Electric Roadster

Thanks!
First reason was that I wanted more power, I love the sabvoton but the most powerful version is still limited to only 260Amps battery, I wished for more.
Also, the 260A version has a crappy form factor, I don't really like it, I prefer the old brick ones.

Last but not least, I got a good deal on this controller as a second hand unit from a good friend, so it wouldn't have been reasonable to pass on this opportunity. :wink:
 
Not much major udates, I'm working on the little stuff.

Essentially tidying up everything and testing the bike. I've made about 300km with it so far and it works okay, but I have some issues with setting up the controller properly. There are two problems, which I guess come from the same cause but I can't quite find it:
-The motor will vibrate and make a terrifying noise at some specific rpms
-If I run both of my bikes at the same stabilized speed, the red one will consume twice the power the black one does. It is super inefficient.

Other than that, the bike runs well already, it makes pretty good power and it outperforms my other motorbike in acceleration. But I'm sure it will deliver even more once properly tuned.
I'd really appreciate some help here, I'm kinda struggling with the stupid Kelly interface and I don't know what I did wrong.

I'll post some screenshots of my settings for the experts to help, but meanwhile here is a video of the issue:

[youtube]PJWWuZ0MdA8[/youtube]
 
Dui said:
Not much major udates, I'm working on the little stuff.

Essentially tidying up everything and testing the bike. I've made about 300km with it so far and it works okay, but I have some issues with setting up the controller properly. There are two problems, which I guess come from the same cause but I can't quite find it:
-The motor will vibrate and make a terrifying noise at some specific rpms
-If I run both of my bikes at the same stabilized speed, the red one will consume twice the power the black one does. It is super inefficient.

Other than that, the bike runs well already, it makes pretty good power and it outperforms my other motorbike in acceleration. But I'm sure it will deliver even more once properly tuned.
I'd really appreciate some help here, I'm kinda struggling with the stupid Kelly interface and I don't know what I did wrong.

I'll post some screenshots of my settings for the experts to help, but meanwhile here is a video of the issue:

[youtube]PJWWuZ0MdA8[/youtube]

Mine made similar, though not quite so loud, noises until I got the controller set right. Look at my final settings on this thread: https://endless-sphere.com/forums/viewtopic.php?f=2&t=111363&p=1653869#p1653869 Cleared up all noises, and made it substantially quicker off the line and overall. I have not yet done a distance test, but I suspect that economy will also significantly improve.
 
I have to comment on your thread, this is an incredible clean build and I'm very impressed at your craftsmanship. I'll be watching future updates.
 
Well... some bad news and some good news, but mostly bad ones

I crashed the bike pretty hard. I was accelerating at full throttle, and for some reason I'm not yet totally clear of, the bike gave me the famous wobble of death. At that time, I was over 100kph, and the wobble was so violent that it actually ripped off the direction stop.
So I fell on the floor pretty violently and slipped for what seemed to be a very long time. The bike did the same and came to a stop around 80-100 meters later, while I stopped maybe 20-30 meters before. Got lots of scratches everywhere, my helmet hit the floor and got destroyed, clothes ruined, etc.

Anyway, I was very, very lucky since I had nothing broken, only scratches and bruises. Went to the hospital the next day just to pass an X ray to make sure my hip wasn't broken: all good!

Now for some good news: while the bike sustained some damage, it is actually incredibly minimal given how bad this could have been. The only annoying part is the scratch on the paint, I'll have to repaint it once again, but it's relatively small damage. I'm very surprized about how tough the 3D printed side covers are, the bike grinded the floor for about a hundred meters but the cover is still in once piece, without any crack! Insane.

The right handlebar broke off, since it's carbon fiber it can't really bend. But it took me 15 minutes to make a new one so that's really no biggie.
The direction stop is gone, I'll have to make a new one.

Aside from these, there seems to be no other damage to the bike. I've already repaired most of it and tested at low speed and everything seems fine.
It was two weeks ago, I've now almost entirely recovered from the crash so it's all good. I'll try to be more careful now and also check the bike again to make sure there is no mechanical issue with the fork.

Some pics of the damage, it really doesn't look like it was such a big accident looking at the bike, but it was:
IMG_20210526_190119.jpg
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:shock:

Glad you didn't break anything and are almost fully recovered :thumb:
Maybe mount a steering damper to prevent a future speed wobble?
 
Did you figure out why it went into a wobble? I've had bikes that did that at high speed. A steering damper can help, but shouldn't really be needed if everything is built right. I've heard that a loose front wheel bearing or loose swing arm bearing can cause this. Steering head angle also makes a big difference.
 
