EMAX 250 Pro FPV mini build (with Naze32 GPS experiments)

[jhitesma]

I've been looking forward to this for about a month MultiRotorMini's contacted me and asked if I had got my hands on a Naze32 yet as they were looking forward to seeing me do a build with one. I replied that I had just got an afromini and had been playing a little with an acro Naze32 on my friends 450...but no, I didn't have a Naze of my own to experiment with yet. (Ok to be totally honest, I do have one sitting on my desk but it's got a hole through the STM32 so it's not good for much more than mocking things up!) MRM then replied back asking if I'd be interested in trying a new frame they were getting and that they'd send me a full kit along with a full FunFly Naze32 if I'd write up the build and share what I learn about hooking up and using GPS on the Naze32 hardware.

Well, I'm a sucker for anything free so while I was a little worried about whether I'd have time to do the build justice or not they did say it would be a few weeks until they had the frames. And I do want to experiment with Naze32 and GPS. Alright I'm in! I'd like to be totally upfront and transparent about this - this build is only possible due to the generosity of MultiRotorMinis who sent me the full kit as listed on their website: http://shop.multirotorminis.com/EMAX-250-Pro-Mini-Quad-Bundle-E250ProMiniQuadBundle.htm With the one notable upgrade of a FunFly Naze32 instead of the Acro that's included in their Bundle. I'm supplying my own RX, my own GPS, and my own FPV gear, and my own batteries of course.

When I agreed to the build I had no idea what the frame would be. It was only after I said "sure send me free stuff!" that I learned it was a new hybrid G10 with Carbon Fiber veneer "250 FPV" frame. The only real info I found about it on-line was from their post on RCGroups. Once I read that and learned it was a G10/CF hybrid design I got really excited. I've felt for awhile that G10 is underrated as a frame material and that a lot of the CF frames out there may as well be made from G10 with the CF being mostly for looks. I also know that laminates can add a lot of strength and my own experiments with making hybrid laminate from 1/8" ply and hotel room key cards impressed me more than I expected. So the idea of G10 with CF veneer sounded like a GREAT idea to me. Should keep the costs down, the CF could help stiffen the G10 but still keep some of the G10's flexibility, and has that cool CF look everyone loves.

So the main point of this thread is supposed to be to share info about GPS on Naze32...except I'm thinking I'll probably start a second thread dedicated to that once this is built and in the air. So this may be more of a straight build/review thread with a touch of GPS with a follow up thread condensing the GPS info down once this is in the air and I've got things working well.

Anyway, I got an e-mail from MRM on last Friday saying there was just one last thing they were waiting on but the kit should be out to me on Monday and sure enough I got a follow-up ship notification on Monday saying the box was in the mail and should reach me by today. USPS actually did that one better and showed up at my door yesterday. Unfortunately they showed up while I was at work and my wife was at the gym and since they wanted a signature I had to wait until my wife could pick it up at the post office today.

When I came home for lunch today this rather densely packed little box was waiting for me:


I wanted to dig right in...but I did have to eat a bit of lunch first A quick turkey sandwich and apple which I ate in record time later and the unboxing could begin:


Once I got those instructions out of the way I was greeted by some shiny CF in a bag


And proceeded to take inventory:


Everything was there and packed securely in the box tight enough nothing was damaged without having to use any packing materials, very nice! The box was heftier than I expected but was only 1lb 11oz according to the label so it really wasn't that heavy - and there is a good bit of packaging material on the individual components. 2 of the motors are CW and two are CC which is nice since the prop shafts are an integral part of the bell and having the two different threads should help prevent prop loss even without nylocs.

So let's dig in to this cornucopia of quadly goodness!

 

[jhitesma]

The frame is what I was most excited about, but I was also curious about the motors. In our initial conversation MRM suggested sending me DYS motors - but given the issues I've been having with my recent build I have to admit I wasn't super excited about the idea of another set of DYS. I wasn't against them and was curious to see if I just got bum motors or what (I've since come to suspect that it's actually my ESC's causing my problems on that build. But it will be a few weeks until I can get new ESC's to confirm or deny that suspicion.) When I saw MRM was including the EMAX motors with their kits I started to hope I'd get the EMAX motors to try instead - I'm always up for new things and I'd heard decent things about the EMAX motors. So when I opened the box and saw the EMAX motor boxes I was excited to learn that I'd get to try a different brand of 1806 motor.

