My First E-Dune Runner

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RCDAD said:
You could also take just a bit of material to line up the pulleys.
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Do you mean off of the gear plate for the A shaft? I have thought about that but I was hoping to do a little modification as possible. But I suspect in the end I'll have to do that anyway.
 
I'm trying to figure that one out. I guess you mean take material off of the A pulley?
 
Corect.

Or.....

You could replace the outer section of the 2 piece lay shaft with one for the square drive gear. It's longer. Then you could just throw a washer behind the "D" pulley.
 
RCDAD said:
Corect. Or.....

You could replace the outer section of the 2 piece lay shaft with one for the square drive gear. It's longer. Then you could just throw a washer behind the "D" pulley.
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I like that, do you have part # or pictures of these parts?
 
So is the inside portion of that part still a hex so it fits w/ the existing coupling to the center gear? You have any in stock?

Is that the same as this, this one is square on the inside?

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The D shaft that uses the square drive is a bit longer than the 4 pin D shaft that U have. Other side is same hex that fits into the brake hub.
 
Thanks, that sounds like the right part for this conversion. I'll have to find one.
 
Here's the first crack at this. It actually moved very well w/ the belt setup. The first issue I need to solve is getting a nut on the A shaft to keep the pulley from loosening it's set screw. The D pulley seems to be doing well but its nut loosens up easily, I'll try some thread lock and see if that helps. The flanges on the pulley are simply snap on and the one on the D pulley fell off during machining (wish I had a tig welder). But the belt coming off hasn't been an issue. I do (I think) still have to come up w/ an idler pulley. With the 14t and 24t pulleys I have a 1.7:1 ratio on the gear plate. I use to have a 1.5:1 w/ my gears. But, the speed run I did the car seemed faster (no gps to back that up).

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Kaz the Minotaur said:
That is dope.The belt looks loose though?
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I'm pretty sure you want some slack in the belt, it's not like a serpentine or v-belt type setup. But I could totally be wrong, this is my first time w/ them. Maybe RCDad could set us straight on that on.
 
mulepic said:
I'm pretty sure you want some slack in the belt, it's not like a serpentine or v-belt type setup. But I could totally be wrong, this is my first time w/ them. Maybe RCDad could set us straight on that on.
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Looks Monster! Those teeth look huge.

I think you have enough wrap around that the slack won't be an issue.

How are you calculating the ratio?
 
krashkrieg said:
How are you calculating the ratio?
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This is just at the gear plate, not the final drive ratio:

24/14=1.7

The gear set up I had was:

35/25 = 1.4 then 26/24 = 1.08 total ratio: 1.4*1.08 = 1.5

So I have a 12% reduction currently. I would expect the top speed to be less w/ the belt drive.
 
mulepic said:
I'm pretty sure you want some slack in the belt, it's not like a serpentine or v-belt type setup. But I could totally be wrong, this is my first time w/ them. Maybe RCDad could set us straight on that on.
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You don't want it too tight, just tight enough for the teeth to grab. An over tight belt will get hot and prematurely fail.
 
I made a bolt that fits inside of the A pulley and threads onto the A shaft. The bolt is longer than the pulley so I can get a wrench on it from the outside of the pulley, think of it like a threaded coupling. This keeps the A pulley wobble free. The D pulley is giving me grief. The bolt does not want to stay on. I put some thread lock on it and I'm going to let it set for an hour before I try it again. Once the D pulley starts to wobble the belt wants to fly off. BTW, the belt doesn't look to be holding up too well. It's already showing signs of fraying. But that might be b/c of the D pulley wobbling. We'll just have to keep an eye on it. I was able to do another speed run and it's still looking a little faster to me. I'll have to get the GPS on it.
 
I ran the car again, this time w/ the GPS. It topped out at 34 mph which I believe that is where I was w/ the gears. So the motor must be happier since I lowered the gearing.

But the D pulley is still give me trouble. I might have to get a new pulley and do the bolt idea that I did for the A pulley. I'll have to post a picture of it so you have some idea of what I'm talking about.
 
I had a second pulley for the D shaft, it's a 22T. This would bring the gearing back down to 1.5 which is what I had before this belt conversion. I duplicated the long-bolt idea from my A pulley. But, then the belt I was using w/ the 24T was too long. So I made an idler pulley which worked out well with one major exception. Because of the stiffness of the belt, after I would hit the brakes the belt would raise up ever so slightly above the A pulley. Then when I'd get on the throttle hard the A pulley would slip under the belt and the car wouldn't move. I like the idea of the idler pulley but it seems to great more problems at this point. So I'm going back to the 24T pulley and see if I can come up w/ a way for that thing to stay on better.
 
mulepic said:
I finally drained my batteries to the lvc and was able to charge them in series w/ the psu's in series. It worked out just fine, nothing caught fire or over heated. I took just over 30mins to charge these bricks!8024770799_7a6b6e2dd5_z.webp
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30 mins? Nice! That setup looks impressive.
 
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