Posts: 23 Threads: 4 Likes Received: 14 in 8 posts Likes Given: 4 Joined: Mar 2020 Reputation: 0 12-Mar-2020, 10:27 PM (This post was last modified: 12-Mar-2020, 10:29 PM by Sketchy_D.) Hey folks! So I pulled the trigger on an ImpulseRC Reverb clone frame with 290mm wheelbase for my first build. I'm looking into getting the DJI FPV complete package (radio, goggles, Air unit) as they're pretty easy to source locally, while they're on backorder as separate items (particularly radio and goggles). Empty frame:  Now, I've seen the method where the rear standoffs are removed and the Air unit is mounted in the back with a 3D-printed frame extension. Personally I don't think this is aesthetically pleasing, and I'd rather have the Air unit somewhere in the frame -- either mounted right behind the FC-ESC stack, or hung on the top plate. Having done some eyeballing and measurement, I'm pretty certain there's no way to fit the Air unit within the frame, unless I get rid of the middle standoffs like such:  Measurement details of the rear:  Further eyeballing suggests that I could probably fit a Caddx Vista while keeping all the standoffs. I'd rather use the Air unit though, because DVR  My question is: can I get away with getting rid of the middle standoffs and just mount the Air unit on the top/bottom plate? As an aside -- I'm planning to run the Diatone Mamba F722S FC-ESC stack and a top-mounted Dinogy 1800mAh LiPo pack. ![[-]](https://intofpv.com/images/collapse.png) • Posts: 21,174 Threads: 581 Likes Received: 8,920 in 6,599 posts Likes Given: 1,425 Joined: Jun 2018 Reputation: 786 Yes, you can omit those standoffs. You just need to understand that there will be less strength in that part of the frame, so if you crash, that will be a weak point and you could end up with cracked top and/or bottom plates with a risk that your stack could also get crushed in the process.
Another option would be to design a 3D-printed mount that houses the DJI Air Unit and provides securing points at the same hole positions at the top and bottom of the frame where the stand-offs are missing. I guess that depend on your 3D printing capabilities, or if you know someone who could do that for you. • Posts: 23 Threads: 4 Likes Received: 14 in 8 posts Likes Given: 4 Joined: Mar 2020 Reputation: 0 13-Mar-2020, 01:07 AM (This post was last modified: 13-Mar-2020, 01:17 AM by Sketchy_D.) (12-Mar-2020, 10:57 PM)SnowLeopardFPV Wrote: Yes, you can omit those standoffs. You just need to understand that there will be less strength in that part of the frame, so if you crash, that will be a weak point and you could end up with cracked top and/or bottom plates with a risk that your stack could also get crushed in the process.
Another option would be to design a 3D-printed mount that houses the DJI Air Unit and provides securing points at the same hole positions at the top and bottom of the frame where the stand-offs are missing. I guess that depend on your 3D printing capabilities, or if you know someone who could do that for you. I was worried that taking the standoffs would have structural repercussions -- thank you for confirming this. As for a 3D-printed caddy for the Air unit... Probably something like this?  (I suck at designing stuff, please don't shame me) The idea is that the caddy would be bolted from the top, while relying on friction at the bottom. • Posts: 21,174 Threads: 581 Likes Received: 8,920 in 6,599 posts Likes Given: 1,425 Joined: Jun 2018 Reputation: 786 13-Mar-2020, 01:19 AM (This post was last modified: 13-Mar-2020, 01:19 AM by SnowLeopardFPV.) Yes, that's exactly the sort of thing I had in mind. I would keep the rear metal stand-offs running the complete height of the frame and just use the caddy to provide support for the missing stand-offs in the middle. So design the caddy whereby the rear stand-offs run through the caddy, and where the front of the caddy itself acts as the structural support/standoffs with it just bolting to the top and/or bottom plates of the frame. I'm also a noob to 3D design so there will be no design shaming from me I use Tinkercad if I can get away with it, and Fusion 360 if I need to do something more complex. • Posts: 23 Threads: 4 Likes Received: 14 in 8 posts Likes Given: 4 Joined: Mar 2020 Reputation: 0 • Posts: 21,174 Threads: 581 Likes Received: 8,920 in 6,599 posts Likes Given: 1,425 Joined: Jun 2018 Reputation: 786 Yep, that should do the job nicely  • Posts: 23 Threads: 4 Likes Received: 14 in 8 posts Likes