skaako

Hi thanks so much for the quick reply

Hi, I have been looking on bricklink to find a replacement motor and i noticed there a 2 types.. ones with short or ones with long couplings. Could someone please tell me which one is the same as this set? Thanks in advance :) Mike

Hi Johnathan, thanks for info about the IRLink, i won't be recommending using this then. I havn't had any experience with using this product, i was just under the assumption that it had a decent IR transmitting range. Do you know if their IR Transmitter has better range? i think they have this as another product. Thanks again :)

Hi Shane, that's good if you can get them at a reasonable price. I was having a look today, but i couldn't find any local suppliers. I found a supplier site to give a bit more details of the motors here. And also another interesting page i found here that makes good use of this type of motor. As for the shaft it was about 1mm. I think the same for the motor you're looking at, 2mm sounds too large for this size motor. Let me know how you get on with finding something suitable :) Mike

Thanks, your most welcome :) It will still be a while before me and my Lego are reunited again, but it will be fun when i can get something up and running. Oh yea i forgot to mention, to use App Inventor it doesn't even require you to have an android phone to make the apps as it has a good emulator too, although you will need a real phone to make use of the bluetooth functions.

Hi everyone, i have been playing around with Google App Inventor for a while now and realized there was no mention of it here on Eurobricks. My original post was here on the Lego Technic/mindstorms forum but my first idea was how it can be used to control Lego trains :) I think by using an NXT hooked up to an IR transmitter such as the Hi-Technic IRLink, it can be used to control PF trains quite easily. And with a bit more programming can be used to control many layout features, such as lighting, remote operated switches etc. The app connects to the NXT via a Bluetooth connection and many commands can be sent and received by using the built in Mindstorms components in App Inventor. I'm currently away from all my lego at the moment :( so i havn't been able to try it out in practice yet, but it looks like there can be a lot of potential :) To make apps in App Inventor is really quite simple by use of a Visual designer for the screen layout, and then a block editor for creating the programming behind it. It does have potential to make some very complex and sophisticated apps though. I look forward to seeing and making some cool controls in the near future :)

Hi everyone, I just wanted to know if anyone has tried using Google App Inventor to make apps for controlling the NXT yet? It looks really simple, i have made a few apps with it for connecting with data online etc. but i don't have my NXT with me to try out the Mindstorms commands. To create the programs is really simple and even though the programs are made with a block editor rather than typing with code, they can produce quite sophisticated apps. And another great thing is all the software to create the apps is free. Here are some of the views for the commands and a simple program in the block editor (although i havn't been able to test it with an NXT yet) And details about the NXT commands are here. It looks like some really interesting controls could be made using this, and Google App Inventor is under constant development with more to come in the future.

Hi Shane, I'm sorry to hear you didn't find any of the motors in the drives that you had. The first time i used these motors i had 20 old drives from my brothers work and i managed to get 14 motors from them. The next time I got given 10 from a friend and i only found 4 that had the right type of motor. I found that the older CD only drives seemed to have these motors, but i have found one in a DVD writer too. It's best if you can get broken old drives for free from computer repair shops etc. The motors are from the part that moves the laser assembly back and forth, it takes a bit of disassembling to get them out. The motors you have found are larger than the ones from the CDROM drives, i don't have one handy to measure but they were 12mm wide and about 29mm in length as they could fit snugly into a 2x4 brick, and about 15mm high so they can fit into 2 bricks high. I couldn't believe how well they fit inside the bricks, the top 2x4 brick fits on tightly without the need for gluing or fastening in any way. As for attaching the lever, i drilled a 0.8mm hole into the piece and push fitted it onto the shaft, the motor doesn't have enough torque to slip inside the piece. For the first few i made i had to use a little superglue as i drilled the holes too big. As for being purist or not is up to personal preference, i'm not sure how many varying degrees of purism or non-purism there is. I guess there are some that use only official bricks produced by Lego, some that use bricks made by 3rd parties such as BBB wheels or Brickarms, some that use any sort of bricks available, some that modify bricks, some use non-Lego items for scenery, etc etc and the list goes on. Some of the most impressive MOC's i have seen have included slightly modified bricks and non-Lego scenery. I think for competitions etc, the use of only official Lego components is fair, but for me i find it more fun to combine non-Lego hobbies. Thanks for the interest, i hope you have some better luck with getting the motors :)