So let's take a quick look at these motors first. Specs from the package:

Framework: 12N14P
KV: 2280KV
Length: 26.7mm
Diameter: 23mm
No. of Cells: 2-3S
Max.thrust: 460g
Shaft: 2mm
Propeller: 5"-6"
Weight: 18g

They come more impressively packaged than any motor's I've bought so far:


And once you open that nice little case there are 3 sets of mounting screws (8mm, 6mm, and 4mm.) and a ball end hex wrench the right size to go with them. Nice touch!


The motors themselves are TINY, I thought the DYS 1806 were small when I got them but these make the DYS motors look big!


Either my scale is off by 1g or EMAX is a bit optimistic on their weight (maybe they didn't include the prop nut?) My spare DYS motor came in a few g heavier at 23g with it's wires trimmed just a bit shorter than the emax wires.


The rest of the quoted measurements matched up with mine exactly.

I'm curious to see how these do. From Mustang's tests they sound like they should be very similar in power to the DYS 1806 motors but not quite as efficient. They're lighter than the DYS motors but I'm a little worried about how well they'll hold up as they just don't feel very substantial compared to the DYS motors. The bearing is only 5mm wide compared to 6mm on the DYS and they both have 2mm shafts so the bearings on these are going to have slightly smaller balls. They also don't have the option of using flat mount CF props like the DYS motors since they have the prop adapter built in - but on the other hand that means there shouldn't be any alignment issues with the prop shaft. On my DYS motors I noticed on a few of them that I had to be careful to keep the shaft centered or had to rotate it 90 degrees to get it to mount centered. Of course that also means that if you do bend a prop shaft an emax motor is toast while a DYS motor you can pop a new shaft on.

I'm still not sure I'm a big fan of 18mm motors, but I'm looking forward to seeing how these do in the air. And the arms are drilled for both 18mm and 24mm motor mounting patterns so it's possible to step up to 24mm motors which is good to know. It's not that I dislike 18mm motors...it's just that having experienced 24mm motors it seems like the extra couple of dollars is worth it for the big step up in performance with 24mm motors. But in a package deal like this at a price like this the 18mm motors should have no problem flying this around and honestly I don't NEED the power of 24mm motors with my current skills.

Speaking of the arms being drilled for both 18mm and 24mm...let's take a look at the frame!

 

[jhitesma]

The little I could find about this frame was what MRM posted on RCGroups - the bulk of which was:

Looks like the frame was built around the 1806 size motors by featuring 2mm mounting slots and an extended wheelbase of 280mm to allow six inch props to swing comfortably. The arms are a 5mm thick carbon fiber veneered glass fiber material which is generously over engineered to stand up to just about anything. This helps the lower portion of the body to be deep enough to enclose most ESCs and keep all of the wiring nice and tidy. The rest of the body portion of the frame has well laid out mounting holes and slots for straps to allow you to secure any accessories you could want, including a FPV camera mount.

Note - they mention 2mm mounting slots designed for 1806 motors while I said the arms are drilled for both 18mm and 24mm. Well, apparently EMAX made some adjustments to the frame between when that was posted and when the latest run of frames was cut. The arms now have a different design with both 2mm and 3mm slots designed to accommodate either 18mm or 24mm motors. Nice upgrade!

The arms were also described as 5mm thick but as I'll get to in a moment I found they're actually closer to 4mm. Otherwise the description is pretty spot on as this is a fairly standard "all dirty" FPV frame design with a clean pad designed to fit a mobius sized camera. You might be able to put a gopro on there...but it definitely seems to be designed more for a mobius or keychain cam. Enough chat, more photos!

Of course since I have the scale out I just have to toss everything on it. All the CF (I'm just going to refer to it as CF from here on out since it's easier than repeatedly saying G10/CF) pieces together come in at 131g:


Arms come in at 15g:


And out come the calipers....the arms...are not the 5mm I was expecting. 3 of them were 4.08mm-4.09mm I was really impressed with how consistent they were!


