D's RC Drive Kona DC1

saturday :mrgreen:
well im hoping, bob was lacing my hub and i need to mail him and see if its ready - im hoping so, i need it !!
parts are here too so i can measure up for cranks and all sorts.
i still have the problem of ordering the crank pulley and motor drive pulley (now 3/8 bore ;) ) but as im going to steves im hoping he will have time to go over the plan and i'll ask him to try and get me a sample set from cdrive, at least he has a legit company lol.

D

yes bed time.... thanks miles.
 
D,
I was about to ask you if SDP/SI had contacted you about those pulleys. I don't understand why the general public does not have access to these, what the F*$%? :evil: Anywayz, I ordered mine from McMaster Carr. I don't know if they have your size but they had what I needed. The only downside was the price and the weight, these bad boys are steel. I will have to drill them out to lighten them up. It's a great website to search with cause it narrows everything down depending on your requirements. The biggest pulley they have is 72 tooth which can be matched to a 11, 12 or 14 tooth pulley. Hope that helps.
 
D,

For those power levels, I think you'll need to rethink your pulley sizes. By my calculations, the small motor pulley needs to be, at the very least, 16t - preferably 18t (assuming 15mm width belt).
 
Etard,

That is a XL pitch pulley. Not the correct pitch for D. :(

SDP has most everything in aluminum. I have not checked for 8mm pitch, though.

Miles, yes that is one issue I have run across is torque handling for a given tooth count. I have had a number of people ask for 11 or 12 tooth pulleys. But, for high torque handling, more tooth coverage is needed.

Anyway, I have not run any 8mm pitch belts and pulleys to have experience with them.

Matt
 
recumpence said:
Anyway, I have not run any 8mm pitch belts and pulleys to have experience with them.
Matt
Click to expand...
Matt,

The smallest 8mm pitch pulley recommended and the smallest normally available from stock is 22t. I've used down to 16t - below that the geometry starts to get problematic, I think. 8mm pitch pulleys for GT are the same tooth profile as HTD.

SDP don't stock pitches larger than 5mm AFAIK.
 
Hi All,

i see what your saying miles and i may have to have a rethink :(
i'm just glancing at the thread as im supposed to be working :lol: i'll read up properly later and see how we stand.
It looks like bad news tho :( as i had my calculations set using the smaller pulleys.
If i have to increase the size due to the torque i will have to stick with say 3kw, any pulleys that have to increase will effect my reduction maths i guess :cry: :cry: :cry:
i'll look later and do the math, then once miles corrects my math i'll do it again :)
Matt,
im still good for anodizing and i may or may not have some mounting info for you, this is why i was trying to pick a motor with miles's help last night but it seems complications arise with the astro 3220 due to its power (and size).
would you guys say that i can run with the smaller pulleys at 3kw? that would make the decision easy i guess and i'll just try a 3210 instead? that will leave me with the problem of having to limit the pack to 3kw peak but as miles said i think Gary's and Richards throttle board has this capability?
Just out of interest guys does the hv110 not have a current limiting function?

Cheers,

D
 
Maybe you could get more stealth and more power by changing to a 2 stage gearbox? The large pulleys could be much smaller.....

deecanio said:
Just out of interest guys does the hv110 not have a current limiting function?
Click to expand...
No, not the present version.
 
mmmm maybe miles but im well on the way with single stage now.
I didn't want dual as i dont have space to mount it unless i use my downtube which i was trying to avoid.
I'll do some more working out when i get home tonight (v late) and see where i am, it's fairly depressing to change at this point but i'll have to think about it if it's a choice between 3k and 5k.
dammit.

Cheers,

D
 
deecanio said:
would you guys say that i can run with the smaller pulleys at 3kw? that would make the decision easy i guess and i'll just try a 3210 instead?
Click to expand...

I still think 12t is too small for 3kW at those rpm. Of course, you can always crank up the static tension on the belt but that also increases the load on the motor bearings....

Remember these posts?: http://endless-sphere.com/forums/viewtopic.php?f=28&t=7641&st=0&sk=t&sd=a&start=172

Don't be disheartened, this is often the way things get designed - chasing round in circles till you find the best compromise...
 
Well this is an issue we all may need to resolve eventually. Is the main problem gearing the bike so that you can pedal with the motor? If so, you might have to either have a pulley machined to spec, or go chain right? If the problem is just geardown, you might get the reduction with a Shimano Alfine rear hub with an extra large rear sprocket. I know, you have already ordered an extra stout built rim, but these internal hubs have potential.
 
Hi D,

how do the inrunners bear the load of the shaft? wasnt that a concern and thats why the norm was an outrunner with good shaft support at each end?
Click to expand...

I think inrunners normally have bearings at both ends of the shaft but most outrunners only have bearings at one end. The Pletti and this Hyperion mentioned by Gary are the two exceptions that I am aware of:
also used to like the Korean-built Hyperion motors, as the quality was better than the Chinese variants. I see they now have one with very similar specs as the A60-18L, the Z5045-18. I'm still technically a dealer for these, so I think I will get one to campare with the Hacker. The specs nearly are identical, and it is about $100 less expensive.
http://www.empirerc.com/z50all.htm
Click to expand...


I didn't want dual as i dont have space to mount it unless i use my downtube which i was trying to avoid.
Click to expand...

