Refurbishing propeller blades?

[vindibona1]

Like some, maybe all drone pilots, particularly us newbies, we all get a little too close to stuff. Mea culpa. I had a brush with a few tree leaves or blades of grass or landed 1/2" short of a bannister and nicked the very ends and sometimes leading edges of prop blades. Being extra careful I dutifully changed out the props, largely because I'm unsure of my skill level and don't want to add an extra element of surprise and unpredictability to flying.

I'm holding one of the "damaged" props in my hand and can feel a slight burr on the very very tip of the propeller. The leading edge is fine. I've got a few other blades with similar condition.

Would I be asking for trouble if I carefully filed down the burr (on the very end) and put the blade back into service as a "spare" if ever needed?...

...What about the leading edge? If just nicked up a small amount, could one carefully smooth out the nicks taking care not to change the attack of the leading edge and likewise using it for a spare if needed?

 

[ATP]

My concern would be an imbalanced prop situation, unless the same number of carrots (weight) were removed from the other prop on the same motor.

 

[old man mavic]

@vindibona1 balancing the props is the main issue ,but to be really honest ,its just not worth trying to use damaged props,as a further failure could spell the end of your drone

 

[BigAl07]

Props are a Single Failure Point on your aircraft.... It's not worth the risk.

 

[vindibona1]

My concern would be an imbalanced prop situation, unless the same number of carrots (weight) were removed from the other prop on the same motor.

Good thought. I do have a jewelry scale that measures within 1/100 gram. I had two blades from the same pair, one I filed gently and the other was undamaged, but both were replaced. They weigh exactly the same to 1/100 gram. Both are smooth now. Would this pose an issue in your opinion?

0.5 grams each... Can you say "light weight"????

 

[bumper]

If it's just a burr on the prop tip, no material missing, lay the prop on a hard flat surface (like a granite counter top etc). Use the round bottom of a spoon to press down on the prop and move the spoon off the tip. Repeat to "flow" the plastic back in shape. Carefully inspect prop to be sure there are no splits or cracks.

 

[vindibona1]

If it's just a burr on the prop tip, no material missing, lay the prop on a hard flat surface (like a granite counter top etc). Use the round bottom of a spoon to press down on the prop and move the spoon off the tip. Repeat to "flow" the plastic back in shape. Carefully inspect prop to be sure there are no splits or cracks.

Good suggestion. The amount of damage on the very tip was so minimal that as you can see from the photo above, weighing the good one vs the repaired one on a very sensitive and accurate scale I took virtually no material off. I wonder if I should always weigh my props to make sure I have "matched pairs"?

 

[DrizzyDrones]

Ive seen some pretty dmgd props with nicks on edge and they were not something I would feel comfortable flying with but they performed just like always I think the shape/ curve is more important/ more likely to cause problems but when in doubt change em out

 

[vindibona1]

Ive seen some pretty dmgd props with nicks on edge and they were not something I would feel comfortable flying with but they performed just like always I think the shape/ curve is more important/ more likely to cause problems but when in doubt change em out

I would tend to agree. I wouldn't want to fly with anything other than pristine props. However, it isn't so quick to get spares these days, at least at a competitive price. I wouldn't think of flying any distances with less than perfect new props, but in a pinch I want something so at least I'm not totally grounded.

 

[KB4MTO]

For the cost of new blades, I wouldn’t chance it. I went months without damaging any props. As I have gotten better and more comfortable with the sticks, I have pushed the boundary a little (low altitude and within visual). I have swapped out blades 3 times in 2 months. But I always know that the blades are good and the drone less likely to drop out.

At my favorite flying spot, there is a patch of trees and tall grass. I like navigating through that field and between the trees and branches. However, lately I have felt like lawn maintenance or a tree service flying in that patch of trees, trimming leaves, weeds, and grass with my drone. But my skills are improving and blades are cheap ?

 

[vindibona1]

For the cost of new blades, I wouldn’t chance it. I went months without damaging any props. As I have gotten better and more comfortable with the sticks, I have pushed the boundary a little (low altitude and within visual). I have swapped out blades 3 times in 2 months. But I always know that the blades are good and the drone less likely to drop out.

At my favorite flying spot, there is a patch of trees and tall grass. I like navigating through that field and between the trees and branches. However, lately I have felt like lawn maintenance or a tree service flying in that patch of trees, trimming leaves, weeds, and grass with my drone. But my skills are improving and blades are cheap ?

I don't disagree... But while I could get blades from Amazon 2 weeks ago for $12 today they were $20. And wouldn't you know I always nick the ones that have the double line. So while I have single line replacement blades (not sure which is clockwise or counter... or anti as the Brits say) for the single stripes I'm low on the doubles and they only come with even quantities for both. I did find one source for $12 blades including shipping and ordered some yesterday and should have ordered two sets but I'm not that smart. They'll be here by the end of the week.

 

[BigAl07]

I don't disagree... But while I could get blades from Amazon 2 weeks ago for $12 today they were $20. And wouldn't you know I always nick the ones that have the double line. So while I have single line replacement blades (not sure which is clockwise or counter... or anti as the Brits say) for the single stripes I'm low on the doubles and they only come with even quantities for both. I did find one source for $12 blades including shipping and ordered some yesterday and should have ordered two sets but I'm not that smart. They'll be here by the end of the week.

Blades should be considered "consumable" and you need to have several on hand for replacement. As you get better you'll "consume" fewer and fewer.

 

[bumper]

Blades should be considered "consumable" and you need to have several on hand for replacement. As you get better you'll "consume" fewer and fewer.

I guess I'm dang good then! I've had the same propeller blades (and hub) on my Mooney 201, since 1991 and through two engines!

Truthful embarrassing disclaimer time: Okay, I did replace the prop on my Husky (in avatar) once, pretty much destroyed it in a botched off field landing. That little goof cost me the equivalent of approximately 12,000 spare props for the Mavic 2 (a bit more was trashed than just the prop).

 

[Deleted member 103366]

With regards to balance and removing deformed material, if I remember correctly it is not only the actual mass removed that is important but its position as well, it shifts the CoG of the blade.
Maybe someone will confirm or refute that but currently with that thinking in mind I think Bumper's 'undeforming' is better than filing or shaving etc.

 

[WithTheBirds]

You get away with retreaded tyres most of the time to save a penny and without too much luck your disk rotors might work ok with new pads even if they are machined below the min thickness spec. The question is for the minor expense involved is it a risk your comfortable taking?

Props are very cheap in the scheme of things. Once you learn to fly you won't need to replace often but you should throw a set on even f the damage is minimal. One less thing to worry about.

 

[scro]

With regards to balance and removing deformed material, if I remember correctly it is not only the actual mass removedthat is important but its position as well, it shifts the CoG of the blade.
Maybe someone will confirm or refute that but currently with that thinking in mind I think Bumper's 'undeforming' is better than filing or shaving etc.

You do indeed remember correctly. The further from the hub the mass is the bigger effect it has on balancing. A small mass at the prop tip puts it out of balance as much as a much bigger mass near the hub.

 

[jnatt]

For the cost of new is it worth it..?

 

[Ol' Sparky]

Don't mess with things that spin at hundreds or thousands of RPMs. Imperceptible discrepancies can cause unseen issues at that speed. Buy some new props and a prop guard.

 

[vindibona1]

For the cost of new is it worth it..?

I agree... I've got 2 more sets of replacement props on the way. I still have one set in my kit so I should be good for awhile. Advice taken.

 

[Coco 60]

Why would someone even THINK about using refurbished props !!!!! It is the cheapest part of your drone ! just replaced with brand new ones, don't risk your $400 bird to save ten bucks !!?