Until I got to the 4th arm and it was 4.21mm. Not a huge difference, but enough it made me take a few more measurements from the arms. I found that the arms aren't super consistent. Most of the arms varied about .2mm - .3mm along their length depending on where I measured them. The thinnest spot I found was 3.99mm at the end of one arm and the thickest was 4.25mm near the middle of another.


Next up I measured the plates.

The top plate was nominally 1.5mm, I didn't get a photo of it because I forgot to measure it at the time (I had left it on the couch while eating my sandwich and didn't find it until later) but the camera plate was also 1.5mm:


The bottom plate came in a little thicker at about 1.7mm:


The main body was closer to 2mm measured 1.9mm:


The FPV cam mount plate was actually the thickest at just slightly over 2mm, this will come up later when I get to assembly:


Overall the quality seems pretty good. It's not quite as nice as the carbon on the warp quad or the G10 from twitchity were - there's a little bit of roughness to the edges of the cuts but you really have to be looking for it to see it. There are some small scratches on most of the pieces which is probably just from them shipping all together in a ziploc.

One thing I will warn anyone getting this frame about is to wash the parts immediately. There was a lot of carbon/G10 dust on them and I was excited and in a hurry so I just started test fitting things ASAP figuring I'd come back and finish the edges with some 400 grip wet dry sandpaper under water later. But I'm regretting it no was my fingers are still itching from the carbon and fiberglass dust that got on them assembling it right out of the bag. One of the 4 arms had a LOT more dust on it than the others. It doesn't appear that EMAX bothers to dust these off at all after machining - just grab them off the CNC table and toss them in a bag it seems. Not a big deal, but save yourself the discomfort and wash that dust off and hit the edges with some sandpaper under water before building.


The hardware that came with the kit is nicely packaged and labeled.

The individual baggies of parts are nicely organized in a larger pack to keep it all together. I don't know if a color choice is normally available on the spacers but I wasn't very big on the green I got. I can't complain since it didn't cost me anything, but the blue and red in MRM and Mustangs photos look a lot nicer than the pea green IMHO. Of course, I plan on flying this mostly FPV so I won't be looking at it very much - and now that I have the frame assembled the green seems to be growing on me a bit:


In the words of EMAX "Each screw an self-locking nut and Rubber shock absorption ball one more." Or in english "we gave you one spare of everything". They also seem to include more hardware than actually needed. There are 21 m3x8 screws but the frame only calls for 4 of them (to mount the landing pegs) - I suspect the other 17 are meant for mounting 24mm motors as there are also a set of m2x7 screws for motor mounting. Since the EMAX motors came with suitably long screws these are essentially spares for me but it's a nice touch that they include them:


So with all the bits here let's start putting it together!

 

[jhitesma]

Actually before we dig in on assembly let's take a quick look at the parts that MRM adds in to make this a full kit.


The Naze board includes pins, I'm not sure what I'm going to do for pins just yet but it's nice that they were included. The afro PDB is kind of interesting. It appears to do what I'm planning on the v2 twitchity PDB with one entire side being positive and the other negative. But what's interesting is that TC filled each pad with vias to get to the other side which is an interesting design I was thinking of trying but hadn't seen actually done before. There are also small pads around the outside that are unlabeled but all positive on one side and all negative on the other where you can tap in smaller connections. The afro PDB is made from the same very thin G10 as the afromini and appears to be very well made. MRM also includes a breakout cable which I don't plan on using as I plan to run a serial or PPM RX. (Probably PPM so I don't tie up any serial lines and can run GPS and OSD easier):


Another bag includes both a set of JST connectors and an XT60. I'm not sure what the JST connectors are included for - maybe to provide a connection off the afro power board for FPV gear? The bullet connectors are a nice touch and I'd strongly recommend them to novice builders - but I don't plan on using them in my build since the last 3 quads I've assembled all had motors directly soldered to their ESC's and I'm not scared of it anymore. Mounting hardware for the PDB and Naze are included as is some heat shrink and wire for a battery cable. I may substitute some slightly heavier wire for the battery though, 18ga is just a bit thin for XT60's IMHO and I'll probably use some 16ga I have on hand instead. The battery strap is nicer than what I get from harbor freight but I'll probably still give it a spray with plasti-dip to give it a bit more grip. Overall for a novice builder this is a great selection, for an experienced builder chances are other than the mounting hardware this is mostly unnecessary but nice to have as an option.