Will it fit if its folded with smaller large pulleys? It might help you with plan the best layout if Matt (if he doesn't mind) ships you the drive with no motor slots to use to figure out the fit on the Kona. Then when you make a final motor decision you could have the motor drop shipped directly to Matt and return the motor stage of the drive unit for machining. The extra coast of one round trip airmail for the one stage shouldn't be very much.
 
Hi All,

Thanks for all the input guys i've just been picking through it and i've a lot to think about now.
i guess i have to figure out which way to go now, the least favourite to me is dual stage,the best solution for the problem is dual stage :roll:
Miles, do you think i may have the same issue running at 5kw with the 8mm drive at 14t/80t? or is this issue worse on smaller pitch belts/pulleys and i only have to worry about the 5mm?
if the motor pulley were 16t/60t thats down from 5-1 to 3.75-1, leaves me a crank speed of 315rpm ish.mmmmm.how big was the 100t again miles 220mm? :lol:
i'll have to think about this some more, i want to remain on single stage but it isn't apparent to me how yet.

Cheers,

D
 
deecanio said:
Miles, do you think i may have the same issue running at 5kw with the 8mm drive at 14t/80t? or is this issue worse on smaller pitch belts/pulleys and i only have to worry about the 5mm?
Click to expand...

Probably - depends on the first reduction ratio, though - remember I said that if you were going to use 12t for the 5mm then that would be the weak link and you might as well try 14t for the 8mm.

The other possibility is to use #219 chain between the GB and the crank - that would allow a ratio of up to about 8.2:1 (11t to 90t) instead of the 5.7:1 that you have with the 8mm belt. This would reduce the reduction needed for the first stage to 3.5:1 so, you could then use 17t to 60t. Even then, you'd probably need a 25mm wide belt... One of the Extron composite sprockets would minimise the chain noise.
 
I'm using a first stage with a 17T/70T combo. I'm pretty sure this will be fine up to the same power levels you are looking at. The ratio is 4.18:1, which is a bit better than using the 60T.
 
Hi D,

deecanio said:
Hi All,
i guess i have to figure out which way to go now, the least favorite to me is dual stage,the best solution for the problem is dual stage.

i'll have to think about this some more, i want to remain on single stage but it isn't apparent to me how yet.

Cheers,

D
Click to expand...

Would it work to mount Matt's single stage unit above the suspension pivot, and mount a jackshaft below the suspension pivot above the crank?

The jackshaft would be your "second stage". This would be more flexible and probably require less space than Matt's full 2 stage unit. This might allow dual stage without mounting on the downtube.
 
Hi All,

Thanks for the responses, i have been thinking about it over the weekend and i'm now swaying towards using chain for the second stage :shock:
Miles said:
deecanio said:
Miles, do you think i may have the same issue running at 5kw with the 8mm drive at 14t/80t? or is this issue worse on smaller pitch belts/pulleys and i only have to worry about the 5mm?
Click to expand...

Probably - depends on the first reduction ratio, though - remember I said that if you were going to use 12t for the 5mm then that would be the weak link and you might as well try 14t for the 8mm.

The other possibility is to use #219 chain between the GB and the crank - that would allow a ratio of up to about 8.2:1 (11t to 90t) instead of the 5.7:1 that you have with the 8mm belt. This would reduce the reduction needed for the first stage to 3.5:1 so, you could then use 17t to 60t. Even then, you'd probably need a 25mm wide belt... One of the Extron composite sprockets would minimise the chain noise.
Click to expand...

the more i think about this idea the better it seems miles thanks, if i go this exact route will using a #219 (whats that? go kart?) cure any power handling issues at 5kw using the 11t/90t sprockets you suggest? i know the chain will work better for torque/power handling but i need to be sure thats the end of power handling issues to covince me its the way to go.
on the upside mounting a small chain drive will be easier imo so there are some benefits, others should be smaller width drive overall im hoping.

GGoodrum said:
I'm using a first stage with a 17T/70T combo. I'm pretty sure this will be fine up to the same power levels you are looking at. The ratio is 4.18:1, which is a bit better than using the 60T.
Click to expand...

Hi Gary,

this is 17/70t on 5mm pitch 15mm width belt yes? and you think it would handle it 5kw at those settings?
if go to #219 chain secondary and get a great 8.2:1 reduction i was thinking i'd stick with the 17/60t,i thought this might be ok with 15mm width saving me from going to 25mm miles suggests, what do you think?

MitchJi said:
Hi D,

deecanio said:
Hi All,
i guess i have to figure out which way to go now, the least favorite to me is dual stage,the best solution for the problem is dual stage.

i'll have to think about this some more, i want to remain on single stage but it isn't apparent to me how yet.

Cheers,

D
Click to expand...

Would it work to mount Matt's single stage unit above the suspension pivot, and mount a jackshaft below the suspension pivot above the crank?

The jackshaft would be your "second stage". This would be more flexible and probably require less space than Matt's full 2 stage unit. This might allow dual stage without mounting on the downtube.
Click to expand...

Hi Mitch,

im desperate to stay with a minimal fuss system which for me is plain single stage to crank, the use of the chain will allow me to continue the setup exactly as i want it and allow me the power that i want through it, soooo it looks like thats the way to go.



Cheers,

D
 
Hi D,

Yes, a heavy duty go-kart chain should be able to cope with that. You might need to use an idler on the chain, to get sufficient wrap on the small sprocket.

Re. the belt pulleys, it's only the size of the small pulley that's critical (for that stage). How about settling on 19t to 66t, 15mm width? ;)
 
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