D's RC Drive Kona DC1

[liveforphysics]

I've been making this with your build in mind D. Also, don't pay me anything for it. Paypal Thud. He is the guy who did all the work to make the sprocket. I just taped down a sheet of Lexan in my machine, centered the spindle where he said, and hit "run". lol

He also designed an adapter to made from the ENO freewheel to the lexan sprocket all nice and neat.

 

[deecanio]

indeed Luke,

Thud also made my direct drive adapter and drive sprocket.
beers on the way Thud, and thank you both muchly


D

 

[deecanio]

Luke,

show us the moster
also any pics of Thuds adapter?


D

 

[liveforphysics]

I tried to write my own code to thin the edge down to the needed thickness, and obliterated the sprocket, and another endmill.

Thud sent me some more files I haven't had a chance to try yet though. We definately need to thin the edge FIRST before the teeth are cut, then cut the teeth. lol

This makes 4 squares of 1/4" lexan down the drain so far. lol Good thing lexan is a hell of a lot cheaper than CF.

Still, this is the cheapest education on CNC'ing I could ask for, and I'm extremely thankful to Thud, Kburn77, and the other folks who are helping this newb get a handle on CAD, CAM, and CNC setup. Thank you so much guys!!!

 

[graemebc]

Hmm custom sprockets with any bolt hole pattern you like & custom writing in the centre out of alloy at reasonable prices Luke???
Cottage industry time????

60 tooth for my front crank cyclone build cheers! name you price! I would like "chain guards are for wusses" cut out of mine

 

[liveforphysics]

Hmm custom sprockets with any bolt hole pattern you like & custom writing in the centre out of alloy at reasonable prices Luke???
Cottage industry time????

60 tooth for my front crank cyclone build cheers! name you price! I would like "chain guards are for wusses" cut out of mine

lol.

It's my pleasure to cut some sprockets out for you guys. However, I do not have the skills yet to do the code work. If you want to program it, I will cut it at the cost of materials for you.

If you suck at programming like I do, lucky for us, Thud happens to be an outstanding professional CNC programming guy though. Kick some cheddar$ to Thud and tell him what you want, he can send the code to me, and minor contribution in the whole process is tapeing down the material and hitting "run". lol

 

[MitchJi]

Hi D,

Miles uses the term synergy, this is what im after but on an adjustable scale controlled by throttle.
to be absolutely honest, ive been trying to emulate the exact performance i had with my hub motor for the last two years i would still be using that setup had the hub been upto the task of offroad, my end goal is to have that throttle controlled synergy but with a system that lets me ride rough, the sram may or may not last we'll see.

Problems with the previous build were this feeling of controllable synergy was totally gone, driving through the crank meant massive drag when pedaling only, i could only assist the motor briefly in each gear before the motor took off making the pedals obsolete so i ended up with an electric motorbike when all said and done, not what i want. The main problem was that i had to use battery power ALL the time, even pedaling on flat, i can normally go out for two hours on 6ah riding synergy in my noraml style, with the last setup i was home after 45 mins having wasted 8ah.

Even if you don't blow the SRAM your proposed build doesn't give you multiple gears for pedaling, independent from the motor. If you can solve the chain growth issue, either with your secret Decanio Gizmoâ„¢ or by mounting the Astro/reduction on the swingarm you might want to consider:

• Astro 3220
  First stage reduction with #25 of 4-5:1
  Second Stage 16t Eno to 48t-56t chainring on the left
  Standard FW hub with 3 sprockets on the right

Assuming the 3220 has equivalent power to the Puma and is geared properly the result should be almost the same, single speed motor independent of the three pedal speeds.

The #25 will be a little noisier than your belt but much quieter than your planned 11t/165t #219. I think Matt posted that his drive is limited to about 4:1 first stage with #25 but I think that might be due to length. With the dual motor mount I think you might be able to get 4.5:1 or 5:1 (check with Matt).

With 3:1 or 3.5:1 Eno to rear wheel I don't think back-pedaling effort will be an issue. If you have any doubts you can ask Matt, he does similar setups all the time.

