Microsquirting the NC30, part #48: Voltage stability

It’s been almost a year since the last NC30 post, where I had fabricated a new battery and found that the bike tune had changed and it ran poorly. The bike sat for a while since I got busy working on the Sonex, but I was forced to take it out last month since it …

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Microsquirting the NC30, part #47: New battery

As I mentioned in the last post, I left the key on and ran down the Ballistic Lithium battery. Instead of just forking over another $100 I thought it would be fun (and “cheaper”) to make my own pack. This is what the Ballistic battery looks like if you crack it open. The battery cells …

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Microsquirting the NC30, part #46: Tricky Tuning

Since the last post only got to the first tricky thing, here’s the sequel. In addition to getting the air density right, the second tricky thing has been parametrizing the volumetric efficiency. The Megasquirt engine controller can use different parametrizations of the VE. It always depends on the engine RPM, but there are several alternatives …

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Microsquirting the NC30, part #45: More tuning

The blog was down for just over a week, the machine hosting it just suddenly refused to post. This was one month after the three-year warranty ran out, but Asrock came through and replaced it anyway, probably because there is a known hardware problem on these low-power “Avoton” boards. Anyway, I’ve done a lot more …

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Microsquirting the NC30, part #44: Fuel filter bracket

As the last post ended, I had to pull out the welder and fix the leak in the fuel pump housing. Even though it’s been a while since I welded aluminum last, the corner weld worked OK. There were a few little snags but after letting it cool down I put the housing under water …

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Microsquirting the NC30, part #43: A small setback

While doing the tuning rides on the NC30, I’d noticed a faint smell of gasoline from the seat area. While there shouldn’t really be a way for fuel to get out of the system, that’s where the fuel pump housing is located, so I figured the smell was making its way out somewhere. There was …

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Microsquirting the NC30, part #42: Tuning

Over the past week, I’ve done a bunch of tuning rides on the NC30, logging data and tweaking the tables. Compared to the first run, it’s now fully rideable with only a few touchy points. The main task when tuning the fuel injection is to calibrate the “VE table”. VE stands for “volumetric efficiency” and …

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Microsquirting the NC30, part #41: It moves!

On Sunday, I rode the fuel-injected NC30 for the first time! It’s great to finally be at this point. Before I got to that point, there were a few final issues. After putting together, hooking up the fuel system, and verifying that all the sensors worked, I noticed that the throttle position sensor reported “20%” open …

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Microsquirting the NC30, part #40: Finishing up the throttle linkage

When the last post finished up, I had the link piece for cylinder 3 left. Since it’s basically just a longer version of the one for cylinder 1, it was pretty quick to get that done.   With that completed, it was time to put it all together and see if it worked. Testing revealed …

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Microsquirting the NC30, part #39: More throttle linkage progress

I cranked in another full day on the throttle linkage, and today went a bit more smoothly than yesterday. It turned out to be pretty painless to mirror flip the tabs holding the springs. Those were one of the first things sketched out in the design and often when you change things that far upstream …

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