I was hoping to do about 3kW peak with this setup yet it seems that could be out of the question. Don't those pocket bikes put out more power than that? I guess I'm not too surprised at the mediocre power handling capability -- you can't ask for a whole lot at a cost of $20 + shipping. Do you know of any other gearboxes with a similar compact profile that could handle the power and torque of the large RC motors? It just seems like an elegant drive train solution that lends itself well to easily configurable gearing. Back to the drawing board then...Whiplash wrote:I have done this already and I can tell you to keep the amps down LOW, I sheared the teeth off the pinion gear with only 1200 watts..... Not very strong gearboxes, I think its the cheaply made gears...
Thanks for the tip on the 80-85. Do you know if the mounting hole locations are the same as the 80-100 as the motors have the same diameter? Almost a drop-in replacement if the 80-85 also had a 12mm shaft instead of 10mm.spinningmagnets wrote:You might consider the option of using the 80-85 in this application. If you drove the rear axle directly, that would draw more amps than this project. By driving the BB, you will be giving the motor some gears to use. 80-100's barely get warm in the rear axle drives (except perhaps when racing), and in this application there would be even less motor heat, so the extra mass of the 100mm length may not be necessary.
http://www.gizmology.net/gears.htmBluefang wrote: So who can explain how to measure a gear like the one we have?
Identifying Unknown Gears
Count the teeth;
Divide by the Outer Diameter.
This gives me the Diametral Pitch. It rarely gives me an exact pitch, due to errors in measuring, but it is usually very close to one of the common pitches of 32, 24, 16, etc.
If this gives me a goofy answer like 22.1, I suspect it is a metric gear, and divide 25.4 by the pitch (or divide the pitch by 25.4 and hit the 1/x button on the calculator) and see if it comes reasonably close to one of the standard metric moduli of 0.5, 0.8, 1.0, 1.25, 1.5, 2.5, etc.
If this still gives me a goofy answer like 1.14, then I figure it might be a Stub Gear, and try this:
Count the teeth (it doesn't usually change from the last time);
-Divide by the Outer Diameter (which also doesn't usually change).
-It should be close to one of the common pitches, but, alas, it often isn't. If I have a gear with which it meshes, I try this:
Add up the teeth on BOTH gears;
-Divide by two;
-Divide by the Center Distance.
-If this doesn't work, it must be a profile-shifted gear, so I try swearing, which also doesn't work.
I'm sure this would have occurred to you soon on your own, but...The peak power of a gasoline engine is at the higher RPMs, when the gears and chains are already spinning very fast, and the load is more spread out.I was hoping to do about 3kW peak with this setup yet it seems that could be out of the question. Don't those pocket bikes put out more power than that?
I could try to source higher quality helical gears (if they exist) for the cheapo gearbox. I would still be limited to an input shaft diameter, using existing bearings, of 9mm. This seems to be the weakest link to this setup. I did some searching for a similar gearbox with higher performance (for the larger scooters) but have found nothing yet. Do you have any links to this 7-1 gearbox?Bluefang wrote:Well that sized gearbox should be able to handle quite abit if the gears are good quality, a 50CC scooter has a 7-1 gearbox at the end of the CVT that is about the same size and handles up to 20hp in a tuned scooter, not for long tho. But back to my point it should be fairly easy to find a pinion gear thats alot stronger then the current one to replace it with? That would also solve your problem with the input shaft been too small. Even replacing the main gear should not be that hard, with the sheer number of these boxes around you would think they are all the same basic design. Or you can go out and buy the high end version which will certainly handle the power.
Thanks Adrain.adrian_sm wrote:Very nice. Great to see you get a dual suspension/RC build up and running. Oh, and I like the digital dash.
Be careful with the clearence to the front wheel, wouldn't want the motor mount bracket to hit the wheel at speed.
What speeds can you actually pedal assist to. Looks like a pretty small chainring.
The 80mm motors are not that big or heavy really when you think about it. Not having everything running on the limit is a good thing in my book.spinningmagnets wrote:Too bad there is currently no affordable outrunner motor selection halfway between the 63mm motors and the 80mm
I couldn't agree more. I just bought a house in Kansas, so I am fresh out of time and money, but if I suddenly found myself with a lot of both, I'd say the 80-85 is the hot ticket for this application. Even with a complete reworking of the motor immediately upon arrival, The shaft/shell/baseplate/and magnets are worth the HK price.Not having everything running on the limit is a good thing in my book
The plan is to clean it up and add 10 to 20 Ahr, 18s pack. I have tried a number of times to tear it down for rework but I can't seem to bring myself to doing so as I am having too much fun riding this thing. I like to call it extra qualification and validation testing... I plan to get the controller out of the triangle and reserve that space just for batteries. I'm really enjoying the off-road experience this bike has to offer and in the process I'm noticing how crappy the suspension is. It has me wondering whether I should invest in something a bit more modern and capable? In any event, lots to do to make it better - after I ride it a few more times.knoxie wrote:very nice looks and sounds like a good setup there, be interested to see it all tidied up and how it fares on longer rides, you figuring to up the battery capacity then?
I used iMovie '09 to edit the video. It's really the only thing I use my mac for.AussieJester wrote:That is one of the best edited e-bike videos I have seen what program do you use? Nice job on the setup will look slick when finished !