finhudson

Eurobricks Vassals
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Posts posted by finhudson

  1. Posted · Edited by finhudson

    Glad to hear some others loving combining RC an lego too!

    your model 2.0 will be best served looking at how the hull can reduce the drag.

    I completely agree, after sailing it, it became very obvious that it was too heavy and had too much drag, but it didn't make it any less fun.

    I didn't need any grease to avoid excessive wear, but then I'd designed the drivetrain so that there were only 3 points of contact between the spinning axle and other parts. It handled the brushless power surprisingly well. It could be to do with the entire drivetrain being submerged in water for the whole time.

    PF is way below what Lego can handle, even if a stupidly down-geared XL motor can snap gears. Just keep this at hand...

    silicone-grease-250x250.jpeg

    ...and enjoy some RPMs

    I totally agree about PF being way weaker than what lego can handle, the lego RC system was better, but just too heavy.

    Good idea with the grease, I'll probably try that for the version 2.

    One other point to make is how much smaller and lighter the brushless motors are than lego motors. The small one I used on this boat is equivalent to more than 10 RC buggy motors at full throttle.

  2. Posted · Edited by finhudson

    I recently built a Lego boat using a non-lego electric system. I instead used a brushless motor and ESC, a servo, a receiver and a 3S lipo battery. I also designed and 3D printed a better, bigger propellor than anything lego has to offer. More details in the video:

    IMG_20160403_152505149.jpg

    IMG_20160403_151806004_HDR.jpg

    I managed to find a motor and servo with mounting holes that are the right distance apart to use with lego, and I used a reasonable slow motor (1000kv), as not to cause excessive wear to the lego parts. I didn't pay any real attention to the looks of this model, it was just made to be fun to sail.

    It came out so much more fun to sail than any boat I have ever made with the Lego PF or RC system.

    Have you guys ever built something using non-lego parts, and if so (or if not), what do you think of it?

  3. Posted · Edited by finhudson

    Have you done any testing on how long you can draw 6 amps before something starts smoking?

    Also, here's a tip to those who are new to soldering: use a flux core solder or just get a little jar of flux. It makes a huge difference in the work.

    I haven't tested 6A continuous, but I have tested 4A with a prototype for an inline voltage booster I'm working on. It all worked fine, the batteries just warmed up a little bit.

    I agree with you about the rosin core solder, it make the whole process much easier

    Would it be better to desolder the polyfuse from the board and solder in a small piece of wire or flat metal in its place? It looks like it is just surface mounted.

    Electrically, this would make no difference, but if you needed a polyfuse for another project I guess it could be worth doing :laugh:

  6. Posted · Edited by finhudson

    Performing this modification will allow you to draw more current from your battery box. I tested the maximum current before the modification at 0.3A and the maximum current after at 6A.

    I have often found the over current protection built into the power functions battery boxes to be set a bit too low, for example, it is very limiting when using RC buggy motors. I opened up a battery box to see how easy the over-current protection would be to bypass, and it turned out to be very easy. My method is shown below:

    (Warning: performing the following modification will void the warranty of your battery box. Do not draw high currents for long periods of time because it may lead to overheating.)

    (I will not be responsible if you try it and break something)

    1) Open up the battery box to gain access to the circuit board

    IMG_20150721_183651908_HDR.jpgIMG_20150721_183845056.jpgIMG_20150721_183925705.jpg

    Remove the screws, then use a screwdriver to begin to pry out the battery holder, once it is about 5mm out, push in the plug on the top, and then fully remove the battery holder.

    2) Prepare the electronics tools for bypassing the over current protection

    IMG_20150721_184354612.jpg

    You will need: A soldering iron, solder, wire cutters, wire strippers and tweezers.

    A helping hands tool is optional but it helps.

    3)Bypass the over-current protection

    This step is much simpler than it sounds, all you need to do is solder a wire over the polyfuse on the circuit board.

    First you need to locate the polyfuse, as shown in the image below

    polyfuse.png

    The polyfuse rapidly increases in resistance when a high current passes through it. This is how the over-current protection works: when a high current passes through the polyfuse, the increase in resistance causes the current to drop back down again.

    To bypass the polyfuse, all you need to do is solder a wire across it. First you need to tin the wire so it can be soldered more easily.