Hadn't come across this build before, stunning work! Shame to hear about your spill though, not nice at all :(
Frame design is notoriously difficult, manufacturers didn't get in consistently right until the 1990s and still make screwups today.

It's amazing watching road racing here in Ireland, superbikes on poor quality public backroads quickly shows what works and what doesn't. Classics are particularly interesting, as fast as some of the modern classes but where the stiff modern designs are putting up a fight, the better of the classic frames are soaking up the irregularities.

Personally I'd start with a clean slate after a spill like that, probably go for a perimeter or even simple spine with the packs re-shaped around it but my feeling is it's stemming from the single downtube. Bringing the twin bottom tubes up to the headstock might make a big difference and could be tried out by adding to the existing frame (ie. three downtubes temporarily to test). Some torsional tests could reveal a lot, putting side and linear loads on the front wheel and measuring deflection.
 
Looking at your frame design versus common motorcycle designs.. i cannot identify any causes for this wobble off the top of my head. Perhaps the angle of a wheel is slightly off.. headset bearings would be the most likely place to find this misalignment of course.

Glad you survived the fall at such high speed without broken bones. Praise physics and the creator of your choosing. :thumb:
 
neptronix said:
Looking at your frame design versus common motorcycle designs.. i cannot identify any causes for this wobble off the top of my head.

If I had to guess, I would bet on torsional flexibility between the headstock and swingarm pivot. Many motorcycles using frames of this layout have the motor as a stressed member. Those that don't, still have motor mounts that can constrain torsional movement beyond some point.

Contributing factors to wobble that I have seen are excessive steering trail and worn front tires.
 
Very good point.. i cannot really tell from the pictures of the battery but it does not seem like the battery is providing that support in the middle of the frame.
 
Thanks everyone, your nice comments made my day!

I'm not sure yet what caused the wobble, it could be something wrong with the bike itself, but I was also ticking most of the wrong boxes while driving this day:
-full acceleration
-small pothole
-very, very heavy bag (about 20kilos). To add a little bit to the drama, the bag contained several relatively high power lithium batteries, they took a serious hit too... :roll: So yeah, first thing I did after getting up was to throw the bag away, in case the batteries inside would catch fire :lol:
Total recipe for disaster as you can see.

My bike is very lightweight, so my own weight (90 kilos) + the 20kilos of the bag was almost equal to the bike dry weight (113kg). I'm not sure wether that was part of causing the wobble, but it really didn't help to recover from it and avoid crashing.

I'm fairly confident that the frame geometry and stiffness probably isn't the cause, because it is exactly the same frame as for my black motorbike and I didn't have wobbling issue driving it everyday for four years. Rake is the same, geometry is the same, only the rear swingarm system is a little bit different, the red bike is using some rocker arms. The only difference between both frames is that I cut off the rear on the red one, but that should have no impact on twisting the front, or very minimal.
But it's just my opinion and I'm no frame expert so I still keep this possibility opened.

I will check my wheel alignement, bearings and make sure everything is properly tightened though.
Also, I don't know much about suspension tuning, so it is plausible that I didn't set my fork correctly after putting is back together. I'll need to educate myself on that matter so if anyone had a good youtube video to recommend on that I'm all ears!
 
Dui said:
The only difference between both frames is that I cut off the rear on the red one, but that should have no impact on twisting the front, or very minimal.

Well... if this really is the ONLY difference, it COULD be the reason.
Do not underestimate that you (in this case 90+20kg) sit on this part, and you are not as stable as steel tubes - I mean: a body is also kind of "wobbly", with all the meat, and joints which can move...
Maybe you can post a picture of both rear ends in comparison, so that we can have a look at the differences?
 
Dui- you were very lucky to have escaped serious injury with that crash. A death wobble is not normal and indicates a design problem or faulty assembly. I primarily suspect those thin plates that the swingarm attaches to that are not triangulated to anything- coupled with that very heavy hub motor rear wheel... I'd also gusset the joint between your downtube and the dual tubes under the battery.

Then methodically go front to back over every bearing and fastener, especially the head tube, and also check for lateral slop in your wheels/axles.

The geometry of your build would exacerbate any "perfect storm" of bad road condition events, with the steep seat angle, clip on bars and high pegs, and no gas tank to grab with your thighs to stay connected. Any head tube angle steeper than 73* isn't very forgiving. Also, if your front tire happens to be a bit smaller actual diameter than your rear tire you can get head shake.

Clean build though. Hope you get that sorted...
 
