Aluminum arms for dji flamewheel frames

[HighGainTuning]

I'll measure it -- what height measurement are you looking for exactly?

*These arms are slightly shorter in height than the stock DJI arms.

The measurement that is between the 2 plates when the arms are installed. Basically the maximum height that accessories can be and still fit between the top and bottom plate.

 

[bisenberger]

aluminum = 30mm (the measurement was taken with the arms installed so I couldn't get an exact measurement flush with the flat end, but should be within a couple mm)
DJI = 37mm

 

[econfly]

aluminum = 30mm (the measurement was taken with the arms installed so I couldn't get an exact measurement flush with the flat end, but should be within a couple mm)
DJI = 37mm

That's about what I got --- 31mm between top and bottom plate with the aluminum arms, 37mm for the DJI plastic arms.

 

[HighGainTuning]

Good... That will allow DJI's 5.8GHz downlink TX to fit with room for the fan to move some air. I was a bit concerned as some of the aftermarket arms like the RCT's are so thin you can't get anything between the frames.

 

[hurseyc]

I'm about to out-grow my Phantom. I love the idea of building a 450 with these arms. Can anyone recommend motors, props and batteries for a setup that would lift a FPV TX, GoPro and Gimbal and fly for around 15 min?

 

[econfly]

I'm about to out-grow my Phantom. I love the idea of building a 450 with these arms. Can anyone recommend motors, props and batteries for a setup that would lift a FPV TX, GoPro and Gimbal and fly for around 15 min?

Good timing on that one. I liked the results on the 550 so much that I am thinking of moving my stock 450 (with an H3-2D and GoPro) to these arms too.

I was playing with ecalc and looking at specs this evening and came up with an idea of trying Tiger MN4010-11 motors (KV 475), 14 x 4.8 Tiger Motor carbon fiber props, and a pair of 4s 35-70 3300 Turnigy nano-techs (in parallel). With a GoPro and the H3-2D, I think my all up weight with this setup would be around 2.1kg. Ecalc is giving me just under 18 minutes of hover, with the hover pulling about 4.7amps/motor at 60% throttle. "Mixed flight time" is 9+ minutes, but I always seem to be closer to the hover time when flying nice and easy for AP. If I get this thing built I'll report back with results.

 

[hurseyc]

That's excellent. Please let us know if you work that out and how it performs.

Im confused about the numbers on the motors. What is a 900kv vs. 700 for instance? What do those numbers mean and how does that translate to performance?

Thanks!

 

[econfly]

That's excellent. Please let us know if you work that out and how it performs.

Im confused about the numbers on the motors. What is a 900kv vs. 700 for instance? What do those numbers mean and how does that translate to performance?

Thanks!

KV (as I understand it anyway) is RPM per volt assuming no torque. That doesn't translate so well to anything intuitive as far as I know. For example, that KV 475 motor I listed above is turning at about 5800 RPM at full load running at 4s voltage with 14" props. I'm just a hobbyist so my understanding is limited at this point, but I've found the KV ratings to be a generally useful guide for relative RPM between two motors otherwise similar. For anything really useful it seems like ecalc combined with reading the motor spec tables is the way to go.

As for my build plans above, those motors are probably overkill, but I may do it anyway just to see how they perform. I could probably get similar results in a lighter motor with a little more RPM running 12" props. The nice thing about doing this for fun is trying things out just to learn how they work!

 

[plasticjoe]

Anyone have an idea if using these arms helps with vibration or jello ? I have noticed that the stock 550 arms twist rather easily. Do these tame down that "twist" ? If it does... do they assist in lowering the vibration to the center plate ? They look pretty cool, just was curious if anyone had checked the vibration side of it.

 

[Maymidroix]

Hi Everyone,

I'm really happy that there have been very good feedback about the AIMDROIX arms. For those people that want to stay with the same size of their multirotor, but want to have the benefit of the aluminum arms, I'm proud to announce that we are releasing this week the stock length AIMDROIX ARMS. Now you can keep the same size of your quad or hexa to flight around tighter spaces but with the increase in stability do the high stiffness of the AIMDROIX Aluminum Arms.
View attachment 14536View attachment 14537

The Arms have already arrived to Readymade Rc so they will appear in stock soon. You can order yours now. They are posted as Aluminum replacement arms.:nevreness: http://www.readymaderc.com/store/index.php?main_page=index&cPath=165_295

Enjoy your flights.

