Posted on 14/02/2023 at 22:02

Mini Thing : Chassis, Motor, Electricity, and first ride!

Chassis, Motor, Electricity,
and first ride!
Mini Thing
Here's a project that sat in the attic for 16 years!

The project was on hold since I had sold my VW Thing, I had then lost the motivation to make a scale version of it... But I managed to buy back my Thing in September 2020, 13 years after selling it!

But more important, in the meanwhile my son was born (2017), and when the little one saw, two years ago, the body/shell of the Mini Thing collecting dust in the workshop, he started a constant and intensive lobbying to get the project re-prioritized. icone smiley laugh

Chassis

Back in 2007 I had started a chassis from square steel tubes, but it was not looking good from the beginning. I had built it in a hurry, as I had convinced myself I could get it to drive within 48 hours for an upcoming meeting. Unsurprisingly, it did not work out. To give you a glimpse of the "quality", as I did not own a lathe back then, I chose to directly spot weld the brake disc and transmission sprocket on the axle! icone smiley meh
Add on top of that the long welding session in an underground parking box, until 2AM, wearing a tank top, resulting in an unforgettably glowing sunburn... Talk about a disaster. icone smiley laughicone smiley laugh

So, long story short, I started again from scratch, by sourcing two go kart chassis as base. One I bought for cheap (50€, thanks Gus!), and the other one discarded on the pavement just 100 meters from my place - fate! But you should have seen the face of the 2 cops that crossed my path, while I was dressed in a shirt and tie (I was heading to work), at 5:30AM, holding a wrecked go kart on my shoulder... Fun times. icone smiley laughicone smiley laughicone smiley laughicone smiley laugh

After some Sketchup design to figure out the best way to optimize my cuts, I begin with the rear end of the chassis. I cut away a section of the go kart chassis, and weld it back together, while putting it upside down to gain some much needed ground clearance. A go kart usually sits like an inch from the ground, and that's not the stance I'm going for here. icone smiley wink
For the front axle I first trace everything on an OSB sheet to figure the total width... Which turns out to be 102cm, that I need to cut down to 58 cm to align the wheels with those of the rear end. So 44cm to be removed from the middle, not much is going to be left after that!

I make temporary little brackets/mounts to keep the geometry of the front axle while I cut everything, not that I intend to drive it very fast, but to ensure the steering wheel will go back to neutral on its own. Said brackets were actually cut out of the first chassis I made back in 2007, which I dug out of its rusty grave - at least it will have served a purpose! (in the end I'll have recycled most of it in this project! icone smiley laugh)
But with my method to cut the front axle, I end up with a massive spike in the front of the car, not exactly child-safe, so I take care of that...
In the back and the front, I build stands/brackets to hold the body shell, and later on attach the bumpers. Never underestimate the destruction power of an overexcited 5 yo. icone smiley wink I add a plate to bolt the motor on, then it's primer, two coats of dark gray, and the chassis is ready.
Let's be honest here, I was low on gas so some of my welds here are nothing short of atrocious, and the actual relative geometry of front and rear axles is faaaaaaaaaaaaar from perfect, but since the objective has never been to do time attack on a race track, that will have to do! #goodenough icone smiley laughicone smiley wink

As for the steering parts, I pick in the stock of go kart parts I've accumulated along the past 15 years. I turn down on the lathe the aluminium steering links, leaving the left-handed thread on one end and re-threading the other, to keep the adjustment like on the original go kart. I also drill new holes in the spindles to increase the steering angle.

Motor

I dropped the initial idea of a gas-powered engine, not suitable for a kid, noisy... I switched to an electric brushless motor 2000W, bought on AliExpress (159€).
The motor kit comes with a controller, a throttle pedal, a key-activated main switch, a 3 positions selector to limit the speed (not a bad thing to have when giving the bloody thing to a little boy), the sprocket and chain...

The controller comes with an input to activate the motor electric braking, which gives me the opportunity to add a remote control to stop the car at a distance, in case the little one gets a bit too enthusiastic behind the wheel. icone smiley wink

To adapt the sprocket on the rear axle, I used a brake hub I found on one of my sacrificial chassis. Turned it down on the lathe, 6 M6 threads, and done.

Brakes

I start with a 20€ disc-brake kit for bikes, mechanically actuated, not hydraulically. First because again, I'm not making a racing go-Kart, but also the maintenance will be much easier, limiting the risks of seizing (not even mentioning cost).

I modified and moved the original go-kart brake pedal, with a linkage rod to action the lever on the caliper. The caliper got modified as well to adapt it to the kinematics of the movement. The disc is secured on the axle using a wheel hub I modified on the lathe.

