Tom's BEAST

[E-bike4life]

Maybe this could work.

[motomoto]

motomoto wrote:

Looks like a lot of chain.

And then I"d like to point out.


"Looks like a lot of chain".

[lostrack]

I would use a roller there, a fixed style like on a dirtbike will shred in minutes of use, trust me I tried it. You have to remember on a dirtbike, the suspension is compressed most of the time and there is little chain actually dragging on those under load. In your case the harder you pull the chain the harder it drags on that slider. An idler is a much better plan but make ut strong ir it will bend or break!

That's a really good point - I was trying to keep the chain as low profile as possible. Any idea what kind of roller or idler would work well under pressure?
I guess abec bearings for skateboard wheels roll under immense pressure all the time, this might work.

[lostrack]

Maybe this could work.

Thanks so much for the graphic idea. I could show you some front-on pictures - basically there is no straight line through the frame from the sprocket to the freewheel on the motor. The only way to link them without some really ugly chain bending is to go low (which hits the motor) or to go high (with the roller idea).


*EDIT*
Having taken a closer look I really like the simplicity of this design. It will hit the motor on the way down though.

[lostrack]

motomoto wrote:

Looks like a lot of chain.

And then I"d like to point out.


"Looks like a lot of chain".

Yeah, There was a 2 for 1 on chain, so I thought I'd make it as hard as possible to mount...why make it easy?

[markt108]

Hi tom I met you at jozztek last week came across this pic though it might be of interest to you http://www.maguda.com/image-site/DELETE.jpg

I pick up my specialized dh bike this weekend let the build commence

Thanks mark

[lostrack]

Hi tom I met you at jozztek last week came across this pic though it might be of interest to you http://www.maguda.com/image-site/DELETE.jpg

I pick up my specialized dh bike this weekend let the build commence

Thanks mark

Good to meet you Mark! It was a long day of soldering and steep-learning-curves:) Well, more the learning curves bit as Steve did all the soldering, but hey.

PM me a pic of your setup. Let me know how those Makita batteries work out too.

T

ps. picture is helpful - thanks

[lostrack]

awesome.
Looking forward to the vids and completed bike.

D

Deec - yo - just skipped through 78 (!) pages of your build...damn, that is a huge communal effort!

Did your 50A fuse work out OK? I'm not sure whether that's enough - probably better it blows than anything else though.

Also - you don't remember the best HV160 settings that worked, did you?

[recumpence]

awesome.
Looking forward to the vids and completed bike.

D

Deec - yo - just skipped through 78 (!) pages of your build...damn, that is a huge communal effort!

Did your 50A fuse work out OK? I'm not sure whether that's enough - probably better it blows than anything else though.

Also - you don't remember the best HV160 settings that worked, did you?

you want a 200 amp fuse, trust me. Also, if the fuse blows during use, it can blow the controller.

[lostrack]

awesome.
Looking forward to the vids and completed bike.

D

Deec - yo - just skipped through 78 (!) pages of your build...damn, that is a huge communal effort!

Did your 50A fuse work out OK? I'm not sure whether that's enough - probably better it blows than anything else though.

Also - you don't remember the best HV160 settings that worked, did you?

you want a 200 amp fuse, trust me. Also, if the fuse blows during use, it can blow the controller.

I thought 200 amp fuses were meant to blow at around double their rating...bad news about the controller!
So the fuse is to stop the batteries going nuts, but won't protect the gear, if I'm understanding correctly?

[MitchJi]

Hi Tom,

There is no way to get the chain line straight - and bending the chain up/down is much better than around objects.

Thoughts?

Not sure if this will work but how about extending the pivot point shaft and mounting sprockets on a bearing on the extension?

If this will work it will eliminate chain growth and you could also get an additional stage of reduction if that helps.

[lostrack]

Hi Tom,

There is no way to get the chain line straight - and bending the chain up/down is much better than around objects.

Thoughts?

Not sure if this will work but how about extending the pivot point shaft and mounting sprockets on a bearing on the extension?

If this will work it will eliminate chain growth and you could also get an additional stage of reduction if that helps.

Yo dude!

I'll have a look into this. Would be a pretty neat solution, and tough as nails with the right bearing. I think the only shaft that could be made larger is the bottom bracket, as the rear frame is fixed.
Idontwanttopedal also came up with a really good idea on the phone today - really appreciate all the thought.
I promise to return the Ebike love with some cool videos:)

[Whiplash]

The aebc bearings should ne ok, but you need to mount them to a steel sprocket or if you use plastic, it will wear very quickly, I tried it already. I would possibly use a freewheel from a bmx bike, remove the pawls so its just a bearing and figure out how to mount it where you want it...

[recumpence]

[quote="recumpenceAlso - you don't remember the best HV160 settings that worked, did you?

you want a 200 amp fuse, trust me. Also, if the fuse blows during use, it can blow the controller.[/quote]

I thought 200 amp fuses were meant to blow at around double their rating...bad news about the controller!
So the fuse is to stop the batteries going nuts, but won't protect the gear, if I'm understanding correctly?[/quote]

The problem is, if the controller see cut power under load, the FETs will see a huge current ripple that can cause them to blow. Yes, the fuse is to protect the system of you have a short in the wiring at some point. Basically you want to use a fuse or breaker than can handle 200 amps for 4 or 5 seconds at a time. That is what your drive system is capable of pulling.

Matt

[deecanio]

awesome.
Looking forward to the vids and completed bike.

