GNG, 1000W 48V BB-drive, $400

[bee]

I 3d printed an adapter that adds some teeth to the existing pulley. It fits great, but I won't know if it's strong enough until I install it on a bike.

 

[spinningmagnets]

Well done, sir! I think the big pulley will be more than fine with your 3D mod. It might not hold on the small pulley.

What would you charge for full retail price to a stranger to make one of these? I am certain that LightningRods will want one of these to test in a 20mm wide variation.

 

[spinningmagnets]

Another Pulley source for bigger 5mm-pitch belt units. Split type. http://www.cometkartsales.com/store/belts/5sprockets.htm

I believe these use the Extron Karting interface of (BUT, I am not certain):
Extron sprocket 5-1/4" 5.25 133.35mm Bolt Circle Diameter (BCD), Six 5/16-inch mounting holes

 

[spinningmagnets]

bee, would it be possible for you to try and make a 14T with a 10mm bore, 20mm wide and a keyway?

 

[speedmd]

Another Pulley source for bigger 5mm-pitch belt units. Split type. http://www.cometkartsales.com/store/belts/5sprockets.htm

I believe these use the Extron Karting interface of (BUT, I am not certain):
Extron sprocket 5-1/4" 5.25 133.35mm Bolt Circle Diameter (BCD), Six 5/16-inch mounting holes

They list a 105 tooth and up. Possibly Good for up to 120 volts! Listed as Closeouts! Possible to use stock pulley for hub?

 

[Cyclebutt]

I 3d printed an adapter that adds some teeth to the existing pulley. It fits great, but I won't know if it's strong enough until I install it on a bike.

Holy smoke! What material is that? Have you tried making a slip-on that fits the drive pulley? Can you cut these in teflon? This thing is giving my brain a snyapses attack!

 

[gwhy!1]

I have no idea how strong the martial is from a 3d printer but it look like a very good method to make a positive to make a mould to be able to cast it in a resin , I have played around with the larger 60t + timming pullys and they hold up quite well with some ali power added to the resin , ( only very limited testing has been done ) .

 

[bee]

The pulley was printed on a reprap FDM 3d printer using ABS. I also have access to a similar printer that prints with teflon if ABS isn't strong enough. In the above pics I only printed about 80% of the pulley just to test fit. The whole thing looks like this:

I put a solid cap on the end so that I can make a 20mm one that overhangs past the edge of the metal pulley but won't flex/buckle at the lip.

Well done, sir! I think the big pulley will be more than fine with your 3D mod. It might not hold on the small pulley.

What would you charge for full retail price to a stranger to make one of these? I am certain that LightningRods will want one of these to test in a 20mm wide variation.

I can make one for LightingRods to try with a 20mm belt for the cost of shipping to see if it'll work.

I don't have time to print more than a few, I'd prefer to just post the source/models for people to print up themselves. There are plenty of affordable 3d printing services, and you can generally use the 3d printer at your local hackerspace for free if you're up for learning a little bit about them.

For smaller stuff, shapeways might be affordable for strong steel pulleys: http://www.shapeways.com/materials/steel

I print the smaller pulley but there's no way that keyway will hold up on a plastic pulley, you'd need to cast it in metal.

I've been meaning to make a small foundry for casting my plastic prints, but the bike project got in the way! Still looking for a decent full suspenion bike on kijiji.

 

[spinningmagnets]

If we could just get two good ones, that would be quite valuable, and since this might only be done once, then 25mm-wide would be better, since these will be easy to trim shorter, and a mm or two may be needed to get it to work right. The SDP-SI pulleys apprear to be plastic cast over a metal core (I have a couple 15mm wide examples). It shouldn't be difficult or expensive to make a silicone mould, then create a keyed metal core for insertion, and cast the teeth.

I could send you some endless-sphere stickers and paypal for the postage and your time?

Perhaps if you drew such an item up and posted the file here on ES, several people could use the file to commission a 3D service to produce it?

 

[LightningRods]

I'm also looking into having one set of pulleys CNCed and then pulling a mold off of them. I can try 2 part industrial resin (like hard hat material) and see how that holds up. It pours into the mold like water and has a perfect finish. People make small boat propellors with the stuff.

