Using pixhawk running 3.2 on f450 quad build, 3s lipo, 1045 props, 935kv motors. When in stabilize mode, throttle is roughly 60% to get a hover, but switch to altitude hold and alt shoots up, as only 50%throttle is required for a held altitude, so I quickly drop the throttle to get the hold going. Then drop out of AltHold back to Stabilize mode and (you’ve guessed it) it drops as throttle is now too low for a hover. Is there a setting to fix this? Or is my setup just not providing enough thrust to maintain a hover at mid-throttle?
Your THR_MID is not set correctly.
You should study the wiki a bit as to how both the Stabilize and AltHold modes work. In Stabilize the throttle stick works in the traditional manner. But in AltHold it’s completely different. In AltHold mid-stick means the quad is directed to hover. Move the stick above and below the center and it either rises or descends. So what you describe is close to proper operation. Switching to Stabilize from AltHold (or PosHold or Loiter, too) can be…interesting and you have to pay attention. As already mentioned, setting your THR_MID will improve things a bit.
What about the TRIM_THROTTLE setting. Noticed mine is set to 395.
[color=#008000]Paul:
Please deactivate your aggressive spamfilter or change your email address to one without that service! For each email notification you receive from the forum e.g. for a subscribed topic, etc., your spamfilter sends a confirmation request email to the admin team ticket system, creating a new ticket. This is creating a huge amount of workload.[/color]
[quote=“StefanG”][color=#008000]Paul:
Please deactivate your aggressive spamfilter or change your email address to one without that service! For each email notification you receive from the forum e.g. for a subscribed topic, etc., your spamfilter sends a confirmation request email to the admin team ticket system, creating a new ticket. This is creating a huge amount of workload.[/color][/quote]
Stefan, My apologies. I have added ardupilot.com to my whitelist, so you shouldn’t get any more verification emails - sorry! I have been trying to change my e-mail address to the one I actually wanted to use during signup to this forum, but it says that its already in use. I logon using tapatalk with my tablet and that appears to have created an account for me under a different login, but I have no idea what the password is, and a reset password request for that account does not send me an email respinse, so I have not figured how to access that account. I am guessing however that it is called athertop and its registered against my other email address. If you could please locate and delete that account then I can change the e-mail address on this account to my personal one.
Thanks, Paul
Paul,
thanks for your understanding! I have deleted the user account “athertop”.
Have a good time in our forums! 
-S