my 800 to 700 mod

[hobaoe]

hey, id thought i share my new project,, downgrading my trex 800 pro dfc to a 700 pro dfc
when i crashed my 800 the batteries got damaged, and i started to wonder if i should buy the 700 instead, because i get longer flight time, if i wanted the same flight time for my 800 i must buy 6000mah batts, and thats more expensive, so a 700 size would be great for me.

after some research i discovered that the frames on the 700 and 800 is indentical, the only thing different is at the bottom below the canopy mount is about 15-20mm higher than the 700, so you could get the 800 frames for a 700 to get more room for the batts. another thing is the 2 canopy mounts at the bottom on the 700 you can see 2 flat circles just below the canopy mounts, if you drill those holes you can fit a 800 canopy, the same on the 800 were the circle marks is above if you want a 700 canopy on it

so, for my mod. im gonna chop the boom to 785mm and get a 110t main and 13t pinion, and 105/690 blades, torque tube, tail rod and a 700 size main shaft, since i dont need the longer 800 shaft.
thats it

so the power and gearing will be the same as the new 700L dominator TOP version, but ill have the 800 canopy and a thicker boom,,, im also going to fit my whiplash landing gear on this, its gonna be sweet

[TdB]

Don't shorten the boom to much, for longer flight times you might want to run 710 blades one day
Good luck with your project!
Edit: check the length of the 700N DFC boom, that's what I'll be using on my 700E Pro with 713 mm blades...

[hobaoe]

the boom wil be the same length on the 700... 690 is what i have laying around

[hobaoe]

i think the nitro boom is 800mm

[TdB]

805 mm for the boom is not a bad idea IMO, but suit yourself

[hobaoe]

im also starting to learn 3d, so i think the 690`s and shorter boom will help get it more agile

[utrinque]

Do not cut the boom at all. Look I was flying 700 with 600mm blades. No problemo.

800 with 700 blades will fly OK. Later you can put back 800mm blades.

Keep in mind Align 700 boom will not fit Align 800 frame. 800 boom is not only longer but also thicker. Boom from stretch kit is also thinner than boom from 800.

[hobaoe]

i know the 800 boom is thicker, the 700 boom wil fit the the 800 frame, you only need the 700 size tail boom mount.
but i want to shave off as much weight as possible, thats why im cutting the boom. i first wanted to just get the original 700 boom, but then i must get the tail boom mount, boom support brackets and the tail torque tube unit. i dont have the money yet, thats why im just cutting the boom.

[arpakorn]

Hi you did try 600 mm blade on trex 700e, how was it going....., did it really save
the burden of speed, batt .
I am so curious , please let me know....

[utrinque]

Actually it was only few test flights to check airframe. I did not look for better flight times nor less "power consumption". It was flying ok. That's it. By the way it was clone of 700.

[cbrkhan]

Originally Posted by hobaoe

so you could get the 800 frames for a 700 to get more room for the batts

How much more battery room (height) does 800 frame has compared to 700?


I like your mod, I was thinking of doing the same because of added battery space but was not sure how much more space I will get if I bought and modded a 800. Depending on the room, I was also thinking about a possible 7s setup for 800size to get at least 5 minutes flight time but again, was not sure about the battery space.

Has anyone done 7s with 800 DFC Pro?

[hobaoe]

after doing some side by side eye measuring, i woulld say that the 800 frame is 21,5mm longer than 700 frame.

i just measured the 800 pro frame, and you can fit a 86.5mm height, 49.5mm wide battery.

so a 7s batt will more than fit.

[cbrkhan]

Originally Posted by hobaoe

i just measured the 800 pro frame, and you can fit a 86.5mm height, 49.5mm wide battery.

so a 7s batt will more than fit.

Thanks for the quick reply. is 86.5mm height of the entire battery compartment or from the bottom of a battery tray to the base. i.e. if you were to slide in a empty battery tray and then measure.

[hobaoe]

yes, i measured it like that,,, bottom at battery tray to the base, but did one more measurement and its exactly 87.5mm hight,, but that is the MAX you can go...

[cbrkhan]

Thank you for your help! This is really helpful. I will go home and round up some batts to see what all will fit.

[Excalibur3]

Def just leave it alone and run smaller blades. Like radix 710's

Trex700ProDFCHV,Goblin 770,Goblin 570, 14SGH