Ok, now that I've finished rebuilding my scooter it is time to work on the naked bike again.

First thing was to work on the saddle. This part was the one that worried me from the very beginning. The saddle is rather small and I can't really add too much material without making the thing ugly. I tried many things on CAD and the bike wouldn't look good with a huge and bulky saddle, it has to stay small, which makes for a big challenge: how to make this both small, comfortable, easy to build and look as professional/high quality as possible?

I decided to experiment with flexible 3D printing filament (TPU). I made a few samples, several tests... and finally came to this one
IMG_20211009_195245.jpg

I haven't made much change to the shape itself (smoothed a few sharp edges, made it a tad wider), but I did try several infills and print thicknesses. The part is mostly hollow with a 3D honeycomb pattern which speads the internal loads equally all over the saddle.

Well, it's a total success.
The saddle feels exactly the same as any other motorbike saddle, can't tell any difference while sitting on it. I made lots of test rides and no problem whatsoever. I can definitely ride the bike for a while without feeling sore!
Super happy with it, this method will be my goto for the final version, I'll just have to cover it with a layer of nice leather.
So yeah, you can totally 3D print a motorbike saddle, turns out it works great. It feels much better than the one I made using silicone, huge win! 8)

So now that I know that the saddle will work, I started working on the carbon fiber battery covers. My plan here is to try to 3D print the mold directly.
So first I 3D modeled the thing, then I bought a big spool of 3D printing filament.

IMG_20211003_012945.jpg

And then I launched the print:
IMG_20211003_191023.jpg

This is the largest part I've printed so far with my machine. It took 40 hours to complete and about 2.5kg of filament. Went smoothly.
IMG_20211004_132031.jpg

....and done! no warping or anything, perfect print.
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It's a bit hard to grasp the size of this thing but it is really huge.

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Anyway, after that I sanded the thing and applied bondo to make is as smooth as possible in order to hopefully get a good surface finish on the carbon part and help with mold release:

IMG_20211005_204828.jpg

Now I have to protect it with some kind of paint or gelcoat, and it should be ready to build the first carbon cover. What's great about this technique (if it works at all) is that I can make perfectly symetric parts since the molds directly come from my 3D files. Plus it's not too much workload, the only time consuming part is to sand and bondo the whole thing, but I'd have to do this no matter what other method I'd be using anyway.

So hopefully the next step will be to lay up the carbon, but I'll have to buy all the stuff first.
 
The saddle sounds really interesting, I'd love to know what sort of durability you get out of it - really cool!

Makes me want to try printing a replacement for an existing bike just to try it out!

Very cool stuff man, love your work.
 
Some more work done on the roadster over the past week: I'm building the light system.
Starting with the rear light first, since I'm still not clear yet about how I should make the front light.

So, I made a first relatively crude prototype in order to see if it would look nice, before comitting to the idea and build a more durable version.
First, I 3D printed the frame of the light, and mixed some red pigment into some transparent epoxy:
IMG_20220115_170543.jpg

Then I poured the epoxy into the 3D print and waited for it to cure:
IMG_20220115_171810.jpg

I then checked if it was working as intended, using a flashlight:

IMG_20220119_152715.jpg

It was a bit too dark at first, so I cut the part a bit shorter so the light had to travel a shorter distance throught the red epoxy.

Then I used some white led strips, I taped them on the back with painter tape:
IMG_20220119_210949.jpg

The camera doesn't really capture it, but it is very weird, kinda half way between a 2D and 3D effect, you can't tell what's going on and it is hard to guess wether it is hollow or not, it looks both hollow and not hollow at the same time. In real life this looks amazing and the color is much a richer red than what you see on the picture, I really like it.
Only problem is I'd like it to be a little bit brighter, especially while braking. I will need slightly more powerful LEDs on the final version.

I've then installed in the bike, to see how it would look like:
IMG_20220116_002637.jpg
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I'm very happy with the result, it's even better than what I had in mind. So I'm gonna make the final version based on this success, I'll need to design a custom PCB for the LEDs and think about a passive cooling system since LEDs are getting a bit hot after a while.
Next I'll have to start working on the real challenge: the front light... I still don't really know how I will design it. I'm just not satisfied with anything off the shelf I've seen on the market, I'll probably have to design something from scratch.
 
Just finished rading the entire thread. Amazing job! The design of the bike is superb. The wheel motor really gives you a whole new way of designing a bike. Love it!