Are you running 15s4p Dewalt? If so, if you can fit 15 Cellman 20Ah or even 15Ah cells, your capacity will be about double. The sizes are:
Capacity: 20Ah
Size:
7.0mm X 166mm X 227mm
0.28" x 6.54" x 8.94"
Weight 467g

Capacity: 15Ah
Size:
6.8mm X 150mm X 211mm
0.27" x 5.9" x 8.3"
Weight: 401g

Luke's Cell Testing thread is here:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=15093

Testing the big 15 and 20Ah LiFePO4 cells is tough! *Pics*

More info here:
http://endless-sphere.com/forums/viewtopic.php?f=9&t=14832

2.5USD per Ah for 15Ah and 20Ah 30C LiFePO4 cells

 

[AussieJester]

I think Matt posted that his drive is limited to about 4:1 first stage with #25 but I think that might be due to length.

I think you will find it also has something to do with being able to get to the motor mount bolts, i know with my setup
the pulley can only be so large before it obscures the path to the bolts. I managed to go up i think an extra 2? teeth size pulley but it requires a fancy rounded end allen key to get to the motor mount bolts...my reduction is now ~4.5 IIRC...

Poor ol Deec and his need to 'pedal' hehe... dual freewheels on the crank would solve all your issues Deec...

Even if you don't blow the SRAM your proposed build doesn't give you multiple gears for pedaling, independent from the motor.

Time for RC build #3

KiM

 

[MitchJi]

Hi Kim,

I think Matt posted that his drive is limited to about 4:1 first stage with #25 but I think that might be due to length.

I think you will find it also has something to do with being able to get to the motor mount bolts, i know with my setup
the pulley can only be so large before it obscures the path to the bolts. I managed to go up i think an extra 2? teeth size pulley but it requires a fancy rounded end allen key to get to the motor mount bolts...my reduction is now ~4.5 IIRC...

Poor ol Deec and his need to 'pedal' hehe... dual freewheels on the crank would solve all your issues Deec...

4.5:1 would probably be good.

Sounds like its time to put a bunch of holes in your pulley or sprocket (to reduce weight ).

With dual freewheels on the crank he still wouldn't be able to change the pedal gearing without changing the motor gearing, which he could do with the Puma.

 

[AussieJester]

Sounds like its time to put a bunch of holes in your pulley or sprocket (to reduce weight ).

hehehe...sheesh...anyone would think i put lightening holes in everything listening to you lot

I actually did contemplate it hahaha...its a lil small though the weight saving would be very minimal
i need to take the pulley off today actually, i might see what i can do about some holes for the
aesthetic side of things

RE: dual freewheel on the front...i meant he could do this with a 'standard' cluster on the rear
have two chains, one for manual pedal one for motor, motor large sprocket, pedal
to the cluster...might get a lil confusing for the Deecmiester though LoL

KiM

 

[deecanio]

Hey Mitch,Kim,

its been two years or so since my beloved puma setup died and if truth be told my ride quality only went backwards with my first rc effort.
to mount a dual reduction is a total pita on a full susser, i'm barely managing to mount single stage so i dont want to further complicate the setup with an extra reduction, i just dont have the room for it. the kona was bought with a hub setup in mind,and was perfect for purpose - im trying to fit as best i can a better drive sytem but know its custom frame time to get things how i want them exactly so whatever i do with it now is solely to get at least few rides in this year that dont depress me
Im open to any drive suggestion but the route im persuing isn't very costly, bar the dual drive i have everything i need already an i have bought a few little bits that leave the door open for a few different setups, direct drive cog and adapter (thx thud) new rim for the dual drive so i can revert to normal wheel if i change my mind on setup.
I guess im at a point with it now where the kona will only get as good as a bike can that isn't custom built from the frame up.
i realise the new setup won't give me total indepence from the motor, as in if the pedals are in 2nd the motor is too but it doesnt matter as it does give me normal pedal gearing when im not using power, hopefully with unoticable/small drag.
the puma could easily outrun my pedaling but could be throttle modulated at low rpm smoothly through its range so i just applied the amount of gain i wanted at any given time, im not sure how close i can get to emulation with the rc kit?
Dual freewheel cranks would be nice to explore but i think all the freewheel shananagans should happen at the rear wheel, i keep having the image of a freewheeling cluster crop up at the moment.
Battery tech has crossed my mind a few times too, i realise things have moved on and i could have much more ah/bang for my buck but that said im still happy with my A123's so im not really thinking about upgrading, again custom frame time if i was to bother.
theres a little testing in this bike yet but im finding it hard to maintain interest when i know how much better i could do things if i was starting from scratch, i already said ,dont hold your breath :lol:


