FYI Prop+Hub Balancing

[z-axis]

I have always balanced my props for other multirotors and before I did any video with my new Solo, just for good measure, I balanced my props.

What I can tell you is that all four needed balancing, and the HUBS were especially out of balance. When your hubs are out of balance, the prop will turn left or right when the blades are set vertically on the balancer. Once your props and hubs are balanced, the prop will stay in *any* position of the circle without moving.

My point is that with both prop+hub balancing, my first gimbal video had no jitter. I also had done the HDMI cable rerouting.

If you are going to balance your props, balance your hubs, too. Mine needed a lot of weight, way more than I expected, to get them right. I do the props first (blades horizontal), then the hubs (blades vertical). I use aluminum tape (like the kind used in duct work, not duct tape, though), cut into ~1/4" x 2" strips and cut down to whatever size is needed for counterbalance.

I'll post a pic of my balanced set later today so you can see what I mean.

 

[Lamda]

I used thick CA for balancing the hubs. Was a slow affair - I didn't think I would need an accelerator to help with the curing. I got fed up and eventually used a little rubbing alcohol, which made it haze whitish, but at least it froze the CA in place.

I too was surprised by how much I would need. In contrast, the blades required just small pieces of scotch tape to balance but like you, I had to balance all 6 of my props. The scotch tape has yet to fall off after flying for the last couple of months.

The black props needed less balancing than the silver ones.

I will tackle balancing the motors next.

 

[User Name]

Has anyone tried using hot glue to balance the hubs? My wife picked up a hot glue gun for crafts, and I've been surprised at how well the glue sticks. On the hub, there shouldn't be significant centrifugal force, at least compared with out on the blades.

 

[Lamda]

Has anyone tried using hot glue to balance the hubs? My wife picked up a hot glue gun for crafts, and I've been surprised at how well the glue sticks. On the hub, there shouldn't be significant centrifugal force, at least compared with out on the blades.

Personally, I think it's too brittle and easy to knock off. But I guess it wouldn't hurt for you to try and let us know?

 

[Maddog]

Has anyone tried using hot glue to balance the hubs? My wife picked up a hot glue gun for crafts, and I've been surprised at how well the glue sticks. On the hub, there shouldn't be significant centrifugal force, at least compared with out on the blades.

I used hot melt glue and it works fine. After about 10 flights it's still there! It cools quickly which speeds up the balancing process and it can be removed, unlike CA.

 

[nexxypoo]

Has anyone tried using hot glue to balance the hubs? My wife picked up a hot glue gun for crafts, and I've been surprised at how well the glue sticks. On the hub, there shouldn't be significant centrifugal force, at least compared with out on the blades.

Good idea

 

[User Name]

Personally, I think it's too brittle and easy to knock off. But I guess it wouldn't hurt for you to try and let us know?

Huh, maybe it's the brand, but the stuff my wife has remains slightly flexible, not brittle at all, and sticks like heck. You can peel it off, but it takes quite an effort.

 

[Brian Mowry]

I've also been very happy with the hot glue method. I dries fast and sticks well. Like User Name said, "you can peel it off, but it takes effort". I used scotch tape to balance the blades and after a few weeks it is still there. Even after a short flight in the rain. I am planning on checking the balance again tonight to see if anything has changed just to be sure.

 

[z-axis]

I'm sure hot glue will work, but will just say that aluminum tape is much much easier and precise, and not messy. Same for CA...tried that (and the sanding method) till I got turned on to the aluminum tape method.

 

[User Name]

I'm sure hot glue will work, but will just say that aluminum tape is much much easier and precise, and not messy. Same for CA...tried that till I got turned on to the aluminum tape method.

So you're using aluminum flashing tape that you can get from Lowes or Home Depot?

I balanced the hubs on two of my props, and they required so much glue, I'd be concerned about the amount of tape I'd need to use.

 

[z-axis]

So you're using aluminum flashing tape that you can get from Lowes or Home Depot?

I balanced the hubs on two of my props, and they required so much glue, I'd be concerned about the amount of tape I'd need to use.

yes, that's what I use.

 

[z-axis]

Pics of balanced props


Cool thing about using the tape on the hubs is you just stack the tape one at a time till it's the right weight. All four props had hub tape but my 5-year old son got a hold of them and peeled it off of the other two before I could stop him.

