IMU Mount Options on S800

[ProPilotWannaBe]

As we all know, the IMU mount on an S800 with the anti-vibe kit means the taking apart the S800 isn't as easy if you glue/tape IMU on the tray as recommended. In my case I mounted the MC on top of the S800 and now unplug the IMU cable... but it is loosening that connection.
Has anybody explored options for easy attach and removal from the tray?
What would you guys think if the IMU was stripped securely to the tray? Such as maybe using zip ties? Or a Velcro strap (definitely not Velcro under the IMU because of the squish factor, but just strapping it down)? Other ideas?

 

[deluge2]

Been thinking about servo tape mounting of IMU to CF or thin plywood plate, and then using zip ties or light bolts (nylon or aluminum) to attach plate to s800 frame. For take down just cut the ties or loosen the two bolts. The key is to allow install / removal without disconnecting the electronics and to achieve a mount rigidity comparable to the typical IMU direct install.

Steve

As we all know, the IMU mount on an S800 with the anti-vibe kit means the taking apart the S800 isn't as easy if you glue/tape IMU on the tray as recommended. In my case I mounted the MC on top of the S800 and now unplug the IMU cable... but it is loosening that connection.
Has anybody explored options for easy attach and removal from the tray?
What would you guys think if the IMU was stripped securely to the tray? Such as maybe using zip ties? Or a Velcro strap (definitely not Velcro under the IMU because of the squish factor, but just strapping it down)? Other ideas?

 

[ProPilotWannaBe]

Been thinking about servo tape mounting of IMU to CF or thin plywood plate, and then using zip ties or light bolts (nylon or aluminum) to attach plate to s800 frame. For take down just cut the ties or loosen the two bolts. The key is to allow install / removal without disconnecting the electronics and to achieve a mount rigidity comparable to the typical IMU direct install.
Steve

Steve, I'm not following. With the IMU anti-vibe tray, there is already a mount point for the IMU on the frame. As you not using that, and coming up with your own tray? Do you have a diagram of what you are thinking?

 

[deluge2]

Ill try to be clearer. Im not proposing a new tray, just a secure and reversible manner by which the IMU is mounted to the existing tray. The new plate is intended to mount to the tray, in a secure but easily and quickly reversible manner. Thus the mounting of the plate to the tray produces an IMU+plate assembly that can be securely mounted and easily dismounted without unplugging the IMU cable.

This can't be accomplished (easily) with just the IMU and the tray because there are no good secure and reversible mounting options (afaik). And the tray assembly itself also cannot be easily removed.

Most likely I will just mount the IMU to a CF plate that has tabs extending beyond the sides of the IMU that overlap the tray mount cross pieces (ie at the front and back of the left and right sides of the IMU). A small hole in each tab allows a short bolt to thread into a nylon-insert nut epoxied onto the bottom of the corresponding hole drilled in the tray mount cross piece. Believe me this is much simpler than it sounds. In fact it's the simplest mounting solution I can imagine that will be both secure and easily reversible.

For takedown, remove the 4 small aluminum bolts, lift off the IMU+plate assembly which remains connected to the FC by its CANbus connector, and then thread the bolts back in place for storage.

Steve

Steve, I'm not following. With the IMU anti-vibe tray, there is already a mount point for the IMU on the frame. As you not using that, and coming up with your own tray? Do you have a diagram of what you are thinking?

 

[ProPilotWannaBe]

Ill try to be clearer. Im not proposing a new tray, just a secure and reversible manner by which the IMU is mounted to the existing tray. The new plate is intended to mount to the tray, in a secure but easily and quickly reversible manner. Thus the mounting of the plate to the tray produces an IMU+plate assembly that can be securely mounted and easily dismounted without unplugging the IMU cable.

This can't be accomplished (easily) with just the IMU and the tray because there are no good secure and reversible mounting options (afaik). And the tray assembly itself also cannot be easily removed.