Like us on facebook. https://www.facebook.com/aimdroix

 

[Maymidroix]

One thing I really like about this build is how smooth it runs now. I don't know if it's the stiffness of the arms, the motors, or the props, but all together this combination is really working out well. Good note on the loctite. A screw on anything that flies, vibrates or goes bang needs a little blue loctite (and if substantial heat is present, go with the red stuff). One more nice thing about these aluminum arms is no worry about the interaction between the loctite and plastic.

Yeah I am running 11x5 props and are very happy with the stability ans smoothness. Just a note on loctite... i used the Red one and it is way to strong... i have had to take my MR to an engineering workshop to get them to remove the screws. Will be going to the Blue or nothing and checking them after each flight. Hopefully these arms become more readily available and perhaps therefore cheaper

Blue loctite is enough for what you need. I used to race Rc nitro touring cars for years and they vibrate a lot more than multirotors. I never lost an screw where I used the blue loctite on aluminum parts. Don't use the RED LOCTITE, PLEASE. It's like welding the screw to the part LOL.

 

[HighGainTuning]

Hi Everyone,

I'm really happy that there have been very good feedback about the AIMDROIX arms. For those people that want to stay with the same size of their multirotor, but want to have the benefit of the aluminum arms, I'm proud to announce that we are releasing this week the stock length AIMDROIX ARMS. Now you can keep the same size of your quad or hexa to flight around tighter spaces but with the increase in stability do the high stiffness of the AIMDROIX Aluminum Arms.
View attachment 18248View attachment 18249

The Arms have already arrived to Readymade Rc so they will appear in stock soon. You can order yours now. They are posted as Aluminum replacement arms.:nevreness: http://www.readymaderc.com/store/index.php?main_page=index&cPath=165_295

Enjoy your flights.

Like us on facebook. https://www.facebook.com/aimdroix

This is a very odd marketing move.... $27.99 vs $4.00 for the same length arm. I would have gone longer but looked at the cost of doing this and it just wasn't feasible.
I would forget about any advantages at this point and sell it for what it is. an anodized aluminum arm with bling. Some people will spend 7 time more for something like that.
If they were a direct replacement they would be 37mm high at the mount but I understand that 6mm of aluminum milled away.

 

[bruce365]

Hi HighGainTuning, they are milled C&C out of square aluminium tubing. regards - bruce

 

[HighGainTuning]

Bruce

I completely understand that.

I do my own CAD work for my (non RC related) business and have many custom items C&C milled from Billet 6061 aluminum stock.
I know the associated costs with doing this. Even though I am an engineer with a business degree that has been involved in RC flight for over 40 years as a hobby, that does not help me to understand buying characteristics of people.
I can only use my personal experience and that of others to understand why I would want to spend $27.99 for a multirotor arm vs $4.00 and essentially loose the fuse that protects my frame from being damaged in a crash. I think it was said somewhere else in this thread or maybe another that this is the item that you want to be the weakest link. Trust me, if there were enough benefits to outweigh the cost I would be putting them on my personal DJI crafts and suggesting that they also be made for the S800 and smaller F330.

Pictured are some of my airframes that use DJI arms so it's not that I have nothing they would fit.

 

[Maymidroix]

This is a very odd marketing move.... $27.99 vs $4.00 for the same length arm. I would have gone longer but looked at the cost of doing this and it just wasn't feasible.
I would forget about any advantages at this point and sell it for what it is. an anodized aluminum arm with bling. Some people will spend 7 time more for something like that.
If they were a direct replacement they would be 37mm high at the mount but I understand that 6mm of aluminum milled away.

There are many other frames that uses the DJI style aluminum arms and many people were asking for the stock length arm because they liked the size of their multirotor. I know that they are pricey but it's because they are made in the U.S. and you can notice the high quality finish of the parts because of that fact. The $4 bucks arms are made in china, in production of about 1000 pieces a day, they are very soft and don't provide any heat dissipation from the motor and look cheap. You are saying that they are the fuse, but you have a very soft fuse that when you fly on windy condition you ask yourself why the multirotor is so unstable. It's because when the wind hit the propellers it creates a torque on the arms and cause them to flex. The direction of the thrust force of the propellers is constantly changing by a few degrees causing the multioror to be very unstable. The height difference was unavoidable for the production of these arms because of the manufacturing costs, adding 5.5mm of aluminum to match the height of the stock arm would have increased the cost even more. There are spacer available to match the height of the stock arms and I will release aluminum spacers in about a week. If you haven't try them out you can't be judging the arms because of the price, hundreds of these have been sold already and users have gave very good reviews about them. The stiffness and heat dissipation benefits are something that you notice right away when you use them on your multirotor. This is not just a piece of aluminum, I did a lot thinking and engineering to release these arms to the market.

