We, Team Infento, are delighted to announce the publication of the inaugural issue of the Infento Masters. A dedicated journal is the ideal vehicle to build on the community we have created together. In this first issue, we will cover Jan Wittholz’s work on Ride-on mower. In the coming months, we will continue in the same lane, with the focus being on custom-made complex creations that showcase what’s possible to be built with Infento.
Infento: Can you please tell us a bit about yourself?
Jan: My name is Jan. I am 44 years old, a design engineer and DIY enthusiast, and a dad of 6 kids ranging from 3 to 15. We live near Schweinfurt, Germany.
Since I was a 12 year old boy I was dreaming about building a moped engine into the back of my scooter or kettcar. But I just didn’t have the knowledge nor the technical abilities. This is challenging even for an adult because you need to buy bits, bolts and belts, just not stuff I could buy at our local hardware store. And if something was finally welded together, I could hardly vary anything.
I like about Infento is that we can build a new ride as soon as the kids lose their interest in the existing one – usually after 2 weeks. It is also cool that you can experiment with chassis parameters so easily and explore the effect e.g. by changing 2-wheelers the steering angle.
Infento: What would you recommend to people who are trying to make more complex creations – what’s a good place to start?
Jan: Of course the principal idea comes first – motorbike, truck, plane or a cable winch? Next I make up my mind about the functions of the ride apart from driving and steering, and how this can be solved regarding the limited quantity of parts on my shelf-does the plane need a rotating propeller, or the excavator a moving shovel? Think of alternative usage other than the parts’ primary purpose – a seat pad can be a car’s bonnet, two axle flanges can be a bevel gear.
Often underestimated but challenging is the ergonomy. How tall is your kid, will it reach the pedals, is there enough space between steering wheel and backrest? Take a folding ruler and measure the arm and leg length of your kid(s) if your kids are not available while you build. Finally – check if the ride will fit through your front door ?
Infento: How did you find out about Infento?
Jan: Before I started with Infento, I was known among my colleagues not only for having many kids in my house but also for being an AFOL (adult fan of Lego). One day in late 2017 one colleague forwarded me a link – he assumed a modular XXL-play system would find my interest. When I saw there was even a motor included, it was like a lock and key.
Infento: When did you decide to make your first custom creation and what led you to it?
Jan: A side car for the mini bike was our first self created addition to an Infento standard ride, perhaps 2 months after we got our Legend kit. Well, there were plenty of parts left on the shelf, and the kids asked me to add a 2nd seat. But there was just no space on the mini-bike’s frame, so I built the side car from what I had.
Our sons were proudly driving their little sister through the neighborhood. Not only kids and parents were totally amazed and delighted – also elderly people, maybe because they have seen these vehicles more often in the old days.
The Ride-on Mower
Infento: What inspired you to build this creation?
Jan: Real functions bring a creation to life – and the kids love them. Construction rides and tractors are always admired by kids, but also the ride-on mowers of the community and the local soccer field.
I had the 43cc brush cutter in my shed, and we had already used it in one previous Infento ride – but now we wanted to use it for mowing and not for driving the ride. It was a bit of work to modify it (shorten the long shaft, build a wooden clamp, conversion to a Grip-Shift hand-throttle), but this part was pretty straightforward.
Infento: What was the most challenging part about building?
Jan: Well, the question was how to steer and which axle will be driven? You can’t steer nor drive the front wheels because in between the front wheels sits the mower. The rear wheels can’t steer either because they need to be driven (driver sitting at the back – good for traction). A steerable AND driven axle is almost impossible to build from today’s Infento parts. So the steering HAD to be an articulated steering. But that was a great opportunity to tick off another point from the list of things I wanted to build from Infento.
Next question was how to take account of going off-road? Meadows are not always perfectly flat. A 3-wheeler? To tippy! A suspension? Too complex! The solution was a swivel joint so that the front part including the mower can roll to the side if it needs to.
The mowing mechanism was supposed to be retractable, or even better, adjustable in height, for various terrains as well as for the street.