MRM also includes 2 sets of GemFan 6030 props. I've used the 5" gemfan props and wasn't impressed by them at all. These seem a little nicer than the 5" gemfans and I'll give them a try. But they're not nearly as stiff as the HQ or FC props and the root on them looks insubstantial as well so I'm not expecting them to hold up very well. I've mentioned to MRM that I'd love to see them carry HQ props and hope they can do so in the future as I'm really not that impressed with gemfans overall and that's all MRM carries right now.



Ok, so that takes care of first impressions out of the box. Overall I'm really happy and for the price MRM is charging for a kit it looks like a very good value and I'm super excited to get this assembled and in the air. So let's dig in on assembly! I like to do a "dry fit" first and just assemble the frame to get a feel for it before I dig in on real assembly. So that's what I'm going to do to finish off today (Whoops, past midnight...didn't quite make that cutoff but I'm still awake so it's still "today" to me )

I'm a man so of course instructions are by default kind of optional. There is a sheet included though so let's take a glance at it. Not much more than a parts listing, a rather cramped exploded view and some measurements/specs:


No big deal, though like I said I'm a man and instructions are optional. It is nice to have a bit of a reference as to where which sized screws are meant to be used - but the diagram is still a bit hard to read. I got mixed up a few times but overall if you pay attention to the number of parts and how it's meant to go together it's mostly obvious other than the M3x8 screws I already mentioned where you get 21 but only seem to need 4.

I only had 10 minutes of my lunch hour left at this point so I decided I'd quickly try to get the lower frame assembled to get a "big picture" view. I put the 8 (9 provided because "one more") M3x17 screws through the main body plate and slid on the four arms, then held them in place by threading on the 8 5mm aluminum spacers. Then put the bottom plate on and secured it with 8 of the 9 m3 nylocs. The resulting subframe was nice and stiff and really put me in a good mood to go back to work:


What they heck, let's toss it on the scale...122g. Not bad. You could build this up as is and make a pretty decent if not somewhat awkward acro quad out of it:


I went to install the top plate...but the FPV camera mount (remember it was the thickest part?) didn't want to fit into the main plate. I figured I'd have to do a little bit of sanding to get it in, then I realized I'd probably have to take the bottom plate off to install the upper deck and I really should be heading back to work. Good thing this put me in a good mood because my afternoon was horribly frustrating and I spent most of it on hold with godaddy trying to find out why they're blocking one of our servers even though it's not in their blacklist After over an hour on the line they hung up on me and I got to spend the next hour going through the same BS with another tech for the 3rd time today. Bleah. Wound up having to stay past quitting time waiting on the last tech who still didn't solve the problem. Got home and took advantage of my wife's schedule having her home for lunch right then to quickly assemble the rest of the frame before going into Mr. Mom mode for the rest of the night.

Turns out I was wrong at lunch, EMAX included access holes in the bottom plate so you can reach the screws for the upper plate supports with the bottom plate installed. I still took it off just so it would be easier to put the screws in. Used half of the M3x6 screws to attach the 6 35mm spacers to the main plate then put the bottom plate back on. I then installed the rubber isolation mounts and camera plate (which thankfully I found on the couch before my daughter did!) which went fairly easily with the help of some hemostats. Side note - if you don't have any hemostats you should get some. They're SUPER helpful, I have both straight and curved in various sizes since they're really cheap at hamfests and fleamarkets. More blunt than tweezers so you don't poke through things plus they can be locked to hold things very securely. Only downside is all the jokes about "roach clips" from friends who lived through the 60's.

I then attached the top plate with the rest of the M3x6 screws. The landing gear are made from 20mm aluminum spacers attached with M3x8 screws in the center of the 4 arms. 4 nylon screws are provided to go in the bottom of them for a softer touch. Not sure I'm big on such stiff landing gear, I'll probably take them off. But they don't seem to be in my way and help hold it up off the table so I left them on for now.

