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Fortis TITAN Build

FinalGlideAus

terrorizing squirrels
#21
If you want to do it properly then it would be case of getting a flying weight, working out what power to weight ratio you want (at least 2.1/1) and then plugging in the motor/battery/weight selection into ecalc to get an idea of what you would get. If it looks pretty good including current draw then do some searching for anyone who has done an actual thrust test of the motor for real world answers. Also remember that the brand of prop can have a big effect on the final thrust. Soma has shown me the light on this subject. I've seen upwards of 200 grams thrust difference using the same dimensions but different brand.

Here is a thrust test of the 2212 980kv sunnysky's I use on my Titan for an example of what I'm talking about:
http://m.youtube.com/watch?v=VuupNMUhSz4
Note that this test doesn't show prop speed. That can also be a factor for performance.
 

ikem

Senior Member
#22
got a scale, and she's a heavy one... 1277g without a battery.

i dont understand ecalc's figures though. I put the battery in and it says that a 2100mah weighs 55g... it is like 200g... also what is Drive Weight, All-up Weight, and add. Payload.

my 2200mah is 199g, and my 3600mah is 300g.
 
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FinalGlideAus

terrorizing squirrels
#23
Holy moly, how much does the gimbal weigh? My Titan with 16' arms, full APM setup and GoPro is only around 900 grams without battery. You're starting to come accross the short comings of a tricopter with regard to lifting ability. You cannot put everything on there and expect no compromise.

I'd have to check ecalc again to answer your questions. I put in the all up weight of the copter at the top which is the flying weight. From memory include drive weight is include the weight of the prop/motors in that figure. Payload is just if you wish add a pay load.

You're going to need a larger motor than what is usually used on the Titan and low KV with bigger props. Then you will loose your speed and agility. This then starts to defeat the purpose of having a tricopter vs quad hex and octo. The bigger props will also get buffeted by windy conditions. Then you'll probably need a bigger battery for the bigger motors then the weight goes up even more. Can the plastic motor mounts and frame handle the bigger motors? Compromises... Get where I'm coming from? This is why you don't normally see gimbals on tri's. I'm not saying it's not possible but the heavier you go the harder it all gets.

Where can you shed weight? Loose the hybrid booms, loose telemetry. Every little bit helps.
 

ikem

Senior Member
#24
yea thats why i was asking in the first place. i know that is the problem with tri's. o well. i guess I will have to deal with it some other way. I still hover at 50%, i just wanted to increase flight times.

Holy moly, how much does the gimbal weigh? My Titan with 16' arms, full APM setup and GoPro is only around 900 grams without battery. You're starting to come accross the short comings of a tricopter with regard to lifting ability. You cannot put everything on there and expect no compromise.

I'd have to check ecalc again to answer your questions. I put in the all up weight of the copter at the top which is the flying weight. From memory include drive weight is include the weight of the prop/motors in that figure. Payload is just if you wish add a pay load.

You're going to need a larger motor than what is usually used on the Titan and low KV with bigger props. Then you will loose your speed and agility. This then starts to defeat the purpose of having a tricopter vs quad hex and octo. The bigger props will also get buffeted by windy conditions. Then you'll probably need a bigger battery for the bigger motors then the weight goes up even more. Can the plastic motor mounts and frame handle the bigger motors? Compromises... Get where I'm coming from? This is why you don't normally see gimbals on tri's. I'm not saying it's not possible but the heavier you go the harder it all gets.

Where can you shed weight? Loose the hybrid booms, loose telemetry. Every little bit helps.
 

FinalGlideAus

terrorizing squirrels
#25
Maybe try some 12" props and a motor in the 700kv range. More lift for less current. Maybe also confirm that your batteries are not aging. I'm sure it should be still possible to increase the gentle flying time to around 8 minutes with careful motor/prop choice. Remember that prop brand can yield bigger than expected thrust gains if tested properly.
 

ikem

Senior Member
#26
so wait... i weighed my fram without any fpv gear, camera tray, gimbal or battery.

frame, motors, servo, apm, telemetry, reciever, and escs. 886g. how is your entire copter only 900g?

batteries are brand new.
 

FinalGlideAus

terrorizing squirrels
#28
900grams is for my Titan with out battery. 1.1kg with battery

16" carbon arms. Not hybrid
2200 3s battery (I also fly 4s 2200 on it)
SS 2212.980kv 10x4.5 gemfans but changing to carbon shortly
Camera tray with GoPro 2
APM 2.5 with GPS, Minim OSD and power module. No telemetry.
JRDS368 tail servo
I think it was orginally weighed without the VTX.