Most likely I will just mount the IMU to a CF plate that has tabs extending beyond the sides of the IMU that overlap the tray mount cross pieces (ie at the front and back of the left and right sides of the IMU). A small hole in each tab allows a short bolt to thread into a nylon-insert nut epoxied onto the bottom of the corresponding hole drilled in the tray mount cross piece. Believe me this is much simpler than it sounds. In fact it's the simplest mounting solution I can imagine that will be both secure and easily reversible.

For takedown, remove the 4 small aluminum bolts, lift off the IMU+plate assembly which remains connected to the FC by its CANbus connector, and then thread the bolts back in place for storage.

Got it. So we're on the same page. I was just going to do it without the tray. I was going to just strap the IMU to the tray with zip ties which I can cut easily and replace, as you stated. I may have to put some anti-slip tape underneath it. That is, unless someone sees that as non-advisable.

 

[jrlederer]

Got it. So we're on the same page. I was just going to do it without the tray. I was going to just strap the IMU to the tray with zip ties which I can cut easily and replace, as you stated. I may have to put some anti-slip tape underneath it. That is, unless someone sees that as non-advisable.

Sorry guys for the implied ignorance here, but I am a recent owner of a new Evo S800 and don't understand what you guys are talking about.?

 

[ProPilotWannaBe]

Sorry guys for the implied ignorance here, but I am a recent owner of a new Evo S800 and don't understand what you guys are talking about.?

On your EVO the IMU mount location on a tray that spans the frame below the main rotor/hub assembly. Typcally, a person places the IMU main controller on the main rotor/hub piece, but then places the IMU on the tray on the landing gear assembly. So if you want to take the S800 apart, now you have a cable spanning the two assemblies. This used to not be the case when originally the recommended IMU installation was on the rotor/hub assembly area. You could detach the landing gear assembly without much fuss. So the dilemna is, how to put the IMU on the lower assembly, and main controller on the top assembly, and quickly separate the two for dissassembly. For me this is becoming a regular routine since I have to pack up the S800 for airline travel. The way I went was to mount the main controller on top of the main hub assembly, and simply disconnect the IMU canbus cable during disassembly. The problem is that the connector is now getting loose from all the plugging/unplugging. Also, I would prefer to move the main controller inside the main hub between the two plates (but then the canbus connected is no longer accessible).

All that to say, I would like a way to keep the IMU plugged in, but simply and quickly release the IMU from the tray on the lower assembly. But that would mean not using the double sided adhesive tape, and figuring out a different way of securing the IMU on that tray. I am inclined towards simply zip-tying it to the tray, but I may have to put some anti-slip tape underneath (not something that glues the two together, but just something that prevents the IMU from sliding around under the ziptie).

Make sense?

 

[srbell]

I used an extension cable from one of my DJI Helicopter autopilots as I didn't need the length for the install. It seems you can buy these, but you could simply make your own. Ashlok connectors would be great as they lock in place. http://www.thunderboltrc.com/ashlok/AshlokInfo.html I've used these on turbine jets for years, very reliable.

As we all know, the IMU mount on an S800 with the anti-vibe kit means the taking apart the S800 isn't as easy if you glue/tape IMU on the tray as recommended. In my case I mounted the MC on top of the S800 and now unplug the IMU cable... but it is loosening that connection.
Has anybody explored options for easy attach and removal from the tray?
What would you guys think if the IMU was stripped securely to the tray? Such as maybe using zip ties? Or a Velcro strap (definitely not Velcro under the IMU because of the squish factor, but just strapping it down)? Other ideas?

 

[srbell]

Oops, I have no idea how the third image got there, not relevant lol!

I used an extension cable from one of my DJI Helicopter autopilots as I didn't need the length for the install. It seems you can buy these, but you could simply make your own. Ashlok connectors would be great as they lock in place. http://www.thunderboltrc.com/ashlok/AshlokInfo.html I've used these on turbine jets for years, very reliable.

 

[ProPilotWannaBe]

I used an extension cable from one of my DJI Helicopter autopilots as I didn't need the length for the install. It seems you can buy these, but you could simply make your own. Ashlok connectors would be great as they lock in place. http://www.thunderboltrc.com/ashlok/AshlokInfo.html I've used these on turbine jets for years, very reliable.

