Trouble with ceramic decals

[broken glass]

I ordered some ceramic decals, and applied them correctly, pushing air bubles out, and let them dry. The trouble i have is that when i try to fire them, My kiln AIM (biggest guillotine model, fuji controller) goes over the recomended temp of 1050. The result is that the decal looks like spots of the image have been burned off.

When i set my program (soaking schedule)for the night, even if the kiln is at 1050, it will ramp up to 1075 for some reason and then takes mabey ten minutes before it creeps back down to 1050, does any one else have this problem?? It is supposed to take 10 minutes to get to the desired temp of 1050,a nd hold for 30 minutes............... but allways jumps to 1075 first, going past my desired temp.?!

[The Lorax]

my aim (ls99 digi) also will also kinda range in temps.
say i am garaging at 1050, sometimes i will randomly notice it just dropping to 1030 or a little bit higher... it does it no longer than a few minutes... kinda lame, but not a problem or a issue yet..
interesting that decals are ceramic.. always wondered what they were made of. you are talkin about decals like on Roors or Toro Tubes right, just to be sure hehe.

[ech]

Digital kilns mainain temperature by turning on and off. When they go on they go to full power. The chip inside is internal programed to allow the air temp inside the kiln to sway 20-30 degrees in either direction from the temp Set point Temp. The actuall temperature of the glss fluctuates maybe 5 degrees. It won't cuase a problem. Every digital kiln I ever seen worked this way. I don't build the things and I'm not certain of exactly how the controllers are internally programmed but thats the basic jist of it.

You can always call aim and ask them to explain it to you.

[brettodie]

IM NOT SURE HOW BUT YOU CAN SET THE RANGE THAT THE KILN VARIES WHEN IT CYCLES ON AND AFF. CALL FUJI THEIR VERY HELPFUL WITH PROGRAMING THEIR CONTROLLERS AND ANY QUESTIONS YOU MAY HAVE. PEACE BRETT

sry bout caps damn video games :)

[mer]

my digi gives more play when i ramp the first time than when i make small adjustments. you might try ramping to 1000 and then slowly working up to 1050.

[kilgroth]

The fugi controllers have a setting to control the on/off duration. The setting on the aims is rather long, as to extend the life of the mechanical relay. The cycle can be set to anywhere from .1 seconds (i think) to 999? For more precise control you could set it to 2 seconds or so. This will however destroy relay more quickly. I think they are expected to operate 100,000 cycles or something. I recommend that you change the setting for firing you decals, and then change it back to the original setting. This will give you much more control. Mine is set at 2 seconds and my temperature is totally stable. I don't have the data sheet in front of my for the controller, but I will get it shortly. It is pretty easy to change.

[Swampy]

What Ech and Brett said, just to add;

The CAL controller I use has a 'holdback' value' that the user can specify, maybe there is a facility for that with your controller.

Imagine an aircraft climbing after take off to 1000ft... the flight controller levels off at target altitude... if it under -or overshoots the altitude, the controller adjusts the aircraft to target altitude.

Just the same as your controller does when the amount of tolerance you allow the controller to accept before it applies a correction.

So you could specify a 1 degree value before it makes a correction or 25 degrees.

If you specify 1 degree, it will take a long long time to creep to temp.

If you specify a wide tolerance of 25 degrees it will reach target temp quicker and either overshoot or undershoot by 25 degrees.

Now, imagine a man sitting on a mountain top, clapping just one hand.

See, it's easy!

[Swampy]

Oh, and if you can't adjust the holdback value, why not just set your target temp to 1000degF?

Definitely your decals are overfiring.

[max16o2]

where did you get the fire-ons?

[broken glass]

Wale has them, but if you google ceramic decals, I think you get to the places that Wale orders from. If i knew someone who spoke german, I believe the biggest best company is in Germany, not sure though, they seem to have the best website.

[canaan]

10 minutes to ramp up to 1050 ?

Is it me, or does 10 mi nsseem a bit hasty. Your kilns firebrick, foam or whatever wont absorb that heat evenly in that timeframe.

I ramp up to 1050 over a period of 1 hour. It's better for your kiln elements, and provides a more even absorption of heat throughout your kiln.

[broken glass]

yeah, when my running temp is 1050, and i set a ramp that goes from running temp to soak temp (also 1050) I set it to go from running temp to soak temp in ten minutes, this is 1050 also the soak time, also the running time, also the soak time also the running time, i set it ten minutes to get from the running time to the first soak time. The same temp....

So you go from 1050-1050 in one hour and then let it soak for an hour?? Mabey you should have read the post better. I am no fool.

[Greymatter Glass]

Any kiln can heat up to 1050 in 3-5 minutes no problem. It all depends on in 3-5 minutes if you have the right elements and enough power.

A 220 kiln can heat up MUCH faster than a 110v kiln of the same size also.


As for the controller... the Fuji is a great controller. the fuzzy logic and the 60hz output can be used to drive an SCR/IGBT device in place of a mechanical relay. An SCR or other solid state power device can be switched at high frequencies and are good for tens of millions of cycles or more.

With an upgrade to the power system your little Fuji controller can actually controll the amount of power going into the elements beyond full on/full off (sort of, it switches so fast the full wave can't get through so it clips the power, reducing the peak voltage by an adjustable amount).

When your mechanical relay blows it's something to look into. A decent upgrade. if you already have a digital controller the SCR and required wires are about $20-30 surplus or $100 new.

-Doug