RAnst4038
Vir Cotto
After researching drones for a week and watching SeByDocky & Quadcopter 101 reviews that verified the 300 meter range. I chose the JJRC H8D from Tom Top . The availability of cheap parts due to the H8C was a big plus. The top shell comes in Red, Orange, Green, Black & White. The bottom in Black & White.
It arrived 12-8-15 & the first thing I wanted to do is balance the props with the magnetic carbon fiber, red tube & blue nut unit that doesn't seem to have a name. I had already sanded the blue nuts balanced. Found that the B's were almost perfectly balanced. The A's were real heavy on the end that had A molded in. With the excellent macro photography seen on web I was surprised just how tiny the parts are. Handling 4mm jeweler screws with my 57 year old HVAC mechanic shoe leather fingers with no feeling left in them is a real challenge.
When you fob it they get sucked onto the highly magnetic micro motors which requires fishing with a jeweler loop & tweezers. And the heads of those screws once installed are hanging out like hand grenades. So much for balancing the props.
I think I got the transmitter bonding & gyro calibrating translated well enough. But why does the screen show Mode 2 when I turn it on and the Mode Switchover button do nothing? Checked the quad battery voltage out of box & it was 8. Linked transmitter & calibrated the gyro, Take Off & sure enough the right joystick spins it. I’ve flown R/C since a teen but this is my first quad, and never had anything but what JJRC calls a mode 1 so I’m lost. But I kept it in the air long enough to press the video button then crashed it. And after it was on the ground I had a chance to look at the trans & saw why. I was now in Mode 1 the mode button does nothing & the video button above it puts it in mode 1 & turns on the video at the same time. When you press video again to stop & save it pops back to Mode 2. Well now that I know how to get into mode 1 I flew it till the dead battery lights started flashing & landed. Charged up the battery again until the charger light turned green & checked the voltage, 8.4. Went out for another flight & the right rear motor would not start unless I spun it. I had spent a week reading the reviews, boards & watching the videos. I knew the failure rate of this shoddy Chinese junk was 50% the first hour but you hope that 50% is other guy. Flew it again until the lights flashed but this time it was much shorter. Almost dead motor probably sucking more juice.
JJRC Transmitter Error Video
Got a $45 refund from seller which was enough to get another transmitter & parts to make a second H8D in Orange & White minus the receiver. I ordered a V666N receiver for it. I find that 55% pitch is the max for sustainable altitude at full throttle with ball bearings doused with Liquid Wrench dry lube, camera & no guards.
Update 1-16
When searching for small DC brushed motors in this class there are only 2 to pick from. The 8.5mm round & the ones with flattened sides. Both are rated at 6 volts max & were designed in pre Li-Po days for Ni-Cads. The 8.5 x 20mm motors in the H8C & D have microscopic reed brushes which are split in half leaving two hairs running on a pentagon shaped commutator at up to 14,000 rpm. What really kills the motors is any power at all when they are locked rotor. Those 2 hair sitting on a point of the commutator last milliseconds. If you want to save the motors you have to be at 0 throttle the moment you even think you're gonna crash. And in general can’t give any throttle unless you are sure all props are 100% free to spin. And don't slam them to 100% on takeoff. The prop guards help a little with ground but not with bushes & trees.
In conclusion I have been flying most days for a month. Replaced 2 motors both because of trees & bushes. This quad is very tough and has survived hard crashes and falls from 100 ft.
It arrived 12-8-15 & the first thing I wanted to do is balance the props with the magnetic carbon fiber, red tube & blue nut unit that doesn't seem to have a name. I had already sanded the blue nuts balanced. Found that the B's were almost perfectly balanced. The A's were real heavy on the end that had A molded in. With the excellent macro photography seen on web I was surprised just how tiny the parts are. Handling 4mm jeweler screws with my 57 year old HVAC mechanic shoe leather fingers with no feeling left in them is a real challenge.
When you fob it they get sucked onto the highly magnetic micro motors which requires fishing with a jeweler loop & tweezers. And the heads of those screws once installed are hanging out like hand grenades. So much for balancing the props.I think I got the transmitter bonding & gyro calibrating translated well enough. But why does the screen show Mode 2 when I turn it on and the Mode Switchover button do nothing?
Checked the quad battery voltage out of box & it was 8. Linked transmitter & calibrated the gyro, Take Off & sure enough the right joystick spins it. I’ve flown R/C since a teen but this is my first quad, and never had anything but what JJRC calls a mode 1 so I’m lost. But I kept it in the air long enough to press the video button then crashed it. And after it was on the ground I had a chance to look at the trans & saw why. I was now in Mode 1 the mode button does nothing & the video button above it puts it in mode 1 & turns on the video at the same time. When you press video again to stop & save it pops back to Mode 2. Well now that I know how to get into mode 1 I flew it till the dead battery lights started flashing & landed. Charged up the battery again until the charger light turned green & checked the voltage, 8.4. Went out for another flight & the right rear motor would not start unless I spun it. I had spent a week reading the reviews, boards & watching the videos. I knew the failure rate of this shoddy Chinese junk was 50% the first hour but you hope that 50% is other guy. Flew it again until the lights flashed but this time it was much shorter. Almost dead motor probably sucking more juice.JJRC Transmitter Error Video
Update 1-16
When searching for small DC brushed motors in this class there are only 2 to pick from. The 8.5mm round & the ones with flattened sides. Both are rated at 6 volts max & were designed in pre Li-Po days for Ni-Cads. The 8.5 x 20mm motors in the H8C & D have microscopic reed brushes which are split in half leaving two hairs running on a pentagon shaped commutator at up to 14,000 rpm. What really kills the motors is any power at all when they are locked rotor. Those 2 hair sitting on a point of the commutator last milliseconds. If you want to save the motors you have to be at 0 throttle the moment you even think you're gonna crash. And in general can’t give any throttle unless you are sure all props are 100% free to spin. And don't slam them to 100% on takeoff. The prop guards help a little with ground but not with bushes & trees.
In conclusion I have been flying most days for a month. Replaced 2 motors both because of trees & bushes. This quad is very tough and has survived hard crashes and falls from 100 ft.
Last edited:
