Max Team XL, part 2: What needs to be solved when doubling the size

Jirka knew that it would not be a “walk in the park” and that it would not be easy to simply double the size of the Max Team model. But as he began his careful preparations, he started to suspect how much work was still ahead of him. With each successive task, he wondered if he had accidentally invented a challenge that would take much more time than it seemed at first.

Jirka finally started

The first task on Jirka’s journey was to reconfigure the print profiles in the slicer, which was just a warm-up. Some of the print plates were easily changed to Original Prusa XL and the parts were enlarged to 200 %. Parts with built-in 3D Sets supports had to be adjusted outside the PrusaSlicer.

Then Jirka had to calculate how much filament would be needed for such a huge print (for comparison, the smaller 1:8 scale Model 14 Max Team uses over 4 kg of material). You can imagine that printing a 1:4 scale model is going to be a bit of a strain on your filament supply. Not to mention finding the right non-printed hardware. Jirka had anticipated all of this, but what really took him by surprise was when he remembered that he needed 671 nuts and bolts.

Due to the size, all parts are printed with a layer height of 0.25mm and 3 perimeters for added strength.

For example, a side door with filament changes, even though the head change on the XL is very fast and efficient, will print for about 55 hours and will consume

• Prusament Vanilla White – 550 g,
• Prusament Galaxy Black – 420 g and
• Prusament Prusa Orange – 190 g.

This means one print will consume over 1 kg of filament. And that’s just one side door :-).

As we mentioned earlier, Jirka has to find and test these non-printed parts to fit the 1:4 scale model:

1. Pins – they need to be resized and the clearance needs to be correct. There is a set clearance in the model and simply enlarging it will increase the clearance, but this is not acceptable and it is necessary to adjust the parts with the correct clearance.
2. Servo – Must be correctly fitted and secured to the linkage. An M3 thread on the servo lever is used as a standard.
3. Bearings – Double size bearings are not widely available or are very expensive.
4. Transmission – Cannot simply use a belt twice the size. The gearbox will need to be modified for different belt types.
5. Engine – It is essential to use a more powerful engine to meet the new requirements, not just twice the size.
6. Rims – The wheels need to be adapted to the tyres available.
7. Supports – They cannot simply be made bigger as the offset would increase too.
8. Hollow parts – Our reinforcements are designed to be printed with two perimeters.
9. Shocks – There are no shocks on the market for M6 bolts, it is necessary to modify their mounting.

And this is the list that Jirka is well aware is waiting for him. Who knows what else will turn up.

While Jirka is working on these hardware requirements, he has started printing parts that are not affected by the enlargement, such as the seats.

How will Jirka cope with all these challenges? That remains to be seen. Stay tuned for the next parts of “Max Team XL” series, where Jirka will take us through the printing and building steps. We in the team are somehow expecting the first “f*ckups” in 3… 2… 1…

By the way, so far it looks like a little over 20 kg of filament consumption. We would like to thank Prusa Research for supporting Jirka and 3D Sets in this activity!

You can find all articles at 3D Sets Max Team XL Challenge.