
Show HN: Hacking a Mercedes GLA Class Ride-on kids car - AnnoyingSwede
http://ihackshit.com/blog/?p=101
======
edraferi
> 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.

~~~
andrewstuart2
I'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
Also, 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...

~~~
cr0sh
> 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?

Have you priced a multi-process welder (plus all the extras) by a decent brand
lately?

Most people would "nope" out of there seeing such prices, especially for a
tool which they may not even manage to get the skills to use effectively.

While it is cheaper to go that route, vs going stick, then wire MIG, then TIG
(and needing the room to store each machine) - if you purchase new equipment -
it still is a big chunk of money to swallow.

The cheapest route is to instead make friends with someone who has welding
equipment; learn to use everything there, then when you get to whatever point
you're best at - buy your own equipment.

Myself, I've done a combo - I purchased a used cheapo 120 VAC buzz-box stick
welder, which worked ok for small jobs - but I had learned on my brother-in-
law's Lincoln Tombstone 220 VAC/DC system. Later, I met a friend who has a
complete shop, and I can do just about any process I want there.

Back home, I purchased a HF cheapo 120 VAC flux-core wire feed welder (mainly
because I wanted to see what an $89.00 wire-feed welder could do - it's
actually not a bad piece of kit, and people do all kinds of mods to it, too -
including conversion to DC).

One of these days I plan to get a 220 VAC line run to my garage, but that
won't be any time soon; at that point I'll probably purchase a decent MIG
welder w/ CO2...

~~~
TheSpiceIsLife
I'm a metal fabricator by trade, twenty years next year! I've owned a couple
of $2000+ inverter TIG / Stick welders, but not any more. My work place still
buys the name brand units for reliability and serviceability.

The DC TIG / Stick inverter unit I have at home is a AU$280 one off eBay. It
even has high-frequency start for the TIG.

I rent a tiny bottle of argon from one of the industrial gas supply places in
town for $5 a month, just to have argon at hand if I suddenly want to TIG weld
something, and can get a larger bottle delivered next day if I need it.

This is the unit I bought about 18 months ago, they're currently selling for
less than when I got mine: [https://tinyurl.com/ebay-dc-tig-
au](https://tinyurl.com/ebay-dc-tig-au)

~~~
asteli
I've done a little welding, using the really nice TIG setup at my work's
machine shop. I've contemplated getting a cheap TIG setup for home, but was
wary that they'd be unusable compared to a nice unit.

Sort of like soldering irons, where the <$40 ones are typically trash, the
$40~$100 ones are probably fine for home use, and the ones that I bought for
work start around $500 (JBC btw, I've convinced our entire engineering lab
that they're the best).

When you go really cheap on soldering gear, overall power, tip temperature
regulation, tip plating quality, and iron longevity are all reduced, sometimes
to the point of unusability.

What do you lose when you go cheap on TIG machines?

~~~
convolvatron
not too much really. power. 200A gets you pretty far, but 100 isn't enough for
some things. if you don't get AC you can't weld aluminum. without a water
cooler you have to make sure not to run the head too long without a break, but
for personal use its not too bad. if you get one without the argon valve and
control its a pain, but its usable (you have to stopcock open the argon before
use and turn it off, so you go through more gas). cheaper ones might not have
the HF start so you need to scratch start, which is a pain, but livable.

the only thing to really be wary about with the cheaper deals is that they
often don't include the head, sleeve, controls, ground clamp, argon fittings
and regulator. so those might add some hidden cost. regardless you need to
budget another ~$300 for a tank and gas.

but the difference between low end and low end professional is alot of money,
so I would definitely recommend skimping a little. since the tips are consumed
there isn't much of a wear issue really.

a super cheap option is a used stick machine with a tig head if you can live
with all of the above limitations. if you upgrade you can carry forward the
tank, regulator and head.

~~~
TheSpiceIsLife
This comment does a pretty good job of covering the important things.

My work has an AC TIG so I'm covered for aluminium welding if I need it.