D

 

[MitchJi]

Hi D,

Hey Mitch,

its been two years or so since my beloved puma setup died and if truth be told my ride quality only went backwards with my first rc effort.
to mount a dual reduction is a total pita on a full susser, i'm barely managing to mount single stage so i dont want to further complicate the setup with an extra reduction, i just dont have the room for it.

I thought your current plan is:

• 1. Use Matt's single stage reduction for the first stage
  2. Use a 12t #219 from the output of Matt's drive to a 92t mounted on a FW on the SRAM.

My suggestion is to:

• 1. Use Matt's single stage reduction with #25 for a reduction of between 4:1 and 5:1 for the first stage
  2. Use a 16t Eno from the output of Matt's drive to a 48t to 56t sprocket mounted on the left.

The differences are more reduction in the first and less between the drive and the read hub and connecting on the left instead of the right. No extra stages or complexity. Both plans require solving the chain growth issue.

i realise the new setup won't give me total indepence from the motor, as in if the pedals are in 2nd the motor is too but it doesnt matter as it does give me normal pedal gearing when im not using power, hopefully with unoticable/small drag.
the puma could easily outrun my pedaling but could be throttle modulated at low rpm smoothly through its range so i just applied the amount of gain i wanted at any given time, im not sure how close i can get to emulation with the rc kit?

I'm sure Matt can tell you how much drag will result from my proposal. I think its not much since most of his builds use a similar configuration.

If a 3220 geared with about 4:1 to 5:1 (limited by single stage) plus about 3:1 or 3.5:1 to the rear hub (limited to minimize drag while pedaling) has similar power to the Puma it should be very close to the same. My suggestion and your Puma both drove the motor with a single speed and gave you multiple speeds for pedaling.

I'm sure Miles knows the answer on the performance of the 3220 vs. the Puma. Unless Matt or Miles sees something I'm missing this should give you what you want without a new bike or a custom frame.

 

[deecanio]

Sorry Mitch i misunderstood.
if i drive on the left wont that mean loss of disk brake, also when pedaling i'd be driving the second chain which would freewheel at the output shaft yes?
i thought gary said previously that with single speed motor that to have any decent torque the top end would be low, around 17mph?

D

 

[MitchJi]

Hi D,

Sorry Mitch i misunderstood.
1. if i drive on the left wont that mean loss of disk brake,

2. also when pedaling i'd be driving the second chain which would freewheel at the output shaft yes?

3. i thought gary said previously that with single speed motor that to have any decent torque the top end would be low, around 17mph?

D

1. I'm not sure about the disc brake. I think you can use something called a "top hat adaptor" to mount a disc and a sprocket. Not sure if this can be configured to fit the Kona and not sure how large a chain ring you can use with it.

http://motorbicycling.com/f3/installed-top-hat-adapter-wheel-2846.html

2. Yes. I'm pretty sure that pedaling resistance won't be an issue with 16t/48t or 16t/56t (16t eno) configuration but you can check with Matt if you have any doubts.

3. I think a with a 3220, properly geared it will be fine since you are looking for a relatively low top speed but I'm not positive so you should definitely check with Miles, Gary or Matt before attempting this. EDIT ADDITION: If the top speed is insufficient when geared for the required low end torque you could either use Burties sensor mod and go back to 72v or use Delta/Wye.

I"m not absolutely sure there isn't a show-stopper problem but if everything works this should give you exactly what you want, so I think its worth investigating.

