Hey guys.

So i'm struggling to find spare arms for my hex.  
https://hobbyking.com/en_us/h550-v4-pro-...tore=en_us

That is a very similar drone to mine. I've measured 600mm from tip to tip of my drone. F450/550 flame wheel arms turn out to be too small. They would fit but i would need to get 9x45 props as my current 10x45 props over lap by quite a bit.  
  
I've searched online everywhere and i just can't find any arms with the 4 holes at the top and 2 on the bottom. Is there anyway other arms i could potentially use? For example: If i was to get 300mm carbon fibre arms for another drone and drilled new holes in the arm to mount them to my plates? I see these tube style arms which would be perfect but i have no idea how i would mount them and get the two plates to fix together.  
  
It's driving me nuts. If anything i'd like to rebuild the hex and just hang it up on the wall if it's the last 6 arms in existence.

When that was a popular air frame, there used to be round carbon tube conversion kits like this one on ebay.

https://www.ebay.com/itm/DJI-Flame-Wheel...1368248089

Bummer is there is only one available, you would need two.  Maybe the seller could make some more if you contacted them.  Or someone here on the forum with a 3d printer could make them.  Very simple parts.  Then all you have to do is source the carbon tube from someplace like McMaster Carr.

Or just convert to the shorter DJI F550 arms, props are cheap.

(17-Apr-2020, 03:55 PM)Sugs Wrote: When that was a popular air frame, there used to be round carbon tube conversion kits like this one on ebay.

https://www.ebay.com/itm/DJI-Flame-Wheel...1368248089

Bummer is there is only one available, you would need two.  Maybe the seller could make some more if you contacted them.  Or someone here on the forum with a 3d printer could make them.  Very simple parts.  Then all you have to do is source the carbon tube from someplace like McMaster Carr.

Or just convert to the shorter DJI F550 arms, props are cheap.

I bought 8 F550 arms and screwed them on. Just the 10" props didn't fit. 9" i think would be good but unsure yet.

I'll contact the seller and ask if they can print any extra. Failing that i need a reason to buy a 3D printer anyway. £100 for unlimited arms when i build a smaller quad! Sound's worth it.

(17-Apr-2020, 04:09 PM)MrTrendizzle Wrote: I bought 8 F550 arms and screwed them on. Just the 10" props didn't fit. 9" i think would be good but unsure yet.

I'll contact the seller and ask if they can print any extra. Failing that i need a reason to buy a 3D printer anyway. £100 for unlimited arms when i build a smaller quad! Sound's worth it.

That frame on eBay is using proper carbon fibre weaved arms, not 3D printed arms, so it's won't be just a case of the seller simply printing more. They would have to be properly fabricated. Maybe you can just buy some carbon fibre tube and make your own (HERE). That will be way stronger than the plastic F550 arms. If you do that, be careful cutting it, or wearing a respirator because if you breath in carbon fibre dust it can cause lung damage. Just make sure you take any relevant precautions.

As for 3D printing arms for a smaller quad, unless it's for a toothpick size quad then it's not even worth considering because the arms just won't be strong enough. And if you were to make them strong enough then the extra weight in doing that would be prohibitive. Many people have tried and failed. You will be constantly crashing a 5" quad so 3D printed parts just won't be able to take the abuse. Carbon fibre has a very low weight to high strength ratio and it's why you only ever see carbon fibre frames for quads. When you buy a frame, just buy some extra arms, or buy an Armattan frame which has a lifetime warranty even if you break the frame through your own doing.

(17-Apr-2020, 05:14 PM)SnowLeopardFPV Wrote: That frame on eBay is using proper carbon fibre weaved arms, not 3D printed arms, so it's won't be just a case of the seller simply printing more. They would have to be properly fabricated. Maybe you can just buy some carbon fibre tube and make your own (HERE). That will be way stronger than the plastic F550 arms. If you do that, be careful cutting it, or wearing a respirator because if you breath in carbon fibre dust it can cause lung damage. Just make sure you take any relevant precautions.

As for 3D printing arms for a smaller quad, unless it's for a toothpick size quad then it's not even worth considering because the arms just won't be strong enough. And if you were to make them strong enough then the extra weight in doing that would be prohibitive. Many people have tried and failed. You will be constantly crashing a 5" quad so 3D printed parts just won't be able to take the abuse. Carbon fibre has a very low weight to high strength ratio and it's why you only ever see carbon fibre frames for quads. When you buy a frame, just buy some extra arms, or buy an Armattan frame which has a lifetime warranty even if you break the frame through your own doing.

I was more looking at the mounting brackets that hold the arms. I could use the fibre rods like you linked but i'd need the mounting bracket that holds them in place.

(17-Apr-2020, 05:14 PM)SnowLeopardFPV Wrote: That frame on eBay is using proper carbon fibre weaved arms, not 3D printed arms, so it's won't be just a case of the seller simply printing more. 

Snow, that kit on eBay is only for the mounting brackets which are 3d printed, doesn't include the tubes which is why I said he could source them from McMaster-Carr.

Have you tried 3D printed arms?