Dogati Electric Superleggera

@j3tch1u simply brilliant build mate, definitely set the bar high for e-MTB builds...
Outstanding...

KiM

mucho gracias luke. frank will get his leckky power cherry popped on Dogati tomorrow

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didn't you say the torque murdered the clutch bearing?

i'm game for a quick china trip. lets get luke's itinerary and see.

ghettoracer said:

mucho gracias luke. frank will get his leckky power cherry popped on Dogati tomorrow

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didn't you say the torque murdered the clutch bearing?

i'm game for a quick china trip. lets get luke's itinerary and see.

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it's fixed...sort of. took out the clutch bearing and just locked the freewheels to the shaft with a keyed adapter. however, without the one-way clutch, you need to open the throttle slightly to overcome the motor cogging when pedalling. advantage...eliminates a failure-prone component. i will add a torque sensor with variable pedal assist...which should also be a nice thing to have.

Be careful, the HV160 tends to blow with too much EMF feed from the motor with throttle off.

Matt

recumpence said:

Be careful, the HV160 tends to blow with too much EMF feed from the motor with throttle off.

Matt

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do you think it could blow from just the pedalling input? the rear hub freewheels so it won't be driving the motor when coasting.

j3tch1u said:

recumpence said:

Be careful, the HV160 tends to blow with too much EMF feed from the motor with throttle off.

Matt

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do you think it could blow from just the pedalling input? the rear hub freewheels so it won't be driving the motor when coasting.

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I think it would be tough to kill it just from the speed you can develop pedaling. However, I would definitely avoid using the motor to get up to a high speed, then letting off the throttle and pedaling at the high speeds the motor brought you up to.

Worst case though, it's not going to hurt the motor, and it would only cost you an HV160, which is all ready pretty much assured to fail at some point in the future anyways (though it is the best of the RC controller options), so it's not too big of an increased risk or anything to worry too much about.

Also, with your cap placement and wiring, its really really important you keep the wire length between the cap module and the controller PCB as short as physically possible to have it help. This will help the controller have it's best chance at life. If you want some of the best low ESR caps (that are in a small form-factor) that I was able to find in all my cap testing with my ESR meter, I can send a box to Frank or you for free if you want to PM me your address.

Any chance you could put the pictures back up, please?

(I just get a message like this when I try and view any of them:

"Information
The selected attachment does not exist anymore.
The file ./../files/7956_6bb93bf91e3aab6b04dc98729fcfb969 does not exist." )

This build sounds great from the comments.

Jeremy

It's a board crash problem, hopefully KnightMB can fix it. Posts are missing, too.

Jeremy Harris said:

Any chance you could put the pictures back up, please?

(I just get a message like this when I try and view any of them:

"Information
The selected attachment does not exist anymore.
The file ./../files/7956_6bb93bf91e3aab6b04dc98729fcfb969 does not exist." )

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KiM

niiice kim.

liveforphysics said:

Also, with your cap placement and wiring, its really really important you keep the wire length between the cap module and the controller PCB as short as physically possible to have it help. This will help the controller have it's best chance at life. If you want some of the best low ESR caps (that are in a small form-factor) that I was able to find in all my cap testing with my ESR meter, I can send a box to Frank or you for free if you want to PM me your address.

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wire (16AWG) is about 1 1/2" from the mains solder joint. this is about as close as i could come while still allowing the module to be disconnected for break-downs. thank you for the generous offer re the ESR caps--will send u a pm

btw, tested the theoretical no-load top speeds:

11th gear wye: 124 kph @ 7.44 amps
11th gear delta: 215 kph @ 33.82 amps!!!

torque is pretty crazy already and wouldn't want to gear it down any more so i guess the only thing left to do is upgrade up my insurance

i love the bike j3tch1u it is an absolute masterpiece.

regarding the gearing......have you got the castle data link cable? I am curious to know what the temperatures got like riding around. I think I read that yours is a 5t 3220 which is the same as what I had on my dual drive. When I tried just one motor (in an attempt to tame the bike down a little) I did a few short take offs, say 3 and around 500 meters of total run time and the temperature of the hv160 went through the roof! and thats with it geared for only 80km/h. I believe some of the heat or maybe alot was due to not being able to reduce the gear ratio as it was a single speed. So what is your no load speed in 1st gear?

Cheers

rodgah said:

i love the bike j3tch1u it is an absolute masterpiece.

regarding the gearing......have you got the castle data link cable? I am curious to know what the temperatures got like riding around. I think I read that yours is a 5t 3220 which is the same as what I had on my dual drive. When I tried just one motor (in an attempt to tame the bike down a little) I did a few short take offs, say 3 and around 500 meters of total run time and the temperature of the hv160 went through the roof! and thats with it geared for only 80km/h. I believe some of the heat or maybe alot was due to not being able to reduce the gear ratio as it was a single speed. So what is your no load speed in 1st gear?

