While this may not be a full blown build and more of a "Kit" assembly I thought it would be good to post it anyway, I think it will be a popular 3"

First up,  the frame, a unibody style with 3mm carbon fiber. Being a one piece design means if you break it you need a new frame, not just an arm. And being a new pilot I am pretty sure I will break it , But I have the ability to cut these so the first thing I did was to make a 3D solid model of the frame. This way I can generate G code for my CNC mill.



And now that I have the solid model I thought it would be fun to 3D print it and check my model.



And just for the record, the 3D print is way too "bendy" to be flyable. But it only weighs half of what the CF does so maybe twice as thick would work ?

I used a small sanding flap wheel to lightly radius all outside edges on the CF frame. It was pretty sharp. ( I wore a dust mask )
I had some 1/2" clear heat shrink that just fit over the ends of the arms. I cut 4 1" pieces and forced them on.



Next up , Motors
The motors have hard wire with plastic coating and were actually kind of tuff to get straightened out nicely.



After installing the motors I double checked all the screws to be sure a long one didn't get past me.



Then I tucked the wire ends into the loose heat shrink to keep them out of the way while installing the ESC.



And Yes , I am running "props out"

Next, ESC.

I used the frame as a jig to hold the ESC while I soldered the XT30 pigtail from the bottom.



And ESC installed, ready to solder motor wires.




More to come, stay tuned

Quick question on battery straps, you can see in the pictures that the frame has slots for a strap. I tried to fish one in to those slots while the ESC was mounted. Not going to happen. so do I pull the ESC and install the strap in the slots or just go around the whole frame ?

Scott

You can snake it through the bottom of the ESCs without going through the slots. Otherwise, intofpv Kevlar strap should never need replacing.

BTW, did you model through measurements or a scanner? I assume you just measure it and build it through a 3D modeling program.

Thanks voodoo.
Yes it fits under the ESC no problem but trying to get it in the slots after the ESC is there makes it pretty un-doable.
The other issue is, it is a skinny strap 14mm the slots are 14mm as well. ( .562" or 9/16" ) If I skip the slots, I can use most anything that is not too long.

I measured everything, even the radii. It's always right that way . I do a lot of prototype and design work and have all the measuring tools and do this sort of thing almost daily so it is no big deal. I also like to do it first, while it is still clean and in one piece , it is much harder to determine actual dimensions with 2 broken pieces.

Scott

I would just snake it under and would not bother with the slots.

In a bind, if you don't have small width strap, I trim a wider strap at the area that needs to be narrow. Works great.

That's some really impressive work on the design and copy of the frame 

"Clone frames available for sale soon on the SDM Fabricating website at half the cost of the original Tyro79 frame"  (only kidding )

Great progress on the build. Keep the pictures coming

Thanks guys !
Don't hold your breath on those cloned frames  Looks like snow was doing some investigating
But BG gets about $12 for a replacement frame. I can get a 12x12 sheet of G10 phenolic for $15 and probably get 5 frames out of it. The G10 is almost as strong as the CF. It even comes in black. OTH a 12x12 sheet of CF goes for about $35.
I can afford a $12 frame, but where is the fun in that. I like to make stuff !


Soldered the motors to ESC.




Scott

(18-Feb-2019, 11:47 PM)Scott_M Wrote: Looks like snow was doing some investigating

I didn't need to. YouTube already took care of advertising the name of your company

https://intofpv.com/t-profile-badges-for...7#pid50807

oh ya, forgot about that.

No problem !

Scott

I will be using my bench power supply ( cc/cv ) to apply first power. I didn't make a smoke stopper, I figured this would actually be safer. I was planning on setting voltage at 9.6 and slowly turning up current and see where it levels off.
What I don't know is when to get scared.
I hooked my tyro 99 up like this and with VTX, GPS , and LED strip all powered it was only pulling 370mah.  I thought it would have been more.

Any suggestions on what numbers to use or be afraid of ?

Thanks

Scott

I do not know about numbers. I usually take a deep breath and plug a 3S pack into the smoke stopper. It either beeps or burns. I am super lucky so I have only had the burn once!

Looks like a really fun build! Cannot wait to see it aloft

Use a DMM and check continuity. If you don't have any, then likely you will be fine.

(19-Feb-2019, 01:10 AM)Scott_M Wrote: I will be using my bench power supply ( cc/cv ) to apply first power. I didn't make a smoke stopper, I figured this would actually be safer. I was planning on setting voltage at 9.6 and slowly turning up current and see where it levels off.
What I don't know is when to get scared.
I hooked my tyro 99 up like this and with VTX, GPS , and LED strip all powered it was only pulling 370mah.  I thought it would have been more.

Any suggestions on what numbers to use or be afraid of ?

I also use a Bench PSU instead of a smoke stopper and yes, using one of those which has CC/CV is better/safer than using a smoke stopper. I've set up 3 pre-saved voltage/current outputs on mine for testing quad electronics with:-

1. 5V / 1A
   
2. 12V / 1A
   
3. 16.8V / 2A
   

Before I connect any power I first do a DMM continuity test across the LiPo connections and then on each of the various power rails. Then I connect up my PSU to the XT60 on the FC/PDB and do the following:-

1. Start with the 5V / 1A setting. This is only enough to power the FC and anything hanging off it that only needs 5V such as an LED strip, so not the VTX and not the ESCs which means you won't get the singing motors at power on, just the buzzer beeping (if you have one fitted). If that goes without any issues I then move onto (2).
   
2. Switch to the 12V / 1A output. This voltage is equivalent to a 3S LiPo so the VTX will now also fire up and you will now get the singing motors too. If that all goes OK then I move onto (3).
   
3. Switch to the final 16.8V / 2A output to mimic the voltage of a fully charged 4S LiPo. If this final step all goes well then you are good to go
   

The lower the voltage, the higher the current draw will be (Ohms Law). At 5V my FC/PDB/LEDs pull 0.85A, At 12V my FC/PDB/LEDs/VTX/ESCs pull 0.47A, and at 16.8V my FC/PDB/LEDs/VTX/ESCs pull 0.4A.

If your PSU has over current protection (OCP) then switch it on. If the current draw then exceeds the amount you have set the maximum output to be, the voltage will immediately be cut off to prevent your electronics from being fried.

Thanks Guys !!
Exactly what I needed to know.

I gotta say this forum is the best !


Scott

Loving the assembly, Scott.        And you have good soldering skills as well.  I concur with VooDoo.  With a continuity check you should be fine.  But a smoke stopper check is so quick and easy you should make one.

Busy week, no time to play   ( pesky customers ! )

So next up is the Flight Controller. This has a plug and matching cable to attach to the ESC so no real excitement here.
You can also see in this picture that I shrunk the heat shrink on the arms.



At this point all continuity checks were good so I plugged it in to my bench power supply and followed Snows recipe above on voltages, I stopped at 12 V.
All Good !
I hooked up a battery and connected to Betaflight to check motor rotation. 2 were wrong so I switched them in BLheli.

Next was the receiver, I had already bound this to my QX7,  I am using FPort. If you are interested there are 2 other posts detailing the R-XSR hack and FC work around  Here   and  Here .  After those 2 hacks I have a plug in receiver   In one of those post I mentioned that I would put a wad of glue behind the plug socket on the R-XSR to stabilize the pins. You can see that in the next pic. Also covered in heat shrink, I double checked that the bind button is clear of the HS.





I hooked it back up to Betaflight and set all my modes and switches.

All is responding as expected !!  no surprises  ( Yeah )  so far so good.

More to come. Hopefully this week will have more play time

Scott