 

[recumpence]

D,

Remember, the issues with your bike are primarily related to things you were knew early on, but said would not be an issue.

#1 I mentioned the added drag you would have from the freewheel in the pulley so the jackshaft would be spinning fast with the cranks. You were aware of that and did not seem too concerned.

#2 You were fully aware that your pedal cadence would be very high to keep up with the motor.

I remember these things both being discussed early on.

I am trying not to be harsh. I just want to be clear that both issues you have addressed are things that were clear from the beginning.

That last issue you have been having is battery efficiency. That was something none of us were that aware of early on because no-one was running a single 3210 so hard before. Ypedal has the same issue. A 3210 is very efficient if run at 2kw or so. Above that, it will put out power, but it the efficiency goes in the toilet. That is something that was a surprise to me.

Anyway, I know this stuff can get frustrating at times. I went through the same thing with my recumbent at the beginning.

I am pulling for you to get this whole thing all worked out.

Matt

 

[swbluto]

Utter garbage. Sorry.

 

[MitchJi]

Hi,

Matt:

That last issue you have been having is battery efficiency. That was something none of us were that aware of early on because no-one was running a single 3210 so hard before. Ypedal has the same issue. A 3210 is very efficient if run at 2kw or so. Above that, it will put out power, but it the efficiency goes in the toilet. That is something that was a surprise to me.

What are the comparable efficiency figures for the 3220? 4kw or so?

D:
Edit Addition:

Remember, the issues with your bike are primarily related to things you were knew [told?] early on, but said would not be an issue.

This should mean that if you run your plans by Matt, Miles and Gary before your build you can eliminate most or all of the potential problems.

 

[flyinmonkie]

Hey D,

A couple of thoughts for you.
option 1
You can use the sram dd and with 3 chain rings on the crank, you will get a few pedal gears independent of the motor.

option 2
Use the sram dd and put one large sprocket on a splined freewheel for the motor to drive. Then put as many sprockets as you can from a cassette on the rest of the dd hub. Run the pedals on those sprockets through a derailleur. This will require a freewheel crank to not drive the pedals.

option 3
Use the sram dd and do the the reverse of the above. Run the pedals to the freewheel with a smaller sprocket, and run the motor through the other sprockets through the derailleur. This will not require a freewheel crank, but will require a freewheel some where on the motor or reduction to drive the motor while pedaling. This will not totally separate the gears of the motor and the pedals, but if you shift the hub, you can shift the derailleur to match.

Option 2 and 3 will not make the drives totally independent at the rear wheel. One drive will be independent and the other will drive both chains.

All three setups will require a second chain tensioner somewhere in the system for the chain growth.

Clay

 

[deecanio]

Hi All,


3 rings up front is an option, i know 32/42/52 to 15 was pretty good, mounting the deraileur might be tricky as the foot will be clamped there, hopefully.
with only the freewheel extron fitted to the splined hub i can fit four normal sprockets : 16t (unusable as too close to adapter)14t/12t/11t sprockets on with correct indexing and locking up with all normal parts, this would give me good pedal gearing but i'd have to stick with freewheel cranks - not unthinkable given this will have least drag to pedaling?
no disk brake or freewheel would make left hand drive a no for me, particularly when my rear brake outshines my front
I did indeed get those reminders matt but in my naivity i thought it wouldnt matter as i could low rpm my way to cadence match, heat in esc and motor quickly followed
does anyone else think the freewheel crank with 4 pedal only sprockets help match cadence best?
what i need here is a steer to end up with freepedaling as best can be but be able to control the amount of assist reasonably, the idea of one freewheel and 4 sprockets is growing on me as although the pedal gearing will move with the motor gearing when shifting on the hub, i will have three more gears for the pedals only, would that increase the chance of matching?


D

 

[recumpence]

I hope you do not feel like I was bashing you. I just wanted this to be made clear.

Each build has something specifically special about it that requires a different setup. Your setup happens to be the great challenge!

I am excited to see your build come together.