    IMG_20150721_184540849_HDR.jpg

    With some solder on the tip of your iron, heat up the wire from the back. Apply solder to the wire from the front and you will see the stands of wire absorb some of the solder. Now tin the other end of the wire and move onto the next step.

    Now all you need to do is solder the wire over the polyfuse. Use tweezers to hold the tinned end of the wire on one side of the polyfuse, then heat it up with the soldering iron to reflow the solder joint. Repeat this with the other end of the wire to achieve a result like in the picture below:

    IMG_20150721_184942927.jpg

    4) Reassemble the battery box and you are done!

    Notes:

    Do not embark on this project if you do not trust your soldering skills, soldering irons get very hot and could easily burn you.

    If the switch does not move after the battery box is reassembled, open it up again, remove the piece of wire, and replace it with a thinner one so that is does not jam against the switch.

  7. Posted

    Firstly I want to apologise for bumping the topic, at the time it seemed a good idea, but looking at it now it does seem quite immature.

    This product is not meant to compete with the SBrick, if you want a simple, elegant solution, then the SBrick is definitely the way to go.

    My products instead offers a bridge between the Open source Arduino platform and your LEGO creations.

  11. Posted

    I just thought I should mention that the shield can be programmed to respond in different ways to the remote control commands by editing the code on the Arduino. For example, I could program the Arduino such that the drive and steering commands from the controller would correctly control a skid steer vehicle. (Demo coming soon). I will publish the bluetooth commands the app sends if the project is funded to make it easier for you to program custom responses.

    If anyone has any questions just ask.

  12. Posted · Edited by finhudson

    My app allows full control of the PFShield, which roboremo could be configured to do with some different code on the Arduino.

    My app also allows basic programs to be made and executed of the PFShield, which Roboremo cannot do.

    I am also providing the Arduino shield and Arduino sketch to work with my App, there is no hardware part to Roboremo, it is just a control app.

    The full version of my app will also be free.

    So to conclude, I have a hardware solution that can be installed directly into your creation and controlled or programmed with my app.

    EDIT: I explained this terribly, basically, roboremo is an app to control Arduino projects you make, I am selling a complete control solution with my Arduino shield and the Android app

    Second edit: I don't know if I'm allowed to say this on the forum, but please back the kickstarter :wink:

  14. Posted · Edited by finhudson

    So I know it's bad to double post...but...

    I think you guys might want to see this:

    I have added a simple programming environment to the android app that can be used for simple programs by people with no experience with coding. It could also be useful for testing parts of a program you are making quickly and easily with using the Arduino IDE.

    The video explains it much better(select HD quality to see the app better):

    Note: The same app is used for the remote control functionality, and that remains unaffected by this update. You can select 'Program mode' or 'RC Mode' from the main menu in the app

    What do you think to this?

  18. Posted · Edited by finhudson

    I have not used features from the app you mentioned, but instead coded my own, and the same goes for the arduino code.

    The framework is there in the app and the arduino code; proportional speed control will be featured in the next version of the app, which will be released on the play store if the project is funded.

    The Bluetooth module is the small board mounted on the top of the main board, and it will be included in the kits sold. The circuitry for it is in the shield, so integrating it is as simple as plugging it in

    Is there anywhere specific I need to post for it to be featured on the front page?

  20. Posted · Edited by finhudson

    I'm not making you buy an arduino: all I'm selling is a shield for your current one.

    The controller is in the sleeper cabin, and I'll upload a video of the driving tomorrow.

    Currently there is only a version for the uno/Leonardo, and if the project is funded one for the micro/nano will be made (mini pfshield).

    I hadn't thought of a mega version, but I like the idea, so I'll look into it.

  23. Posted

    Also, if you sell this, please have a version without an Arduino- I wouldn't pay for a second one.

    Interesting idea, but the product is designed at combining Arduino and Power Functions, so a non Arduino version would defeat the aim of the project.

    I wouldn't worry about it damaging your Arduino, I accidentally drove an early prototype off a table when I was testing it, and the Arduino's still fine.

    What do you guys think of this?

    I modified the 8285 tow truck with the PFShield, 8878 battery, servo motor, m motor, and an XL motor

    DSCF4333.jpg

    DSCF4334.jpg

    DSCF4337.jpg

    DSCF4343.jpg