When is a prop too damaged?

How do you decide when to change props?

I’ve attached a few pictures. These are all HQ 3x5x3 props.

One is brand new. One has a small chip. One has had some shaving down on the leading edges due to a crash. One has the tips shaved down due to a crash.

Do you change props as soon as there is visible damage? Do you have a certain threshold of damage before you change props?

Does it depend on how aggressive your pids or other settings are?

Do you not bother changing props until one is bent or broken?

Depends on what you want from the flight. I mean, definitely when your motors catch on fire due to D-term oscillations, but besides that there's a lot of factors.

- Am I flying for footage? You can't fix jello is post and can't always see it in the FPV feed, so I usually change more often.
- Are you flying a bit sneaky? Chipped props are louder.
- What direction is it? I always seem to break CW props more, so I let them get more wear than the CCW ones to try and even it out.
- Is it a regular flying spot? If I know I'll be back here next week I don't mind flying ratty props as much.

Normally I bite out any dings in the blade, but once the tips start chipping off I swap them out. It might be my imagination, but I feel like that has more impact.

Fire is definitely bad.

Does direction matter? I mean, for me, I tend to always crash on the right hand side, but that damages a cw and ccw prop.

unbalanced and damaged props does cause noise and lower the performance.
on a new build, i change them instantly after crashing, to prevent any damage to motorwindings and esc. i dont throw them away, i use them later on a not fresh build if they are still somhow flyable.

in a race or befor a race, any prop issue is very important to the overall performance: the general rule is if there was any contact in the air or to the ground, replace the full set of props. doesnt matter if the still look brand new, bo risk for lowered performance or burned escs or motors on a race.
on racedays alot still good props landing in the trash, sometimes i grab some new looking ones befor the land in the trash :-)

its kind of compromise, the best is to switch them on any contact but there is a difference about flies perfrct and flies ok... it depends on personal focus overall.

for sure any hot or warmer motor in comparison does show that the prop should be replaced.
as bigger the power to weight ratio, as more dramatic results from a bad prop.

(29-Mar-2022, 08:16 AM)Banelle Wrote: - Am I flying for footage? You can't fix jello is post and can't always see it in the FPV feed, so I usually change more often.
- Are you flying a bit sneaky? Chipped props are louder.
- Is it a regular flying spot? If I know I'll be back here next week I don't mind flying ratty props as much.

once the tips start chipping off I swap them out.

This is exactly the kind of detailed answer I’m looking for, so thank you.

I vacillate between swapping out at the first sign of damage and not swapping until a blade is missing or bent.

Sometimes I get superstitious and don’t want to change a prop because I think that as soon as I have a new prop on I’m going to crash.

(29-Mar-2022, 09:27 AM)hugnosed_bat Wrote: in a race or befor a race, any prop issue is very important to the overall performance: the general rule is if there was any contact in the air or to the ground, replace the full set of props. doesnt matter if the still look brand new, bo risk for lowered performance or burned escs or motors on a race.
on racedays alot still good props landing in the trash, sometimes i grab some new looking ones befor the land in the trash :-)

Any contact is a full prop swap?
I guess that makes sense in a race situation. If I was driving an f1 car and a tire made contact with a wall or anything else, I think I’d want all four tires swapped out because the other three would have wear on them that the new one didn’t.

…but yeah, I would totally grab those tires for daily use.

yes, any contact on a single prop result in switch to a full fresh set of four rotors. it doesnt make sense to swap three perfect props either but the risk to miss something and get any kind of issue seems more important than the 5bucks for a fresh set.
even if there are two backup quads or more, switch the quad is imergency situation, even expecting any kind of issue and any troubleshooting during a race isnt what we want.

the most important part of the rotor is the end of the blade, the one which receives damage first. the focus for performance quads should be that part of the prop, way befor that true damage like bending.

I only fly freestyle for my own enjoyment with no regards for capturing video. I run the PB&J which are pretty resilient but I only change a prop when it's mangled or it sounds wrong, sometimes that's not so easy to spot the bad one. Some are obvious and you can see the crease where you folded it back. Others are more subtle where it's bent at the hub but the blade appears fine.

If it can still do tricks without the motors catching on fire then all good  

But when I get back home, that's when I'll usually change out props even if they are still flyable.  And not just the damaged ones but the whole set.

When I race 3" micros, I pretty much fly them until the props are ground to a pulp because if I changed them every crash I'd be broke.

Freestyle, I fly PBJ's and usually replace if there's like 5mm missing off one rotor. If they bend I'll bend them back but if there's a solid crease I'll swap it.

One of the *serious*, really high level racers I've flown with will go thru 40-50 props in a few-hour practice session. 80% of what he throws out, I'd consider keepers. But performance is everything to those guys.

(30-Mar-2022, 02:18 AM)JinxFPV Wrote: usually replace if there's like 5mm missing off one rotor.  If they bend I'll bend them back but if there's a solid crease I'll swap it.

Pretty much what I do usually.

Sounds like the general consensus is:
If your racing, any contact is a full swap.
If you’re cruising/freestyle, as long as nothing is on fire and there’s no severe damage, if it flies it’s still good?

I always start worrying about vibration when I’ve got one prop in worse shape than others, but I think that might just be a holdover from my nitro rc plane days- where if you didn’t balance your prop it’d shake so much that the engine mount would try to come off the bulkhead.

All depends on how high your d gains are. I run pretty high d gains (50-60 on a 5"). Even just a few scratches with a slightly shaved prop or 1mm of a tip missing will lead to d term osvilation and hot motors. But the aggressive tune gives me the best prop wash handling. If you're running BF defaults then you can usually have pretty damaged props and be fine.

Also if you run high d gains don't expect to be able to turtle mode out of a crash and fly back. You will usually smoke a motor in the process because of the damaged props.

Guys, do you think my 3520 props are still usable after damages depicted below?

(13-Apr-2022, 01:04 PM)versus Wrote: Guys, do you think my 3520 props are still usable after damages depicted below?

I can fly those and it usually does not make much of a difference with small dings and bends and chip offs.

If the prop breaks at the hub or losses a blade that warrants immediate replacement.