Scotts 5th - uh 6th build! now with a video - sorta!

[scottclarke]

Really can't be bothered with resizing them all so I've dumped them to some webspace.

Goto http://homepage.ntlworld.com/scottclarke/marin/

To view all the pics taken so far - these are all (except those renamed) quite hires and show all the nasties!

Scott

 

[tropmonky]

Nice photos. Thanks for posting them up! Looks like the motor is going to eat a lot of dirt and road grime!

So personal thoughts, would the larger motor be a better motor for this application (minus the fact that it wouldn't fit in the same location)?

Kyle

 

[scottclarke]

Nice photos. Thanks for posting them up! Looks like the motor is going to eat a lot of dirt and road grime!

So personal thoughts, would the larger motor be a better motor for this application (minus the fact that it wouldn't fit in the same location)?

Kyle

Dirt and grime yeah - hence the jet wash! The mudguards and motor cover will sort that out TBH though - the motor is pretty well tucked away - only the endbell projects from behind the frame and then its shrouded by my leg and the chainwheel so its only the rear I have to worry about.

With the 6KW motor you get more than double the mass and fewer rpm/v meaning gearing would be 'easier? but only if you run on 24/36V. Run it on 48 as needed to realise the full potential (why?) and you are back to silly speeds again. The only way I could justify using it would be the increased surface area = more cooling but since my journey is not stop/start I'll see the motor temperatures I have had on test - something like a 50C rise or even as low as 30C on a long flat road with no wind. The motor is probably good to 110C+ but I don't plan - and in fact don't need to explore that

OK - so today it got hot - but that was the best launch I have ever pulled - zero cut-outs - and it involved 100A+ the whole - what - 10 seconds? I could still hold my hand on it afterward so it wasn't scorching (70C+) and since I didn't plan on it as such I wasn't equipped to measure anything!

If you plan on drag racing I guess you may have an application - but you will need to take a very serious look at your rear end especially the wheel!

Scott

 

[tropmonky]

With the 6KW motor you get more than double the mass and fewer rpm/v meaning gearing would be 'easier? but only if you run on 24/36V. Run it on 48 as needed to realise the full potential (why?) and you are back to silly speeds again. The only way I could justify using it would be the increased surface area = more cooling but since my journey is not stop/start I'll see the motor temperatures I have had on test - something like a 50C rise or even as low as 30C on a long flat road with no wind. The motor is probably good to 110C+ but I don't plan - and in fact don't need to explore that


If you plan on drag racing I guess you may have an application - but you will need to take a very serious look at your rear end especially the wheel!

Scott

I have no plan on full out Drag racing, but having the larger motor would be nice at 24v-36v and not worrying about the heat as much. Plus the torque at the lower voltage would be great to. The fact that it's a lower RPM per Volt makes it a little more appetizing as well! I'm starting to think a 7 or 8 to 1 ratio running on 24v would be a good place to start. Any thoughts on that?

Kyle

 

[Dee Jay]

lol, dee jay i hope your no older than 16!!!!

Oh come on, adulthood started around 16 in the old days , he he . . .

Besides, "16" is just a number in some cultures . . . :lol:

I jest. :wink:

Now, the one behind the camera - now your talking

enjoy Enjoy ENJOY! :wink:

J

 

[recumpence]

Hmm, not too sure I want in on this exchange. I am 37 years old and very happily married (for 15 years I might add).

She is cute, though. :wink:

Matt

 

[scottclarke]

Guys, she is 11 years old - time to lay off please!!!!!!!

 

[johnrobholmes]

:lol: :lol:

I hope they didn't already know that

 

[deecanio]

Guys, she is 11 years old - time to lay off please!!!!!!!

thats why i hoped deejay wasn't much older? anyway enough.



Cheers,

D

 

[tropmonky]

So did you hack off the shaft with the threads on it or does it have some way of being pulled off?

Thanks,

Kyle

 

[AussieJester]

Really can't be bothered with resizing them all

Excellent pics, little annoying having to load each one though. I use a free program called Pixresizer you can resize multiple photos with the click of a button...might be useful in future...again though awesome work on the bike

Took the liberty too resize the pics for you hope you don't mind

 

[MitchJi]

Hi Scott,

Very impressive 8) !

My bike definitely corners well at 50+...

Sounds like the high speed handling issue can be sorted out. Please let us know how it goes.

then - as I have always done - made something useful out of a water bottle - a sweet ali bottle now holds the esc and the throttle assembly. With this build I opted to eliminate all the problems I have experienced with all makes of throttles tried - that is - when it pours from the sky I have seen glitching/full throttle/zero throttle. On this I have used a motorcycle grip the cable feeds into the bottle where it attaches to a spring that pulls the throttle back to zero. A linear 10K pot is securely attached to the spring/cable join and also features its own 'return to zero' spring should the joint fail. The esc also sits within and a pc fan is mounted at the base - this powered up whenever the esc's auxiliary supply is. Air inlet is via a series of holes along the length of the bottle right between the holder rails.

I am considering using RC components for a build but I'm concerned about exposing an RC motor to rain. It looks like the motors are open and some even have fans. If the motor is open, possibly with a fan how do you plan keep it dry (and clean)? You could enclose it but then there is the potential of overheating...