The brake works fine, but it doesn't have the "bite" I was hoping for, due to the linkage rod buckling under the effort, which reduces the power transferred to the caliper.
To compensate for that, I have added a micro switch on the brake pedal to activate the electric braking of the motor (which recharges the battery as well!). This will do until I modify the system, so the linkage would be pulled instead of pushed, or maybe replace it with a cable... Room for improvement.

Interior

OK, "interior" might be a bit of a stretch, but anyway, I wanted a "child safe" place for my son.

So I build a floor, seating area and dashboard out of 10 and 12mm thick plywood ; this will prevent the little one from putting his fingers in the rear chain and sprockets, or his feet in the steering in the front.
Sanding, gesso, some more sanding, and two coats of glycerophtalic paint using a foam roller (flashy green, but I had the pot left on a shelf).

The board in the front under the hood will hold the battery, controller, and most of the electrical circuit. Two pieces of aluminium angle on the sides will hold the body shell in place.
On the "dashboard" we have the key switch, and the switch for the headlights. Below the seat, on the right hand side, a switch activates the reverse. Upcoming : a gauge to track the battery charge status.

Windshield

I found at my local DIY store 2 hinges that look a lot like those of the original VW Thing...
So with a bit of acrylic glass, and a length of aluminium U profile, I got myself a scaled version of the windshield! I even have some rubber seal (initially intended to be put on your car's doors to protect them from impacts/scratches) that will look great around it once everything is painted. I'll keep the blue tape on the glass until everything is painted too.

Assembly and electrical circuit

Time to put everything together!
The beast is powered by an e-bike battery, the biggest expense on this build : 295€ on AliExpress. It comes with a standard XT60 plug, 52 Lithium-ion cells type 21700 3.7V/4800mah arranged in a 13S4P pattern, for a grand total of 19.4AH at 48V. Most probably way oversized... icone smiley wink

I install a voltage reducer to get 12V from the battery 48V, and put a fuse box to power each of the elements :
  • a buzzer as horn (activated from a push button on the steering wheel)
  • LED headlights in the front (T10 LED lamps)
  • rear brake lights (48 smd LEDs boards), activated by a micro switch on the start of the travel of the brake pedal)
  • A remote controlled relay, to activate the electric brake (security when the little one is driving) - with 2 relays behind so that the brake lights turn on as well.
Ok, one single fuse would probably be enough, but hey, let me have some fun alright? icone smiley laugh

First ride!

The project is finally on its wheels, 16 years after starting it! Yeah, I know, I'm not exactly fast... icone smiley laugh
Initial feedback :
  • 2000W accelerates hard! I had to put a piece of wood underneath the throttle pedal for my son to be able to drive the thing. And the 3 speed selector is a blessing!
  • When giving it full throttle, the front axle loses grip and the steering becomes nothing more than a recommendation... icone smiley laugh The lack of differential on the rear axle doesn't help, for sure.
  • Boy am I glad I included the remote control to stop the Mini Thing at a distance, it has effectively prevented many accidents from happening to my son. In his defense, he's constantly improving his driving skills, and keeps beating his own time on the Nürbur-Green (aka our garden icone smiley laugh)
  • High stance + reduced track width + high speed = if you try to steer too tight, the wheels on the inside of the turn will lift... And, yes, admittedly, I did manage to end up on the side myself. icone smiley laugh
  • I need to shorten the steering links by a few millimeters ; right now, even adjusted at their minimum, the front wheels have a pretty massive toe-in, giving some random behaviors when steering on mixed-grip terrain.
  • In hindsight, I should have reduced the caster angle on the spindles, it makes the steering a bit hard for the little one.
  • I should have made a more serious frame/jigs, as the geometry of the chassis is off by quite a bit... I managed to compensate with some adjustments, but it could have been much better.
  • The tires, at over 15 years old, are dead dry, and don't hold pressure any longer. I'll swap them shortly.
I'll gladly admit this last picture gives me a big smile, for more than one reason. It took 16 years to get there, but it was worth it! icone smiley wink

I still have quite a few things to do on this project before I can consider it complete : paint, bumpers, headlights, brake lights, seating, battery gauge... But the little one was able to drive it for Christmas, and that's all that matters!

Stay tuned for the finishing touches... Soon!
Posted in : Mini Thing
Displayed 12190 times.
icon permalink
Posted on 21/11/2022 at 23:19

Elvira : Rebuilding the 36hp, episode 11 : engine installation

episode 11 : engine installation
The engine is finally back on the car after almost 13 years out! I took it out back in 2008 to get it restored...

