As silly as this sounds...

[Penged]

Should I do a PID aoutotune for the HE280 hotend? I have been doing pretty well with it "out of the box" until i printed with a temp of 225. It would only go up to about 218 until I turned up the temp a few degrees and it rose a few degrees. it seems to be consistently 5 degrees low.

[mhackney]

PID is not going to affect the target temperature. It's a control process to reach a set point as efficiently as possible without overrunning. Make sure all your connections and solder joints on the hotend are perfect. You should not have any problems getting to 225°C so something is not quite right. I would not muck with PID.

[IMBoring25]

I'd command it to temperature using a host software that has a PWM history record and review what the PWM does as it approaches the setpoint. If PWM goes down significantly, your PID may be contributing. If PWM stays at 100%, that would suggest you either have a physical problem with the circuit (possibly a bad connection) or the power supply is not delivering full voltage under load.

[rurwin]

PID is not going to affect the target temperature.

It can do. The proportional element is proportional to the error. So the higher output you need, the higher error you are going to get.
To correct that you use the Integral component. That has an increasing output as the error continues to have the same sign. However integral suffers from something called "integral windup" which causes huge overruns and the cure for that is to cap the integral component.

So I agree with you that the problem is probably hardware. But if the hardware is forcing the power output to be excessive in order to reach setpoint, tuning the PID can allow that setpoint to be reached.

[mhackney]

I agree, I was making the assumption that he has the stock PID settings and they should work fine to get to his target temperature.

[IMBoring25]

Since he asked about the HE280 and not the v3 it's probable this is a v2 that may have v2 PID settings and maybe even an old ATX power supply.

[mhackney]

Good point, we don't know what he has!

[Penged]

I have a v2 that I just (two weeks ago) installed the HE280 hotend on. I bought the v2 in November of 2015. I'm pretty sure it has the newer power supply. Much of what your saying is a little over my head in terms of understanding. I am confident in my mechanical skills but the software side of life often leaves mt glassy eyed.