keskiviikko 26. helmikuuta 2014

Throttle success

Thanks to picoamps I now have a working throttle solution using the car's original carburetor and TPS. The throttle shows correctly 0% with no "gas" and 100% when gas pedal floored. And I have video to prove it.

 Jake_offset_4p is the one I've got in the controller now. It was picoamp's idea to have that notch in the beginning. They use it in their products to take the play out of the system. I'm excited to try it out. Now if I could only get the motor back in. Perhaps which a clutch after all...

ps. I can't recommend picoamps enough. They've been really knowledgeable and fast to reply.

maanantai 17. helmikuuta 2014

Battery and throttle installed... poorly

It's been pretty quick and dirty all the way, but this is pretty ugly even for me. I installed the 12V battery and the original carburetor on a aluminum plate and bolted that next to the power steering pump. Maybe I'll clean it up later. Maybe.

The TPS in the carburetor is working fine. I found +5V for it and it's giving a nice signal of about 0.65V to around 4.50V. The problem is that at the other end it's too high for the AXE controller and at the other too low. With the best custom throttle curve map I found online I get 6% minimum and 80% maximum throttle. So it's a bit of mixed bag. It works, but not prefectly. I've sent an email or two to Alltrax and hopefully they'll be able to help me out.

If anyone else has a tool for making hex-format maps for AXE 7245, do throw me an email.

sunnuntai 16. helmikuuta 2014

Power brakes too

Today I installed another long standing piece of the puzzle. Namely the vacuum pump for the power brakes. In addition to the pump itself the system consists of a vacuum sensor, a relay controlled by the sensor, a vacuum tank and tubing. The pump is installed on some flexible rubber mounts to prevent extra vibration noise. The pump doesn't seem to come on too often, so there's plenty of good vacuum there.

The wiring needs to be cleaned up. Again. I also now have the AXE 7245 controller instead of the Kelly I had before, because the AXE can use the 0-5V from the carburetor TPS, which I'll try to use as the throttle.

A bonus picture: Vacuum pump and a valve I attached with Sugru. The valve stops the vacuum from escaping. It's made from a 4.99€ brake bleeding set from Biltema. Inside the metal part there's a ball and a spring, which let air go out, but not back in.

lauantai 15. helmikuuta 2014

Power steering success!

Great news, everyone! I finally got my electric power steering pump installed and it works like a charm. That really sounds like not a lot of work when you write it like that and I have to admit that the actual installation only took a couple of hours, but I had to have a part made and think the whole thing through more than once.

torstai 6. helmikuuta 2014

Lithium battery lecture

Extremely interesting lecture on lithium batteries and what affects their lifetime.

I may add more comments later, but here's the quick take:

Charge fast + cool temperature + low end voltage = LONGEST LIFE
Charge slow + hot temperature + high end voltage = SHORTEST LIFE

Rather sounds like Bottom Balancing done properly might just be the best way, eh?

Prolonged Top Balancing at artificial high voltage? Not so much.

tiistai 4. helmikuuta 2014

Heat or no heat

So my pretty heating element seems to be another disappoinment in the heat department. Perhaps I'll need to look into burning some dinosaur fuel after all to keep the officials satisfied. Oh, well. We'll see.

On the other fronts, which there are many, I've made some progress. Well, at least some steps forward and some back. The good news is I think I've found a good place for  the charger and a way to make it pass the inspection.

I think I'll mount the charger this way and put it all behind a big piece of plexiglass to make it untouchable by inquisitive fingers and inspectors with their testing sticks. I'll need to make sure there's some room below the charger to allow the fans move air as they are meant to.

My potentiometer based throttle has always seemed a bit flimsy, so I thought I'd give the carburetor and it's TPS (throttle position sensor) a go. Well, success ensued. 5 volts and ground in, 0-5 V signal out. 0.65 V at the lowest and 4.75 V at the highest with a cheap 5 volt power brick.

Problem is, the Kelly controller I already have mounted in the car only does 0-5K potentiometers. The AXE7245 I have the motorcycle accepts just about any imaginable throttle input. Looks like I'll need to swap the controllers. The motorcycle uses a 0-5K hand throttle, so the Kelly is fine there.

The AXE manual states 0.15 V as the lowest value, but the TPS gave 0.65 V. Remains to be seen if that's a problem. Of course I have the whole motor coupling thing still on the table as well.