Engine Bay

As it was inconceivable to put back my beautiful engine in a dirty engine bay, I decided to get rid of the original sound deadening cardboard, as it was pretty banged up - and I much prefer that look, even if it means a louder engine. I also get rid of the little cushions hidden in each side of the body top, as they tend to promote rust.
Then I'm in for a long session of acetone cleaning to remove all traces of glue (they had kind of a heavy hand with glue at VW back then). I then grind off the pointy tabs that used the original cardboard...
I masked everything, protected the workshop around... Which won't be enough in the end, I had underestimated the overspray, the workshop floor will keep some marks...
Then primering, light sanding, and finally painting the engine bay using 2-components polyurethan spray from VerniciSpray - this is not a sponsored message, I quite like their products and service (already used on the engine tins).
The result is pretty neat actually, don't you think? (brand spanking new engine seals too, while I was at it)

Pre-install preparation

Since the engine was out, I took the opportunity to replace the gearbox stands, including the nose one, a specific model for year 1960 (VW reference 111301265C).
I also replaced the gearbox drive shaft seal, split-case specific model (VW reference 111307113C) : it has a sort of lip around it as its housing does not feature any shoulder to hold it. I still have the original 1959 seal in place, which was hard as hell and screaming for a replacement...
Gotta be cautious when installing it, as because of the lack of shoulder to stop the seal, it's rather easy to tap it a bit too much and have it go too far into the gear case. It's then pretty difficult to get it out without damaging it - don't ask me how I know that. icone smiley wink)...
The gearbox gets an oil change, the last time was 25 years ago... icone smiley laugh
The clutch lever spring on the gearbox was broken (no idea why/how, it broke on its own), so I replaced it too. Warning, it's specific to split cases too, VW reference 111141723A.

I've replaced all the fuel lines, the fuel filter (installed under the tank), and the fuel tap under the tank that always leaked a bit since I had this car. I'm a bit paranoid about fire, I'll probably install a Blazecut too in the near future...

I replaced the spark cables with new Bosch ones, while installing the little rubber cable supports specific to 59-61 models (VW reference 113905451), with a dab of vaseline so they mount easier on the fan shroud. I keep the original distributor, I'll replace it at some point with a 010...

Engine reinstall

Well... I guess time has come now, the engine is now ready to go back in its bay. Which I manage to do alone in 15mn, one of the advantages of small stock engines... icone smiley laugh
I can then mount the VintageSpeed stainless exhaust I bought 6 years earlier (!). Nice piece! This model is designed for different widths of engines, which is a good thing for me as since I modified the cylinder heads (see "closing the block" post), the engine is 6.4mm narrower...
So for once that was pretty easy, at least something not fighting me! icone smiley laugh

With a bit of adjustment on the engine tins I fit them under with the heater boxes (see their restoration on my previous post), and finally connect everything to the exhaust.

First start

Finally, April 13th 2021 (yeah, yeah, I know, I'm Hell behind my articles publication schedule!), everything is ready for a first crank... I wasn't feeling so sure I gotta admit. icone smiley wink

Setting the ignitor at 7.5° static advance, adjusting the rockers, priming the fuel line and pump with a vacuum pump (one of those used to purge brakes, works great for fuel too)... I also primed the oil circuit by unplugging the ignition coil and cranking the starter until the oil pressure light blinked out (takes 20/30 seconds on a brand new engine). This will prevent the crankshaft from running dry on its bearings...

And then, well... A squirt of Start Pilot, deep breath, and...
Phew, that was one serious step crossed here! Gotta do some small crab adjustment, shoot my stroboscopic lamp to check ignition, plus a couple of small things here and there, and back on the road! icone smiley laugh
OK, my very first drive out ended up on a tow truck because of a failed fuel pump lever, see my edit from 2021/10/22 on the dedicated post... But since then it drives great! icone smiley laughicone smiley laugh Second gear cracks a bit more than I'd like when gearing down, but for now I'll keep drivin'! icone smiley wink
Posted in : 1959 Beetle
Displayed 24490 times.
icon permalink
Posted on 08/11/2022 at 17:20

Worshop : workbench 2.0

OK, my "Workshop 2.0" is pretty cool, but without a "workbench 2.0" to go with, it's difficult to work comfortably. I've been tinkering around until now on the top of my rolling tool chest, but now it's time to shift gears...

