Neills DIY Gimbal Design

[R_Lefebvre]

BT, nice work. Are you updating your design files as you go?

If you want to take a crack at some home made vibration dampers, I've been making these for a while. They are relatively trivial to make, but work very well. You can vary the amount of damping by changing the tube material used, and the wall thickness. I've used kevlar reinforced automotive hose that is fairly stiff. As well as non-reinforced silicon tubing, with latex tubing being the softest. I have some 1/2" OD, 1/16" wall latex tubing that is *rediculously* soft.

All you have to do is cut a short piece of hose, pierce it in two places, and push screws through. It is based on an industrial rubber ring damper, but I DIY in order to scale it for the load they are carrying.

 

[BIGTACO]

Thanks! I have updated my solid model assembly somewhat per the design changes but not all. Really time consuming to go back through ya know and re-draw.

Anyways, in regards to the vibration dampners you made. Very nice design. It looks relatively simple and if it works well there isn't a better combo. I plan on seeing how well these rubber grommets work I have separating the gimbal from the multirotor frame. If they don't work well enough I will for sure look into applying your bits.

What chopper is that? Looks like a solid build.

BT, nice work. Are you updating your design files as you go?

If you want to take a crack at some home made vibration dampers, I've been making these for a while. They are relatively trivial to make, but work very well. You can vary the amount of damping by changing the tube material used, and the wall thickness. I've used kevlar reinforced automotive hose that is fairly stiff. As well as non-reinforced silicon tubing, with latex tubing being the softest. I have some 1/2" OD, 1/16" wall latex tubing that is *rediculously* soft.

All you have to do is cut a short piece of hose, pierce it in two places, and push screws through. It is based on an industrial rubber ring damper, but I DIY in order to scale it for the load they are carrying.

 

[jes1111]

If I knew what I know now when I first started...

Oh, yes! Sigh!

 

[R_Lefebvre]

That's an HK600GT. I don't use that subframe or aluminum case anymore, just have the APM mounted on a little cantilevered "pad" hanging out the back of the frame. The aluminum case was supposed to protect the APM board, as well as give it some mass for vibration damping. It worked well, but I am not sure it was necessary so I tried to simplify it. I had it flying pretty well on it's simplified incarnation.

I'm currently looking to build the whole thing into a 550 frame to simplify the servo mechanism, and may separate the power section from a stabilized section. (ie: shaky bits isolated from stable bits, including batteries for mass damping).

 

[PairAir]

Thanks for your effort, and for sharing it!

/Pär

 

[BIGTACO]

Of course! I made some more progress last night and will post up pics soon. She is coming along! Only thing thats been bugging me is having to wait on aquiring a decent gimbal controller. The offerrings that actually work well are so damn expensive.

Thanks for your effort, and for sharing it!

/Pär

 

[PairAir]

a decent gimbal controller. The offerrings that actually work well are so damn expensive.

I have a F550 with a AG550 gimbal. After watching some of the promoting videos from PhotoHigher I went along and bought the Skyline RSGS. They're having MAJOR problems solving servo jitter, yaw-roll issues and other stuff. A lot of upset customers out there. My personal opinion is that the Skyline works best on a really stiff and rigid gimbal, and that the AG550 lacks some of those qualities.

Hoverfly gimbal controller seems to do a decent job from what I've seen, but they too cost a bit..

/Pär

 

[BIGTACO]

Thanks for the heads up on the RSGS. I'll know to steer clear from it, atleast till photohigher works through its issues. It was on my radar though so this really narrows it down to only one controller, Hoverfly :-/

In the coming years we will see more and more usable controllers. All this gimble control technology is still in it's infancy.

I have a F550 with a AG550 gimbal. After watching some of the promoting videos from PhotoHigher I went along and bought the Skyline RSGS. They're having MAJOR problems solving servo jitter, yaw-roll issues and other stuff. A lot of upset customers out there. My personal opinion is that the Skyline works best on a really stiff and rigid gimbal, and that the AG550 lacks some of those qualities.

Hoverfly gimbal controller seems to do a decent job from what I've seen, but they too cost a bit..

/Pär

 

[BIGTACO]

Ok so here is my latest update. Got all the carbon plates drilled/cut to accept my Savox servos. I went with 1258TG on both axes. After installing them and getting belt tension correct I performed some backlash and general movement testing. OH MAN! These GT2 toothform pulleys and belts have zero perceivable backlash. No matter how small the movement I make with the servo pulley I cannot find any delay on the final rotating structure. Perhaps under load I will get some backlash, but it looks great so far! There is a tiny amount of backlash within the Savox servo geartrain of course but, compared to other servos I have used these have very very low backlash.