Hi Thorsten, your welcome about the info :) I just remembered i had a copy on my hard drive and when i posted the link from a quick search, i realised i have given you an older version. Then i saw the version i have on my hard drive is 1.20 dated 26/02/2010. I found the link to this file here after a more thorough google search. I havn't had the time to see what differences there are from the 1.10 version, but it looks quite similar. That is really interesting about the extra channels available, i have heard that it was possible to expand the channels but i havn't looked into how this is achieved. I thought from looking at the protocol it would be possible to extend to 8 channels as there is the extra 'address bit' that could be used. I would be interested in reading about it if you have some links? Your very right about the all Lego solution being quite costly. I havn't needed to build a RF-IR transceiver for power functions yet, but i don't think it would be too difficult. I think it would be more easier than the RF link i made for the RCX. I had such a headache working around the parity that is used for communications, but it turned out that was why the transceivers were so cheap at $20 each. They didn't create a parity bit as they were suppose to, so i had to calculate and send the bit with the ic.

Hi Rob, Thanks for the interest, but i did have to reduce the friction in the switches to get them to work with this type of motor. I experimented too with about 10 different types of DC motors that were available to me at the time. Even with a much larger motor it still didn't have enough starting torque to throw an unmodified switch. It would really require a motor with internal reduction gearing, but all the motors i could find were much larger than what i wanted. I would have liked to have found something small that could do this, but without reducing friction in the switch it takes quite a bit of force to throw the switch. And it seems like the newer RC Switches have more friction than the 9V ones. Even when switching by hand it feels too much sometimes, my little nephew agrees too :) Thanks again Mike

Hi Rob, i agree with aprendiendo, servo's do give more accurate positioning but is not really required in this case. The motors i selected have more than enough torque to throw the switch (reduced friction) but not enough to cause damage when the end of the throw is reached. I control these motor with a microcontroller through a low power motor IC. I could reduce the timing down to 20ms and would still throw the switch, however i kept it to 50ms just to be certain, and would give a nice click when the switch is changed. If you want to try building something similar to mine Brickshelf Gallery, i just use the small motors that can be found in old CD or DVDROM drives, not all of them have this motor but most do, and the good thing is that the motors always seem to be the same for different brands. I use 2 hollowed out 2 x 4 bricks to house the motors, but can be housed any way up to you. The friction does need to be reduced in the switch for the motor to work effectively, but no modifications need to be made to the topside of the switch like in deejay's solution.

Hi Thorsten, Yes you are correct about the PF Train Remote, it only sends to the receiver for the channel to step +1 or Step -1 with the dial, and to stop with the button. Although this type of transmitter operates in this way, the PF Receiver has the ability to receive commands in many different modes. From reading the Lego PF Document it describes in detail all aspects of the RC Protocol. The different modes are: Extended mode This mode is able to control: Brake, increment and decrement PWM in 7 steps on Output A and toggle Forward/Float on Output B. Toggle bit is verified on receiver. No timeout for lost IR. Combo direct mode This mode is able to control: Two outputs float/forward/backward/brake. This is a combo command controlling the state of both output A and B at the same time. Toggle bit is not verified on receiver. This mode has timeout for lost IR. Single output mode This mode is able to control: One output at a time with PWM or clear/set/toggle control pins. Toggle bit is verified on receiver if increment/decrement/toggle command is received. This mode has no timeout for lost IR on all commands except “full forward” and “full backward”. Combo PWM mode This mode is able to control: Two outputs with PWM in 7 steps forward and backward. This is a combo command controlling the state of both output A and B at the same time. Toggle bit is not verified on receiver. This mode has timeout for lost IR. I assume this PF Remote must operate in Single Output Mode, as it can increase/decrease the PWM and also it has no timeout for IR. Also this mode is capable of directly sending the power value directly to the receiver ie. Set Channel A power to Step 3 Forward etc. Therefore it would be possible to make a IR transmitter that was capable of sending speed values to the receiver. The document contains all the details of the IR protocol too. As for using RF transceivers.. now that's what i'm talking about :) 2 way communication with trains, excellent non-LOS range. I can't wait until i can get back with playing around with my trains again :) Thanks Mike

