Impact1

I'm curious what frequency you used for PWM. PF and PU both use PWM to control their motor speed, at 1150Hz I believe.

If you're going to go the non LEGO route. You might as well use a PWM supply. As opposed to a varied voltage supply. These keep a constant voltage, IE 9v, but turn on and off rapidly to control the speed. I combined a combined a 5 amp variable voltage regulator, normally set to 10v, in series with a PWM motor controller and a reversing switch. One of these per pair of PWM: AliExpress. Power Supply 12V 5A Adjustable https://a.aliexpress.com/_mOGksM0 And one of these per track: 80W DC Motor Speed Controller PWM Speed Adjustable https://a.aliexpress.com/_mq4y2BQ

Go to aliexpress website and search for power functions. https://m.aliexpress.com Search

That is a fantastic build. First rate.

Success on loading the software! The file was downloaded while I was at work, and my son installed the "Teacher" version last night. All well and good, he wrote a couple of simple programs. Only to discover that the brick was not connecting to the computer. I tried the mini USB and Bluetooth. removed and reloaded the software, nodda. Niether one would install the drivers correctly. I called and described the situation to a LEGO support person. He asked what kind of computer I have. It's a Dell laptop. He had me turn off the desktop "Accuweather" app. And now the USB installed fine. I still don't have Bluetooth working, the third of 3 drivers won't load. But I'll deal with that later. The software did an imediate update of the firmware to 1.03E. I also asked about the battery. I was told that I was not the only one to have this issue. The update in firmware didn't resolve any of this. The bad news is that the core set was given out as a promotional item at a LEGO convention (bricks By the Bay). So we may not be getting a free replacement, as there is no reciept. I'm wating to hear back. If anyone else is having the Lipo battery issue, and finds a resolution, please post here. I've already gone through two sets of cells trying to get it to work, and testing. I've tested the battery, it reads 8+ volts with no load. I'll have to gets some leads and test it under load.

Over the weekend my son was gifted a LEGO Education EV3 Core set. He was also given a single user software license. Which is good, as the home software isn't released yet that I can tell, and I believe doesn't work with a couple of the sensors in the education set (gyro and ultrasonic). We plan to pick up the new IR sensor and transmitter as well, so he can build some of the non educations models. Neither he or I have used NXT. And my use of Technic is limited to what I've needed for trains, so this is all new to us. We've had a couple of glitches with the software. First the license key was mis-printed on the paper, withe the first letter being cropped. So if you have the same issue, I was told by support that it's always a letter "W" for the first character. The next issue is downloading the software. I have a zippy internet connection, but it will only download at a few kilobyte per minute. I'll let you know my impresions if it ever finishes downloading. Another issue I'm haveing is the rechargable battery. We left it on the charger over night. But when we tried it this morning the EV3 wouldn't boot. And it booted fine with AA cells.. The green power light comes on, and the charging light is red. Then the red light goes out after about 20 minutes. There are no instructions for charging. So it may be another call to customer service.

The search engine won't let me search for 3 letter words. How do I search for the topics regarding the new EV3 kits?

I did somthing similar a few years back. Yours is cleaner, and has a more pro look to it. In my version I take up the power throught the axel using a bronze spring. I first experimented using coper tape over plastic wheels. I Later used a Lionel wheel the I shaved a bit thinner using a belt sander. And built a small moterezed truck. http://www.brickshelf.com/cgi-bin/gallery.cgi?f=100739 http://www.brickshelf.com/cgi-bin/gallery.cgi?f=120463 MAC

I did something similar a few years back for the lights on a observation car. test wheel Power pickup I had a few wheels done up in steel by a machinist friend later. But it turns out that Lionel wheels are already a near perfect profile. I bought some at a train convention. Bought an old cabose for $3. And removed a bit of material from the front and back on my belt sander to make them overall thinner. I wasn't interested in making a 9v motor at the time, as they were still avalible, but the metalwheels could be drilled out, and glue in a technic axle socket, then add a pair of brass leaf spring contacts to a PF train motor.