How about having the part 3d printed and making a mold from that? Might be slightly less expensive.

That's good thinking. I should at least get a quote from a service bureau with a good 3D printer. The tempting thing about the actual CNC'ed metal part is that the company also does all of the CAD work correctly whereas I'm just experimenting. Plus I'd have a really nice usable pulley.

 

[gwhy!1]

I'm also looking into having one set of pulleys CNCed and then pulling a mold off of them. I can try 2 part industrial resin (like hard hat material) and see how that holds up. It pours into the mold like water and has a perfect finish. People make small boat propellors with the stuff.

How about having the part 3d printed and making a mold from that? Might be slightly less expensive.

ali powder mixed into the resin really works well for pulleys, I have done this and they do hold up ( only done 60t+ big pulleys ) . I didn't know this has been already discuss in this thread, sorry guys

 

[LightningRods]

I can make one for LightingRods to try with a 20mm belt for the cost of shipping to see if it'll work.

I don't have time to print more than a few, I'd prefer to just post the source/models for people to print up themselves. There are plenty of affordable 3d printing services, and you can generally use the 3d printer at your local hackerspace for free if you're up for learning a little bit about them.

For smaller stuff, shapeways might be affordable for strong steel pulleys: http://www.shapeways.com/materials/steel

I print the smaller pulley but there's no way that keyway will hold up on a plastic pulley, you'd need to cast it in metal.

Man, if college were this much fun, and the people this interesting and generous, I'd still be there!

I apologize once again for being absent. I'm buried in paying work right now. I'd so much rather play with this stuff that I have to make myself stay away to get anything done.

You guys really are amazing. I love all of the creative problem solving going on.

Bee, I'd love to see one of your 3D printed pulleys. I've had 3D objects printed at a number of different vendors. Some of it is flawless, some of it is kind of Lego-land. It would be good to have a smooth master to start with. For sure I will pay postage to get one to play with. Let's connect on that by PM.

One good solution for vinyl/resin pulleys is an aluminum or steel core that's embedded in the center. Then you bore the center hole and cut a keyway.

Something in my gut says that molded resin is going to work great for the drum of the pulley. My point again is that it's better to change out a $30 pulley and a $20 belt once a year rather than a $20 belt every week. Way less hassle and cheaper by far.

 

[LightningRods]

I 3d printed an adapter that adds some teeth to the existing pulley. It fits great, but I won't know if it's strong enough until I install it on a bike.

This gets the Thinking Outside of The Box award. If I had an applauding smiley, I'd use it. Kudos!

 

[crossbreak]

This gets the Thinking Outside of The Box award. If I had an applauding smiley, I'd use it. Kudos!

still thinking inside the GNG box

 

[bee]

I'm also looking into having one set of pulleys CNCed and then pulling a mold off of them. I can try 2 part industrial resin (like hard hat material) and see how that holds up. It pours into the mold like water and has a perfect finish. People make small boat propellors with the stuff.

How about having the part 3d printed and making a mold from that? Might be slightly less expensive.

ali powder mixed into the resin really works well for pulleys, I have done this and they do hold up ( only done 60t+ big pulleys ) . I didn't know this has been already discuss in this thread, sorry guys

There was a guy selling brass powder resin cast pulleys for 3d printers, it was a gimmick for 3d printers where plastic parts are strong enough, but maybe it'd be strong enough for our GNG kits.

Bee, I'd love to see one of your 3D printed pulleys. I've had 3D objects printed at a number of different vendors. Some of it is flawless, some of it is kind of Lego-land. It would be good to have a smooth master to start with. For sure I will pay postage to get one to play with. Let's connect on that by PM.

One good solution for vinyl/resin pulleys is an aluminum or steel core that's embedded in the center. Then you bore the center hole and cut a keyway.

Something in my gut says that molded resin is going to work great for the drum of the pulley. My point again is that it's better to change out a $30 pulley and a $20 belt once a year rather than a $20 belt every week. Way less hassle and cheaper by far.

Sure I can print out a bunch of them for you to experiment with in order to figure out what works best. Can you give me some specs for teeth, width, etc? Does the GNG belt have any problems with sliding off the pulley? I can add a lip to the print to keep it in place.

