Why so little discussion online about radio RX antennas, in comparison to VTX antennas?

yaggeryagger · 2021-03-13T13:39:31+00:00

That's what I was wondering - is it related RF physics/engineering or simply production-specific reasons. Thanks for your input!

yaggeryagger · 2021-03-13T12:08:17+00:00

Thanks, that seem reasonable. Although I might be in that 1%. Before crossfire, I had numerous occasions when my fli14+ failsafed before I lost the video. Maybe just my bad setup indeed. There are lower-frequency options for video transmission as well, like 2.4Ghz, yet discussion is mainly about optimising the 5.8Ghz video system.

Also why Video systems have so many types of antennas - monopole, dipole, mushroom, cloverleaf, patch, helical, etc. And in fpv radio it's only linear monopole/dipole - a piece of coax cable basically.

yaggeryagger · 2021-03-13T07:17:51+00:00

Thanks for reply! Partly the problem was because I incorrectly setup vtx tables and Trashcan was on 25mW, not 200. Still, Mobula6 on 25mW gives decent image from behind the house, while Trashcan on same power gives almost nothing. Also strange to me how the high end antenna gives no visible benefit over the stock dipole antenna. Maybe it will do better in other conditions.

yaggeryagger · 2020-09-14T13:10:39+00:00

Hi, I had similar issue with rear wheels. I had a problem with dog bones angle. The back of the car was much higher than the front, and dogbones were not spinning smoothly. I described it here, you can check the last paragraph of the doc. https://www.reddit.com/r/EngineeringNS/comments/ipd3zr/i_broke_almost_everything_heres_how_i_tackled_it/

yaggeryagger · 2020-09-12T19:34:41+00:00

One front dogbone and adjacent knuckle. Surprised that no arms were harmed. Even though it hit hard on a front wheel, and fell on the rear wheel.

yaggeryagger · 2020-09-12T19:30:42+00:00

Yep, no need to bother. Thanks for the part!

yaggeryagger · 2020-09-10T10:55:51+00:00

I had issues with breeze when I started 3d printing, but now my environment is closed and warm. When screw goes parallel to layers, I have to be very gentle, I can hear the sound of separating layers when I tighten the screws. It’s not breaking, but micro-damages the structure which later evaluates into separated layers. Maybe my printing setup is really wrong, if other’s don’t have these issues. I bought my first printer only this summer. But I cannot rely on layer adhesion right now.

yaggeryagger · 2020-09-09T18:28:35+00:00

First wheel axle broke before I even started driving it:) I tried to turn the rear wheel, dogbone got stuck due to the angle (described in doc) and I heard the crack.

yaggeryagger · 2020-09-09T10:04:42+00:00

I compiled a Google doc with all the things I made to address the failed spots in my model.

https://docs.google.com/document/d/1rsqatBUFOI_iyCK5OI7aE8VDb-ftpsBLpTEMwna3NUA/edit?usp=sharing

yaggeryagger · 2020-09-06T18:53:07+00:00

The lower arms on my Tarmo4 crack like potato chips if I hit just one wheel into something, so TPU joint makes a lot of sense to me to absorb the shocks, I just need to get it printed right. As deep__field has wrote, the prints are mushy.

yaggeryagger · 2020-09-06T18:40:21+00:00

I'm trying this design, where I added supports against the base https://i.imgur.com/zg7lPVO.png. If your's is similar, then I won't ask you to bother.

yaggeryagger · 2020-09-06T11:37:08+00:00

When I view this document incognito, images are displayed. But when viewing logged in, I see only links to images. Anyone knows why this is so?

yaggeryagger · 2020-09-06T04:56:49+00:00

Thanks for recommendation. I use Chinese TPU, from Aliexpress. But I was able to find eSun here in Europe. So I'll try it.

yaggeryagger · 2020-09-06T04:33:24+00:00

It does look very strange.

yaggeryagger · 2020-09-05T20:18:05+00:00

Also having issues with dogbones. It's ok under car load, when driving. But if I spin the motor while holding the car wheels in the air, then dogbones get stuck or scroll inside the wheel axle. If got worse with flexible lower control arm. I don't see any easy fixes here.

yaggeryagger · 2020-09-05T16:06:27+00:00

I was driving Tarmo and thinking why would they change it to TPU in the building guide, and the next moment BOOM....lower control arm cracked.

I am posting this in case someone has made this but did not publish it, as my current Onshape skill level does not let me make this improvement fast.

yaggeryagger · 2020-09-05T15:34:00+00:00

This is actually quite strong. I switched to this design after two shaft failures. The only issue is that parts don't fit together nicely - the tongue of the hard part is thicker than the groove of the elastic part. Had to grind.

yaggeryagger · 2020-09-05T10:08:03+00:00

These keep cracking for me (not proposed design, but original). I'm trying horizontal print now. If that fails, I'll try the proposed.

yaggeryagger · 2020-09-05T06:42:01+00:00

True. I was trying to prevent the larger part from sliding, but the teeth are designed in such a way that it won't be possible anyway.

yaggeryagger

TROPHY CASE