My First E-Dune Runner

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ChuenouXiao said:
It looks like a HPI filter? Can I buy it separately? Is it a good filter?
Click to expand...
I wouldn't trust it. The filter elements are sketchy, and the inner cone isn't completely covered by the filter. If that cap flexes, dirt gets sucked in. The HPI filter is better, for sure.
 
25+ mins of runtime!

I just took the car out to see what difference the capacitors and motor fan would make. One of the reasons I did this is b/c I'm a firm believer that cooler electronics are happier and more efficient. I took the car to a wide open dirt parking lot where I was able to run WOT for about 6 seconds before turning. It's a huge lot. I was really trying to drain the batteries so I could charge them w/ the bulk charging method. Several times I temp'd the esc and motor. The motor high was 148f (I believe 170 was my last high b4 the fan) and the esc never felt much warmer than ambient. The esc had the most improvement for sure. The caps really made a big difference.

I was also keeping track of the total run time. I tried to mix it up w/ hard stop and go's to draw high current. But most of it was slow turn -> WOT. In the end I had to stop after 25mins b/c my kid needed to get to school. I measured the voltage of the batteries, they were 41.8. The fully charged packs are 50.4 and lvc is 38.4 (3.2v/cell). So w/ 3v left in a 12v range I'm sure I had at least a few more minutes left. I can envision some changes to get this thing to run 30 mins which I never would have imagined. So the cooler components improved my run time by 50% (i.e. 18 mins last track outing).

Not related to this but I keep forgetting to mention this. The conversion has produced a very nice low COG. Check this out. When I built crawlers and SC's I'd always try to achieve this:

[to explain, the car is able to stand on its side on it's own. it's not top heavy at all, very stable]

8009078741_07b0ec67a5_z.webp
 
ChuenouXiao said:
It looks like a HPI filter? Can I buy it separately? Is it a good filter?
Click to expand...
desismileys_6173.gif LOL JK. It seems better but not as good as the HPI or DT1.

Can't buy them separately yet, that I know of.
 
mulepic said:
I just took the car out to see what difference the capacitors and motor fan would make. One of the reasons I did this is b/c I'm a firm believer that cooler electronics are happier and more efficient. I took the car to a wide open dirt parking lot where I was able to run WOT for about 6 seconds before turning. It's a huge lot. I was really trying to drain the batteries so I could charge them w/ the bulk charging method. Several times I temp'd the esc and motor. The motor high was 148f (I believe 170 was my last high b4 the fan) and the esc never felt much warmer than ambient. The esc had the most improvement for sure. The caps really made a big difference.I was also keeping track of the total run time. I tried to mix it up w/ hard stop and go's to draw high current. But most of it was slow turn -> WOT. In the end I had to stop after 25mins b/c my kid needed to get to school. I measured the voltage of the batteries, they were 41.8. The fully charged packs are 50.4 and lvc is 38.4 (3.2v/cell). So w/ 3v left in a 12v range I'm sure I had at least a few more minutes left. I can envision some changes to get this thing to run 30 mins which I never would have imagined. So the cooler components improved my run time by 50% (i.e. 18 mins last track outing).

Not related to this but I keep forgetting to mention this. The conversion has produced a very nice low COG. Check this out. When I built crawlers and SC's I'd always try to achieve this:

[to explain, the car is able to stand on its side on it's own. it's not top heavy at all, very stable]

8009078741_07b0ec67a5_z.webp
Click to expand...
Great progress man.
 
I just finished bulk charging my batteries that I depleted this morning. If I keep the current constant at 20a from the PSU I can charge 1x6s 8A battery in 24 mins. This isn't difficult to do and is very straight forward. What will be complicated is running 2 PSU's charging 2 packs at the same time. The bulk charging process is a bit involved b/c you have to constantly increase the voltage to keep the current up. Doing this for two PSU's could be a bit to handle.