I am using the openscad script I linked to previously to generate these btw, it's a straightforward parametric 3d object generator that's easy to get started with if anyone wants to have a go at designing stuff themselves.

 

[crossbreak]

I dont get it. Why 3D print something that can be bought for cheap? Did I miss something?

Also, why post this to a thread that has already 90pages???? There IS a SPECIAL THREAD FOR GNG DRIVE CONVERSIONS!!!
http://endless-sphere.com/forums/viewtopic.php?f=28&t=46738

95T pulley, that should fit the GNG drive exactly : http://tncscooters.com/index.php?route=product/product&path=63_94&product_id=463

I also have some friend who prints 3D parts for me for free. But material is so expensive, i did not print anything yet :?

 

[Miles]

95T pulley, that should fit the GNG drive exactly : http://tncscooters.com/index.php?route=product/product&path=63_94&product_id=463

No one took any notice, when I posted it.... I even gave an approximate specification...

 

[LightningRods]

95T pulley, that should fit the GNG drive exactly : http://tncscooters.com/index.php?route=product/product&path=63_94&product_id=463

No one took any notice, when I posted it.... I even gave an approximate specification...

I noticed Miles. Thanks for taking the time to chase that down. I'd be interested to know whether virtually all of the GNGs problems come from the too small driver with sharp teeth or if the cheap cast driven pulley contributes. I think that the driver is most of the problem.

 

[Miles]

I think that the driver is most of the problem.

I agree.
With the 95t pulley, a 20mm belt and a new 16t drive pulley, you should see be a big improvement.... Certainly worth trying before spending time and money on custom solutions... Good to see so much creative thinking, though...

 

[crossbreak]

seems like the GNG is good for at least 50amps. Noone ever tried that either. Of course, this will need a belt to chain conversion, or a better belt like you just suggested

It's not so good for overvolting it, but that was already tried :lol: :lol:

 

[justlooking]

95T pulley, that should fit the GNG drive exactly : http://tncscooters.com/index.php?route=product/product&path=63_94&product_id=463

No one took any notice, when I posted it.... I even gave an approximate specification...

I noticed Miles. Thanks for taking the time to chase that down. I'd be interested to know whether virtually all of the GNGs problems come from the too small driver with sharp teeth or if the cheap cast driven pulley contributes. I think that the driver is most of the problem.

one thing i have thought of is that there is nothing to take the shock out of the system when accelerating or throttling up whilst under way ,, yes it is obvious that the drive pulley is machined wrong ,, but mopeds used to have a rubber connector in the rear wheel to take the shock, just like a clutch has springs to take up the shock, this stopped the chains stretching , cut down wear on the sprockets, and breakage of the crank and rear wheel spokes ,,
with the 3D printed pulley, that should help a lot to take the shock ,,

as for the small drive pulley i would still like to find a pulley that would fit straight on top of the original, thus making the conversion easy for those that do not want to try their luck at filing the drive pulley down ,,

 

[bzhwindtalker]

seems like the GNG is good for at least 50amps. Noone ever tried that either.

I doubled the phase wires and i'm tying the gng motor on 80 amps ATM
I needed something to ride and was bored after exams so I hacked this together :

Mid range accel is brutal

 

[Volts]

hay Lighting Rods are you still selling them plates for the gng

 

[crossbreak]

seems like the GNG is good for at least 50amps. Noone ever tried that either.

I doubled the phase wires and i'm tying the gng motor on 80 amps ATM
I needed something to ride and was bored after exams so I hacked this together :

Mid range accel is brutal

WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!!
ok... someone who really thinks outside the GNG box! I would die to drive this one.... someday

guess this would suck dry my battery within.... seconds?

Are you in the 50mph+ club now?

 

[justlooking]

seems like the GNG is good for at least 50amps. Noone ever tried that either.

I doubled the phase wires and i'm tying the gng motor on 80 amps ATM
I needed something to ride and was bored after exams so I hacked this together :

Mid range accel is brutal

WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!! WTF!!!!!!!!!
ok... someone who really thinks outside the GNG box! I would die to drive this one.... someday

guess this would suck dry my battery within.... seconds?

Are you in the 50mph+ club now?

80amps ?? wat voltage