https://emlid.com/reachrs2/?utm_source=phantompilots&utm_medium=banner&utm_campaign=rs2_phantom_feb2021_leaderboard

Inexpensive but excellent upgrade - fixed prop wobble

Kevbac

Premium Pilot
Joined
Jan 14, 2021
Messages
6
Reaction score
13
Age
63
Location
Fredericton, NB, Canada
Some background... I bought a used P4 standard a couple of weeks ago. It was owned by a young person who had not been excessively gentle with it. The price was good and it's not in bad shape other than some discolouration and abrasions on one set of props and the little covers are missing from the top of one of the landing gear.
It flies well and the images and video are good.
But, during a couple of landings, I noticed some wobble when it was just a few inches above ground. I figured I had an unbalanced prop, so I bought a P4 shaft for my DuBro balancer. It arrived today, but the balancer isn't available to me right now - I'm in the middle of a move from one province to another. I also bought some new (non-DJI) props but they didn't solve the problem. They also didn't make it worse, so I figure it isn't a balance problem, unless the imbalance is the same in two sets of props, but on the same motor.
That got me thinking that there might be an issue with one of the motors being a bit loose - there are signs that the previous owner opened, or tried to open the shell apart at some point. So, I tried wobbling the motors - nope, they seemed solidly mounted. I put on the props to give a little more leverage and to see if maybe there was internal play. WOW... there wasn't play in the motors but two of the props had a bit of play between themselves and the mounts, AND... the other two had much more play. The two with a bit of play just made that nice whirr sound when I spun them. The other two rattled so loudly that I couldn't hear the motors' whirr at all.
These are quick release props. The mounts are the ones with the flat springs. I took the props off and bent the contact points on the springs up a bit to take out some slack. All four props now spun without rattling, but they all still had a bit of play.
A quick visit to Amazon later and I found the newer quick release setup for the 4 Pro. These use a coil spring to supply upward force and engage the locking mechanism. They were $20 (Canadian), so I figured I'd give them a try.
The props now have zero play when they're mounted. And, ok, I didn't think the two mounts with a little bit of play rattled - until I put one prop on the older mount and one on the new mount. I could easily hear the difference. I've attached pictures to show the difference between the old and new. You have to push down a little harder when you mount the props, but they are FIRMLY locked in.
I'll add another post after I fly with the new mounts.
P4 OLD mount.jpg
P4 NEW mount.jpg
 
Joined
Aug 17, 2014
Messages
1,440
Reaction score
659
Location
Long Island, NY
Thanks for that tip. Can you post the link to that product?
 

Kevbac

Premium Pilot
Joined
Jan 14, 2021
Messages
6
Reaction score
13
Age
63
Location
Fredericton, NB, Canada

Kevbac

Premium Pilot
Joined
Jan 14, 2021
Messages
6
Reaction score
13
Age
63
Location
Fredericton, NB, Canada
I just noticed that you can see on the picture of the older style quick mount, that there is still some evidence of the previous owner using the P4 to do some tree pruning.
 
Joined
Dec 25, 2016
Messages
1,836
Reaction score
1,098
Location
Tucson, Arizona
This issue is not newly discovered. The upgrade to the p4p style hub is one of the best that can be done for a p4. Probably countless p4’s have been saved from the death dive because of a loose prop from the issue you describe.
Glad you found the solution!
 
  • Like
Reactions: Kevbac
Joined
Dec 25, 2016
Messages
1,836
Reaction score
1,098
Location
Tucson, Arizona
I just noticed that you can see on the picture of the older style quick mount, that there is still some evidence of the previous owner using the P4 to do some tree pruning.
You should feel lucky. I have seen far worse.
Some props I’ve seen made me think the pilot was on the lawn mowing crew.
 