I already had built a workbench in my previous workshop : you can find all the details of its construction here ; it had even gotten a lick of paint later...
But the main difference is that back then the workbench was squeezed in between two walls, fixed on each side : in my new workshop I can not do the same as the walls are made out of insulated sandwich steel panels, which is not structurally sound. Here, the only points I can affix the workbench to are the workshop steel beam in the right corner... and the floor. The workbench structure will therefore have to be very sturdy, so as not to giggle around when I'm struggling with something in the vise....

So this time around, it won't be made out of wood, but out of steel : I'll built the structure out of 40x40mm and 80x40mm tubing (#overkill). I had some 40x40 left from the workshop building, so I tried to optimize my stock... Yes, I know, I have a severe case of undersizophobia. icone smiley laugh

Design / Marking

Here we go : if it's not your first time here, you won't be surprised I started by a Sketchup design to find the best configuration :
The outcome is 315cm long, 80cm deep, and 1m high, because I'm tall and tend to break my back on standard-height benches..
I had initially planned on putting my rolling tool chest under the bench, but it would then have been too high, since I have a large shelf-like mezzanine above at 2m10. So I decided on putting the chest on the side, with a piece of countertop on it, to get a L-shaped workbench. OK, let's get to it!

I start by precisely marking, on the floor and the walls, where the workbench will fit, which I will use as a reference later (a laser level is perfect for this task). As the floor is not perfectly level, each of the 8 legs may have a slightly different length, so I'll build everything "on site" to ensure a square structure and a level top.
Additional reason to build everything in place : the walls in that corner are not at a 90°, because of a shared wall with my neighbor, so this section of the workbench will not be at a square angle with the back wall, gonna have to adapt...

Structure

I then proceed to order the necessary steel from a wholesaler nearby, namely Durcomfer in Villeneuve Loubet : the 6m long 40x40 tubes cost me 36€TTC, while it would have taken me back 15/20€ per meter in a DIY superstore. Cheap, delivered the next day (for a 30€ fee), very welcoming people, I'll gladly do business with them again.

To bolt them to the floor, each foot will be welded on a flat steel "sole" 40/8mm thick. Each "sol" is then bolted with two M8 70mm screws, into two Ø12mm steel pegs. That's a total of 16 M8 screws, I'm confident this bench is not going anywhere soon. #overkill4ever icone smiley laugh
The rightmost leg is a bit special, as this is the only one bolted to the workshop structural beams. To make sure I made good welds, after spot-welding in place, I took it away to finish welding. For all the other legs, I welded everything "in place", using a mason straight edge and a plumb-line to align everything.
Welding is like painting : prepping is 80% of the work... So before I even touch the MIG, every zone needing welding is thoroughly cleaned of paint and rust. Then only I can spot weld on each side, to prevent warping, before finishing the complete weld.
That being said, full disclosure : I'm not going to win any competition with my welds, but they should hold!

Painting

I had initially planned on unbolting the structure from the ground to move it and finish my welds, as well as paint, behind it... In the end, I did nothing of the sort, so much for the 3 missing welds, the result is so much sturdier than I ever hoped it would be ; even when trying to jiggle it as hard as I can, it barely vibrates a millimeter. I even bought rubber pads to put between the legs and the wall to avoid any impact, but there is absolutely no risk it will ever happen.
And my very OCD self will have to live with the fact the rear face of the structure is not painted (that one actually bothers me!) icone smiley laugh).
The reason why I did not move the whole thing, is that the welds tend to put stress on the structure : if I had removed the screws from the floor, it would have been Hell to realign everything back in place... And this workbench is first and foremost a tool I wanna use as soon as possible, sue me for taking a shortcut. icone smiley wink
Long story short, 4 layers of anti-rust paint (Syntilor Polyuréthane gris clair RAL 7035) later , I finally have a clean structure ready to receive it countertop.
The top of the back legs is left unpainted on purpose, as I will weld stubs on them to hold the back shelf.

Countertop

I ordered 2 counter tops from Leroy MErlin (french DIY store), 315cm long and 38mm thick, instead of the 58mm I originally wanted, just because it multiplied the cost by 3. I prepared the fixation by drilling 22 ø5mm holes in the structure, so I can screw the countertop from below.
I just cut slightly the right end so as to adjust the top to the not-square wall, and I secured it with 70mm screws.
Then I added the back shelf on top of the bench : I find it super useful to be able to store stuff right above the work area, plus it provides a vertical plan on which to put two dual electrical outlets... I can't remember where I salvaged the two lengths of perforated angle iron from, but it was maint to be, exactly the size I needed!
Finally I add a piece of countertop on top of my rolling tool chest : the result is an L-shaped workbench, whilst keeping the tool chest mobile if required. I had calculated the workbench height based on the tool chest so they would end up aligned...
To keep the countertop piece in place on the chest, I routed grooves underneath that nicely fit over the tool chest flanges around its work area. It doesn't move at all, without any modification of the tool chest. The countertop is then cut to fit snugly around the steel beam.
And since I was left with another piece of countertop, I've put it on two sawhorses to get an additional, temporary/removable workbench (spoiler alert of the project I'm currently working on)...

