DIY Trampa long 35 E-MTB | Dual VESC SIX | Sensored EMAX GT5345

Sweet! Like how your builds are so well finished :ok_hand:t2:

“LET THERE BE LIGHT! 
THERE WAS LIGHT”

And here is my new charging set up, the best thing is the PSU cost me arround 50$ (1200W):

I just came back from 14km long ride, I charged each cell to 4.18V, and after this distance I finished with 45.5V on a display so arround 3.8V per cell, decent stats :smiley:

3 Likes

Best lawn mower EVER!

1 Like

Thanks mate! I reached 66.6 km/h on this lawn mower from hell!

3 Likes

Bloody fantastic !!!

The build is awesome! Just one thing about the max speed, unfortunately, the speed tracking because is GPS based, is not reliable when you invert direction, the GPS thinks that you traveled forward more than you actually did and then at the end of the inversion, when it re-picks the signal after the position adjustment you get increased lenght traveled, thus increased speed and that massive spike in the chart, I guess your max speed on flat and smooth ground is around 45km/h maybe? Which is still impressive for me considering that I freak out on flat ground at 30 km/h already :slight_smile:

1 Like

You’re right, I came to the same conclusion after all
 Need to test it on a straight road to measure max speed, I’m curious how fast it can go.

Hey @squad how are those motors holding up. 
was just on @barajabali build and u came up and I was curious on your thoughts on them

They’re good, however, when reaching top speed get noisy.

Do you mean “coulometer”? Which one did you use? Are you happy with your one?

Yep, that’s correct. I like it, it shows current, voltage, and used Ah. I changed shunt that came with the coulometer with smaller one, so I could fit it in my electronics case (You can change shunt resistance in settings to adjust it in order to measure current properly). I used this model http://www.aliexpress.com/item/Battery-Indicator-Tester-Battery-Voltage-Current-Power-Capacity-Charging-time-Digital-Monitor-Meter-Coulometer/32461792151.html

Do you have the 50V or 100V Version? Because you have 12S =50,4V fully charged

I went for 100V version, just because it’s like You said, at fully charged batteries it’s over 50V.

can’t find the 100v vesion one? would u mind to share the link??? also if you could pass the link for the 200A shunt, would be awesome :thumbsup:

Search for: “EJ-FG09B” it’s 100V version, here is first offer I found on alie.

To find shunt just type “200A shunt” in aliexpress search bar, it’s not that hard to find
 (75mV is the version You’re looking for)

Thanks for helping bro, much appreciated it

SO
 recently I sorted out all problems, learned to replace drv chips on my VESCs (which failure causes 90% of vesc problems :smiley: ) and now am just enjoying ride. Had some offroad fun today, it’s really impressive how steep hills this board can handle. My passive VESC cooling system seems to work fine, idea is similiar to @chaka high output VESC. My observations show that with 12/60 gearing, with 10Ah 12S Lipo batteries, riding really hard, few hills here and there, I get roughly 20km range while discharging each cell from 4,18 V to 3,8-7V. I think that’s really decent, pneumatics are not most energy efficient to get them rolling, they generate some serious rolling resistance compared to urethane longboard wheels.

Here are some pics from my evening ride.

9 Likes

Nice that you are back on the road.

The air pressure on the tires affect the efficiency. You’ll get better battery range by inflating the wheels at 55 psi almost at the maximum. because when disconnecting the air nozzle from the tire you’ll lose a little air and that can make the difference. Give it a try.

you can try 15mm pulleys and belt, the ride and range will improve a lot.

I already pumped those tires at 55 psi :wink: As to belt drive
 I don’t see it perform as good as chaindrive in offroad boards, there is lots of debris, small rocks that may get between pulley and belt, and even get embedded in aluminium pulleys, I’ll stick with chaindrive. With 2 swappable packs, a 45-50 km range is more than enough for me :smiley: My charger shows that today, after riding 20km, I drew about 3500 mAh from each of four 6S 5Ah bricks I use as as single battery pack, so there was some juice left.

The swappable battery pack is nice.

On The belt so far I’m liking them more each day, before I had that impression of the little rocks getting in the pulley but after using it for about 200km not even once I had something get in the drive system.

Besides when you get a flat tire on the road is more easier to change the belt drive wheel, just unscrew one nut and swap the spare in, with the chain this was a long walk home or have to unscrew the motor in order to release the chain.

Now days I just use the chain drive on specific occasions I know the terrain will be extreme.

But that’s just a preference, what I really like is seeing more people on eMTB, the ride is more smooth and not having to worry about cracks, sticks, rocks and others stuff on the way. To me this is more relaxing experience.

Keep up the good work :slight_smile: