Aixun T3A overshooting with JBC tip - Page 1
Forum section: electronics / general

author: tony359
author_rank: Frequent Contributor
timestamp: September 12, 2023, 02:10:49 pm
content: Hi all,I've got an Aixun 3TA and I've been experimenting a bit.I've noticed that the station tends to overshoot a lot but mainly only with a genuine JBC tip I purchased. When sitting on the thermometer, the power level sits at 0-3% as you'd expect then suddenly jumps to 100% for a moment and the temperature jumps to +40C above the previous recorded temperature. The temp then slowly drops down to the setpoint again. The display - of course! - doesn't record that!Is that kind of expected for whatever reason?

author: mastershake
author_rank: Frequent Contributor
timestamp: September 13, 2023, 02:28:49 am
content: what firmware? i know one of the older ones used to do this for me. i cant remember which one it was but it did say something about it in the firmware notes if i remember righthttps://aixun-updates.github.io

author: tony359
author_rank: Frequent Contributor
timestamp: September 13, 2023, 09:10:10 am
content: latest 1.34. Yes there is a note in the changelog about overshooting but that's an older version.I made a video of the issue here:https://youtu.be/z6oj99W5PH0I'm not using a wet sponge or anything, the tip is just sitting on the probe.I contacted Axiun, they replied that that behaviour is intentional to give the tip a little boost when the solder is being melted. I admit that sitting on a thermometer is not a "real world" situation as the probe doesn't have any mass there and you'd never keep the tip sitting on a solder joint for so much time.In real world you place the tip on a joint, the circuit detects a temperature drop and it sends a short burst to the heating element to quickly counteract that without waiting for feedback. However if there is no mass where to dump that energy, you then measure an overshoot.I suppose that if you measured on an actual joint, you wouldn't see that.Still, I would expect the tip to be able to keep a stable set temperature if not doing anything and I do not observe the same behaviour with the Axiun kinfe tip - which is smaller than the JBC.Aixun further commented on my query and stated that being a "non-Axiun" tip, "there maybe some little unstable factors occured during soldering". Uhm...What is the general consensus on Axiun tips? Haven't tested mine enough and JBCs are so very expensive!

author: c0d3z3r0
author_rank: Regular Contributor
timestamp: September 13, 2023, 05:28:31 pm
content: Quote from: tony359 on September 13, 2023, 09:10:10 amI have both Aixun and genuine JBC tips and working with JBC tips is waaaaaaaay better than Aixun

author: tony359
author_rank: Frequent Contributor
timestamp: September 13, 2023, 05:53:10 pm
content: As I suspected. When I got my Aoyue years ago it was UNUSABLE with Aoyue tips. It became a massive different iron with genuine Hakko tips.I'll keep buying JBC tips, thanks for the hint.Also thanks you and everybody else for answering my question on the other larger T3A thread. Just to close this thread, which I also have misspelled, the issue is with FW 1.34. Reverting to 1.33 fixed it.

author: thm_w
author_rank: Super Contributor
timestamp: September 14, 2023, 09:12:28 pm
content: Out of curiosity whats the tip geometry being tested here?Is it possible they've optimized for a larger tip size and didn't test with something small that might see a larger overshoot.I believe JBC might have some more intelligence in terms of detecting tip type/mass on first power up, but I could be wrong.

author: slavoy
author_rank: Regular Contributor
timestamp: September 15, 2023, 10:02:36 am
content: The initial overshoot is deliberately programmed into the software. However, the temperature should stabilize after a short while and fluctuate within 1-2 degrees. Unfortunately, I no longer have that station, and I don't remember which software version I had, but it worked perfectly for me regardless of whether the tip was JBC or Chinese-made.//Now I've noticed that reverting to version 1.33 solved the issue. Apparently, there's something wrong with the new software, and it's worth informing AiXun.

author: tony359
author_rank: Frequent Contributor
timestamp: September 15, 2023, 05:03:45 pm
content: Quote from: thm_w on September 14, 2023, 09:12:28 pmThis is a JBC 2.2x1mm chisel tip. Actually I experienced that with the larger JBC and not with the smalle "knife" tip from Aixun - I thought the same but in theory a larger tip would absorb those spikes more easily in theory.I'm told that with 245 there is no intelligence, the station doesn't know which is which. But I do remember watching a review (SDG electronics?) mentioning that the reason why a particular tip was not getting 100% of power it because it was being recognised as "small" and as such not able to take the whole 100% from the station.Quote from: slavoy on September 15, 2023, 10:02:36 amWith 1.33 there is no overshoot, not even when it starts from cold or when I put a wet sponge on the tip!Aixun "BS" me with some marketing stuff so I am not sure they would be interested in hearing my feedback to be honest.

author: Marcel
author_rank: Newbie
timestamp: May 10, 2024, 02:07:10 pm
content: Had the same problem with 1.35. Just wanted to downgrade to 1.33, but saw 1.56. With 1.56 the overshooting problem seems to be fixed.

author: ukmechanicalengineer
author_rank: Newbie
timestamp: December 13, 2024, 10:14:42 pm
content: if the problem with overshooting has been solved? thinking of buying T3A

author: DavidAlfa
author_rank: Super Contributor
timestamp: December 13, 2024, 10:20:24 pm
content: Quote from: tony359 on September 15, 2023, 05:03:45 pmNah... the reason is much simpler.A small tip have has less metal, thus above certain power it won't be able to transfer all the heat, self-limiting the power.The thermocouple might read 400º, while there's 300 at the end of the tip.

author: ukmechanicalengineer
author_rank: Newbie
timestamp: December 13, 2024, 10:31:57 pm
content: so is it worth buying T3A in 2025? or there some better stations for this budget?