tjavery

Nice! Very nice. I like the main driveshaft and built-up U-joints. I guess that's what it takes to handle two XL motors. Could you please take some close-up shots of your boom construction? It looks great from a distance.

Cool. Thanks. No Rush. I'm about to go on vacation myself

Cool. But I'm completely uneducated when it comes to that stuff. If you could please, generate a parts list of off the shelf compoents that could be assembled to create a RC receiver and transmitter system? That would be pretty cool Perhaps there's a short-circuit (or a circuit with a resistor or something like that) in the 9V Technic battery boxes that engages once you release the power button? The old geared 9V motors are so efficient that if you just short them out and try to turn them manually, they're very difficult to turn. The PF system doesn't appear to have this "dynamic braking" effect, i.e. the motors coast a little bit once you let off the power. What I was first describing wasn't necessarly this effect, but rather that the PF system is still giving the motor juice for a second or so after you accidentally break IR contact. If you combine that with the lack of "dynamic braking", then you've basically have a run away motor for a few seconds That could be really bad in the wrong situation

Check out Philo's motor specs and testing page: http://www.philohome.com/motors/motorcomp.htm It's hard to compare motor output torque because nearly all of them have internal gear reduction (i.e. output shafts all spin at different RPM's). But, if you look at efficiencies and output torque, the XL motors do look pretty good strength-wise.

It's the little 4x6 "box" on the top of this thing: (the receiver is hollowed-out gray bricks with white electric plates on top and black plates on bottom)

A while back, I built a tractor MOC that could move 43 kg (a very small adult) http://www.texbrick.com/model_tractor I think it's quite feasible to build a motorized platform/trailer that could move a lot of weight. It's just a matter of spreading the weight out over multiple wheels and motors.

After playing with some PF trains just this past weekend, I have to say that my opinion has lowered a bit. The limited range and line-of-sight problems were definitely issues in controlling the trains. We were using the new variable speed train controller, and we had to get within 4 or 5 feet to make it work (I don't recall the range of the simple, two-stick "on-off" controller being as limited as the new variable speed controller). Maybe it just needed new batteries... Another disadvantage of the PF system (now that I'm thinking about it) is that a short "pulse" is too long, i.e. if you want to turn a motor on for a fraction of a second, and you flick the PF controller, then the motor will go for a longer period than you've engaged the controller. With the HiTechnic RC system, when you hit the button real quick, the motor will come on for just an instant. This may not be important in some MOCs and sets, but sometimes you want to very carefully control a function by incrementally moving it in very small amounts. This type of feature is much more usable with the HiTechnic controller. Also, something else... when you're operating a PF motor via the IR controller, and the controller loses line-of-sight, then the motor will continue to turn for another second or two. I.e. it does not stop instantly as soon as the line-of-sight is broken. Again, this may not be important for all models, but sometimes when you want your model to stop, you need it to stop NOW and not 2 seconds later after it rolls off a table Anyway, I'm about to talk myself out of using the PF system So what would it take to make a home-made RC system like the old HiTechnic one? Would this be difficult? Or is it just a matter of buying the components and soldering them together? This is something I'm interested in.

Thanks! Thanks!

Right. And that's probably another good reason to invest in the new PF system, just because it's currently being produced. I just hope that they stick with it for a long while

Thanks! Thanks everyone for the welcome and kind words.

Thanks! Glad to be here. Yeh, lugnet.technic just kinda fizzled out (and so did I - I've had a "gray" or semi-dark age recently). Anyway, it's good to see an active Technic forum here The trouble I've experienced is with the geared 9V motors (and I'm not sure if it's 71427 or 43362, or both - I'll have to go home and take a look at my 5 seized-up motors). My first motor seizure happened quite a while back and I actually got a replacement from LEGO. They quickly sent out a replacement motor and an envelope to return the bad one. Kudos to LEGO for their excellent replacement service! Before I returned the bad one, I broke it apart and inspected the innards. IIRC, some of the internal gears had become bound up. I can't remember if something broke loose and damaged the gears or if one of the gears had become unseated and crushed up against another gear, but something did some bad damage and enough to render the motor useless. Hopefully the PF motors will not have those issues.

I've been buying mine from LEGO.com. Perhaps the BL prices will come down over time? The PF system is still relatively new. Good. Keep them! They are excellent motors and are slightly more efficient than the new PF motors. I probably have about 30 myself, although I've had several die - something inside locks up and they just won't spin anymore. That worries me about the fate of the rest of my old 9V motors

I've lurked here long enough, I guess the time has come to join I've been building with LEGO since about 1980. I've had a website for over 8 years now, and I've recently updated it: http://www.texbrick.com I've added a few new things and also a blog. I'm still building, although at a much slower rate than I used to. Having kids has slowed down my hobbies But my oldest definitely loves the brick and is into building his own stuff (and messing with mine).

I don't know of any source and I've never seen a used one for sale. Those old RC receivers were great and I'm highly disappointed they stopped making them. I have only 1 (a 4-channel) and it's not leaving my possession until someone rips it from my cold, dead fingers From talking to the guy that built them (John Barnes), he was having increasing difficulty in getting the white electric plates needed to make them (this was in 2002 or 2003, IIRC). I think the sensor gig was a much better prospect, so he stopped making the RC units. I wouldn't be surprized if he had advanced knowledge of (or even helped with) the PF system. IMO, the new PF system is worth investing in. Not only can you remotely control motors, but you can keep adding components and ultimately have control over 8 different functions in one model. The parts are relatively cheap, and they are reliable (in my experience). If something breaks, you can get a replacement (I doubt you'll be able to get the old HiTechnic RC receiver serviced or replaced should it fail). If you're heavily invested in the old 9V motors, then just buy the PF extension cords to make them work with the PF receivers. The only big drawback is that the PF system is IR (i.e. you have to account for the "line-of-sight" thing) and not radio like the HiTech ones. But the PF system seems to be robust and reliable (plus I like those huge XL motors).