I also went to great lengths to minimize the wiring and power loom but I will shortly redo the power loom to try out another idea.

I also plan to mold up my own carbon booms using Rohacell foam for core material, 3k carbon tow for the walls and finished in 10mm carbon sock for torsional stiffness which hopefully be the same weight as the stock carbon booms but as strong as the hybrid booms. That's down the track though when I have spare time to fiddle.
 

ikem

Senior Member
#29
mine is 1086g with the original camera tray and gopro. the gimbal is an extra 150g. i really dont have anything extra just hanging off the copter.. but what time do you get with a 3s 2200mah?
 

Cyberdactyl

Misfit Multirotor Monkey
#30
I also went to great lengths to minimize the wiring and power loom but I will shortly redo the power loom to try out another idea.
Absolutely. Wiring is somewhat heavy, and if can be routed efficiently, you can shave off 10-30 grams on a wise layout on a regular size quad. Another thing that bugs me, is when a solder connection takes more solder than the minimum for... whatever reason. :mad:
 

FinalGlideAus

terrorizing squirrels
#31
You have hybrid booms and telemetry don't you? That's 100grams plus right there.

I'm getting around 12 minutes with easy flying down to 3.6v per cell on 3s. Still playing with props and so forth so it's all changing and I'm busy working on other projects right now so titan is on the "to do" list right now.

150grams for the gimbal is not too bad.
 

ikem

Senior Member
#32
You have hybrid booms and telemetry don't you? That's 100grams plus right there.

I'm getting around 12 minutes with easy flying down to 3.6v per cell on 3s. Still playing with props and so forth so it's all changing and I'm busy working on other projects right now so titan is on the "to do" list right now.

150grams for the gimbal is not too bad.
Total weight is 1482g with a 2200mah. It may just be the props... even with my old setup, which ran around 1286g (no gimbal) ran only 5 min on a 3s 2200mah. so either my props suck, or my motor/prop setup is just crazy inefficient.

Thanks again for the help. I think I am narrowing down the problem.

EDIT: took my tablet out and watched the amp draw in a hover. it is right around 24amps. I know this is at hover, but that's around 8 amps per motor... not pushing the limits of them anyway.. im guessing it is an inefficiency with my props.
 
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Montiey

Master Tinkerer
#34
like i said waiting on hobbyking! had to get the motors from international warehouse...
Oh dear... How long have you been waiting? I took months for stuff to arrive from the EU warehouse, but I'm not sure if thats the same as the international warehouse.
 

ikem

Senior Member
#35
Oh dear... How long have you been waiting? I took months for stuff to arrive from the EU warehouse, but I'm not sure if thats the same as the international warehouse.
i got the gimbal parts about 6 days after I bought them. Shipped from the international warehouse.
 

FlyingMonkey

Stuck in Sunny FL
Staff member
Admin
#36
Lucky, I've been waiting over a month for my gimbal package from the international warehouse. I think it got lost in shipping.
 

baddox

Senior Member
#37
Lucky, I've been waiting over a month for my gimbal package from the international warehouse. I think it got lost in shipping.
Stay strong. That's by far the worst part about this hobby. It's scaling so fast that any product that's gets a decent review or even a mention from anyone with any credibility is sold out for months. Plus so much stuff ships from who knows where and takes a month to arrive. It's getting better though, as more vendors in Europe and the Americas realize there's money to be made and the market's only getting bigger.
 

ikem

Senior Member
#38
finally! aftering burning an osd I have gotten it to work.

It still charges my gopro with the vTX but i have clean osd

IMAG0715.jpg IMAG0716.jpg IMAG0717.jpg
 

ikem

Senior Member
#39
:O went out with my 3600mah, AUW 1700g.

Hit 50mph in alt hold. :D. On 3s!

Got my Sunnysky x3108 900kv. I dont think the multistar escs like them. When arming, they spin for a while, and then stop. Then I have to disarm and re-arm and quickly put the throttle up a bit to keep them spinning. Also there is a little pulsing while in alt hold or loiter, but not in stablize. Though it isnt that bad.

What escs would you guys suggest? around 30a
 

FinalGlideAus

terrorizing squirrels
#40
F20A or F30A works well for those who use them. I have Afro's on my titan because back then I coldn't be bothered flashing an esc but if you are willing to flash the esc yourself the F20A are better. You could also buy some preflashed from RTFQ if you're prepared to wait. The F20A are easy to flash SimonK onto as well. 20a or 30a depends on your current draw. I would have a guess that you would only need 20a but as I said I'm just guessing.

It would be best if you replaced those multistars. You could use them in the same manner I have used mine... to prop up a short table leg :)
 
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