I also don't understand the RC motor specifications, the drive options etc. If knows of a link to a overview or tutorial on RC motors and controllers please post it.

Thanks!

 

[scottclarke]

Mitch - quick reply - better later on

Brushless rc motors are not too adverse to water - within reason. In theory they can be submersed and still run but in practice the action of moving all that water increases current draw big time..... I have run it in heavy rain with no problems and tbh I think as long as the motor is spinning no water will actually get inside - it will simply be thrown off due to the 3 or 4 thousand rpm............ bear in mind the whole outside of the motor spins.

I do plan on some simple measures though - hard to explain so you will have to wait for pics - but they are very simple measures that will work wonders to keep water off - this is in addition to the full mudguard that is going to be fitted to tthe rear wheel. Clearance is an issue here - so the part between motor and tyre will be very thin - around 1mm.

Scott

 

[MitchJi]

Mitch - quick reply - better later on

Brushless rc motors are not too adverse to water - within reason. In theory they can be submersed and still run but in practice the action of moving all that water increases current draw big time..... I have run it in heavy rain with no problems and tbh I think as long as the motor is spinning no water will actually get inside - it will simply be thrown off due to the 3 or 4 thousand rpm............ bear in mind the whole outside of the motor spins.

Thanks I was afraid water or dirt might be deal breakers. Now I only have gearing on the potential deal breakers list.

Care to comment on the noise? I want to hear someone say damn thats noisy -
or something - anything! It's almost like the post is invisible - I expected
all manner of abuse but nothing - whats up!?!?!???

Loud but not an obnoxious sound (for a while ). Reminds me of the Honda F1 cars in 1965. I think they were V12 that wound very high (something like 12k rpm). Very distinctive high pitched sound.

It's not the chain making so much noise on mine - its the vibrations due to the motor
mounting method chosen. I have reduced the noise considerably and at 20mph it really
is quiet - it gets noisy over 35mph though. At 35 its still nowhere near as loud as a
petrol engine - you can actually hear cars approaching from the rear.

What other mounting method would have been quieter? What did you do to reduce the noise?

I do plan on some simple measures though - hard to explain so you will have to wait for pics - but they are very simple measures that will work wonders to keep water off - this is in addition to the full mudguard that is going to be fitted to tthe rear wheel. Clearance is an issue here - so the part between motor and tyre will be very thin - around 1mm.

Do you think those measures will further reduce the noise?

EDIT - yes, belt drive - great idea until the teeth in the gears get contaminated
with road debris and you need to replace them. It is something I am looking at
but 'slowly' due to that issue. In addition, belt toothed gears come at silly
high prices and are massively overbuilt since invariably they end up on full
scale cars/big machinery! You could turn one down of course but right now I
have little chain noise so the cost of that doesn't appeal!

A friend mentioned a couple of days ago that some Harley's use Belt Drive. Probably still expensive but maybe (or maybe not) sized more appropriately for your use.

On this build I opted to use passive radiator cooling by way of heat transfer
through the motor plate to a finned heatsink. Other than this - the motor sits
behind a whole chunk of ali in the form of the crank, the seatube and elements
of the rear swingarm - hardly good for airflow. On a previous build using an
AXI I incorporated very effective active cooling that turned out to be essential
so going passive seems a retrograde step - and indeed it is.

Do you have any links or postings about the active cooling system? If not if you don't mind, and when its convenient I would like to see more information.

The motor is rated at 2800W but is intended for RC vehicle use. As those who do
RC flyers know - the motors rating system is a bit of a nonsense - in as much it
is rarely a continuous rating - nor a 5 minute or whatever rating - nor is it the
max volts X the max current the wire can take!

That is one of my questions. Do you just cut the rating by an arbitrary figure, maybe half for example, then monitor the temperature to see if its OK?

Given the relatively low cost of wire (in terms of overall build) - I
say - use as thick as you can - you won't lose anything except money doing so!

You also lose stealth. Those cables look like umbilical cords for a tugboat .

 

[scottclarke]

Mitch,

A soft mount would have been ideal but finding one that would fit, be the right density and keep perfect sprocket alignment is not something I have been sucessfull doing! I have filled the tubes around the BB with expandite foam and used a very exotic solid foam on the inside of the motor closure plate. It has reduced noise but by how much is only a guess.

The weather protection for the motor may in fact increase noise - time will tell!

A belt to handle the 3KW available would be over 2 inches wide in industry. I am not convinced the 1/2 inch wide belt (biggest that would fit) would suffice!

Active cooling was simply a fan attached to the end bell, so it span at motor speed. I fried a motor without one (expected it really) but fitting a fan cured all ills. I don't have any pictures of that MTB since it was a long time ago and I'm not really one for taking pictures of everything I do or places I go! That used a worm gear as reduction and I got good efficiency from it but I hated the fact the pedals turned with the motor so I didn't keep it long.

Motor rating - well I look at the wire gauge and judge that to be the maximum (initial) long term power limit. Short term has to come down to testing because it depends on available cooling.......... Such testing enables one to refine the maximum continuous rating................