 

[HighGainTuning]

Like I said, I clearly understand the cost associated with doing C&C work in the US. I do it weekly and have been for 13 years now.
I too believe in keeping my production in the US so your preaching to the Choir on this topic. With that said, as the remaining craft is all
Chinese built, I doubt anyone cares. Again, cost isn't why I won't be installing these.

I am sure after a few of these get crashed, buyers will go back top their $4.00 breakable arms.

 

[AboveAllAP]

Like I said, I clearly understand the cost associated with doing C&C work in the US. I do it weekly and have been for 13 years now.
I too believe in keeping my production in the US so your preaching to the Choir on this topic. With that said, as the remaining craft is all
Chinese built, I doubt anyone cares. Again, cost isn't why I won't be installing these.

I am sure after a few of these get crashed, buyers will go back top their $4.00 breakable arms.

I have got a set of these on my F550 and my initial concerns are as you raised the likelihood of the central frame being damaged instead of the arms in a crash. I recently had a bad crash with the stock arms with extensions mind you but I am certain it was due to over flexing of the arms which caused uncontrollable spin. Broke 3 arms... the processes of stripping down and re building would be much the same to replace the center frame of which the cost of is negligible, there is of course the risk of damaging the electronics etc, but I weighed off the risks of this compared to a more stable and controllable flight and therefore less likelihood of a crash caused from instability. There are of course other factors such as battery and ESC failure. If I have too many crashes I for one could not continue to afford to replace these aluminium arms (let alone other components) and would be forced to go back to the stock arms as you stated. I have put them on as a calculated experiment and so far I am happy with the results.

It is a buyers market as you seem well aware. Maymidroix has taken probably a large financial gamble and provided a product to market for which he saw and believed there to be a demand / requirement. I see no reason to berate him over this. You as you have stated can choose not to purchase them why not leave it at that.

 

[HighGainTuning]

I see no reason to berate him over this. You as you have stated can choose not to purchase them why not leave it at that.

I would say Berate is not the term to use here and I personally think they are neat but that's where I draw the line. I think it would be more truthful to market them as BLING... nothing more, nothing less.

 

[Jareth_Atian]

Maymidroix, you should feel proud of your product. Even if HighGainTuning is willing to casually dismiss the consistently-well-reviewed stiffness, reduced torque and heat-dissipation properties of your product, he still thinks that your aluminum arms are so pretty that they qualify as 'bling'. They must be *REALLY* pretty. I mean, I'm ordering two sets and I didn't even *consider* the aesthetic appeal, but now I'm looking forward to them even more!

 

[HighGainTuning]

Maymidroix, you should feel proud of your product. Even if HighGainTuning is willing to casually dismiss the consistently-well-reviewed stiffness, reduced torque and heat-dissipation properties of your product, he still thinks that your aluminum arms are so pretty that they qualify as 'bling'. They must be *REALLY* pretty. I mean, I'm ordering two sets and I didn't even *consider* the aesthetic appeal, but now I'm looking forward to them even more!

So if your not purchasing these for their BLING factor, what issues are you currently having that the aluminum is going to correct?

Motor overheating?
Arm flexing?
Please list the components in your build and it's weight.
Do you have a camera on your airframe and do you use it for video or FPV

For the record, I am not dismissing that the aluminum arms are a much better heat sink than any plastic nor am I dismissing that they are more rigid.... in fact I believe just the opposite that they are too rigid and will cause more damage to your airframe.
My point has always been: Why do you need to cool your motors if your build was done properly?
Why do you need more rigid arms than the stock DJI arms if your build was done properly?

Out of the hundreds of thousands of DJI airframe owners, how many do you see complaining about their arms being flimsy or their motors overheating?

I have 2) 2212/920 DJI motors on each arm of this X8 F450 build and it has some of the best flight characteristics of all my crafts.