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Aztech Aeromodels Spot on Version2 Servo Arms

ghoffman

70cc twin V2
6061 is actually better, but it can't be extruded. 6063 is better able to be pushed through an extruder die. All aluminum alloys have the same modulus (stiffness) but 7075 would be best if I had my choice for a CNC machined arm because it is about 2x stronger than 6061.
 

djmoose

70cc twin V2
Was just curious. When the V1s went on sale I did some quick research to see if I could save money and everything I saw said 6061 was stronger.

(I ordered a bunch of V1s over the winter from Aztek, btw)

This seems to be an example of a company (spot-on) using the term "better" and many folks just assuming the new material is stronger (and publicly stating such in forum product reviews...when in fact it's not.)

It seems like the V2s use a "better" material for making the arms....which in turn might make them easier to apply to servos...but when in fact they're not as strong...which to me is a very important quality of a servo arm going into a GS plane. (to me...more important than how easily they install onto my servos...particularly when the V1s didn't seem to have a insertion/application problem in the first place...at least not enough for me to think there was a problem.)
 

gyro

GSN Contributor
Was just curious. When the V1s went on sale I did some quick research to see if I could save money and everything I saw said 6061 was stronger.

(I ordered a bunch of V1s over the winter from Aztek, btw)

This seems to be an example of a company (spot-on) using the term "better" and many folks just assuming the new material is stronger (and publicly stating such in forum product reviews...when in fact it's not.)

It seems like the V2s use a "better" material for making the arms....which in turn might make them easier to apply to servos...but when in fact they're not as strong...which to me is a very important quality of a servo arm going into a GS plane. (to me...more important than how easily they install onto my servos...particularly when the V1s didn't seem to have a insertion/application problem in the first place...at least not enough for me to think there was a problem.)

The new arms are stronger in that they don't slip on the gears, because they tighten down better and are more secure. Not that they apply easier. I'm guessing the difference between the 6061 and 6063 is negligible in this application, but would love for [MENTION=443]ghoffman[/MENTION] to confirm either way?

Personally, I don't think there is anything misleading about any of the marketing done on these servo arms by the vendor or the forum.
 

Azhar

50cc
DJ,

I will send you a couple of arms of your choice and you will see the difference. And you can let me know what you think once you tried them. Call me.
 

zmonster97

Member
The new V2 arms seem to fit the servo spline much better and tighter, which in turn makes them stronger in that they are not as easy to strip. They also have less play as many people have noted.

I have been using mine for almost a year now and have not had any problems yet.
 

ghoffman

70cc twin V2
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ghoffman

70cc twin V2
Now, if you really wanted the best, one would use aluminum alloy 7085 which has a yield strength of 78,000 psi. This is about 2.5 times stronger than 6063 with the same weight. It is used on the Airbus A380 for primary structure like the wing spars and landing gear parts.
 
ghoffman, that is interesting - that's higher than what I have seen for 6063, I've always thought it was half.

Look here, I wonder which of our refs is really right:
http://www.engineersedge.com/materials/aluminum-mechanical-properties.htm

I usually use that site for quick checks, it's showing yield of 6063 is much lower at 21,000 psi vs. 40,000 psi for 6061. Regardless which is right, 6063 is gummy as heck, it's typically used in shower door frames, window frames, etc. IIRC.

I totally agree 7075 would be the way to go, but it also costs (from our suppliers) almost 50% more. I would have thought 6061 would be OK for this part, that's what I would make it out of.

Plus extrusions makes sense, until you have to write the check! The min run of material through that small of a die is about a mile of extrusion. :) Unless the airplane market is much larger than I think, it makes no sense to run an extrusion (to me). You'd have a couple pallets of bars sitting in the warehouse for a long time! If the model airplane market is actually that big, I'm ready to make parts starting tomorrow. :)

Maybe one other thought and vote to use softer material - were the old arms cracking at all? 6063 is going to be more malleable and probably resist cracking better but I'd prefer 6061. I'd like to hear why they went with the gummy material, though. :confused:
 

Azhar

50cc
I will check but this material is not "gummy". The old material was softer as they were starting to wear the splines after a season or two. To me it feels that this material is harder. I can crank down on the locking screws and not worry of them thread stripping.

We flew two 120cc birds all last season watching for wear. If you have seen the videos of the Slick and Raven, you will know we spanked those birds hard. And after going over the airplanes for this season, we have found no slop or plays in the arms. We will continue watching and learning. So far, I have not heard any bad feedback from the V2 arms from customers.

Joe Smith and AJ are also flying these arms.

And I will always welcome constructive criticisms.
 
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