 

[pyrate]

most people most likely do not understand CA

 

[Lamda]

most people most likely do not understand CA

cyanoacrylate? "Oh, they mean Krazy Glue..but just different varieties and thicker, sometimes..." I felt the same way when first researching what to use.

Then realized many manufacturers don't even call it by it's full name. Never thought it would be so hard to find some reasonably priced bottles locally here on the West Coast of Canada.

 

[Acroduster]

most people most likely do not understand CA

Oh. I thought he was talking about California...

 

[RichWest]

Z - Since you've been balancing props way longer than I've been flying, I trust your insight on the subject. Looking at your representative prop photos, for at least two of the four I can see, could the placement of the weight on the leading edge of the prop possibly effect the hub's balance? The hub weight is on the opposite side of the prop weight for both examples. Coincidence?

I guess my question is, have you placed the prop weight centered on the flat portion of the blade either top or bottom and then lacked a need to balance at the hub? I realize the advantage to leading edge placement, just ruling out other effects weight distribution could have on the props imbalance whether blade and/or hub.

I know this ain't rocket science either...it's just a conversation. I won't have my prop balancer for another week or so. Just asking so that I can reduce my method/effort to produce a balanced prop.

 

[PdxSteve]

I would highly recommend using something silicone based, like this: GE Silicone II 2.8-oz. Clear Kitchen and Bath Caulk-GE284 3TG - The Home Depot

We used that in the electronics industry to glue parts down to circuit boards. The circuit boards were on machines that vibrated a bunch, and also needed to withstand extreme temperature changes, which this stuff does wonderfully.

We used to use hot melt glue originally. Well, it, um, melts when it gets hot. Not very good around anything producing heat or will be in hot temps, or both. It also becomes very brittle when cold, in fact that's what we used to do to remove the stuff when needing repairs was to freeze the control and just chip the hot melt glue off. Going from hot to cold to hot to cold will also crack, weaken and damage it after time. The silicone will remain pliable and durable for many many years. It's an excellent adhesive. Use the same brand for sealing your sinks/tubs, etc. Wonderful stuff. Waterproof, etc.

 

[Del]

I would highly recommend using something silicone based, like this: GE Silicone II 2.8-oz. Clear Kitchen and Bath Caulk-GE284 3TG - The Home Depot

We used that in the electronics industry to glue parts down to circuit boards. The circuit boards were on machines that vibrated a bunch, and also needed to withstand extreme temperature changes, which this stuff does wonderfully.

We used to use hot melt glue originally. Well, it, um, melts when it gets hot. Not very good around anything producing heat or will be in hot temps, or both. It also becomes very brittle when cold, in fact that's what we used to do to remove the stuff when needing repairs was to freeze the control and just chip the hot melt glue off. Going from hot to cold to hot to cold will also crack, weaken and damage it after time. The silicone will remain pliable and durable for many many years. It's an excellent adhesive. Use the same brand for sealing your sinks/tubs, etc. Wonderful stuff. Waterproof, etc.

I'm going with the silicone!!!



Thanks for the info Steve

 

[Burkeam]

I've debated the question myself. I been using the hot glue for about 2 months. I use a paint stick to outline the glue should it would be recognizable if it came off. So far nothing has come of in several dozen flights. Let see when it get freezing out there. The paint also comes in handy to see which blades have been balanced. Just got 8 more.

I don't understand why you would add anything to the leading edge or topside of the blade. These are the twos area that effect the efficiency of the blade with the slightest disruption of the airflow. The bottom side will always have a lower velocity of flow and has far less impact on disturbing the lift of the prop. ???

 

[Maddog]

I've debated the question myself. I been using the hot glue for about 2 months. I use a paint stick to outline the glue should it would be recognizable if it came off. So far nothing has come of in several dozen flights. Let see when it get freezing out there. The paint also comes in handy to see which blades have been balanced. Just got 8 more.

I don't understand why you would add anything to the leading edge or topside of the blade. These are the twos area that effect the efficiency of the blade with the slightest disruption of the airflow. The bottom side will always have a lower velocity of flow and has far less impact on disturbing the lift of the prop. ???

I agree- if it ain't broke, don't fix it. I also don't like placing anything on the leading edge of the prop as it will cause some disruption of the airflow. How much? Who knows, but I do everything I can to minimize vibration. I prefer to sand material off the center of the bottom of the blade.