Project Development

Time Management

For the time management, WOW so much things to say!
The first one is to check what materials you already have. If you live in a country as me, where the shipping time are a bit long, you should buy everything as soon as possible to do not waste precious time at the end waiting for products. But wait ! I made a mistake here because I decided to buy everything without really knowing a lot about BLDs, ESCs or 18650 Batteries... So please first check my project page and MBoards youtube channel where you will find some more information and probably don't make the same mistake than me. So now, the second step is to buy your trucks because it is based on them that you are going to be able to make your motor support, and your wheel pulleys in case they came with the truck as in my case.

You can't imagine how much iterations of the motor support I made (nearly 8) before being able to find the perfect one for me (or at least I though before trying to turn with the Longboard when the angle is very small). So yes, you will probably dedicate between one week and two weeks before being able to build a support that fits perfectly you truck, that can tense the belt enough, and that is easy to install. After that, you will have to design your board, which will take you two or three days to find a design that you love. Once you made your design, you have to make your mold design and mill it in the Shopbot, which takes around 12 hours to mill and in case you need to glue two mdf boards together to have the correct width, it will take you one more day before having them glue as they should. As you can notice, if you thought that the two weeks that you have to make your final project are enough, you are wrong, because we have not made the electronics yet or the board made of composites materials that takes counting the fabrication and the cutting process, around a week to make. To build the first board (the one for outputs, networking, interface programming), it took me around one week, two days to calculate the value of each resistors, to know which components I were going to use, and many more things, but finally I had a first strong idea. The eagle process is divided in two parts. The Sketch part is easy (6 hours I think) but the board part has been a headache. It took me like 3-4 days to make the Board and I had to use three small jumpers. After that you have to mill it for like 9 hours, solder it for like 3 hours. Try to upload the Bootloader, hate yourself because you make a terrifying Pinout, program it, and finally make it again because this one works but is simply a mess. This last part represent probably a week or two of work. Once you finished your final board, and test it, you can finally, make your battery (4 hours), try to put it in the case, find out that your case is too small, print it again, make the whole thing fit (around 30 hours by case), and finally, after all this, when you think that the complicated part just finished, you discover that you have to make a motor pulley, and that the belt that you need, is simply impossible to find, and you have to finish your final project because you present it in one week. The motor pulley has a dedicated part here were you will understand why I suffered that much with it but also how to make yours. This design and prototype process, took me like 4 days before finding the good design, but also the good printer, and most importantly, the hours invested trying to remove the support in the hole.
Definitely, the fabrication of the Longboard took me countless hours, but because I managed to learn a bit from each assignments about thing that I were going to use for the Longboard, and sometimes even made assignments that were part of my Longboard, I have been able to finish the longboard with the quality that I wanted so please have care if you are trying to make an electric longboard, It is a project that use lot of powers and torque, and those factors need lots of precisions and care, and both factors ask lot of time to work well.

What tasks have been completed, and what tasks remain?

For the moment, I made everything except the motor pulley. To be honest, this part of the process afraid me a bit because I am not that good designing in 3D and I don't know if mechanically printing in 3D the motor pulley is a good idea because it will have to make enough torque to beat the inertia of the longboard for a person of up to 100kg. The other small thing that I have to do is to laser cut the cover of the case and to ensemble the electronics and test it for the first time. But It is ok because I still have one week to make the motor pulley because I have already make the motor support, the longboard, the electronics, the decoration (vinyl, grip) and the battery. I also think that once the longboard will be ready, I will probably have to adjust the code.

What has worked?

Well everything has worked, for the moment I am controlling the longboard with the app made with Blynk and everything works very well. The motor support has been adjusted many times but I have finally find the correct characteristics.

What has not worked?

The control with FSRs didn't worked, it is very complicated because you have to calibrate it for each person because you have a different weight and I should create a calibration process in the app, to see the value sent by the sensor when you are on the longboard and when you are not to be able to know when there is a variation of force. This calibration process, would take me too much time, so I think that for the moment I will use the control with the app Blynk where I can also configure the LEDs colors.

What questions need to be resolved?

Will the 3D printing motor pulley work or it will be destroy by the torque?
Will the motors be strong enough?
Will the code work?
The motor support will stay firm or it will vibrate?

What will happen when?

I will try to make a better version of the longboard that can be 3d printed or milled, publish it in my website and very soon sell those parts or the entire longboard (I would like to use the same strategy than Josef Prusa). But for the moment, the most important is to finish the FabAcademy, and for that it is important to finish my Final Project and all the documentation. For the technical part, I am still testing the bluetooth connexion because most of the longboard use Radio communication and there is probably a reason, I don't think that I would remove the bluetooth connexion, but I could use both, I will test it and decide after one month of testing and modifications of the code.

What have you learned?

What I have not learned is probably a better question. The FabAcademy and my final project have been one on the most enriching experience in my life. I have learnt a lot about electronics, 3D designs, materials selection, 2D and 3D milling, Laser and vinyl cutter. I feel like now I am able to build some projects, but most of all, I am ready to learn much more about all those subjects because I have a strong base. I say a strong base because the FabAcademy makes you learn, there is not an easy option and when you really have to learn, you never forget what you have learnt. The last assignments about your business model, have been very interesting because they made me think about my business and now I know that what I want to do is a business very similar to Prusa Research. With that business model, you share knowledge and you create in the users a need for your products because they will want to follow your tutorials. And finally another important think that I have learnt is how important the documentation is because more than one time, I forget the name of the 3D software of the Modela and I had to search the name in my documentation.