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About trevmar

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  • Birthday 11/14/1948

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  1. Yes, I changed the resistors but saw no difference because it is the firmware controlling the speed and load. I am waiting for Alexandre's modified firmware to fix the problem I have with small obstacles (1" gutters, pebbles, pinecones). Meanwhile I did buy a set of tyres from China which is soft and works out well. Ninebot.run sells them too, I believe. I paid $24 each for mine, but I see them advertised at half that now. It is the 85/65-6.5 off-road vacuum tire" like the ones from this seller: https://www.ebay.com/itm/332852828998 They are very wide, hard to squeeze onto rims, but I have been very happy with the way they handle obstacles. Almost the same as the knobblies, but a much lighter tire with no noise or vibration on bitumen. They have soft bouncy walls, rather than the stiff walls of the Ninebot OEM tires. I am heavy, like you, and the Ninebot was designed for riders less than 85Kg. Have you read the blog written by a member of the design team? They give a lot of info about the design philosophy. Google translate it from here: http://bbs.ninebot.cn/forum.php?mod=viewthread&tid=4100&extra=page%3D1%26filter%3Dtypeid%26typeid%3D43 1/23
  2. With the knobblies, there is a resonance on a bitumen road once the tire starts acting like the balloon it should be. Actually, there is always a resonance, but high pressure shifts it up above the riding speeds you normally use. Thus the "roughness" depends on both pressure and speed. In fact, you can use the "rough feeling" or "vibration" to ensure that the knobblies are properly inflated if you ride. Lower pressures mean "vibration" at a lower speed. Interesting that the MiniPRO doesn't seem to be bothered as much as the rider by this (relatively) high frequency "vibration".
  3. Handlebars off-road can be quite dangerous if you rely too much on them to steady you. The MiniPro is not designed to be firmly anchored in space by a heavy weight (a rider firmly holding handlebars), nor is a rider able to trust the minor and major motions a miniPRO transfers to a handlebar when it hits an obstacle (eg a 1" gutter). If you look at my avatar you can see that I made my own soft-handlebars out of plastic pipe. They give a reference-in-space, enough to assist rider balance, but yet compliant ('bendy') enough to absorb the shocks when hitting pine cones, etc. They are also light enough to balance upright without needing a stand.
  4. In dry off-road conditions I use 10-15psi for those tyres. Have gone as low as 6psi without separation.
  5. Put me down for two at that price point! Thanks for all you do!
  6. I use a phone with my MiniPROs that does not have 2G/3G/4G installed so that it is not easy for the Segway app to automatically update, or do anything else to my machines I connect that phone via Ethernet (Android 6+ works via a USB ethernet dongle for data). I never connect the phone to the Internet and to a MiniPRO at the same time. If your Swallowbot app needs online data could you please ensure that it takes data from all Android sources: cell, WiFi and Ethernet Thanks
  7. It isn't any special time of the year to have a sale, so I was surprised to see that Amazon has the MiniPRO for $420 today. This price is for the "US 2018" model with the smaller 4300maH battery, "ships from and sold by Amazon.com"
  8. Oh no! I am sorry to hear that! I fell off my own Minipro several months ago and it twisted my ankle badly by running over me!. But the good news is that the ankle has healed slowly but perfectly! So be encouraged that the body has amazing healing powers! I and my family are so grateful for what you have done for this community, and for us in particular, we will keep you in our prayers this New Year. Looking forward to meeting you when we next travel to Moscow!
  9. I was thinking the same "Thank You Ninebot" last night, as my wife and I cruised our MiniPROs around our district to see all the Christmas light displays which homeowners have put up. We still have a few neighborhoods to tour this evening... A Merry Christmas to all, even if its a bit early for our friends in Russia (Incidentally, those holiday lights and festivities in Moscow looked really nice)
  10. Great News! Just to clarify, you have posted earlier that you bought a new control board from @Ninebot.run yet you seem to be talking here about having sent your own original control board to Russia to have it programmed, and reporting that this approach was the one which worked.
  11. No, I disagree, from a design engineer's point of view you are simplifying the situation too much. The Ninebot design team wrote an excellent blog detailing the safety margins upon which the MiniPRO was built. You can find it with Google Translate in the Chrome Browser at http://bbs.ninebot.cn/forum.php?mod=viewthread&tid=4100&extra=page%3D1%26filter%3Dtypeid%26typeid%3D43 1/23 Truth is that the current firmware still has flaws which can, and do, result in the rider being thrown forward and run over. It happened to me. After reading the designer's blog I formed the opinion (as a design engineer) that many of the current speed and weight limitations were based on requirements by the various country's safety authorities, rather than on limitations of the platform. Additionally, when Ninebot was forced to used high-quality LG batteries by the hoverboard-fires scandal, the amount of power the motors had available was actually increased significantly (see my post on battery peak-power testing). This was never exploited to improve the carrying ability of the platform, and hence its safety margin. All firmware versions have the same balance capabilities, that is how they were designed. Finally, in answer to your question, the current being drawn, and rotational speeds of the motors are what the firmware uses to regulate the power it delivers.The current sensing resistors can be clearly seen at the top of the control board (R004 or R008 SMD power-resistors) If you want to explore this further, MRN76 has produced an app which allows any of the major Ninebot firmware revisions to be programmed into any MiniPRO, and the original firmware replaced after testing. Search here for "JTAG" to find my posts on implementing those changes. You can learn a heck of a lot about the device by looking at the progression of the designers' thought-processes as the device went to market, and was changed through to its current state (v1.4.1) Hope that helps...
  12. Nope. No news. Except for those few trusted dealers who were given a copy of the JTAG firmware, and are programming customers' units with that, none of the rest of us have gotten anything working. My excitement at the news of this potential breakthrough has faded...
  13. When you have ridden 50Km several limits are removed from maximum speed and maximum torque. That made a big difference for me...
  14. It was designed to keep lawyers and bureaucrats happy. Here is the chinese blog written by its design team. View it in Chrome, or run it through Google translate. It explains each of the steps of the designers. The executives, bureaucrats and lawyers then crippled it to provide the "safety margins" http://bbs.ninebot.cn/forum.php?mod=viewthread&tid=4100&extra=page%3D1%26filter%3Dtypeid%26typeid%3D43 1/23