My First E-Dune Runner

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mulepic said:
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).8029782005_bf143cca75_z.webp
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Awesome! Now THAT'S a meat grinder! :D
 
Wanted to show the pins that I described above. The thread on to the A and D shafts and fit tightly inside the pulley. I'm hoping it keeps the pulley running tru and not loosen:

8035717783_75d76bc865_z.webp

8035718127_d0fb4c4c1c_z.webp
 
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I'm having issues keeping belts from fraying. But in all fairness, I don't have this issue on the dirt. This is happening when I'm on the street which has tons of grip then spinning the clutch up to 10k when it grabs. But I'd like to see this not happen:

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I was sort of thinking that too. But brushless motors make most of their torque at lower RPM's. My thought process now is to get it to the track on saturday and see how long the belt lasts. I'll bring my gears along too. If the belt makes it through I'll get another one and just remember not to be so hard on the throttle when I'm driving it on the street. I really do like the belt more than the gears but gears do work great.

I think the belt conversion you can buy is a 3mm pitch. Form my reading 5mm pitch is stronger than 3mm and 8mm is stronger than 5mm. It doesn't sound like anyone is breaking the 3mm belts w/ the gas motor so maybe the brushless motor just hits a lot harder when the clutch engages.
 
mulepic said:
Wanted to show the pins that I described above. The thread on to the A and D shafts and fit tightly inside the pulley. I'm hoping it keeps the pulley running tru and not loosen:8035717783_75d76bc865_z.webp

8035718127_d0fb4c4c1c_z.webp
Click to expand...
The nuts turned out nice.
 
mulepic said:
I was sort of thinking that too. But brushless motors make most of their torque at lower RPM's. My thought process now is to get it to the track on saturday and see how long the belt lasts. I'll bring my gears along too. If the belt makes it through I'll get another one and just remember not to be so hard on the throttle when I'm driving it on the street. I really do like the belt more than the gears but gears do work great.I think the belt conversion you can buy is a 3mm pitch. Form my reading 5mm pitch is stronger than 3mm and 8mm is stronger than 5mm. It doesn't sound like anyone is breaking the 3mm belts w/ the gas motor so maybe the brushless motor just hits a lot harder when the clutch engages.
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Are you loosing belt teeth? The photo looks as if only the edges are fraying.
 
The teeth are all there, it's just the edges are fraying. I thought maybe it was rubbing on something but it coincides w/ heavy throttle on pavement.
 
I just noticed this morning my tires are taking a beating as well, the tried is separating. The plan is to get it to the track and see how it all holds up.
 
You could also instal the clutch backwards. The shoes last a lot longer and the clutch engages a lot earlier to. That may help with the belts fraying.
 
We use the clutch to keep the current through the ESC low. I'll be testing the belt at the track this weekend. I'll report back the results afterwards. The stress I was putting the belt under is probably not seen by a gas motor so it might be just an adjustment I need to make being brushless.
 
The charging station is ready for the track:

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I just need to figure out how to power it :)
 
I'm considering purchasing an inverter to run off the car alternator while I charge the batteries for the DR. But I need to know what size of one to get. So this morning I measured the current coming from the AC plug while I charged the batteries at max current. The AC plug measured 10 Amps, if I add 50% for a little wiggle room I come up w/ 15A x 120v=1800w. It looks like it'll take a 2000w inverter to charge these lipos. This would allow me to run at the track, not kill my car batteries, and not worry if the track has electricity.

What strikes me as funny, is the Alternator produces DC, then the inverter produces AC, which then plugs into my PSU's that produce DC to the lipos. You'd think there'd be a way to just plug the lipos right to the alternator w/ some sort of regulator.....hmmmmm.
 
I ran the car today at that the track to test 3 things:

1. ESC Caps performed great. I ran the car in the sun and it was hot out. The batteries lasted 30 minutes and the esc never temp'd over 130F. That issue is solved

2. The motor fan did great too. Same as the esc, it never got out of 130'sF, it ran great.

3. The belt drive was awesome. The belt stayed together and never came off or slipped. The pulleys stayed on too. I might even gear it a bit higher. But the top speed was the same as the gears but I got much longer run time.

The funny thing about this outing was everything else that went wrong:

1. There was no electricity at fear farm. The reason I went today and not tomorrow w/ the rest of the 1/5 guys was b/c on Sundays there is no electricity. So I went today counting on being able to charge my batteries. Well they had a little generator running all the tables. I knew as soon as I hooked up my PSU's I would of stalled that thing out. So I bought an inverter that I'll report on later

2. I couldn't keep the wheels on the car. After 10 mins the stock tires came apart. Luckily I had a new set of Rovans w/ me w/ RCDAD's 24mm hexes. A couple times the wheels fell off till I realized my hexes had no way of retaining the pin. RCDAD, please help me figure that one out. So I used zipties to hold the pins in. That worked but I need a better solution

Notable:

1. The batteries lasted 30 mins!!!! I couldn't believe it.

2. Temps of the ESC and motor never got out of the 130's, you can't ask for more than that!!

Things to do:

1. Figure out how to hold the hexes on

2. Figure out how to charge my batteries w/ not AC power
 
There's a set screw in the wheel axle that holds the pin in place. Put a notch in the pin so the set screw can lock it in place. Loctite it and use an O-ring to hold the pins in, in case they come loose.
 
Deluge said:
There's a set screw in the wheel axle that holds the pin in place. Put a notch in the pin so the set screw can lock it in place. Loctite it and use an O-ring to hold the pins in, in case they come loose.
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Hmmm, mine didn't come w/ a set screw set up. But there is a groove for an o-ring. Again, they didn't come w/ an o-ring. A snap ring would work best I think.
 
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