I still need to cut down my main shafts. They are a bit too long.

You will notice on the end of my aluminum servo pulleys there is extra shaft length sticking out. I will be placing 64 pitch spur gears on either axis. These spur gears will run up to 64 pitch pinion gear turning multiturn potentiometer. 3 turn pots per axis. The potentiometer gear set ratios are based on my desired amount of angular camera travel on a given axis, while rotating each pot through its entire range of rotation (1080 degrees). This will harness the maximum amount of resolution the pots have to offer. I believe this 2 axis geared external pot design will be unique to my design. Atleast to my knowledge. Hopefully it works!

 

[PairAir]

I like it a LOT!
Any chance you'd be selling plans or even the SW parts files/assembly?

/Pär

 

[BIGTACO]

Thanks! It looks really good I think. It should work well, I hope

I like it a LOT!
Any chance you'd be selling plans or even the SW parts files/assembly?

/Pär

 

[PairAir]

No worries! Maybe I'll get one of those kits one day, maybe you've inspired me to come up with my own design :nevreness:

/Pär

 

[BIGTACO]

I hope I inspire lots of people to build! You included. Competition and exchange of ideas is what makes technology progress. You don't need fancy equipment to build solid designs either. This entire assembly I have built with nothing more than a floor mounted drill press, bandsaw, dremel, basic tools, and beer.

 

[jes1111]

I hope I inspire lots of people to build! You included. Competition and exchange of ideas is what makes technology progress. You don't need fancy equipment to build solid designs either. This entire assembly I have built with nothing more than a floor mounted drill press, bandsaw, dremel, basic tools, and beer.

You see! Our approaches are quite different - you use beer, I use coffee (and a CNC machine)

 

[BIGTACO]

Haha. My morning approach is coffee but late evening can bleed into beer consumption!

I would love a lathe and brideport mill one day and then eventually get CNC added. What you have jes is my goal!

You see! Our approaches are quite different - you use beer, I use coffee (and a CNC machine)

 

[jes1111]

What you have jes is my goal!

What? a coffee machine?

I'd love a lathe and a Bridgeport, too - what I have is a German-made CNC router (720mmx420x110mm work area). Nice toy Cutting sheet GF/CF is easy enough, but I gotta stop breaking bits when 3D-cutting aluminium, Delrin, etc. - good cutters are not cheap!

 

[BIGTACO]

Nice. Thats plenty of work space for RC carbon/G10 parts. I would love to have one of those too! You know the saying "The guy who dies with the most toys wins".

Who am I kidding though. Right now I am at max density in my garage. But, in a couple years my wife and I will be buying a new home so when that time comes a large garage is in order!

What? a coffee machine?

I'd love a lathe and a Bridgeport, too - what I have is a German-made CNC router (720mmx420x110mm work area). Nice toy Cutting sheet GF/CF is easy enough, but I gotta stop breaking bits when 3D-cutting aluminium, Delrin, etc. - good cutters are not cheap!

 

[BIGTACO]

Progress update:

I finished my battery mount plate. Its 1/16" carbon plate attached to some thin aluminum channel for rigidity, and then that assembly is fastened to the underside of the landing gear. I had to fabricate my own rear "crossmember plate" from carbon fiber for the landing gear. I needed a larger hole for the battery to pass through out the back of the craft. This hole is large enough to allow for up to a 8000mah standard sized lipo to pass through. The battery mount plate has velcro all along its length. The battery can be positioned anywhere on the plate for proper balancing of the craft.

I also recieved in both of my external pots. I finished fabricating the tilt axis pot's mounting bracket from some 6061 I had laying around. In the picture below you can see how the pot will be oriented to the tilt assembly. A gear will be attached to the end of the pot and then another gear to the output shaft of the servo. Pot gear reduction will rotate the pot almost its full angular travel of 1080 degress for the 120 degrees of travel I built into the tilt tray (so the camera can look straight down and then 30 degrees up as well). I have redesigned my servo pulley to tilt tray pulley ratio much higher than the 2.5:1 ratio I previously had. Those new pulleys are still in the mail.

 

[PairAir]

Hey, looks good!
Would you share the specs of those pots?

Thanks, Pär

 

[BIGTACO]

Sure. Its a 5k ohm 3 turn precision pot with a .249" dia shaft. About 20 bucks. Was worried about runout since I am using 64 pitch pot gearing but after some testing looks like it won't be an issue.