Joined
Feb 3, 2018
Messages
839
Reaction score
643
Age
57
Location
Albuquerque, New Mexico
Some background... I bought a used P4 standard a couple of weeks ago. It was owned by a young person who had not been excessively gentle with it. The price was good and it's not in bad shape other than some discolouration and abrasions on one set of props and the little covers are missing from the top of one of the landing gear.
It flies well and the images and video are good.
But, during a couple of landings, I noticed some wobble when it was just a few inches above ground. I figured I had an unbalanced prop, so I bought a P4 shaft for my DuBro balancer. It arrived today, but the balancer isn't available to me right now - I'm in the middle of a move from one province to another. I also bought some new (non-DJI) props but they didn't solve the problem. They also didn't make it worse, so I figure it isn't a balance problem, unless the imbalance is the same in two sets of props, but on the same motor.
That got me thinking that there might be an issue with one of the motors being a bit loose - there are signs that the previous owner opened, or tried to open the shell apart at some point. So, I tried wobbling the motors - nope, they seemed solidly mounted. I put on the props to give a little more leverage and to see if maybe there was internal play. WOW... there wasn't play in the motors but two of the props had a bit of play between themselves and the mounts, AND... the other two had much more play. The two with a bit of play just made that nice whirr sound when I spun them. The other two rattled so loudly that I couldn't hear the motors' whirr at all.
These are quick release props. The mounts are the ones with the flat springs. I took the props off and bent the contact points on the springs up a bit to take out some slack. All four props now spun without rattling, but they all still had a bit of play.
A quick visit to Amazon later and I found the newer quick release setup for the 4 Pro. These use a coil spring to supply upward force and engage the locking mechanism. They were $20 (Canadian), so I figured I'd give them a try.
The props now have zero play when they're mounted. And, ok, I didn't think the two mounts with a little bit of play rattled - until I put one prop on the older mount and one on the new mount. I could easily hear the difference. I've attached pictures to show the difference between the old and new. You have to push down a little harder when you mount the props, but they are FIRMLY locked in.
I'll add another post after I fly with the new mounts.
View attachment 121271 View attachment 121272
Are you using aftermarket props? If so, you might want to watch this:


D
 
Joined
Sep 10, 2017
Messages
96
Reaction score
80
Age
65
Location
Devon, UK
Some background... I bought a used P4 standard a couple of weeks ago. It was owned by a young person who had not been excessively gentle with it. The price was good and it's not in bad shape other than some discolouration and abrasions on one set of props and the little covers are missing from the top of one of the landing gear.
It flies well and the images and video are good.
But, during a couple of landings, I noticed some wobble when it was just a few inches above ground. I figured I had an unbalanced prop, so I bought a P4 shaft for my DuBro balancer. It arrived today, but the balancer isn't available to me right now - I'm in the middle of a move from one province to another. I also bought some new (non-DJI) props but they didn't solve the problem. They also didn't make it worse, so I figure it isn't a balance problem, unless the imbalance is the same in two sets of props, but on the same motor.
That got me thinking that there might be an issue with one of the motors being a bit loose - there are signs that the previous owner opened, or tried to open the shell apart at some point. So, I tried wobbling the motors - nope, they seemed solidly mounted. I put on the props to give a little more leverage and to see if maybe there was internal play. WOW... there wasn't play in the motors but two of the props had a bit of play between themselves and the mounts, AND... the other two had much more play. The two with a bit of play just made that nice whirr sound when I spun them. The other two rattled so loudly that I couldn't hear the motors' whirr at all.
These are quick release props. The mounts are the ones with the flat springs. I took the props off and bent the contact points on the springs up a bit to take out some slack. All four props now spun without rattling, but they all still had a bit of play.
A quick visit to Amazon later and I found the newer quick release setup for the 4 Pro. These use a coil spring to supply upward force and engage the locking mechanism. They were $20 (Canadian), so I figured I'd give them a try.
The props now have zero play when they're mounted. And, ok, I didn't think the two mounts with a little bit of play rattled - until I put one prop on the older mount and one on the new mount. I could easily hear the difference. I've attached pictures to show the difference between the old and new. You have to push down a little harder when you mount the props, but they are FIRMLY locked in.
I'll add another post after I fly with the new mounts.
View attachment 121271 View attachment 121272
Thank you taking the time to share this tip. I did know about this upgrade for the P4 but your post has spurred me into action and I have ordered a kit of new mounts. So for the next season I will be flying on new mounts and new props. The props that I have been flying on for the past 3 years still look to be in perfect condition but it makes more sense to fly on the new set and keep the old ones for an emergency spare set.

All the best, Martin
 

New Threads

Forum statistics

Threads
140,277
Messages
1,446,129
Members
102,049
Latest member
rephraim