The frame looks really nice fully assembled (minus the FPV plate which I didn't have time to fit due to the need to do some sanding.) The green is growing on me...but I think I'll try and find some different colored balls as the blue just doesn't go well with the green at all:


With the FPV plate included I got a weight of 167g for the fully assembled frame which is well under the 173g quoted on the instructions. Not sure if they were just pessimistic in their weight or if I forgot something but it sure seems complete Note they also give the "wheelbase" as 280mm even though this is a "250 class" quad. My measurements agree with it being 280. It's a bit of a "deadcat" layout though as the distance from front to rear is 175mm while the distance from left to right is 218mm. It is symetrical front and back though, just more of a rectangle than a square.


And one last photo for the night next to my twitchity quad for a bit of size comparison:


I don't expect a lot of progress tomorrow. I'll probably dry fit the Naze and afro power board and play around with the esc's and motors to get a feel for where/how I want to mount everything up. Then it will be "worse before it gets better" time where I tear the frame completely apart, take some sandpaper to the sharp edges under water, and break out the soldering iron. I'd love to have this in the air before the end of the weekend - I won't have FPV gear or the GPS on it for the maiden...but they'll be following really soon so stay tuned!

 

[Twitchity]

Nice build so far jhitesma. I'm interested to see how those EMAX 1806's perform compared to the DYS's; they do look like some nice motors. I'm really interested in the GPS aspect of this build, so I'll be following really closely when you get to that stage.

I actually like the green, but you need some green silicone mounts for the camera to go with the standoffs, or at least black. The EMAX quad looks a lot bigger by itself, but seeing it next to my quad really shows its true size. That should be one fun FPV machine once you have it built!

 

[cranialrectosis]

The right angle three-deep pins (don't know the proper term sorry) that MRM sent you is an MRM touch and a nice one.

If you order the Naze from DroneMatters in Singapore, you get two layer straight pins only. If you want to lower the profile of the pins, you need to buy your own or make your own or solder leads directly to the board.

I suspect the JST two pin is to solder into your wiring harness so you can connect the Naze for voltage detection. At least, that is what I use them for. I also get spare KK2 piezos from HobbyKing.


Nice build, jhitesma! I can't wait to see this in the air.

 

[jhitesma]

Thanks guys. I really am interested to see how these EMAX motors perform. My first impression on them upon taking them out of the package was that they felt incredibly insubstantial compared to the DYS. But looking at them closer it doesn't seem that it's out of cheapness but rather out of attempting to make them as light as possible. They actually feel much smoother than the DYS motors when turned by hand though the magnets still feel strong. Overall they it seems that despite being a little less substantial they appear to have better precision and more of an eye to detail than the DYS motors. So my expectation is that they will perform equally or better than the DYS motors - but I'm concerned that they may not hold up well to someone who crashes as often as I do with their smaller bearings and lighter construction. For a careful pilot looking to shed every gram they seem great so far - but for someone who bashes around and hits the dirt/pavement a lot the DYS may be a better choice.

My biggest concern about them after giving them a closer look is that there doesn't seem to be any way to epoxy the wires to protect them. Again this is due to the extreme lightweight construction and design.

And just to be clear I'm not trying to criticize them for this - it's a perfectly valid design choice. And they very well may hold up better than I anticipate - this is just my first impression before they're even on the airframe let alone in the air or impacting the ground. Just something to be aware of as things built for light weight performance are by necessity a bit less sturdy than things built without an eye towards weight reduction.


As for the pins and wiring. I'm actually getting further and further from using pins at all. A lot of the problems I've had on my knuckle have been connector related, but I live with them because that's a platform I built specifically to experiment with hardware options - so being able to swap things around is a big part of it. This build I'm looking more to create something that will be built and left as it is other than software changes, so hardware flexibility isn't as big of a deal to me. So I'll probably not be adding the extra weight and potential failure point of connectors and direct soldering most connections. (the RX and gps may be exceptions to that since I do plan on switching them around somewhat.) But I know that's not a path most people would choose so it's good to see the connectors included in the kit as it does make things easier for most builders.

