I bought this original Acrobrat 3" frame about 2.5 years ago along with a load of parts and it went through a few dry build iterations, but I had some issues trying to 3D print some parts for it and then I completely lost interest in the build, so all the parts just got shoved in a box put on a shelf.

Even though this is now an old discontinued frame, I still like the uniqueness of it's design so I've decided to resurrect my original build plans for it and try to get it into a flyable state. It was always marketed as "feels and flies like a 5 inch quad" but I guess I'll decide that for myself once it's finished.

With a dry weight of 54g, a lot of people consider the Acrobrat frame to be a fairly heavy but that's not something which really bothers me. I won't be aiming to get this build below 250g because that weight limit isn't exempt from registration or any regulations in the UK so there is absolutely no point sweating over trying and do a sub 250g build, and I want to have some bells and whistles on it anyway so whatever weight it ends up at is what it will be. At a rough guess I think it will likely have an AUW of 300g, maybe a bit more. I guess we shall find out, assuming I actually manage to finish the build this time round.

       

I did consider making this a digital build but I already previously bought the stack and other parts for making it an analogue quad so I've decide to just keep to the original plan of building it as a traditional analogue quad.

The stack is an HGLRC XJB F440 TX20 V2 which has a 40A BLHeli_32 4-in-1 ESC so it's not a badly spec'd stack and I can't see me using it for anything else, so it may as well get put to good use in this build as per the original plan.

   

The capacitor that came with the stack is a 470uF 35V Sanyo branded one but I may substitute it for one of my trusted Panasonic FR series capacitors.

 

Like my other build threads, this will likely be a long(ish) running thread detailing my progress which is how I like to do build threads. I put them up when I start the build rather than at the end when the quad has already been completed. More posts and photos will come as I progress with the build.

I will be following this build. I have built an Acrobrat (well a clone, but were I live is impossible to get the real thing) as a first built drone and I like to see how it should be done . Also I would like to see an actual PID tunning for BF 4.2, Im currently using UAV presets for 5inch, but with the filter sliders at 1.2 as I had some flyaway's.

My cheap Built:
- "Acrobrat" clone frame.
- Emax ECO 1407 - 4100kv
- Gemfan Flash 3052
- Mamba F405 mini MK2 FC
- Mamba F30 ESC
- TBS UNIFY PRO 5G8 HV - RACE 2
- RunCam Hybrid2 camera
- Lumenier stubby antenna

Ciottifpv has MANY acrobrat builds (and crashes) under his belt.. he can tell you the BEST components for that frame..

You can't get the original Acrobrat frame anymore, and even the Acrobrat Duo that replaced it has also been discontinued, so the only option these days is to get a clone.

I'm not buying any different parts for this frame. What I already have is what will be going into it whether they end up being good or bad. The idea is not to spend any more money and to make do with / use what I already bought for it.

I bought most of the parts for this build back at the end of 2018. Diatone Mamba stacks didn't exist back then and the HGLRC stacks were considered to be a fairly decent F4 stack. Even today it looks reasonable compared to some modern stacks, and the BLHeli_32 ESCs are a bonus. The FC is just a bit lacking in UARTs, but I worked out there are just enough for all the external peripherals I need to fit. This quad won't be getting a GPS module so I don't need a UART for one of those.

I have HGLRC Flame 1407 3600KV motors for the build, also purchased back in 2018. I specifically bought these lower KV motors because at the time some people were complaining about short flight times on the 4000KV and above motors, so I purposely opted for more efficient motors rather than raw power to try and maximise flight time. These will be paired with Gemfan Windancer 3028 props (which I also already have), again for efficiency and flight time rather than outright thrust.

I originally bought a Caddx Turtle V2 camera to go in it but after disappointing reports of high latency on the split style cameras I binned the idea of using that and bought a Caddx Tarsier V2 for it instead.

had this fc in my hands today :-)
i dont like the pin connection and the result of ability to softmount it, but everything else on the very old hglrc 20x20mm stacks is still state of art: size, weight, performance...
i had a dino stack with 40a, blheli_32 and dshot1200 ability xD
do you have a solution to softmount the whole stack?

:-) will you go for emuflight? :-)

edit: some questions still answered :-)
3600kv isnt truly low :-)

(09-Jun-2021, 11:12 PM)hugnosed_bat Wrote: i dont like the pin connection and the result of ability to softmount it, but everything else on the very old hglrc 20x20mm stacks is still state of art: size, weight, performance...

On the Acrobrat frame the whole stack is soft mounted to the frame with rubber vibration isolation grommets that the M2 stack screws then go through, so the pin header connection from the FC to the ESC hopefully won't be too much of a problem from a soft mounting and vibration point of view...

 

The biggest downside with the pin headers connecting the boards is that you can't change the orientation of the ESC in relation to the FC, so if I want the USB socket accessible from the side I have to mount the ESC with the XT30 pigtail pads sticking out the side, and with the ESC motor pads inboard pointing forwards and backwards rather than a traditional setup with those motor wire pads on either side of the quad.

(09-Jun-2021, 11:12 PM)hugnosed_bat Wrote: :-) will you go for emuflight? :-)

I'm not sure yet. I will probably give it a try

Stack now bolted to the frame. You can see from the photos below what I mean about needing to have the XT30 pigtail pads sticking out the side and the ESC motor pads inboard of the frame if I want the USB connector to be accessible...

     

Both the original and the Duo have always been one of my favorite frames. The huge amounts of space make it so versatile. It's the only 3 inch frame that I can think of that can hold a Runcam Hybrid. Heck, I even fit a Fat Shark Shark Byte VTX, FPV cam, and Runcam Split cam in it and it still flew like a champ lol.

HGLRC Flame 1407 3600KV motors prepped and fitted with braided sleeving / paracord ready for installation on the frame. I guess the colour scheme of this quad has now been revealed

   

Prepped HGLRC Flame 1407 3600KV motors installed on the frame. Mixed orange and turquoise-blue theme at the front with all turquoise-blue theme at the back...

   

Man, I forgot that you bought an Acrobrat just before me X-D

Does that whole stack fit? I got a Mamba 20x20 and with only two boards there's not a lot of space. Can you split the VTX off and work around the devil pin headers?

(12-Jun-2021, 11:13 PM)Banelle Wrote: Man, I forgot that you bought an Acrobrat just before me X-D

Does that whole stack fit? I got a Mamba 20x20 and with only two boards there's not a lot of space. Can you split the VTX off and work around the devil pin headers?

Yes, the HGLRC stack "just" fits. I probably need to trim the screws down a bit (or try to find some a tad smaller) because the ends of them touch the top plate. Obviously I can't see the "8" LED display on the VTX but I won't need to anyway once IRC Tramp hooked up and configured.

The pin header setup actually works fine on this stack because the whole stack is screwed together as a solid unit so there is no chance of the pin headers coming loose like they do on some of the GEPRC stacks.

It was after yours and others reports of poor experiences with the Caddx Turtle that I gave up on the idea of using that. It's still in the box brand new and unused. Seems a bit of a waste but never mind.

Motors soldered up to the HGLRC DinoShot 40A BLHeli_32 ESC, then hooked up to BLHeliSuite32 to test the motors and configure their correct spin directions. All seem to be working just fine 

        

Camera cage bumper bars printed and fitted, along with colour-coded orange and blue stand-offs and screws...

       

nice tpu protectors!