Sorry to hear about the crash. Have you removed some parts of the original frame then that could be a reason for wobble. Have you balanced the wheels? Checked the steering bearings?
In my mind a steering damper is just a way of masking out a basic chassi issue if not used on something like a Dakar bike :)

That printer must be massive. I've never seen stuff that big being printed before. And home built. Awesome!

I really like the look of the bike without any side covers but I guess there is a good reason to have them :)

I'm not trying to tell you how to make things because you really seem to have that figured out but here's a couple of ideas regarding the side covers.
A buddy of mine is building a -67 Mini with a turbocharged VR6 and AWD. Really modified body and interior etc. Plenty cool. Anyway... He is using a CF reinforced filament for lots of stuff directly out of the printer. Air intakes/outlets, light holders, different brackets etc. He says the look is really cool and durability seem to be excelent as well. He is truly a master builder so his word goes a long way for me.
But the first thing I thought of was to print a thinner cover and then wrap that in a couple of layers of CF. Usually works really well also.

It is perhaps to big but take a look at the KTM RC390 passenger seat. Looks really cool and is actually really comfy as well. You need to see, and feel, it first hand to really get who cool it is. Maybe to late for this build but could be usefull in upcoming builds.
 
Thanks mate!

Jocke_D said:
Sorry to hear about the crash. Have you removed some parts of the original frame then that could be a reason for wobble. Have you balanced the wheels?

I don't know how to do that, but I don't think they are out of balance that much, I'd feel some kind of vibration if it were the case

Jocke_D said:
Checked the steering bearings?

Brand new, I changed them when building the bike, they are ok, no play, nothing weird

Jocke_D said:
In my mind a steering damper is just a way of masking out a basic chassi issue if not used on something like a Dakar bike :)

Yeah, I agree. Plus it would look kinda crappy, I'm not a big fan of those.
I think the wobble was due to several factors combined, I also found out that some stuff from the front suspension wasnt tightened properly, and also one of the front brakes wasn't properly tuned. Hopefully it should be ok now.

Jocke_D said:
I really like the look of the bike without any side covers but I guess there is a good reason to have them :)

Yeah it looks cool but everything is too much exposed to dirt, water, sun, etc. Wouldn't be durable.

Jocke_D said:
I'm not trying to tell you how to make things because you really seem to have that figured out but here's a couple of ideas regarding the side covers.
A buddy of mine is building a -67 Mini with a turbocharged VR6 and AWD.

Sweet. If there is a build thread I'd be interested to read it. :wink:

Jocke_D said:
Really modified body and interior etc. Plenty cool. Anyway... He is using a CF reinforced filament for lots of stuff directly out of the printer. Air intakes/outlets, light holders, different brackets etc. He says the look is really cool and durability seem to be excelent as well. He is truly a master builder so his word goes a long way for me.

I've tried it before but it wouldn't make much sense for this part. Plus it is extremely abrasive, I'm not sure I could print a full kilo without having to swap my nozzle at least once during the print, this thing grinds them in no time.

Jocke_D said:
But the first thing I thought of was to print a thinner cover and then wrap that in a couple of layers of CF. Usually works really well also.

I thought about that but it takes almost the same amount of time and work, for a lower quality product. Reason being you need to fill with epoxy, sand, fill with epoxy, sand again, etc many many times until you get a decent result. Usually with a mold you don't have to do it so many times, so in the end if you include the time needed to prepare the mould both solutions are equivalent. But the one using the mould will produce a better part in every way (better looking, more dimensionally accurate, more heat resistant and also quite lighter).
Also, and maybe more importantly, my goal is to learn and see if I can 3D print a big mold like that and make some nice carbon fiber parts just like that. Would be a very nice skill to have and a great application for my giant printer.

Jocke_D said:
It is perhaps to big but take a look at the KTM RC390 passenger seat. Looks really cool and is actually really comfy as well. You need to see, and feel, it first hand to really get who cool it is. Maybe to late for this build but could be usefull in upcoming builds.

Yeah it looks nice but it's too big. I've been struggling with the saddle design for a very long time, it was really difficult to make something that wouldn't look too big and awkward while still matching somehow the rest of the frame design. My current design isn't perfect, people either love it or hate it, but it kinda fits with the proportions of the bike. I think it needs a bit of getting used to because the whole design of the bike is very different from what we're used to see, but generally after people get used to it they start really diggin it.
Anything larger than the current saddle and the only thing you'll see on the bike will be saddle. There isn't a big tank to focus the viewer attention like there is on regular bikes, so that makes it quite difficult. But if anyone thinks he has a better idea of design and is willing to make a 3D model then I could totally print it and see how it looks :)
 
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