- This is an incomplete prototype frame (please read description below)
- This frame is a bit annoying to assemble in this current version (read below)
- Please look at the pictures and assemble as seen....this isn't recommended for people with zero experience.
- Pay specific attention to the lower arm plate and how the holes line up with the main deck...because if you don't you won't be able to get your stack screws in.
- For a 20x20 stack in the front, you MUST insert the stack screws in the main deck BEFORE assembling the arm complex.
- The special carbon for the arms is why it costs more but this price is lower than the sample batch price per item still. The final retail will likely be between $60-$65.
- Brain3D has GoPro mounts already designed for this frame. Just ask Brian Phillips for the Sonicare mountThis is a test run so we need feedback on the following:
- Gyro Scaled BB at 1.5k or 2k to look at resonance characteristics in the real world
- Durability of the arm structure and how it breaks
- General feedback of performance
We have spare arm struts and the arm linkage for motor mounting. We don't have spares of other parts for now. Let us know.
This will most likely be the last full size 5" quad frame coming from us in the foreseeable future unless some new development is found that makes a significant difference. Other form factors are being considered for improvements in other areas of flight performance from here forward.
The layout of this frame is very similar to the Prototype 5 however it mixes some elements from the Tooth Fairy 2 and has a very unique arm structure. The arm structure is designed to manage the torsional movement with respect to resonance as well as further dampen any resonance that does occur.
In order to design a frame that eliminates nearly all frame related resonance, the weight would be quite high. With this design, we've kept the built frame weight to 109g and have designed it to manage resonance below ~250hz. This does not mean you won't get ANY resonance below 250hz, it just means that real world testing and the finite element analysis of the structure tells us that the frame shouldn't be the cause of the resonance below that. A quad has a bunch of spinning stuff and other things bolted to the frame structure and everything has it's own resonant frequency which makes it impossible to manage all resonance. The goal here is to develop a structure that is more reliable than in the past. That means, if you build 100 quads on it, 95+/100 will actually work without much fuss. In the past, this ratio has shown to be no better than about 80/100 for any design we've looked at. This means that 80 of the builds will work fine and the remaining 20 will have weird resonance or otherwise odd problems that have to be figured out. This ability to 'just work' is not really a feature we're planning on marketing. It's more of a back end improvement to have less overall issues in the customers hands and reduce our customer service load. Unfortunately, the structure is just a bit more complicated to assemble so we don't really recommend it to people that have zero experience.
The arms have specially designed aluminum inserts that are supposed to be very slightly thicker than the carbon arm.....after a week or two of sitting around. Carbon compresses over time. The day you put together a frame, it'll be nice and tight but over a couple weeks the carbon will feel a bit loose because of this compression. The aluminum inserts are designed to maintain spacing such that the individual arms will have a slight amount of wiggle to them after this compression. Because the arm is an 'A' structure, this wiggle will not affect arm rigidity but it will introduce frictional movements that will dampen resonance. Furthermore, this frame does not require damping grease but it is designed specifically to work best with the addition of damping grease around the arm mounting complex. Damping grease works notably better on this structure than a more typical carbon sandwich structures because of it's design.
All that being said, the aluminum inserts are a total PITA to manage when assembling and we may get rid of the inserts altogether because it's extremely difficult to verify their effectiveness and it's even more difficult to manage the thickness of the carbon arms because we need thickness accuracy in the hundredths for this to be appropriately effective and carbon manufacturing at this grade just isn't that good.
Furthermore, the arms are using a very specific and special layup of carbon to better work with the two piece 'A' arm strut structure. In the past, various layups have been considered but after some testing, they were found not to have much improvement at all and were just more expensive. In these arms, we've traded ALL the 90deg sheets for 45deg sheets. The carbon engineers said this wouldn't work because the tension on the sheet would make the entire sheet bow. They were right about that and it did bow just a bit but it still works for this specific design because each strut is so skinny it doesn't matter....as long as the parts don't fall apart. What we will be looking for in these tests units are if the carbon arms explode or split randomly in minor to moderate crashes. Not the arm ends, the actual arm itself. They really shouldn't and the resulting structure is really quite nice.
Otherwise, the body is unlikely to change and any changes to the arms will very likely be compatible with this version of the frame. The carbon this prototype has been cut from is really nice stuff. A little better than the general run of batches.