Freewell ND Filters for H Plus

[LinsonW]

With a set of ND2, ND4, ND8, ND16, normally one filter is fine or should use two and more?

I think more than 2 would break the balance of gimbal.

 

[TurboDad81]

I'd probably statically balance it using some lead tape. Golf club balance tape works well.

Excellent idea. Thanks.

 

[Eagle's Eye Video]

With a set of ND2, ND4, ND8, ND16, normally one filter is fine or should use two and more?

I think more than 2 would break the balance of gimbal.

When being used on a gimbal setup, I would highly recommend that only 1 filter at a time be used... thus the need for a variety of densities, to handle a range of changing light conditions.

 

[thoneter]

When being used on a gimbal setup, I would highly recommend that only 1 filter at a time be used... thus the need for a variety of densities, to handle a range of changing light conditions.

Ur so bossy

 

[TurboDad81]

Meant to give an update on those filters and the balancing of the C23 camera. I went to a local golf store and bought lead tape. I put one of the filters on and balanced it with the lead. Got it so it was perfectly balanced. I tried to research calibrating the C23 gimbal, but apparently that doesn't exist. I took it for a flight, and the picture was terribly shaky. Kind of like when you leave the gimbal lock on. I brought it down and let it sit on my car hood. The gimbal was clearly shaking and sounded like it was struggling. I removed some of the lead tape to make it slightly front heavy. Same thing. Then, I took it completely off and it works great. I have flown it for about an hour total with no issues with each of the 6 different filters.

 

[PatR]

The combination of the filter and lead tape exceeded the gimbals’s PID settings, or power levels. Evidently they are enough to deal with the weight of the filter alone, but no more.

That’s not surprising for a gimbal designed to carry only a single camera and lens combination.

 

[LinsonW]

Meant to give an update on those filters and the balancing of the C23 camera. I went to a local golf store and bought lead tape. I put one of the filters on and balanced it with the lead. Got it so it was perfectly balanced. I tried to research calibrating the C23 gimbal, but apparently that doesn't exist. I took it for a flight, and the picture was terribly shaky. Kind of like when you leave the gimbal lock on. I brought it down and let it sit on my car hood. The gimbal was clearly shaking and sounded like it was struggling. I removed some of the lead tape to make it slightly front heavy. Same thing. Then, I took it completely off and it works great. I have flown it for about an hour total with no issues with each of the 6 different filters.

does it say the most filled filters in the market could be used without balanced issue?

 

[Phaedrus]

The combination of the filter and lead tape exceeded the gimbals’s PID settings, or power levels. Evidently they are enough to deal with the weight of the filter alone, but no more.

That’s not surprising for a gimbal designed to carry only a single camera and lens combination.

Probably right. Kind of surprised that the range is that tight on it.

 

[DCH]

The combination of the filter and lead tape exceeded the gimbals’s PID settings, or power levels. Evidently they are enough to deal with the weight of the filter alone, but no more.

I am finding the opposite when experimenting with 40.5mm filters and counterweights. I'm in the midst of trying to sort out the Buzz that sometimes still occurs with the Plus, even with the latest firmware. It's too early to say with any certainly, but I suspect there is not enough weight on the camera for the PID settings.

More on this as I learn more, I'm currently trying various filters with and without counterweights, and it seems that the more weight, the less tenancy there is for buzz. For reference, these filters range from 7g to 14g with appropriate weights that essentially double this range to14g~28g. So far the lightest weight combo causes severe chatter, the heaviest combo will cause buzz.

Meanwhile I think I have made what I think might be of interest to everyone with a Plus. I have reason to suspect that performing an accelerometer calibration also calibrates the gimbal. I need more time and testing before I can state this with certainty, but preliminary test results are quite promising! Anyone experiencing gimbal buzz is invited and encouraged to try this. It can't hurt, and in my case it has worked twice in curing severe chatter when I have changed filters and counterweights. Twice I have initiated an accelerometer calibration while the gimbal was chattering or buzzing. Both times the noise stopped at some point during the calibration process and did not return. Subsequent power cycles/flights are free of buzz, until I change out the combination again. Trying not to get excited about this discovery, but this would explain why there is no Gimbal Calibration in the Plus Calibration menu.

 

[Phaedrus]

I have reason to suspect that performing an accelerometer calibration also calibrates the gimbal.

Take a look at this video. The gyro calibration is for the gimbal gyro. If I messed with different weights/filters/balance I would always do the gyro/gimbal calibration before flying.

