3D-print at low costs - this time a Pitbull

Well, point 2 of my basic thoughts:

2. Functional or static model?
Definitely functional! Steering, cushioning, hatches etc.

 

Sometimes it's good to lean back and relax for a while or do something else.

And than - after a few hours or days - DANG! an idea pops up and THAT'S IT!

The tire is now ONE part, no infill except my own, no glue.

 

The tire is ready. And it's okay. No further problems.

Now I'm in need of a test bench. Something like the yellow block:





An unsolved problem is, how to attach the wheel to the wheelmount. I would like to use some kind of quick fastener. Like a petrol cap.

 

It should be more simple to print, like a key wich can be turned:



Looking at this picture I'm happy that I switched from 1:43 up to 1:25

 

I will not make an extra test bench. I will build the vehicle vat:

For that I have to modify my front undercarriage for the rear axles. The rear part of the vat is wider than the front part:

I must cut some holes into it. Unfortunately this will affect the inside:

Well, probably the passengers must close ranks.

 

Cool! Next part, that works perfect:

Good to see what happens at a the end of a part if there is no other part at the same hight. The printer just stirs the PLA. Compared to this the deeper eyes are okay because there were three places to deal with for the printer and the others could cool down while it printed one.

I made the key first:
and glued it together:

After a bit cutting and sanding it worked perfectly:

A very strong connection - as it would be one single part. But removable. You can lock and unlock it by a simple 90°-turn.

I LOVE IT!​

 

Yes! The coolest part of all this is: You design something and it comes to real life in front of you and it works. This is an unbeatable feeling and really pure fun.

Additional I want to mention, what the printers log tells me:
Printing time
25 days 6:34

636 hours of printing! If you would use this printer 2 hours every single day it would be nearly one year meanwhile.
Thumbs up, WANHAO!

 

I decided to use the same parts for the rear axles. I will just change the wheelmount because we have no steering at the rear axles.

Only the seats in the middle are affected:

I will find a soultion for this. No law tells me to copy the original Pitpull without changes.

 

While running several test prints I had another idea. I reduced the former yellow testbench to an undercarriage carrier:

This one should slide into a corresponding nut in the vehicle vat. Than I can use a small bolt to fix it.

 

If you use a parallelogram the wheelmount will stay vertical. But I use a trapeze. This is common. At least at motorsport (where I come from).

The small springs will be enough. There will be 12 of them and the weight of the cabin wont be high ... some 400 g I estimate. The bigger problem will be the frictional resistance between piston and cylinder.

The tire is completely closed:


And since we talk about springs:

 

Just have a look what has been printed and assembled today:

And it works!
Well, it needs a bit fine-tuning. But in general it's okay.

 

Lying at the side, yes. "near vehicle" dosn't matter. It is symmetrically and can be used for the left and the right wheels.

 

No, RC is not possible. You would need a cardan shaft for driving each wheel (or at least for the four rear wheels). My ambition was to keep the construction as simple as possible. That was the reason for point 6 of my basic thoughts:

6. Electric motors and remote control?
Well, such things call for a very special design. I think this would require way more thoughts and knowledge than I am willing to put into this project. My main goal is to print my own 3d-models.
The challenge is big enough without remote control!

An RC-model would be a completely different one.