Builds

As FPV racing matures, new rules and classes are put into place. One of the rule is the “250” size racing quads need to stick with 5″ props. To breath new life into those of use who has the popular H-style ZMR250 frame, I came had an epiphany and learn that you can configure it to have the motors in an X style configuration. Where roll and pitch are exactly the same.

Beyond that…I had a few wish list items I challenged myself with. I wanted all the weight shifted to the center of gravity as possible. Including the lipo…which is the holy grail IMHO. And one day, frame designers and engineers will take this concept more seriously. In the case of us local guys that is racing with the ZMRX…it’s a 4S 1000mAh pack. For me, I like agility for racing tight tracks…so a 3S 850-1000mAh LIHV is ideal.

So begins the next step of the ZMR Lite build…

I think more fun to come up with a design where others can easily follow along with their own frame. So I played with where the existing holes lined up into a perfect X. And then figured out how to cut so it’s easy for others to do. In the end, you essentially “connect the dots” for the most part.

Prototype #1.

Messed with it some more in SolidWorks…

Frame currently looks like this now. Fellow local Team WarpQuad squad is building one. Will update with final build pictures of his and mine at a future date.

Here’s a photo I took before the new antenna plate. Figured it would be easier and more robust with 3D printed antenna mounts.

Some ppl have been asking about my arm mounted ESC treatment…so here’s a closer look on how I do it now. It consist of mylar tape in the color of your choice. I like red. It’s thin, so I feel the FETs can exhaust the heat quicker through this type of covering. Follow by a CF vinyl weave. I use my Silhouette machine to cut it out. The ESC is secure mounted to the arm with Scotch Exterior Mounting Tape. Then cut a strip of Self fusing silicone tape. I wrap the wire/soldered joint and around the arm. The silicone tape only sticks to itself. Holds strongly. And I can easily remove to access the ESC for repair/maintenance.

And a couple of shots from the second ZMR X I put together…

Built with parts I have on hand. So a rev2 AfroMini 32. The new AfroMini 32 rev3 that I used on my ZMRX #1 is even easier to use.

A look at the the rear where the plugs come out of. The receiver and VTX are attached vertically to the XT60 on the 10mm standoffs. The XT60 mounting board can be purchased at BangGood for $1. Or $1.99 with the XT60 soldered. I like the bare plate and solder on my own black, XT60.

I plan on designing a top plate that doubles as a action cam mount for GoPro or Xiaomi Yi camera. This will put the camera at the COG, so you can record your flight without making the quad’s handling too bad.

LED light ring. Color selectable via dip switch on the board.

1st rev of the antenna mount… may add more features to it.

One without the VTX since the current build recommendation has the VTX antenna sticking straight out the rear. So it’s protected by the arms. And still give a good video feed during fast forward flight.

CAD and STL file download:

Update to add (2016-02-08) MultirotorMania has their Switchblade FPV quad frame design that I recommend to those who doesn’t have existing ZMR50 frame…or don’t like to mod their own frame into a X configuration. Perhaps built it with the ZMRX concept would take it to the next level.

Here’s a video of me cutting the plates in realtime to show you the amount of effort it takes so you can make a better decision to tackle this project.

Alternate configuration with the battery plate. Allows more space to hide things.

Just gonna share photos of the acro quad I am building. Thanks to Soma for coming up with the WarpQuad. Looks the best out of all the acrobatic quads out there.

Here’s the center frames. It sandwiches the 4mm carbon fiber legs.

I switched out some of the hardware. Such as the aluminum washer below. And used power cables that comes attached together. For a neater run of the brushless motor wires to the center of the WarpQuad.

Another change from the standard build out. I added 1.72mm washers so I can run the 22guage motor wire underneath the top plate.

Then I modified the XT60 lipo connector so that it can be sandwiched between the frames. Filed down the connector so it can conform to the curve of the top plate.

You can see where the power distribution harness will solder to and subsequently run to each of the ESC.

Those were the early photos. These upcoming photos are where the WarpQuad build out is at now. It took forever to source red aluminum washers with the same bevel as the blue ones I had on hand. Still not perfect but very close. The aluminum TeeNut that the frame is resting on is just to temporary hold the arms in place. And make it easy to disassemble without tools. This frees up my hand to ensure the cable runs are neat and nothing is pinched.

I switch to button head screws. Red aluminum 5mm. The hex size will take the same allen wrench to be consistent with the rest of the screw head used on this quad. The four button head should be strong enough to secure the motor.

Here is a closer shot of the red washers and where I intend on placing the ESC. In the center of the quad instead of on the arms like the reference build out by Soma.

A look at the cable run and how it meets up with the brushless motor. I created a stagger cut because I didn’t want to seperate the wires to fit heatshrinks. The stagger will keep the wires from shorting. As extra precaution, I applied Liquid Electrical tape to insulate. Then follow by a larger heatshrink to cover up the area. To dress up the heatshrink…I used chrome tape and nail art tape. This brings some blink down to this end of the arms.

Additionally, I hope the chrome take will help reflect some of the LED lights up to the props once I place one there.

Here is a look at the stagger cut I mentioned before. Some folks have asked why I choose to use four motor wires when brushless motors only require three. The simple answer is for symmetry once it gets to the center of the frame and have to go to the left and right of the screw.

The quad is ready for the ESC to be soldered on. Easy to do. However, I need to figure out how I want to route the power wires and still have room to fit the Flight Controller between the frame. There’s really no room for both. :)

added August 13, 2014: Check out the complete rev1 build here… http://www.rcgroups.com/forums/showthread.php?t=2176239#post28508149