 

[DCH]

ake a look at this video. The gyro calibration is for the gimbal gyro

You are lucky to step right into the Plus without having an H480 first. It seems that owning an H480 first sets us up for misconception. I have watched this so many times I have it memorized, but he doesn't mention the gimbal at anytime, nor is gimbal calibration mentioned in the manual. I don't even think Chris himself is aware of this.This might be a safe assumption on your part, but those of us who come from the H480 -which has separate Gyro AND Gimbal calibration procedures- would have no reason to assume that the Gyro cal for the aircraft is also now the gimbal calibration on the Plus. -which by the way was not a static calibration for the CGO3+, it sent the gimbal thru it's entire range of motion several times and took a while to complete. (You'll find crazy YouTube videos of this from the cameras perspective) ...All we know is the Gimbal cal has been deleted with no explanation whatsoever in the manual or menus. This is just one of many many changes in procedure that is not covered in the manual.

 

[Phaedrus]

I get that. A lot of the earlier drones required you to mess around with the PID settings to get them to act right. As far as I know the only gyros in these aircraft are in the gimbal. No matter what you call it, if I put a filter, weights, etc. on the camera I would run the "gyro" calibration. I'd also do the accelerometer. May not help, but it most likely won't hurt either.

 

[DCH]

if I put a filter, weights, etc. on the camera I would run the "gyro" calibration.

To be clear, in all the steps I mentioned in post #189, I never performed a "Gyro" cal at any time, only the accelerometer. That is what fixed the buzz or chatter, not a Gyro Cal. This is why I believe that the accelerometer cal is what calibrates the gimbal, because that alone fixed the buzz. I cannot speak to Gyro cal and what specifically has to do with the Gimbal. I have always been under the assumption that the aircraft has gyros that need calibrating. Don't all aircraft use gyros?

 

[Phaedrus]

Not sure about the H+. Both gyros and accelerometers are used for stabilization. I suspect the accelerometer is for the main aircraft and the gyro for the gimbal. But then again, it could be the other way around. I'm going to guess since the H has an accelerometer and gimbal that the gyro on the H+ is for the gimbal.

 

[DCH]

Not sure about the H+. Both gyros and accelerometers are used for stabilization. I suspect the accelerometer is for the main aircraft and the gyro for the gimbal. But then again, it could be the other way around. I'm going to guess since the H has an accelerometer and gimbal that the gyro on the H+ is for the gimbal.

I just created an off balance condition, and the Gyro cal did nothing for it. I'm inclined to think that Gyro cal is for the aircraft, not the gimbal. This is getting out of my area of knowledge and I have to admit I'm not sure what -if anything- is at play for calibrating the Gimbal. I'm still not convinced the accelerometer cal is helping, it could just be a coincidence. I have now had it fail to fix a buzz once. So far all of this is pure speculation. I have no evidence that suggests the Gyro cal is doing anything for the Gimbal, and only some evidence that the accelerometer cal does.

This is gimbal subject is getting off the main topic, but clearly it needs discussing and needs it's own thread.

 

[TurboDad81]

I didn't mention in my last post (because I didn't think it was important), but I did tap the compass calibration menu 5 times and did all 3 of the calibrations in that hidden menu. It never got rid of the buzz, so I googled how to calibrate the gimbal and was brought back to a thread on this forum that said it didn't exist. That's when I removed the lead tape altogether. I'll get me a new kitchen scale and see what these filters weigh. I'm no expert on filters, but I haven't noticed any vignetting from them.

 

[Phaedrus]

Well, there you go. Didn't help. But, since it seems that it is fine without being perfectly balanced, then you can't argue with success. In the past a badly out of balance gimbal would cause all kinds of problems.

 

[DCH]

Well, there you go. Didn't help. But, since it seems that it is fine without being perfectly balanced, then you can't argue with success. In the past a badly out of balance gimbal would cause all kinds of problems.

One thing I have not mentioned that is significant to the balance question, and brings me back to the subject of factory fixed PID settings, the light (sometimes intermittent) Gimbal buzz (as opposed to chatter) is coming from the Gimbal azimuth pivot, not the horizontal or vertical pivots. I had to look and listen very closley, and the slightest side rotational nudge will quiet the noise instantly, while rotating it down will not quiet as quickly, and I suspect that the only reason is because the azimuth is getting nudged while moving the camera in any other direction.

I have also confirmed that the more weight there is, the less buzz there is. I just verified that the heaviest filter (14g variable ND) and counter weight totaling 28g/1oz will eliminate all buzzing problems completely. Anything less I will get the occasional intermittent buzz from the azimuth pivot.

 

[Phaedrus]

The weight making it quiet makes sense. In our RC plane with digital servos with a very tight deadband they will buzz at center as they are constantly holding center. Put just a tiny bit of pressure on them and they stop buzzing.

 

[RPR]

Hello gang,

Just wondering, does the C23 needs balancing with these filters?