Matt

 

[flyinmonkie]

D,

I think my option 3 above would suit you best and give you the most flexability to set the gearing up the way you want. It will tak a while to learn what gear the pedals and the motor need to be in to be in sync for you, but with practice you could figure it out and get good at shifting to the correct combination with all 3 shifters lol.

To recap that set up:
sram dd hub
small splined freewheel for the pedals on rear hub
several fixed sprockets on rear hub for motor to drive (could be modified crank rings to get proper reduction and be shiftable)
3 crank rings for pedals up front
freewheeling drive sprocket on final drive of motor

This will give you 9 pedaling gears and it sounds like 9 motor gears. You would have flexability all the sprockets to change them as you like to get the correct gearing to sync the motor and the cranks.

Major hurdle for this set up:
How to get enough reduction to run the motor through the derailleur and freewheel the final drive.
You could try to see how #219 or #25 chain shifts, but probably not well with striaght cut sprockets. This leaves you with bike chain and huge sprockets or lots of reduction (which you don't have room for).

Which really brings you back to option 2 and a freewheel crank. Unless someone can cut sprockets for #219 chain with shift ramps that slide on a splined hub.

OK, I've jsut had a brian wave after all that. See if you can get a 3 speed freewheel cluster and get it splined like your eno. Then run the motor on one large sprocket on the flanged eno and see if you can get the 3 speed cluster on as well for the pedals. This would eliminate the need for a freewheel crank and with 3 chainrings it would give you 18 pedal gears and 3 motor gears and only shifitng the hub would change the pedals and the motor. You would still need 3 shifters though. Room on the hub and between your chain stays may be an issue, but might be worth checking some dimensions.

Clay

 

[MitchJi]

Hi D,

I think you should check two requirements before trying to decide on a plan:
1. Will a properly geared 3220 configured with a single speed give you the performance you want? If not could you solve the issue more easily another way (Burties sensor mod and 72v or Delta/Wye)? I'd ask Matt and Miles or Gary.

2. Is a FW at the rear required for low pedaling effort if you use something like an Eno 16t drive sprocket with a 48t or 56t sprocket on the rear? I'd ask Matt.

Trying to decide on a design w/o a clear idea of what is required to meet your goals is less likely to produce the optimum solution.

If a single speed 3220 is adequate the following might be good:

• single speed FW Hub
  Belt or #25 reduction using Matts unit driving #219 to an Extron mounted on your splined SB Eno
  3 chainrings at the crank driving your splined 16t Eno for pedaling

 

[gwhy!]

Hi D,

I think you should check two requirements before trying to decide on a plan:
1. Will a properly geared 3220 configured with a single speed give you the performance you want? If not could you solve the issue more easily another way (Burties sensor mod and 72v or Delta/Wye)? I'd ask Matt and Miles or Gary.

Hi D,
I think this is a very good suggestion. Out of interest what sort of top speed from the motor are you after ?. I am currently running 44v ( its not a 3220 motor) with a top speed of about 22'ish mph and it will have a very good stab at climing everything i have chucked it at ( I'm talking very serious hills 25%+ possibly up to 50% ) . I know If I can gear it slightly faster without losing the torque I would be trying to chuck it up near vertical climbs , I would have thought that if you went for say a max motor speed of around 30mph and from what everyone has been saying about how the 3220 performs you should be set with 1 speed for the motor.

 

[damcard]

I am shooting for around 28mph myself with a 3220 wired in wye. 45mph or so in delta. I have a 8150 but decided to splurge on the 3220 so I can get the 6-wire. I got my 8150 before I even knew that was possible. -David

 

[deecanio]

Hi All,


yes Mitch's suggestion is golden gwhy which is why im asking for last orders i need to get a move on or ill miss another season so once we've all had a prod with it im hoping the usal suspects will step forward and commit their views on the best setup, no bashing felt here Matt, step up and tell it how it is.
mitch, the setup you suggest is what were currently on but im just checking all routes before commiting.
at this point the sram can be included/exluded as can the three piece up front the main question is how to gear so that the motor is closer to the cadence but still have plenty of go when im not assisting?



D