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Show HN: Hacking a Mercedes GLA Class Ride-on kids car
- AnnoyingSwede 9y agoPosted a link to this page the other day, but it sunk to the bottom so fast, noone noticed it. I figured this is actually a Show HN, and worthy for others thinking of doing something similar. I would be very happy to see what others have done on the same subject, or to get inspiration on topics i am struggling with in this build.
- matte_black 9y agoProblem with modding plastic stuff like this is that as soon as you make one thing stronger, something else becomes the weakest link, so then you have to replace that with something stronger, and so on, until you've replaced nearly everything. At some point you'll probably need rubber tires or you'll get a lot of wheel spin.
- bri3d 9y agoHe already talks about this at the end of his current post - it sounds like he's basically going the route that full-size drag racers do, and building a tube-frame (or in this case, angle-aluminum) chassis which he is just going to put the plastic body over the top of for some resemblance to the original car.
- AnnoyingSwede 9y agoFirst off: Thanks for showing interest in the post. To counter the weak plastic i vested in a MIG weld and the aluminum profiles seen at the last photo of the post. My intention for the next part will be constructing this support. Finding wheels have proven expensive (but not impossible), and as late as yesterday i was given 2 go kart tires that will become the rear tire set. I was also hoping people interested in this post could suggest other wheels that both are functional and look good. Even though i searched for a few weeks, i am sure i have not turned ever stone possible.
- Peroni 9y agoIf only the rear wheels are powered then you can make plenty of compromises on the front wheels. On that note, make sure to have plenty of weight at the front to prevent your kid from being thrown off when the thing does a wheely on acceleration.
- aidenn0 9y agoOut of curiosity, why aluminum? Isn't steel much easier to work with?
- AnnoyingSwede 9y agoI want to keep the weight down, and i have other applications of this once this build is completed. Also people told me aluminum was hard to weld, challenge accepted. :)
- aidenn0 9y agoBe aware of the safety issues with aluminum too; aluminum has a nasty habit of looking 100% healthy until the moment it completely breaks.
- mhb 9y agoPossibly too big for your project (though the project does seem to get bigger), but wheelchair motors are great - they are cheap, have the gears built in and often come with nice wheels.
- apo 9y agoThought the same thing as well. Ship of Theseus.
- uptown 9y agoI've always wondered why they don't make these things with remote kill switches for parents to control while their kids drive around the yard/sidewalk.
- AnnoyingSwede 9y agoThey do actually, that's the Stop-button on the control. Since i tossed all that out, I will make sure the brake-servos lock up the front-wheels if it losses radio on mine. As my son is very young, i will be in full control until he is getting older, removing the ability for him to just hit a switch and ride off into the sunset.
- djrogers 9y agoThey do now - that’s one of the uses for the remote control these come with
- giarc 9y agoBecause they mostly go slow and you can simply walk up to the car and stop it. It's not until people modify it to go fast that a kill switch is needed.
- jerkstate 9y agoI use a lazybone bluetooth relay for my kid's power wheels. I would like to find one with a better iOS app, though, the lazybone app is very unreliable and crashes constantly.
- wumms 9y agoGreat Scott! If my calculations are correct, when this baby gets an 1 kW motor... you're gonna see some serious shit.
- mikestew 9y agoHuman beings on a bicycle who generate that kind of wattage can (give or take) hit speeds approaching 40mph. Allowing that the final product will probably weigh more than a race bicycle, but the vehicle is carrying someone much lighter than a bike racer, I'm kind of curious what the final top end will be. Some commenters are recommending a seat belt. I recommend a five-point harness.
- ballenf 9y agoAnd a roll cage.
- cr0sh 9y agoMy friend built an electric motorcycle years ago (we call it a "mootorcycle" because it has a metal cow skull with glowing red eyes on the front - and a ribcage, and other "bone" work); a couple of months back we upgraded the motor to one of these larger 1 kw beasts. We use 24 volt lead-acid gel cell batteries - the thing easily gets up to some scary speed (well - scary when you're in nothing but a t-shirt, shorts, and no helmet) on the flat. Plus considering the homemade nature of the whole machine... I can't imagine what a motor like that in a kids ride-on would be like, at full-throttle...