I really like how clean the wiring on my twitchity came out with all soldered connections - and other than making reflashing the ESC's harder it hasn't really caused me any inconvenience. Of course on the afromini I didn't have a lot of choice as some of the connections don't even have a way to use a connector. But here where I do have a choice I will still probably choose to avoid connectors and will just hardwire everything.

 

[cranialrectosis]

I don't solder to the FCB because I want the pins to unplug in a crash. Motors are cheaper and I don't have to re-program them after a crash even if I replace them.

Odd logic, I know, but that's how I think.

 

[jhitesma]

I figure with the FCB buried in the center like this it's not very likely to get damaged. And even if it was exposed I'm not all that worried about damaging a FCB. I'm more worried about pulling wires out of a motor or damaging an ESC. But that's just me

I am thinking about mounting the FCB sideways and adjusting it in the CLI so the USB port will be more accessible though. Especially since I plan on experimenting with various firmware options on this build. But we'll see how access is once I mock it up with my FPV gear.

 

[cranialrectosis]

I am thinking about mounting the FCB sideways and adjusting it in the CLI so the USB port will be more accessible though. Especially since I plan on experimenting with various firmware options on this build. But we'll see how access is once I mock it up with my FPV gear.

The only Naze I have not rotated is on the WarpQuad. All others get rotated 90* to put the USB on the left where I want it.

I love the CLI.

 

[jhitesma]

Got a few interesting updates for later tonight after my daughter goes to bed.

But...got a quick brain pick. I've trying to reason this out and keep getting myself mixed up backwards inside out and confused.

Which motors do I run on which corner. I know which way I want the motors to turn on each corner, motors 2/3 go CCW and motors 1/4 go CW. That parts easy. But I've never used motors with CW/CCW threads like this before. Do I want them to go the same direction as the motor or reverse. My instinct tells me I want them the opposite. So for the motors that turn CW I want the ones that you turn the nuts CCW to tighten and the ones that go CCW I want the nuts that go CW...but something about that still feels not quite right so I'd like to confirm that I'm not getting myself mixed up here. Been a long day and trying to think through the mechanics is just messing me up

 

[cranialrectosis]

I am running HQ 6045s on those emax 1806 motors for my Polakium quad build on a 1300 or 1000mAh 3S lipo. I completely ringed the copter in LEDs. White in front and red rear so I can tell the difference in the dark.

It won't flip like a WarpQuad. It flips more slowly. It flies well and I like flying it in the evenings when the sun goes down at 16:00.

It's not as fast as the WarpQuad but at night I don't want it to be.

 

[jhitesma]

Yeah, but you're not flying in 110F weather either My motors are hot before I'm even in the air, doesn't take pushing them much to get them into the danger zone

Winter will be here soon though and it will be easier for me to push things!

BTW - anyone got a source for 5m nylocs with reverse threads so I can ditch the cones once I figure out which motor to put on which corner? The shafts measured out at 5m and I'm pretty sure I can get 5M nylocs at my local hardware store...but I haven't seen reverse thread nylocs there...

 

[Mustang7302]

Look on the back of the motor’s box, in the bottom right corner, to identify which thread direction each motor will be when you unbox them.

Plus Thread, or clockwise, motors should spin in the normal counter clockwise direction and run non-reverse props. These motors normally sit on the front right and back left corners of a quadcopter.

CCW Thread, or counter clockwise, motors should spin in the opposite clockwise direction and run reverse, or R, props. These motors normally sit on the front left and back right corners of a quadcopter. To tighten these propeller nuts it will spin to the left, and so loosen these nuts it will spin to the right.

By setting each motor to the correct direction of spin, it will keep the propeller nut from coming off and bringing an abrupt end to your flight. Please take special care to orient these motors correctly for the best experience.

You should always check the tightness of your propeller nuts at least once per day of flying.

Consider using the bullets with the stock wire lengths to help you to be able to tuck the ESCs into the center area. Makes for a nice installation.

Lossi, RC off road trucks, I think offers Nyloc M5 in CW and CCW sets as wheel nuts.

 

[x0054]

It's been my experience that you really don't need locknuts if the thread tightens in the direction opposite rotation. If the prop slips, it just tightens the nut. I actually had the 1804s of the same model motor you are installing, and prop loss never came up. I actually experimented with it by leaving it a little loose and then gunning the motor, it tightens right up.