I think the only other thing I've noticed about the cheap DC TIG I've got is
the build quality is, well, cheap, but if you handle it with a bit of care
they seem durable enough. I've accidentally dropped one of the name-brand ones
from 6' up a ladder and it just bounded and kept going. Not convinced I'd want
to do that with my ~$200 unit.

Probably a good idea to let the unit run for a good 5 minutes after you've
finished welding to make sure it has a chance to cool down. I had a MOSFET
blow out on the first one I bought, I think because I was switching it off
immediately after doing quite a bit of welding and the fan didn't have a
chance to blow away the heat build up. But even after buying two of them I'm
still a good ~$1000 in front of a high end unit.

------
jerkstate
This 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.

~~~
jedberg
I've been putting my three year old in her car to drive since she turned two,
but she still drives like a drunk. How did you get him to understand that he
has to keep the wheel pointed in a straight line to go straight?

~~~
jerkstate
It took quite a lot of sessions before he started understanding what to do; at
first, he really preferred to push it from behind rather than sit in it. So I
just kind of let him do that for several sessions and gently coaxed him into
the car for a minute or two at a time. I felt like if I got frustrated he
would get frustrated, and he would just reject the car altogether, so I
basically let him do whatever he wanted with it at first.

Once he was sitting in there and messing with the controls, I would run and
dance around in front of the car to get him to chase me, which he thought was
hilarious. As soon as he was able to go where he wanted and clearly enjoyed
it, I thought he would be ready to listen to me tell him what to do, so we
would take longer trips with a destination in mind, to the playground or to
the drum circle. I would verbally tell him what to do (stop, go, turn left,
turn right, reverse, forward, etc), and if he doesn't do it within a couple of
seconds, I stop the car with the remote start and hunker down and explain to
him what I wanted him to do and show him on the controls. If he continues to
not listen to my instructions we take a few minutes time out out of the car
and sit on a bench or run around or whatever.

Anyways, keep trying! it's a lot of work but so much fun.

~~~
tomcam
Jerkstate, this is one of the best DIY posts ever. You sound like a great
parent.

------
lbotos
Don't show your son Lila Kalis videos yet :P

[https://www.adventuresportsnetwork.com/sport/moto/4-year-
old...](https://www.adventuresportsnetwork.com/sport/moto/4-year-old-girl-
drag-races-her-power-wheels-better-than-you-drive-your-car/)

Is children's powerwheel competitive drifting going to become a thing?!

~~~
tonyarkles
I 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
Is 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.

------
AnnoyingSwede
Update: 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
A 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
Agree 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.

------
AnnoyingSwede
Posted 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
Problem 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.

~~~
AnnoyingSwede
First 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.

~~~
aidenn0
Out of curiosity, why aluminum? Isn't steel much easier to work with?

~~~
AnnoyingSwede
I 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
Be aware of the safety issues with aluminum too; aluminum has a nasty habit of
looking 100% healthy until the moment it completely breaks.

------
wumms
Great Scott! If my calculations are correct, when this baby gets an 1 kW
motor... you're gonna see some serious shit.

~~~
mikestew
Human 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
And a roll cage.

------
dugmartin
If 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
Not 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.

------
4ndr3vv
Obligitory link to the ppprs

[http://www.powerracingseries.org](http://www.powerracingseries.org)

------
chjohnst
I 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=chjo...](https://www.instagram.com/p/BY3X_zhAyY0/?hl=en&taken-by=chjohnst)

------
AnnoyingSwede
My 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

------
teekert
This 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.

------
nathan_long
> 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.

------
bmsleight_
My Dutch is not that good, but looks like the bandwidth limit hit. cc:
AnnoyingSwede

~~~
AnnoyingSwede
I 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?

------
eitland
Another 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.

------
chrissnell
I'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.

------
uptown
I'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
They 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.

------
pryelluw
People 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
awesome 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
Great ideas, might steal a few of them. Thanks for the inspiration!

------
bitwize
Geez, dads are awesome. This is some shit that mine would have totally done
for toddler me, had he the money and time.

~~~
AnnoyingSwede
Besides my interest in builds and electronics, this is why i am doing this. I
never had such a dad either.

------
jordigh
It'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.

~~~
kakarot
As 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
A 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).

