Finished housing most of mine. It's working great as a tempering bath. I like to let it run in the background. I feel pretty satisfied with it. Hah. Waiting on some more parts for it though, and have a lot of testing to do. I especially want independant power switches for the timer relay (to turn the air pump agitation off) and the two PID controllers as I don't intend to run them both always. Was going to also house the circulation pump inside but I'm thinking it might be a bad idea to have the pump right there. I have two outlets on the outside that I can run pumps with. And the bottom two outlets are isolated from each-other and PID controlled for the heating elements. Since the origional elements aren't a good idea at this point, I don't have a need to house it within the case.
Wow, step away for a few weeks, and I see a whole community is forming! Haha!
There are certainly lots of ways to skin this cat. Maintaining temps isn't necessarily rocket science, but it's a lot of fun when you decide to throw a rocket at it! Wayne, I'll be curious to know if the aquarium heaters do it for you. I feel they are sort of weak, and are probably better at maintaining than at initial ramp of the temps. Also, if your container isn't insulated, they might have a lot of work just dealing with the dissipating heat as the surrounding air tries to cool the container.
If you have a big tank, I think your original big heater would be just the ticket. But just make sure you have a strong circulation pump to keep the hot water moving off the heater. If the SSR can drive the heater (big question, make sure it can handle the load), it should cycle rapidly enough that the heater will never get very hot except during the initial heating. Mine cycles at a blindingly fast rate.
My PID controller has the ability to set temperature alarms. You might check that, if you fear the thing getting stuck on. Or, get a separate electronic probe with an alarm if you really want assurance. So far I'm not feeling the need, but I can imagine if you're D&D with big 8x10 sheets you might want some extreme assurance!
I love the simple roaster idea, but for the $ spent, I'm happy with my way-too-accurate bath...
But now Chuck, how do we keep the print drum inside the tempering bath while processing like the Jobo?
IT IS so much fun. Heh.
Originally Posted by chuck94022
I used them before in my kitchen sink for my tempering bath before. They're doing it great. Relatively. I have two 50W heaters. In the small tanks they were working beautifully. Two of them in a larger tank and they work beautifully.
Using them separately with larger tanks, I'm maintaining a stable temperature but it's having trouble auto-tuning. Sometimes it does, sometimes it doesn't.
They're in identical setups so when one did tune, I carried over the settings to the other one and it's maintaining no problem.
And yes, initial heatup on a large volume is going to take some time. Taking about 15min. right now. Scale it up using these heaters, and I'm probably looking at an hour long heat-up.
I have three heaters coming in to try out. Three 200w. Including a stainless steel one. Though I think by accident, I ordered a 220V so it's not going to be any better than the 50Ws I am thinking.
But I'm probably just going to go and find me a 1000W or 1500W heating element and be done with it. Which was the way I was going initially, but forgot. And ordered more aquarium heaters............
Oh, and I'll add that the thermostat (or capability) of my particular heaters are maxing out at 42C regardless of how far I turn it around. One seems to actually stop, the other goes round and round. But the temperature doesn't climb any higher than 42C.
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Ha, Chan Tran, for that you need a Jobo! Or a Sidekick.
Originally Posted by Chan Tran
Seriously though, I think your best bet is engineering something that keeps trays at temp for printing. Drums add all kinds of other variables, like rotation control, for example. Going there, I'd just buy a Jobo (which I used to own).
So for those of you wanting to use aquarium heaters to temper your water / chemistry, I have come across several different types that require different methods to adjust beyond their "maximum" temperature.
These heaters are all goverened by a thermostat that prevents them from heating water past a safe temperature for your fish. Which is always around 32C.
But the thermostat is capable of going above, or when using a PID controlled thermostat, disabled altogether.
In each case, the thermostat appears to be set with a screw on the end of the heater where the cord comes in. Turn one way and a plastic rod screws in to decrease the max temperature, screw the other way and the rod is pullup in the opposite direction.
They all use some sort of plastic limiter tab that prevents the knob from turning too much either way.
Sometimes they are built into the knob. So you remove the screw from inside the knob so it can be pulled off when it can't turn any more. And brought to the lowest temperature indicator, and you do that over and over again until you can't move it any more.
Others use a pointer on the knob that hits a plastic block. You can cut the block off or the pointer so there is nothing to stop it from turning all the way around.
Two other methods had internal blocks. One required pulling up on the knob once it reached the maximum and wiggle it to get past the block.
The other required the removal of the insides to cut out the plastic block. On that particular one, the insides are not epoxied or anything. Just set into a rubber bung to seal everything. Carefull pulling on the cord and knob slowly eased the bung out.
They're in a glass tube so don't put a knife or anything in it to pry it out or you'll just end up breaking the glass. Small $10 loss as that's all these things cost on eBay. But you can often be waiting for up to a month for them to come across on the slow boat.
The best aquarium heater I've found for this purpose is the one Walmart sells. The Tetra 30-60 aquarium heater. To adjust it, simply pull the knob off, re-position it, and keep cranking it to raise the temperature, I've gotten it to hold the temp at 101.8(F). It cost $15.
When my finances improve, I want to find a PID controller with a controlled outlet and let that control the temperature instead of the internal heater thermostat.
The PID controller is definately worth it.
And really, if you're DIYing, isn't that expensive.
My breakdown was this:
PID controller was $13, power switches and socket go for $4, thermocouple is $4, $2 for the plastic Dollarama bucket, $10 (5 each) for DC pumps, $3.50 power cord, $7 heater, $14 for GFCI recepticle. Plus some wire, solder (not necessarily needed), morettes (again, not needed), electrical tape, etc. Everything but the GFCI, wires, electrical tape, etc. were ordered off of eBay with free shipping.
I also purchased relays, but ended up killing one and went without as the PID controller already has.
I use a microprocessor controlled water bath I bought off ebay for $20. the tank it roughly 20" x 20" and 6" deep. I can set it for 105 degrees for E6 and it holds that temp within a quarter of a degree.
I tried the DIY/cheap way out and it was actually more expensive to go that route with buying all the parts and the time involved.