Extruder controller does not heat above 73 Celsius

Hi,

I am trying to extrude for my first time but there is a little problem I came accross: when 73 Celius is reached the extruder turn off even though I have higher temp set (100,130,150). When temp drops back down to 67 Celsius heating turns back on and lifts the temp up to 73 degrees. then heating turns off again... And it goes on and on with no respect to the temp I have set in the software... CAPA comes out under this temp, very slow though... and I think it really need higher temp for lower viscosity...

Has anyone experienced similar things?

Thanks,
adam

it sounds like your capacitor value is either wrong or set wrong in the software, are you using 10nF? which i believe the wiki says the software comes with 100nF or 0.1uF as the default, this is also what you actually need to give reasonable range.

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Ian
[www.bitsfrombytes.com]

Ian,

I was using a 10nF capacitor and I set the value in the software too: 0.00000001F. It reads the ambient temp well but does not go over 73.

Do you think I should use a 100 nF capacitor instead?

Thanks,
Adam

I think the 100nF works better but depends on the Thermistor as well if you look at Steve DeGroof's blog (see one of his postings) he has a really good thermistor calculator that will show you the response to expect.

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Ian
[www.bitsfrombytes.com]

Hi satuna,

did ian's advice solve your problem? we just built a new heater barrel here and are using the RS thermistor, beta values etc are the correct, we are also using the recommended 10nf 0.01uf cap which i've tested to be 9.6nf.

i'm going to try with a 100nf cap now.

johnr Wrote:
-------------------------------------------------------
> Hi satuna,
>
> did ian's advice solve your problem? we just built
> a new heater barrel here and are using the RS
> thermistor, beta values etc are the correct, we
> are also using the recommended 10nf 0.01uf cap
> which i've tested to be 9.6nf.
>
> i'm going to try with a 100nf cap now.

Hi satuana,

The 100nF cap seems to work for now. Room temprature was correctly measured(21 deg. C), and it smoothly heated upto 115 deg.

Hi Johnr,

I have not tried it yet but certanly will tonight. I will post how it went. Thanks for help anyway.

Adam

Hey,

Just tried, works perfectly woth 104 ceramic capacitors. Reads the temp well and I managed to make it up to 130 Celsius. I suppose it would have gone further if I had not turned off the machine but did this convinced me. I need to try it with material too...

Adam

Hey,

Have u tried heating it upto 200C? I cannot go above 169C, and am aiming for 240C because of HDPE.

John

John,

Last night I did my first printing with Capa. I need to do a lot of tweaking yet but it went better then I suspected. The temp I reached was 155 maximum, I did not try to go over it because I did not need it. Tonight I will try to go up to 200 and will tell you how it went.

Adam

johnr,

I've run into the same problem. I've tried switching out capacitors to the suggested ones by using Steve's calculator. I am still not getting the heater response I'm expecting. I think it's due to how I input the capacitor value into the host software. I may just be stressed out and dumb. :-)

Demented

John (and Demented now too)

Last night I did some trials with the extruder again. I reached 167 celsius but did not go further. I am using the same capacitor as I have on my Power and Comm board and the value I have in the software is 100 nF. After Ians suggestion...

Adam

to all, i've now gone back to the original 1uf cap which the extruder board actualy has printed on it, changed the software parameter to match this, and have heated it up to 250c now, and i've printed the virgin section with hdpe.

our group have been using capa, but the thermistor leads broke etc etc and now we have a new barrel and dome, which are a different size to what we originaly have and the capa diameter is slightly larger than that of hdpe so it doesnt fit down the heater barrel smoothly, so we decided to go back to high temps and hdpe.

we'll see how next week pans out....