Yeah you lose some stealth! My new battery placement will lose some stealth too and given recent experience I may have to reconsider plans again - a rear rail mount top box is looking more and more attractive.

Not related to your questions - I think I have nailed the cornering instability above 30mph that gets rapidly worse as you go faster. Front fork rebound is too slow so I need some thinner oil. This became apparent when I did some testing and concentrated on looking at the front wheel..... I wonder if Lowell has oil damped forks or plain springs......

 

[Miles]

A belt to handle the 3KW available would be over 2 inches wide in industry. I am not convinced the 1/2 inch wide belt (biggest that would fit) would suffice!.

The real problem is the available clearance with a large pulley.... What reduction ratio do you have at present, Scott?

 

[MitchJi]

Thanks!

 

[scottclarke]

The real problem is the available clearance with a large pulley.... What reduction ratio do you have at present, Scott?

9.1:1. I would very much like 20:1 though!

 

[Miles]

You should be able to do it (3kW, 9:1) with a rear pulley 290mm in diameter and a belt 20mm wide.

 

[recumpence]

A belt to handle the 3KW available would be over 2 inches wide in industry. I am not convinced the 1/2 inch wide belt (biggest that would fit) would suffice!.

Not true. A 8mm pitch belt 15mm wide would be more than enough. I am pulling 6,000 watts through a 15mm wide 5mm pitch belt. Now, my belt is run pretty tight. But an 8mm pitch belt would have more tooth depth. No worries. 3KW? No problem. :wink:

Matt

 

[Miles]

Hi Matt,

The problem with using 8mm pitch would be a huge rear pulley....

I was calculating for 5M.

If you've got room for a 370mm dia rear pulley, yes, you could do it easily with 15mm wide 8M belt.

You'd have to make the pulley, though

 

[scottclarke]

Not true. A 8mm pitch belt 15mm wide would be more than enough. I am pulling 6,000 watts through a 15mm wide 5mm pitch belt. Now, my belt is run pretty tight. But an 8mm pitch belt would have more tooth depth. No worries. 3KW? No problem. :wink:

Matt

Hehe, I have over 120 motors on a conveyor system to look after - it may well be these are intended to last forever and indeed I have seen no failures so far - maybe they are oversized a tad? :wink:

Actually - thinking on it - my largest belt is 3 inches wide but that has a 30KW motor behind it moving a 24 ton conveyor..... they surely are oversized.

The problem I have is twofold. I am just about scraping the tyre and the swingarm - so both sides - with a 12mm wide chain. I can't use any gear bigger than a 96 tooth which has a diameter around 220mm or I will hit the swingarm. Secondly - the chain noise is completely obscured by the frame ringing/motor hum when under big load. On overun the chain noise is barely audible so chain noise is not a big concern right now! Getting a controller that will deal with 200A is the priority however and you blowing yours up has done me no favours!!!

Actually, losing the gold chain for a belt would increase the stealth some more............. mmm

Scott

 

[recumpence]

Understood.

Oh, the rear pulley could be smooth. If you had a large smooth pulley made, there would most likely be enough surface area without any teeth to prevent slip.

I just ordered some caps for my bike to go along with the new Castle Creations Hydra HV240 I have on order. On top of that, I am moving the ESC right next to the pack. I will be going from about 18 inches of wire between the pack and ESC to about 7 inches. I am also going from 12 guage wire to dual 10 guage. Then I am doubling up my connectors and running a bank of caps.

I would rather go overkill than not enough.

Also, bear in mind, I have been pulling way over 5,000 watts (peaking a touch over 6,000 watts) through my system. When I was at 4,000 watts, I had no issues. But, hey, I have no plans on taking it easy with this thing. I want to see how far I can push it.

Matt

 

[Miles]

Oh, the rear pulley could be smooth. If you had a large smooth pulley made, there would most likely be enough surface area without any teeth to prevent slip.

Agreed. In fact, I've been experimenting with toothless large pulleys - what I did was put a 100t belt on a 100t pulley. Seems quite promising, so far

 

[scottclarke]

Understood.

I just ordered some caps for my bike to go along with the new Castle Creations Hydra HV240 I have on order. On top of that, I am moving the ESC right next to the pack. I will be going from about 18 inches of wire between the pack and ESC to about 7 inches. I am also going from 12 guage wire to dual 10 guage. Then I am doubling up my connectors and running a bank of caps.

I would rather go overkill than not enough.

Also, bear in mind, I have been pulling way over 5,000 watts (peaking a touch over 6,000 watts) through my system. When I was at 4,000 watts, I had no issues. But, hey, I have no plans on taking it easy with this thing. I want to see how far I can push it.

Matt

My kind of thinking

Please do be carefull at high speed (35mph+) - I have found ( at least on my suspended bike) keeping both tyres on the road can be tricky. I don't know how Lowell has no problems at high speed - it may just be his forks are setup perfect - or maybe its the extra weight keeping things planted - if its the latter I (we!) have an uphill struggle! I am going to go with thinner oil in the shocks. Having the front wheel sidestep 2 inches to the right when you lean left is no fun!