Do be careful though, I managed to snap the top of the cone off on one of the motors while taking it off. They are pretty fragile.

Can't wait to see how your GPS setup goes. I have been playing with my APM 2.6 setup with GPS on my tricopter, and my results were less then encouraging. About 50% of the time it thinks that RTL means fly really fast into a random direction, many times sideways. So, I am really curious how well GPS features work on Naze.

 

[rcflyer729]

I just go the same quad and am weighting for the cc3d to come

 

[Cyberdactyl]

Yeah, but you're not flying in 110F weather either My motors are hot before I'm even in the air, doesn't take pushing them much to get them into the danger zone

Winter will be here soon though and it will be easier for me to push things!

Exactly my sediments. In the winter months my ESCs rarely get above my fingertip temp., even lugging all the crap I've come up with.

In the summer, they can get quite warm. A delta-t of 40F really helps.

 

[FinalGlideAus]

Why do the motor makers bother with the opposite thread idea? It just hurts my head and is not needed....

x0054, you'll find your problems with GPS are related to the actual gps and its lock on the sats, not what the APM is doing. The exact same setup but using a Naze would do the same thing. Setting up a GPS system on a multi is a very time consuming process and even then it's not fool proof. It's definately not just a process of slapping a GPS unit to the top of the quad and setting the FC up. That's not even taking into account all the influences outside of your control. At the end of the day now matter how good the setup and how well it's tested you can't rely on GPS.

I'm interested to see how you go with the GPS/Naze setup Jhitesma. The guys that have used it in my group have got it to work fine (after a lot of fiddling) but found things like loiter mode to roam a lot and not hold position very well. Hopefully you can get a better result. Strepto has re-named that flight mode as toilet bowl mode

 

[jhitesma]

Consider using the bullets with the stock wire lengths to help you to be able to tuck the
ESCs into the center area. Makes for a nice installation.

Yeah, I'm going back and forth on whether to tuck them under or mount them on the arms. I like the clean look of them tucked under...but this IS the desert and I do fly in the summer so I'm worried about airflow with them tucked under there. My bs12's routinely hit 115 after just a few minutes of gentle flying on the DYS 1806's even with 5030 props. I suspect that the ESC issues I've been having may in part be due to the heat here. But at the same time I like the clean look and I like leaving the arms unobstructed since they're so wide. I've been playing around tonight with some rubber bands looking at the various options and haven't made a decision yet. Either way I won't be using the bullets though, they're nicer bullets than the 2mm ones I used on my 24g motors on the knuckle quad and are shorter so they won't cause as much binding in the lines as those did...but I'd still rather not mess with them. I don't see a motor getting knocked off on this build unless it's a big enough crash that I've got a number of bigger issues to fix so I'll probably just solder the ESC wires and motor wires even if I don't use the bullets. So if I do go with them mounted under the frame it will give me a bit more flexibility in routing the wires. It is a bit trickier to figure out how to wire them for CW/CCW with the way the wires come out of these ESC's...but I got every motor backwards on my ultra budget mini test build and it took me less than 5 minutes to swap them around. Just have to remember not to shrink the heat shrink until they're right

Lossi, RC off road trucks, I think offers Nyloc M5 in CW and CCW sets as wheel nuts.

Hmm, I may have to check the LHS and see if they have some.

I'm not really looking to replace the cones because I'm worried about them coming off - I've never really had a problem with that. It's more a matter of just not being a big fan of the cones in general as so many of them are inaccurately machined and can cause some minor vibrations. Plus several people have PM'd me about breaking the cones on these so knowing how rough I can be on things I figure I'm likely to do that fairly quick

But that sounds like a confirmation that the threads should go opposite to motor rotation so that's what I'll plan on

As for GPS. Don't be expecting huge miracles. Baseflights GPS code is pretty much an after thought and quite possibly a step behind the latest 2.3 MW which isn't all that impressive itself. CleanFlight as of last week was still using the same GPS code as BF so that won't be any improvement either, though I have seen talk about improving it. Harikiri sounds like the way to go for GPS on Naze but even there I've heard mixed results.