- jordigh 9y agoIt's a bit odd how the word "pimping" has come to mean "embellish". I know how it happened, from "pimp my ride", a show that tried to use "street" language for effect. I can't shake the awful connotations of pimping, though. Nice hardware hack problem, but I hate to think of you pimping your son.
- AnnoyingSwede 9y agoAgree, that word isn't the best, but as long as we are clear i'm pimping the car and not my son it's all kosher to me ;)
- kakarot 9y agoAs individuals, we don't have much personal agency over the evolution of language, so sometimes it's best to just let words change meaning. We wouldn't be speaking English today if people got in a fit every time a word changed meaning. People have been using "pimp" as a verb in this context since at least the 70's, so I'd say this is a lost battle. The phrase did not come from Pimp my Ride. edit: my interpretation of your use of quotations is one of many, but I should give you the benefit of the doubt here
- aidenn0 9y agoA more generous interpretation of the quotes around street is that the commenter thought the language on the show was inauthentic (i.e. not real street language).
- vinay427 9y ago> putting quotations around the word "street" implies a certain attitude about urban culture that I'm going to assume you don't actually wish to convey. I read those quotes as simply indicating that they weren't sure if "street" was the most accurate way to convey what they meant (urban, etc.). It is common to use quotes around a word that is an approximation of the intended meaning.
- thieving_magpie 9y agoIf you're going to rant about how the word has taken on new definitions at least be accurate about how it was used. Pimping my son != Pimping my son's ride
- bitwize 9y agoGeez, dads are awesome. This is some shit that mine would have totally done for toddler me, had he the money and time.
- AnnoyingSwede 9y agoBesides my interest in builds and electronics, this is why i am doing this. I never had such a dad either.
- bmsleight_ 9y agoMy Dutch is not that good, but looks like the bandwidth limit hit. cc: AnnoyingSwede
- AnnoyingSwede 9y agoCRAP! Will downsize the images when i get home. Did not see that one coming :(
- AnnoyingSwede 9y agoI tried to replicate this, but have not managed.. Also you seem to be the only one that got it? Are you by any chance in Russia?
- edraferi 9y ago> I also decided this build will need welding. Having never welded aluminium, i ordered a 200Amp TIG/MMA welding machine, rebuilt the main fuse-box in my house to be able to run it without burning my house down. I am currently waiting for a tube of Argon gas before i can start climbing that hill. I think this is about the point where my wife would have killed the project.
- AnnoyingSwede 9y agoNo woman, no cry ;) UHM: Don't get me wrong. I wish it would have worked out better between my ex and me but stuff happens in life. I am sure she would not have allowed the sawing and welding either, as we lived very confined. Anyway, i stand corrected on this. Sorry if i offended.
- andrewstuart2 9y agoI'll bet that could be one of the easier sells in the long run. A full rack of servers? Not sure that will be the most pragmatic investment. The ability to weld stuff that breaks in the future? Seems like a solid investment, and I wouldn't be surprised if he had other uses in mind already. Sure, the trigger isn't some major value-add project, but if it builds a practical skill and makes other practical repairs/upgrades possible, I'd bet you could convince most people pretty easily. The escalation was a bit unexpected, though, and definitely made me laugh.
- LeifCarrotson 9y agoAlso, OP sounds like the kind of person who would have been talking about a welder for years. And among the woodworking tools, auto repair, painting equipment, electronics, and computing, it's not that out of place. Most people would start with a stick welder and steel tube, but if you're going to end up wanting a TIG and buying one a few years down the road, why not buy the right tool now instead of two tools? Next step is the mill, lathe, grinder, strip sander...
- AnnoyingSwede 9y ago
- 4ndr3vv 9y agoObligitory link to the ppprs http://www.powerracingseries.org http://www.powerracingseries.org
- lbotos 9y agoDon't show your son Lila Kalis videos yet :P https://www.adventuresportsnetwork.com/sport/moto/4-year-old-girl-drag-races-her-power-wheels-better-than-you-drive-your-car/ https://www.adventuresportsnetwork.com/sport/moto/4-year-old... Is children's powerwheel competitive drifting going to become a thing?!
- AnnoyingSwede 9y agoI totally missed this! Thanks a million times. By the time Chris is 5, he will beat her on the strip.