If I could figure out how to connect the PSU's in series and charge the packs that way it would be a bit easier. I've read about PSU's in series but I'm not sure I quite understand the safest way to do it. So for now the PSU's are separate and so are the batteries during charging. Nonetheless, it's very nice to be able to charge these huge packs so fast w/o a $$$$$ charger.
 
Question for you RCDAD, does that belt on the belt kit expand? I'm curious w/ the motor hitting 20k rpm's if the belt is going to expand like the tires.
 
It bounces around a bit but it does not expand. They are fiber reinforced so they stay stable.
 
Thanks, I think the 1st approach to this will be to use a belt that is fitted to the specific pulleys. Then we'll figure out how to get a tensioner in there for different ratios.
 
mulepic said:
I just took the car out to see what difference the capacitors and motor fan would make. One of the reasons I did this is b/c I'm a firm believer that cooler electronics are happier and more efficient. I took the car to a wide open dirt parking lot where I was able to run WOT for about 6 seconds before turning. It's a huge lot. I was really trying to drain the batteries so I could charge them w/ the bulk charging method. Several times I temp'd the esc and motor. The motor high was 148f (I believe 170 was my last high b4 the fan) and the esc never felt much warmer than ambient. The esc had the most improvement for sure. The caps really made a big difference.I was also keeping track of the total run time. I tried to mix it up w/ hard stop and go's to draw high current. But most of it was slow turn -> WOT. In the end I had to stop after 25mins b/c my kid needed to get to school. I measured the voltage of the batteries, they were 41.8. The fully charged packs are 50.4 and lvc is 38.4 (3.2v/cell). So w/ 3v left in a 12v range I'm sure I had at least a few more minutes left. I can envision some changes to get this thing to run 30 mins which I never would have imagined. So the cooler components improved my run time by 50% (i.e. 18 mins last track outing).

Not related to this but I keep forgetting to mention this. The conversion has produced a very nice low COG. Check this out. When I built crawlers and SC's I'd always try to achieve this:

[to explain, the car is able to stand on its side on it's own. it's not top heavy at all, very stable]

8009078741_07b0ec67a5_z.webp
Click to expand...
Awesome! Glad it's working out.
 
mulepic said:
I just finished bulk charging my batteries that I depleted this morning. If I keep the current constant at 20a from the PSU I can charge 1x6s 8A battery in 24 mins. This isn't difficult to do and is very straight forward. What will be complicated is running 2 PSU's charging 2 packs at the same time. The bulk charging process is a bit involved b/c you have to constantly increase the voltage to keep the current up. Doing this for two PSU's could be a bit to handle. If I could figure out how to connect the PSU's in series and charge the packs that way it would be a bit easier. I've read about PSU's in series but I'm not sure I quite understand the safest way to do it. So for now the PSU's are separate and so are the batteries during charging. Nonetheless, it's very nice to be able to charge these huge packs so fast w/o a $$$$$ charger.
Click to expand...
Which PSU's did you get?
 
mulepic said:
Check this out. I never knew how the belt drive system of a snow machine worked. It's very cool: http://www.gates.com/brochure.cfm?brochure=1033&location_id=542I'm sure we'll never get that made but you could sort of imagine using a clutch like we already have to power the belt. Then as the belt sped up the diameter would increase for higher speeds.
Click to expand...
Sweet. If I remember correctly, Demon tossed around that idea, a bit.
 
mulepic said:
Thanks, I think the 1st approach to this will be to use a belt that is fitted to the specific pulleys. Then we'll figure out how to get a tensioner in there for different ratios.
Click to expand...
What about a spring loaded tensioner? That way you don't have to loosen up any hardware. Just pull it and slip the belt on.
 
Deluge said:
Which PSU's did you get?
Click to expand...
I have 2 Mean Well 24v 20A psu's. I'm not sure if other power supplies have this but there is a a little adjuster for the voltage; this is how I control the current.
 
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