Hi Rob, I think for me the order would be.. #1 Price: I know price wasn't originally in the list but for me was the main factor in my solution. If i get around to motorizing all of my switches i would require over 30 motors. Using all Lego components seemed a bit on the expensive side. #2 Small Size (& aesthetics): With my modified switches (shortened, 3 way, etc.) i could have yards where the tracks are very close, therefore i needed something really small, and using non-Lego motors meant i had more choice to choose something compact. But also i wanted something that looked really good alongside the track too, i was fortunate enough to find the motors i used could be encased in 2 2x4 bricks. #3 No Switch Modification: For me the important factor was not modifying any of topside switching mechanism, this means the switch can be used again with the original lever without any visible signs of modification. As for removing friction no parts have to be cut off, the friction piece just needs squeezing together (Although the bottom cover has to be opened). I couldn't find a small motor with greater torque, it would have been nice to be able to add to a switch that has had no modifications whatsoever. #4 Using All Lego Parts: It would be nice if Lego remade something similar to the 9V Micromotor but i don't really see that happening. I did build a switching unit with this type of motor, but i only have 3 so using them for all my switches wasn't and option to consider. Plus these motor have a few drawbacks. Also to add a Lego cover for the motor would have resulted in a unit 4 studs wide, which was larger than i what i needed. #5 Using a Lego Power Source: This was always the least important factor for me because i know i will want it to be controlled by something custom built in the end. Although throughout the building and testing i always use a Lego 9V regulator with a polarity switch. As for using RCX/NXT for the control of the switch motors. I have not considered them myself as i build my own controllers, and i work it out as price per switch. The units i have built myself are daisy-chainable (up to 128 devices, but easily expandable) and control 4 switches each for a cost of about $10NZ in parts. Thats only $2.50 per switch. Whereas using an NXT ($140NZ lowest price i have ever seen) with a total of 4 outputs standard would be $35 per switch. You could buy a 3rd party multiplexer to increase the number of outputs, but then i don't think it would be considered an all Lego solution. Another option that i have used for controlling switches and other MOC's is the older Lego CLI interface. I managed to pick it up for $90 a few years ago and with 8 outputs that's only $12.50 per switch. Thanks for reading. This is a topic i really enjoy :) Mike

oooohhh how much does she want for it? I don't have that set yet

Hi, that's what i mean :) Yea i had the same problem with my design with trying to find a small enough motor with enough torque, the best way i found was just to remove the underneath of the switch and squeeze the friction part together with pliers. And the most readily available motor i could find was from a cdrom drive that controls the movement of the lens. In most drives i found this motor to be the same and took about 5 minutes to disassemble and remove. And these little motors are the perfect size to fit inside 2 stacked hollowed out 2 x 4 bricks :)

Hi there, your points motors look really good. Did you have to modify the switch so it would change with less friction? I had to do that with mine as the motors i use didn't have quite enough torque.

Hi there, i have made similar switch motors using DC motors from old CDROM drives, here is some pics here My link Also on my post on same topic here My link These motors work really well when used with momentary switches or controlled by microcontroller, and really cheap too..free!!!

Wow.. thats cool. Thats the first cable operated switch i have seen on here. I wonder if anybody has tried a rod or linkage controlled switch?

Hi there... if you are not too concerned about using a pure Lego solution, you could try this idea. Using the old tray motors from CDROM drives i have managed to fit them inside 2 hollowed out 2 x 4 bricks, as you can see in the photo... plus a few more photos here My link The reasons i prefer these motors is the size and cost.. which has been at no cost for me, just the time needed to pull the motors from old drives. And also the motor has enough force to change the switch, but not enough to rip the motor from its mounting. I did have to reduce the friction in the switch... but by just squeezing the friction piece (inside the switch) together with a pair of pliers. Mike

Hi, i should be back home next week so i'll find the files and post them, i didnt get around to my full test as i have been at sea for the last few months, i know i changed the design a little bit before i went away so i'll have to get back into it.

Now that is something i am wishing for. Just imagine the possibilities. Mike

Thanks for the info, i might use NXC for now as i have never used RobotC before. Is RobotC similar to NXC, i guessed it was another C variant, with its own firmware.

Thats good to hear, now i just need a Wii remote i can rip apart : ) Whats a good language for the NXT? At the moment i'm using NQC with Bricx for the RCX and its okay. Its been a while since i have programmed in C but its coming back to me slowly.

Thanks, i'll check it out. The Lego Hardware Development Kit for the NXT was very helpful as well. I cant believe they gave all the schematics and everything.