- tonyarkles 9y agoI don't know if I should show you this... http://www.powerracingseries.org/ http://www.powerracingseries.org/ Edit: I didn't realize they were doing autonomous cars now. Past races were definitely done with humans in the cars.
- gm-conspiracy 9y agoIs this still active? I also did not know about the autonomous competition, but the last blog post is three years old, and the 'register today' button takes you to a form for 2015. I only see 'autonomous' once and no further details. If anybody has additional info, I would greatly appreciate it.
- azinman2 9y agoThat’s crazy. She’s awesome! I just hope she stays safe. I worry about jutting out into the street like some of those videos showed — she is only 5 after all even if she drives like a champ.
- AnnoyingSwede 9y agoUpdate: A few safety concerned readers mentioned: Top speed: My aim (until he is older) is 7-10km per hour, but with a torque that allows burnouts and donuts. A safety cage might become part of the build, just because better safe than sorry. Will make sure this post can be read as soon as i can contact my webhosting company, hopefully tonight. Sorry about this!
- jerkstate 9y agoA helmet is a must. I also added a seatbelt to mine, but it really doesn't make sense, the most common thing that will happen is it flips if he drives off a tall curb, and in that case you want to be able to easily get out from under it.
- AnnoyingSwede 9y agoAgree got one. A wider wheelbase of the car, lower center of gravity, and wheels 50mm-100mm wider will help keeping it from tipping over. I have a seatbelt but like a few pointed out that might make the car more dangerous without a roll cage. Both are taken into consideration now.
- 3chelon 9y agoI'm also concerned for your son's safety. Is he strapped in? I seriously hurt myself when I was a kid in a dodgem car at a fairground when my face hit the steering wheel. 7-10km/h may not sound very fast, but trying jogging face-first into a lamppost at that speed and you'll soon change your mind.
- GoodOldNe 9y agoPlease consider some kind of roll cage if you're going to put a 2-3 year-old into this. In the United States we see a tremendous number of toddlers who are very, very badly injured (or killed) in ATV rollover injuries. Obviously an ATV is a much bigger and heavier vehicle than what you're doing (which is cool) but the mechanism itself of rolling a vehicle over onto a child can lead to a very devastating injury pattern.
- jerkstate 9y agoThis is a great project but it sounds a little ambitious. I suggest stripping down to the bare minimum to make your kid have fun and adding new things over time. I am going through a similar line of development for my kid but I started with a cheap power wheels and decided to forego remote control to let him drive. I started putting him in the car at 13 months and he was able to control steering and acceleration himself and direct himself where to go at about 16 months. In time order my mods have been: 1. Soft start (R/C circuit, heat sunk MOSFET) 2. Replace lead acid with 18650 batteries 3. Reverse switch (they make these for big fancy power wheels, they just reverse the polarity to the motor) 4. Bluetooth remote kill switch (Lazybone - I don't recommend it, the ios app is crap) 5. Turbo button, adds a 18650 in series with the 2 other when the button is pressed 6. 2 batteries in the turbo button for a total of ~16v He drives very well himself now, with 2 big issues - it is hard to get him to pay attention to what's in front of him at all times and go slowly around pedestrians (that's where the remote stop comes in), and it's so fast now that I need to figure out how to add brakes (maybe I'll just move him to a real go kart with rubber wheels and mechanical brakes). But he's an excellent driver at just over 2 years old and people are always very impressed. Kids are capable of a lot more than we give them credit for.
- mschuster91 9y ago> and it's so fast now that I need to figure out how to add brakes Why not use electric brakes first? Take some high-load resistors, and use a high-current relay to switch the motor positive line from the 18650 controller to the resistor bank. For more fun, make a stepped resistor bank so you can control brake power.
- jerkstate 9y agoI've thought about doing something like that but I'm not sure if the plastic wheels and gear box can handle it, and I'm not sure how much more effort I want to invest in a limited platform. In the situations he's in now, anticipation is just as good as brakes; being able to see that he's going to run into a person or obstacle and slowing down is what I'm aiming for. In a "racing" situation, braking is necessary to slow down from high speed quickly in order to take a corner without losing traction, but the plastic wheels already have so little traction that we would exceed the performance envelope of the wheels before really getting much speed advantage out of it. Probably what I'll do is upgrade to a basic electric kart at the next birthday and leave this car as it is for Sunday driving and/or the next kid (it'll be easy to reduce the power again by reducing the number of batteries)
- bby 9y agoYour son is going to get all the honeys.