Final Result

And... Tadaaaaaaaa!
The outcome is really close to my initial Sketchup concept, and fulfills its purpose perfectly.
There you go! I still gotta screw in the vise, and run electricity to the outlets, but I already actively use the bench! icone smiley wink
Posted in : Workshop
Displayed 26833 times.
icon permalink
Posted on 06/01/2022 at 11:15

Happy New Year 2022

Happy New Year everyone!
Well, let's do some expectations management here : let's wish for this year to be just slightly better than the previous one, that'd be a great improvement. icone smiley wink

Spoiler alert, real life being ahead of my articles published here (which is a nice way of saying I'm late on my articles) : the '59 beetle is back on the road! The picture above was shot a couple of days ago while cruising around the cape of Antibes.
I'm currently finalizing an article about the engine installation and first start, but it takes time to write, translate, etc... You'll just have to wait a bit longer!

Another article to come soon is the putting the Thing (181) back on the road (again), which has been quite a rabbit hole... Brace yourselves for a lengthy article there. icone smiley laugh

Finally, Santa Claus has been kind enough to give me a 360° camera, so I'm experimenting... And I'll leave you with two videos shot the past couple of weeks. Have a good trip!
Posted in : News
Displayed 63618 times.
icon permalink
Posted on 22/09/2021 at 21:30

Elvira : Rebuilding the 36hp, episode 10 : Heater Boxes

episode 10 : heater boxes
I've never had any heating in this ride, which kinda limits its usage in winter (yes, even on the French Riviera!).. Even though I've owned it for over 25 years! It's high time I do something about it!

Heater boxes

I initially only had J-Tubes on my engine ; so I started by sourcing a pair of used heater boxes. A bit of rust, a couple of dents and holes, a locked mechanism and a missing lever... But nothing patience, WD40 and a MIG can't fix. icone smiley wink
So I start by thoroughly cleaning, followed by sandblasting all the parts. I protect with a bit of masking tape the part of the mechanism that can't be taken apart easily (as its welded in place), to avoid messing with it while sandblasting...

One of the mechanisms is seized by rust (articulated lever) ; WD40 doesn't help, and the bearing finally ripped off as I was trying to free the lever. I finally managed to persuade it to move after clamping it in the vise, so I plug-welded it back on. Done.
On the other side, the mechanism was not seized, but was missing the lever actionnating it. Using a piece of masking tape, I copy the shape of the one present on the other box. Two saw cuts, some filing and drilling two holes, I have a pretty good copy ready to plug weld in place.
All parts finally get a couple of coats of rattle-can Rustoleum hi-temp paint (supposed to handle up to 650°C/1200°F, but I won't hold my breath). All the hardware gets bead blasted, and it's ready for reassembly.

Engine tins

For the whole system to work properly, and for the heated air to be actually forced into the passenger compartment, it requires the under engine tins to be present with their moving flap to redirect the airflow. I did not have those tins on my original engine, and they are getting harder to find (and never built as reproductions). But with some patience, regularly checking online ads, and some bucks, I finally found a pair.
The ones I got were in an ok state, with just a little tab broken on one of the moving flaps. Thorough clean up with naphtha and brake cleaning fluid, then bead blasting to get rid of the flaking paint. And since those are below engine tins,exposed to road gravels, I brush two coats of Hammerite, as it will protect them better than any body paint. Here you can see the left on in its original state, and the right one after full treatment :
I can then focus on fixing the broken tab on the other heater box : only took some MIG persuasion to tackle it.
Bead blasting again it is, and a lick of paint again :
And... Taaadaaaaa!!
While I was at it, I also changed the flaps control cable, the little rubber boots back where the cable gets out of the chassis, and the fittings on the boxes levers ; next I'll put all this back in the car, and make sure the flaps actually move as expected!
But this will have to wait until the next episode! icone smiley winkicone smiley laugh
Posted in : 1959 Beetle
Displayed 78981 times.
icon permalink
1 2 3 4 5 ...62 63 64 65 66  Next page >>>
© Sham 1996-2023