Cheers

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cheers rodgah. i'll take temps and data off the HV160 after next ride (drizzling out today). no load speed in 1st gear is 28kph (wye) if i recall correctly. to give you some idea of the gearing on Dogati:

alfine 11:
gear range: 409%
jumps: 2 x 17% and 8 x 13%

planetary gearbox: 12:1
sprocket reduction: 20:16
pulleys: 1:1

modified motorcycle stand:



left controls.

from the left:
1. Hi-Lo-Off switch (respectively) delta / wye / cut-power to BEC & throttle
2. red switch turns on/off lights
3. lever for seatpost
4. lever for rear shock lock-out



right controls: alfine 11-speed shifter and magura throttle.



carbon-fibre looking wire shield:



wires all tidied up and ready to roll:

Have you ridden it yet? How fast is it? How about some VIDEO! We want to see it in action! Beautiful project bike for SURE! A work of art!

looks like you've been berry berry productive. =) sweet. this sat should be sun shine again. i hope we get some real sun this time!! Whiplash: the weather is uncooperative lately and it's gloomy and wet in taipei mostly. dogati isn't quite water proof so the filming will have to wait until better weather which is hopefully this coming weekend. then ben has promised his pals/gals to wear some leather tights for the video shoot. haha j/k.

ghettoracer said:

looks like you've been berry berry productive. =) sweet. this sat should be sun shine again. i hope we get some real sun this time!! Whiplash: the weather is uncooperative lately and it's gloomy and wet in taipei mostly. dogati isn't quite water proof so the filming will have to wait until better weather which is hopefully this coming weekend. then ben has promised his pals/gals to wear some leather tights for the video shoot. haha j/k.

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yep burning the midnight oil as usual. just finished topping off the pack and keeping fingers crossed for tomorrow. frank, it's not the rain i'm worried about--dogati is not water-proofed against virgins who wet their pants on their first lectric ride :lol:

OMG O_O this is definitively the beautifulest bike I ever seen.. cannot wait to see it driving!!!
Very impressive finish! congrats!
Gruß,
H.

WELL? did it run OK?? WE NEED TO KNOW!!!! LOL!

Whiplash said:

WELL? did it run OK?? WE NEED TO KNOW!!!! LOL!

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took it out yesterday with my friend ghettoracer helmed with the video camera. after a few short runs, my throttle stuck open and i lost control of the bike (the flange on the grips i put on the magura throttle was pressed against the throttle and didn't spring back). wheelie'd and dragged my ass under the rear end of a parked car. no damage to the car and only got a busted spoke and scratched rim. i got away with skinned shins and a bruised ego got back on the bike, kicked the forks straight and we proceeded to film some 65 k'ish runs except...i found out when i got back that the camera was set on very low resolution. i have to say, in 1st and 2nd gear, the bike is a coiled death machine ready to spring. i have the HV160 set on Low (2) start-up but looks like i'll have to lower that to 1. starting in 6th feels a lot more comfortable to both ghettoracer and myself.

later in the day we went to go meet up with a an old motorcycle racing buddy (he's 64 now but in his younger days he's done 8min long 335kph speed runs and even survived a 240kph highway accident). i lead the way with ghettoracer in tow on his 50cc scooter. on the way, there was this long line of cars stopped at a traffic light, so i decided to cross the double-yellow. at the light there happened to be a cop so i immediately starting cranking the pedals. he didn't give me a second look however...g was following me and was stopped by the cop. ended up just giving him a stern warning. we met our friend at the mrt station (he was on a scooter as well). he proceeded to cut through the front of the station when lo and behold there was a different cop which pulled him over now (and didn't give me a second look). my friend knew the precinct chief so he just let him off with a smile and a wave.

on the way back home, i heard a snap and lost traction to the drive--wasn't sure what broke at the time. pedalled the bike home and became a lot more familiar with the alfine shifter at home, i took the drive apart and found out that the 12mm gearbox-to-dual freewheel shaft had totally snapped around the region i cut a groove for the circlip. sooo...it looks like i will need to upgrade the gearbox and shaft. the rear wheel had also shifted...so look like i still need to make the torque blocks for the dropout.

all-in-all, we had a blast. tons of interest from random street people. haven't nearly tested the limits of this bike and i'm sure many other things will break but it will eventually improve in reliability incrementally. to me, the joy is in the journey

the video was such poor quality i decided not to post it. sorry for the delay guys--it will be forthcoming.

hmmm...it must have shrunk in the wash

gramps was quite fond of my bike. after he asked us a million and one questions he proceeded to recite his entire life story and life stories of his kids :|

finally some daylight shots

sad busted shaft and shaft nub. i think it still would've broke even if i hadn't weakened it with the circlip groove (gives himself reassuring pat on the back).

FWIW, the only motor shaft I've broken so far was also at a circlip groove, back on DayGlo Avenger's 2nd friction drive.