- nathan_long 9y ago> I went above and beyond the original motors when i bought a 48 volt 1000 watt motor of amazon. The motor is meant for a e-scooter, is 200 times stronger than the original engine, so the frame will have to be reinforced. This made me laugh.
- chjohnst 9y agoI have done 24V on my sons ride, but I blew the gearbox. Time for an upgrade! Also did LED lights and other stuff. https://www.instagram.com/p/BY3X_zhAyY0/?hl=en&taken-by=chjohnst https://www.instagram.com/p/BY3X_zhAyY0/?hl=en&taken-by=chjo...
- dugmartin 9y agoIf you like this format of DIY posts (which I do) I'd recommend checking out Reddit's DIY subreddit: https://www.reddit.com/r/DIY/ https://www.reddit.com/r/DIY/
- AnnoyingSwede 9y agoNot sure why i havn't considered reddit, will have a look around and many post there when the build is getting closer to an end.
- teekert 9y agoThis got met really interested: I went above and beyond the original motors when i bought a 48 volt 1000 watt motor of amazon. The motor is meant for a e-scooter, is 200 times stronger than the original engine, so the frame will have to be reinforced. Too bad it's just part 1.
- eitland 9y agoAnother blog added to my RSS feed. I've been missing the old web for years now and this makes me a bit happier. I also started writing a web page again recently after throwing away any ideas that it needs a theme or a cms or even a static page generator.
- pryelluw 9y agoPeople in Puerto Rico modify and drag race these cars (mostly kids of racers). They use brushless motors, ESCs, and batteries from R/C cars. They end up being ridicoulsy fast. Some even add rubber tires from gokarts for grip. But like any hobby of the sort, it gets expensive fast. Electronics can run you $300 easily.
- whatismybrowser 9y agoawesome project! another feature idea I just had: put a couple of ultra sonic sensors on the front and back. on the back: to emulate the reverse parking "beep-beep" indicators. on the front: to prevent collisions - if you rapidly get too close to something (a wall, another child), it cuts the power to the motor.
- AnnoyingSwede 9y agoGreat ideas, might steal a few of them. Thanks for the inspiration!
- chrissnell 9y agoI'm a big fan and owner of a Land Rover Defender, so my kiddo car of choice is the Toylander: https://www.toylander.com/ https://www.toylander.com/ These are really fine (and expensive) ride-on car kits. The little Land Rover can easily carry two kids and pull a trailer. I never bought one, though, and I'm kind of glad I didn't. Once you get your kid an electric car, they'll never want to ride a bike again. I see overweight kids riding around the neighborhood on electric scooters and my wife and I swore we'd never buy ours an electric vehicle.
- AnnoyingSwede 9y agoMy webhosting provider removed the tiny video that seems to have slashdotted them a tad after yesterdays exposure here on HN. This video is now on youtube, hopefully i will be within my bandwidth limits going forward. I am also very grateful for all the good and constructive comments made here, this is exactly what i was going for. A lot of concerns about safety was lifted, and a few comments made me reconsider some choices i was about to make. In order to make sure the car does not flip over i will be: Widening the axle base and wheelbase with 100mm. The new suspension will lower the the car quite a lot, and also lower the point of gravity. As i mentioned the motor is a 48 volt running on 12 volt until the little guy grows older and more used to the strength and speed. He will have no control over steering or gas until he understands the very principals of what he is doing. In case of loss of radio control, the servos controlling the brakes will lock up. I made a lot of progress on integrating a signal horn into the steering-wheel yesterday, will show this off in a small update in the end of the week. As for welding, i got a lot of good advise on top of what i knew from researching the subject. If i go for steel or aluminum still remains to be seen, but my Argon gas delivery was postponed 2 weeks, making it likely i will go with steel at least for now. Thanks again for all feedback! If you think of more, feel free to let me know here or on the blog. Kind regards Jonas