Finally, the steering system would have to have a reasonable ratio to keep steering forces low and would allow some freedom of where to place the steering wheel.
Infento: Tell us specifically how modularity of Infento helps you in your building process?
Jan: Axles, bearing blocks and belts can be used for driving as well as for steering.
The 40x40mm aluminium profiles come along in a length in 40mm grid dimension. If you run out of the profile you need, you can choose the next longer one and try to alter the type of connection to the next profile. There are also profile connectors that allow to butt joint two profiles to make a much longer one. There is always a way.
Infento: How did you fit the gasoline engine onto the construction? Have you used any custom made parts?
Jan: Yes, many, but not all of them had their debut on this ride. The gasoline engine is for sure the most obvious part. The shorter shaft was a Sunday afternoon job with my oldest son at my lathe and bench grinder. The engine is fitted to the frame by a beech wood clamp. The throttle is a Gripshift bike lever that will keep the motor running at various speed levels so that you have both hands free for steering. I fitted a silicone hose from a turbo car onto the exhaust to get the exhaust fumes away from the driver. The kill-switch (to shut down the engine) is a universal one from Ebay.
Furthermore, I used some 3D-printed belt sprockets (13 and 18 teeth) to achieve the required steering and transmission ratio. On the steering column I used a 3D-printed cardan joint, but this part is not essentially needed, it makes steering just a bit more convenient. The knob on the steering wheel is a cut-off bike pedal axle. The rear wheels are wheel-barrow tyres for €10 each from Amazon. They are big and have a strong tread, which is important for not getting stuck in a bumpy and slippery meadow.
The rear axle showcases a self-made differential that allows driving both wheels.
Infento: The mower has a functional pedal. How did you make this possible?
Jan: Well, there’s only a single foot pedal, this is for the electric motor. There is no need for a brake pedal because the ride is so slow. This pedal is also an Ebay bargain from China for some €12. I found the right plug and the pin coding to drive the Infento E-pulse motor with it. An ordinary plastic switch that I taped aside of the steering column actuates reverse driving. The adapter for fitting this foot pedal is also a self designed and 3D-printed one. I made all this 3D-designed stuff accessible to anybody on thingiverse.
Infento: The steering system uses belts of different lengths and angles. Can you please describe how you managed to transform the action of turning the steering wheel and getting the chassis to go the same direction?
Jan: I had to solve 2 problems: the steering wheel should not be located on top of the steering axis, but more to the rear of the ride, by let’s say 25cm. A direct belt drive for this axle distance would require an ultra short toothed belt, but that not available anywhere. So I took the shortest belt from Infento, led this one to a pulley at the back of the ride, and took the longest belt and led this one from the back pulley to the steering axle.
The 2nd problem was the steering ratio. An articulated steering requires more force than a conventional steering, especially on bumpy ground. I needed a greater ratio than what is possible with the standard Infento 28/46teeth belt drive, even considering I had smaller 18 and 13 teeth versions available. The 2-stage belt drive offered nicely a solution to multiply the ratios of 2 belt drives. This all sounds terribly complex, but you may have a look at the video I uploaded to Youtube. The final results look quite simple.
There was no need to reverse the turning direction. Unlike on a ride with rear steering like e.g. a forklift, you basically steer in the same direction as you want to go. This would be challenging, as belt drives basically don’t reverse turning directions, but belts are the only transmission element in the Infento product lineup.
Infento: Could you share with us some of the learning points obtained during the building process? Did you come across any unexpected complications?
Jan: No matter how simple is the basic idea for a ride, it ALWAYS seems to end with a bigger and more complex ride than you initially planned. That very challenging, and even more challenging if considering you only have a limited amount of parts. I must confess that I also ran out of parts, but the girls and guys from Infento were very helpful and did their best to provide extra parts in no time. Don’t dare to order a good amount of extra parts when you start with Infento: once your stock has a reasonable size, your orders for extra parts will become much smaller. It would be a shame if you had to slow down your creativity by a lack of parts.
Infento: Thank you for the information Jan, and good luck building the next masterpieces!
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