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AJ Laser 230z 73" Build Thread

3dNater

3DRCF Regional Ambassador
I don't have a link to a resolution discussion but we can have one here. My understanding is that resolution is how many points your radio can recognize in your stick movements. The servo also has limited resolution. Think of it like a TV screen because I think the parralel works. A small (15") display at 720p is going to look real close to the same as a 1080p screen the same size. It's true that you could have more clarity on small objects but from tv viewing distance the difference doesn't really matter. Now, if you scale it up to a larger screen the 720p will start looking like crap while the 1080p still looks pretty good.

The radios we have today have really high resolution compared to the TV example. My Hitec aurora 9x has 4096 resolution. That means there are 4096 points between the bottom of the stick and the top of the stick that can be recognized as inputs. You could scale that up to quite a large travel percentage and it would still be incredibly fine.

I think the resolution argument can be sort of taken off the table except when using less than 100% of travel. The bigger issue is going to be torque.

You read a lot of info about servo speed and torque ratings. Realizing that servos turn a realitvely small cylinder with a relatively long lever attached we know that the longer the lever is the further the surface will move. The trade off is that you also get less holding torque.

The strategy for balancing the throw we want while getting good torque is to maximize end points (make the servo move as far as possible) and have fast servos that can travel their entire range quickly. This takes full advantage of the high resolution of today's radios and gives optimal performance on the plane. To maximize end points you need the right length of arm and consideration and time should be devoted during initial setup of the plane to achieve these ends.
 

Xpress

GSN Sponsor Tier 1
I don't have a link to a resolution discussion but we can have one here. My understanding is that resolution is how many points your radio can recognize in your stick movements. The servo also has limited resolution. Think of it like a TV screen because I think the parralel works. A small (15") display at 720p is going to look real close to the same as a 1080p screen the same size. It's true that you could have more clarity on small objects but from tv viewing distance the difference doesn't really matter. Now, if you scale it up to a larger screen the 720p will start looking like crap while the 1080p still looks pretty good.

The radios we have today have really high resolution compared to the TV example. My Hitec aurora 9x has 4096 resolution. That means there are 4096 points between the bottom of the stick and the top of the stick that can be recognized as inputs. You could scale that up to quite a large travel percentage and it would still be incredibly fine.

I think the resolution argument can be sort of taken off the table except when using less than 100% of travel. The bigger issue is going to be torque.

You read a lot of info about servo speed and torque ratings. Realizing that servos turn a realitvely small cylinder with a relatively long lever attached we know that the longer the lever is the further the surface will move. The trade off is that you also get less holding torque.

The strategy for balancing the throw we want while getting good torque is to maximize end points (make the servo move as far as possible) and have fast servos that can travel their entire range quickly. This takes full advantage of the high resolution of today's radios and gives optimal performance on the plane. To maximize end points you need the right length of arm and consideration and time should be devoted during initial setup of the plane to achieve these ends.

Correct. Though certain systems may have very high and fine resolution (such as Hitec's 4096 on our 9X and Flash models), you always have to keep in mind that servo resolution does play a part. Standard digitals are only 1024 resolution (Hitec 5xxx series), high resolution is double that at 2048 (Hitec 7xxx series), and ultra high resolution are 4096 (Hitec 8xxx and 9xxx series).

You can have 4096 resolution but only a 1024 servo. It's almost a moot point if you're not using the right servos.
 
Hey guys, I have a quick question concerning motor mounting....the AJ Laser manual shows a cutout in the firewall just behind the carb. I've got a DLE 35RA mounted and it clears the firewall - should I cut a hole in the firewall anyway for better airflow into the carb, or should I leave it uncut??

Thanks in advance
 

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AKNick

640cc Uber Pimp
I would leave it uncut. Just make sure you have adequate ventilation using the 3:1 rule (inlet should be a third the size of the outlet) as close as you can to get rid of any cowling pressure. The bottom line is you need to make the surrounding air as ambient as possible for the best performance. This is just my 2 cents.
 

3dNater

3DRCF Regional Ambassador
I agree, no need to cut it.

One thing I would recommend though is to make sure you have done something to address the fact that fuel/oil will be getting on that firewall and surrounding areas. You should take steps to fuel-proof it with thinned epoxy, fiberglass cloth with z-poxy is wonderful. You can also use fuel proof paint.
 
Last edited by a moderator:
I agree, no need to cut it.

One thing I would recommend though is to make sure you have done something to address the fact that fuel/oil will be getting on that firewall and surrounding areas. You should take steps to fuel-proof it with thinned epoxy, fiberglass cloth with z-poxy is wonderful. You can also use fuel proof paint.

Thanks everyone, no hole it is!

I fuel proofed the firewall and the inside of the fuel line/throttle linkage holes with laminating epoxy from Resin Research:
http://resinresearch.net/

Their epoxy is fantastic, durable and super clear...I bought a gallon a few years ago when I was flying and building DLG's and have found numerous uses for it.

 

AKNick

640cc Uber Pimp
Thanks everyone, no hole it is!

I fuel proofed the firewall and the inside of the fuel line/throttle linkage holes with laminating epoxy from Resin Research:
http://resinresearch.net/

Their epoxy is fantastic, durable and super clear...I bought a gallon a few years ago when I was flying and building DLG's and have found numerous uses for it.


Good to know. Which resin (P/N) did you use from their site, I see they have quite a few.
 
For resin I have their 2050 and for hardener I have the 3100s slow. They quote a pot life of 50 mns but here in Florida its closer to 30 mns
 
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