kitedemon

no you should not have too many problems doing that assuming you ca cut the flexwatt at 8" sections some versions you can some you can't.

---

http://www.reptilebasics.com/flexwat...att-heat-tape/

I bought this 11 inch flex watt because it specifically said it could be cut to any size and not just 1 foot panels.

Quote:

---

Originally Posted by Maddumpling

wait how would the dimmer be used as a back up? can you explain

---

From what I have read and understand it works like this (Which should work). You buy a dimmer/rheostat from somewhere like home depot and plug all your flexwatt in and get it to your 91 degrees or whatever you need by adjusting the dimmer. You set it just a few degrees higher. You realize that the when the dimmer is given 100% power from the wall side, you need the dimmer at 80% to get to the given temperature you want and leave it there.

You now unplug the dimmer and plug it into the on/off thermostat. So its:

Wall Outlet>Thermostat>Dimmer>Heat Tape

The thermostat works by turning on when its too low and off when its too high. The point of having a dimmer is that lets say the thermostat fails and get stuck in the on position, not turning off when it needs to. This means the Dimmer is getting 100% power all the time now. But you have the dimmer set to your 80% that you found out would yield that right temperature before which means that the temps are going to cap out there, preventing it from getting too hot and hurting your snakes.

I would assume a nice thermostat like a herpstat wouldn't fail but just in case the dimmer should still regulate the power to keep it from going all out.

Again I havnt done any testing and am not going to purposely break a thermostat to try it out, but in theory it should work.

Quote:

---

Originally Posted by kitedemon

Using a dimmer IMO is a not very useful it bypasses the reason why you would use a t-stat. Personally I'd use a second on off t-stat as a back up.

it is easy and requires no wiring.

http://images9.fotki.com/v114/photos...drawing-vi.jpgHosted on Fotki

---

I completely agree that this works too but is obviously more costly. I think the dimmer would work as a back up especially if you room temps stay pretty decent like mine (72-80)

The problem is, the dimmer limits power from the t-stat. Exactly like you describe. It works perfectly in stable room temps why use a t-stat at all. Stable room temps don't change and a dimmer is all that is needed. Lets say you do not have stable room temps they vary and the use of a t-stat is needed. So you set you dimmer to provide a max temp of 100? say 75% power to the pad. The problem comes in when the room temps drops the t-stat is trying to over come the room temps but the dimmer is restricting the top end temp and at 78º room temp it delivers 100º but at 68 is is maxing out at 90º so the t-stat stays on all the time and the enclosure fails to get over 88 or 90 as the enclosure takes some temps. With tubs that lose heat quickly this can be exaggerated more than my example.

A second T-stat checks temps and as the room temp drops its probe responds the same way. It requires less intervention on the keeper. The part that makes me really question this idea is if it is set in a cool environment and the t-stat fails in a warm one the dimmers maxed out temp could be quite high, too high even. Especially with flexwatt that can get very hot.

Good point. I was assuming it would make the t stat stay on.buy not sure how much more. The herpstat says it has feature that will turn it off if it.fails but I guess a backup is still good

nice work mate!

Herpstast shut down if the probe fails but the unit can also fail and has a good chance of failure wide open. I have had one of 15 probes fail the unit continued to run full blast. I would always recommend a failsafe, a dimmer if you have stability and a second t-stat if you don't. The units don't fail often but pulled off probes is far more common. Failsafes protect against accidents too.

@kitedemon. Thanks again for the input. I just ordered a herpstat for my rack and I think I'm going to order one of those hydrofarms you were talking about in one of these other posts as a on/off back up. What do you think?

I think I am also going to buy a few extra hydrofarms for ambient heat bulb temps for my 40 gallon breeder when the house starts to get a little cooler in the winter. Would you use a back up for the UTH and lamp as well?