I agree. It seems like an extension mounted as you show would be the best. I'm gonna look into getting one.

 

[schwett]

here's what i did to make the IMU "removable" from the mounting plate of the vibration isolation kit without allowing any slop in it's placement or cable detaching/attaching:

it's a little hinged plastic part that snaps over the mount. it's keyed on the two short sides (the long sides of the crossbars) so that it fits exactly. it takes some force to snap it on but the plastic has enough spring.

the bottom notches over the support ribs and has a captured nut since i didn't want to rely on threading the plastic.

it's kinda overdesigned, but it seems to be idiot proof. like everything, it will look better when painted black.

 

[ProPilotWannaBe]

Nice job. As you said, a bit overdesigned, but solid. Thanks!

 

[Jasonpandre]

Hi Schwett. I love the production in your bracket. Excellent work. Certainly seems more secure than cable ties. Did you 3D print yourself?

I can't help thinking that it might be wiser to leave the IMU in place. I'm led to believe it's quite sensitive to vibration and slippage.

 

[schwett]

Hi Schwett. I love the production in your bracket. Excellent work. Certainly seems more secure than cable ties. Did you 3D print yourself?

I can't help thinking that it might be wiser to leave the IMU in place. I'm led to believe it's quite sensitive to vibration and slippage.

thanks jason. i did print it myself, on a dimension 1200es. i have a few other things cooking for the s800, simple camera mounts and things.

i didn't want to use zip ties which would constantly have to be cut and re-tied and potentially not always attached the same.

I'm also torn about leaving it in the original location - very secure and close to the CG, but not at all isolated from motor vibrations. i'll try it both ways and see if there's a difference.

 

[nickedw]

Hi guys, I went a different way with this. with a full system you need a can bus hub anyway, so I fabricated a bracket to mount this on the landing gear rails, that you can see in this picture:
View attachment 15814
You need to get the RC connector for the retracts, and in my case cross feeds from the primary receiver to the gimbal passed between the aircraft and the landing gear. I wanted this in a single connecter, so I just used an RJ45 (ethernet) moulded plug for maximum reliability and wired a standard IDC socket like this:
View attachment 15815

So I have my IMU, Z15, IOS D connected to the CAN BUS on the landing gear, and a single connector back to the Wookong M on the airframe.

This means I can split the airframe from the landing gear with just 4 simple connectors:
View attachment 15816

It's neater than this now, everything is braided properly, but I didn't take photos.


Here is schematic
View attachment 15813

I am also configured for one or two man operation with a simple toggle switch set on the ground.

All works well.

Regards

Nick

yonda aerial systems

 

[Jasonpandre]

Very nicely done Nick. It's a very neat build.

 

[ProPilotWannaBe]

Agreed. You pretty much did what I was in the process of doing myself (i.e. minimizing top and bottom frame connections, with some slight twists. Thanks for sharing!

 

[soler]

I took a slightly different approach to this and added an additional CF plate to the Landing gear in the centre above the cross bar. The CF plate has everything on it except the IMU (this stay on the IMU Plate). I then made a quick connector from the FC to ESC connection point.

With this setup I disconnect the quick connector and the aircraft comes free from the landing gear. As all the equipment is on the landing gear it makes it much easier to work with and no more need to open up the aircraft each time I want to adjust some thing.

 

[craigblues]

I took a slightly different approach to this and added an additional CF plate to the Landing gear in the centre above the cross bar. The CF plate has everything on it except the IMU (this stay on the IMU Plate). I then made a quick connector from the FC to ESC connection point.

With this setup I disconnect the quick connector and the aircraft comes free from the landing gear. As all the equipment is on the landing gear it makes it much easier to work with and no more need to open up the aircraft each time I want to adjust some thing.

Got any pictures?

 

[soler]

Sorry it has been disassembled, but I set everything up on the landing gear., even the GPS was mounted so I could completely detach the main body from the gear