D

Deec - yo - just skipped through 78 (!) pages of your build...damn, that is a huge communal effort!

without ES and moreover Jozz/Knoxie i'd never have a bike at all, these guys rock and supported me in every which way i wanted to try

Did your 50A fuse work out OK? I'm not sure whether that's enough - probably better it blows than anything else though.

IIRC i ran 2 x 50a in paralell just to test the bike (wheelie/stack vid) - i had bought and planned to use big ass car amp fuses, i had 150a and 200a ready, go with Matt's recomendation, no one has more rc experience.

Also - you don't remember the best HV160 settings that worked, did you? Afraid i dont mate, whatever they were i got them from Matt anyhow.

Hope you get this madman running well, should be epic

D

[lostrack]

Bit of a headache this weekend. Got lots done, but the sort of work you know you'll need to do again...

Rolling this thing forward with the current chain line feels like pushing through mud. There's so much resistance.

I currently have a hardcore steel 15mm thru-axle freewheel with bearings on the power side of the bearings, and a pit bike chain guide in the return. Lots of pics.


It turns under power, but doesn't roll at all. And it makes a RACKET!

Pics and videos father the break

[lostrack]

Thanks for tuning in...

A long weekend of building.

I must note, this all looks horrible - it's proof-of-concept / work in progress before I jazz it all up.

The team & I have sorted a high compression roller for the top - this won't move under compression and the bearings from a freewheel inner-part, rolls really smoothly. I cut down a 15mm thru-axle to let it rotate naturally.

The nylon roller is on the return line. It's horrible. It's not wearing down, but it's hideously loud and I completely drowns everything out, I'd be too embarassed to ride it around! I will replace with another heavy duty roller.


Latest pictures: explanation and video below.

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The chain tensioner device is a modified SURLY which I thought would do the job. Unforunately on full travel, the tensioner can't take up enough slack. I'll have to re-design.
The mount is a bodge to see if the concept works....

IMG_1415 (Custom).JPG (55.24 KiB) Viewed 502 times

Ear bleeding noise!! Replace with roller!!

[Whiplash]

Cool, now the real hard part, making it not loud! Lol!

[lostrack]

Cool, now the real hard part, making it not loud! Lol!

God, that's not normal is it??
I need earplugs to ride anywhere!

Need your help Whipper!!

[Whiplash]

Lol! Wish I had an answer for you, but I gave up on my RC drive for that very reason! Too loud! If you get rollers with sprockets it may be better since the chain does not bounce over the roller... Good luck and nice bike!

[lostrack]

I've had an idea...

Video below.

This will sort out my chain tension issue, and also alleviate alot of the nylon roller trouble I've had, so an elegant solution (solving two problems) if I can put it into practice well.

Rather than having a fixed point chain tensioner with spiral spring, I will have a sprung track-roller system, like a curtain rail design, which will rest on the top leg of the chainstay. It will ping back and forth depending on the suspension compression.

It will keep the tension, allow me to add stronger springs should it need it, and also carry alot of force in a smooth way. That's the idea at least!


Has anyone experimented with this? It could be quite neat.

Video will explain :



Something funky happened with the audio from the iPad so you're treated to some pseudo-vinyl crackle. The assembly at the back weighs a ton.

[sn0wchyld]

I've had an idea...

Video below.

This will sort out my chain tension issue, and also alleviate alot of the nylon roller trouble I've had, so an elegant solution (solving two problems) if I can put it into practice well.

Rather than having a fixed point chain tensioner with spiral spring, I will have a sprung track-roller system, like a curtain rail design, which will rest on the top leg of the chainstay. It will ping back and forth depending on the suspension compression.

It will keep the tension, allow me to add stronger springs should it need it, and also carry alot of force in a smooth way. That's the idea at least!


Has anyone experimented with this? It could be quite neat.

Video will explain :



Something funky happened with the audio from the iPad so you're treated to some pseudo-vinyl crackle. The assembly at the back weighs a ton.

interesting idea, I dont have any real experience with this (yet), so I could be wrong here, but... my thought is that under power, the tension on the chain will cause the roller spring to compress, and the chain after the roller will go slack, and likely skip/fall off etc. you could put in a stiff enough spring to stop this... but then it will mean that a larger part of the load from the suspension compressing will be offloaded to the chain, and the roller's spring. Is there a way you can have a single roller on the power side, and a tentioner on the return side? the piston like roller might work well round that way...

[lostrack]

I've had an idea...

Video will explain :

interesting idea, I dont have any real experience with this (yet), so I could be wrong here, but... my thought is that under power, the tension on the chain will cause the roller spring to compress, and the chain after the roller will go slack, and likely skip/fall off etc. you could put in a stiff enough spring to stop this... but then it will mean that a larger part of the load from the suspension compressing will be offloaded to the chain, and the roller's spring. Is there a way you can have a single roller on the power side, and a tentioner on the return side? the piston like roller might work well round that way...

I should have mentioned - the bike is upside down. Th tensioner is on th return line which becomes naturally slack under power

[recumpence]

You could run the return side of the chain under the swingarm. That would drastically reduce the chain growth under suspension movement.

Matt

[lostrack]

BREAKTHROUGH!

Showed this to a good friend, with fresh eyes, and he suggested the below.

It will shorten the chainline (motomoto will be happy), and make the drive line straight, also taking most of the awkward angles out too.

LITERALLY relieved. Totes.

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Goodbye battery box.

I will make a motorcross style HUGE carbon fibre mud guard at the bottom, and use the inside for the controller and some of the electronics. Now I can fit in my switch, too. It might even look cooler.

May be running by this weekend.