Given: 4 Joined: Mar 2020 Reputation: 0 (13-Mar-2020, 09:38 AM)SnowLeopardFPV Wrote: Yep, that should do the job nicely As the caddy will be susceptible to the Air unit’s heat, crashes, prop strikes and whatnot — I’d assume PLA and ABS is out of the question? Would you say PTGE or nylon works for the caddy? • Posts: 139 Threads: 35 Likes Received: 59 in 39 posts Likes Given: 30 Joined: Aug 2019 Reputation: 2 Your Mileage May Vary but I omitted one pair of standoffs on my Source One for this exact purpose and crashed it hard many times without issues. • Posts: 23 Threads: 4 Likes Received: 14 in 8 posts Likes Given: 4 Joined: Mar 2020 Reputation: 0 (13-Mar-2020, 02:29 PM)zenm8 Wrote: Your Mileage May Vary but I omitted one pair of standoffs on my Source One for this exact purpose and crashed it hard many times without issues. Don't tempt me haha!  --- On a lighter note; I've been spending the past few days redesigning my caddy over and over again, and this is what I came up with:  Space is at a premium in my particular frame, so instead of making posts that the rear standoffs could slide into, I decided to ditch all of the standoffs and make the caddy part of the structure -- it will bolt from the top and bottom. Also added a bit of structure at the rear where I could just kinda put my antenna at each slit in the middle and zip-tie them. • Posts: 1,197 Threads: 59 Likes Received: 592 in 395 posts Likes Given: 210 Joined: Mar 2019 Reputation: 42 (15-Mar-2020, 10:17 PM)Sketchy_D Wrote: Don't tempt me haha!
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On a lighter note; I've been spending the past few days redesigning my caddy over and over again, and this is what I came up with:
Space is at a premium in my particular frame, so instead of making posts that the rear standoffs could slide into, I decided to ditch all of the standoffs and make the caddy part of the structure -- it will bolt from the top and bottom.
Also added a bit of structure at the rear where I could just kinda put my antenna at each slit in the middle and zip-tie them. Source one is indestructible... top plate is a bit thicker than what you have lol. Keep in mind if you run a top mounted battery that the retention of the battery is being done by the top plate entirely. Removing the standoffs and replacing them with a print (which is more likely to break or have screws pull out of) will still be a great reduction in frame strength. I'm not saying don't do it its going to break, just make sure you build it so that when it happens you don't destroy other parts in the process. For instance if you mount your VTX antenna off of the rear of the top plate and the top plate snaps in half and goes flying off with the battery you'll likely ruin a VTX or at the least a SMA pigtail, so just keep that in mind when mounting things. Posts: 23 Threads: 4 Likes Received: 14 in 8 posts Likes Given: 4 Joined: Mar 2020 Reputation: 0 (15-Mar-2020, 10:34 PM)bffigjam Wrote: Source one is indestructible... top plate is a bit thicker than what you have lol.
Keep in mind if you run a top mounted battery that the retention of the battery is being done by the top plate entirely. Removing the standoffs and replacing them with a print (which is more likely to break or have screws pull out of) will still be a great reduction in frame strength. I'm not saying don't do it its going to break, just make sure you build it so that when it happens you don't destroy other parts in the process.
For instance if you mount your VTX antenna off of the rear of the top plate and the top plate snaps in half and goes flying off with the battery you'll likely ruin a VTX or at the least a SMA pigtail, so just keep that in mind when mounting things. Yep, this was my concern as well. Some may have had good luck with just a pair of standoffs -- either at the middle-rear or rear-rear -- but I may not be so lucky. So I went back to the drawing board, and... This was the best I could come up with:   I redesigned the caddy so that I could insert the middle standoffs to a couple of thick tabs attached to the caddy. The rears have to be ditched, and instead, the frame will bolt to the caddy from the top and bottom -- there's just not enough space to make the rear standoffs fit while keeping the DJI Air unit in between the standoffs lengthwise. Antennas will be ziptied to the protruding mounts I made at the rear -- the shape and fastening method was inspired by Catalyst Machineworks' DJI FPV Antenna Mount. • |