And on a mini there are still a lot of issues that will make GPS less than stellar. Everything being so close together with a lot of RF you're looking at a marginal GPS signal in most cases. And according to some discussions on MW things like SBAS can actually cause more problems when using GPS for navigation and position hold due to how it corrects the signal. I suspect that until someone fuses the accelerometer data with the GPS data (which I suspect DJI is doing and while I've yet to look at it I've heard rumors that APM has tried) we won't see outstanding position hold. RTH is likewise still fairly primitive. And the big issue is that the mag sensor still plays a big role in any GPS modes and on a mini it's going to be hard to keep interference away from that with a build in sensor like the Naze uses.

For ultimate GPS performance it will probably take considerable work and hackery. Possibly even using the I2C pads to mount an external mag located far from the power loom and cutting the traces to the on-board mag. It could also take some shielding around the GPS antenna to make sure it gets a clean signal with all the RF around it.

I'm still debating whether to try my openLRS (Well, I know I'm going to try it just to see if PPM is working with it on the Naze to help rule out if the problems I've been having are with my openLRS RX or with the Mega board on my Knuckle) but it's likely running 440 for RC control on a mini will give better GPS performance than 2.4ghz. GPS uses several frequencies in the 1.2/1.3ghz band so just like 2.4ghz RC can interfere with 1.2/1.3ghz FPV TX's it may interfere with GPS signal more than 440 does. I haven't run the math to see just how close things are but my gut is telling me 440 is going to be generally better with GPS than 2.4.


Just got my daughter into bed, so going to try and do a little video on something I did today with the frame to confirm that it's a G10/CF hybrid that some may find interesting. Plus I want to install motors on the arms to help me make my decision on where I'm going to mount the ESC's now that I know which motors to mount on which arms. Don't plan on getting it all wired up tonight, but I do want to experiment a bit and come up with a game plan for tomorrow morning. (Hoping to maiden the FT-22 tomorrow then come back and make some progress on assembly.) I'm also hoping to tear it all down and sand the edges of the plates tonight since I'm tired of the sharp edges irritating my fingers

 

[jhitesma]

I'm interested to see how you go with the GPS/Naze setup Jhitesma. The guys that have used it in my group have got it to work fine (after a lot of fiddling) but found things like loiter mode to roam a lot and not hold position very well. Hopefully you can get a better result. Strepto has re-named that flight mode as toilet bowl mode

Oh man, I hope I'm not getting peoples expectations too high here! Like you said getting GPS working well is tricky, and getting it working well on a mini is going to be even trickier!

Even on my knuckle with a very strong GPS signal and the mag mounted away from the wiring loom (originally I had it out and away from the other sensors for a week or so) I wasn't that impressed with GPS. But I also didn't do much tuning of it before I moved the mag sensor and made things a lot worse Hopefully I've learned from that experience

But my hopes for GPS aren't super high. As I've mentioned before I'm not all that interested in Loiter/Pos Hold - even when it works well I get nervous (and bored) after 15-20 seconds and don't take my eyes off the quad or hands off the TX. And RTH just seems like a gimmick to me nd not something I'd ever consider relying on...I may try it in a last ditch "the quad is pretty much lost already so I've got nothing to loose" kind of situation...but I wouldn't rely on it.

My main interest in GPS is still for feeding the OSD. Being able to tell which direction is home is more useful to me than trying to have the quad fly home. And so far in the few FPV flights I've done with my OSD I've found that the home arrow is very accurate as long as I'm more than about 100ft from "home". And if I'm within 100ft a little altitude and yaw is all it usually takes to find myself I also want to get myself a DVR to record my FPV feed soon. Flying in the desert it's really easy to get lost and searching for an hour before finding my quad when I ran into issues while 500m away unsure of which direction from myself I actually was...well, that's not something I look forward to doing again. Telemetry helps, but I don't currently trust my LRS telemetry setup (it failed me that day) and I don't want to strap another set of radios on. So recording the video feed so in an emergency landing situation I can review the last GPS coordinates seems like the best bet to help avoid that happening again. Plus I just want to be able to review my flights from my POV