Marui Samurai 4WD - Another SilverTriple's journey...

[silvertriple]

Decided to restart my Fusion360 project from scratch yesterday night, to do it properly this time...


I do have now a model which allows me to play with the internal diameter of the tyre I want to put on the rim, the width of the rim, and the number of spokes. The spoke will enlarge with the diameter and will reduce when the number of the spokes increases. This may still require some fine tuning to find the right proportion, but at least it's a start. I still need to find a way to add rings for the modern tires, and as well some différent possibilities for the driver (which is currently a friction based driver, but it would be better to allow for an ex driver in some cases...

Here is a sample of the possibilities at this stage, for the front wheel...



I still need to take care of the rear wheel properly (but I have to redo it fully as I completely messed up my initial project doing so beginner's mistakes, and secondly because the hub driver needs more thinking to be able to handle an hex driver (not for the Samurai, but for other purposes)

[silvertriple]

It seems I'm getting faster at it

I now have the front and the rear wheels done.


I've slightly modified the rear driver area as I'd like to be able to handle hex driver for some purposes but beside this it looks like a Samurai wheel in the original dimensions. I've indexed the rear hub on the front hub size. Which means that the front size inflation leads the rear hub size. The rear wheel size is to be set with it's own parameter, and don't impact the hub size.




Few things remain to do, but it is already good for now, and won't require redesign of anything when I will change the slots internal/external diameter to allow some proportionality so it scales better. And for the additional ring, it will be done later on (but that is very easy to do compare to what I've done until now ).

Maybe I should consider catching up some sleep
(Maybe I should also consider doing a 2WD Front Narrow rim with seats for ball bearings as well)

[Dadio]

Now front wheels with a seat for one way roller bearings would be fun

[silvertriple]

Now front wheels with a seat for one way roller bearings would be fun

I need to think: I've tried a bit to play with some parameters, to introduce features which would happen or not happen depending of a value... Unfortunately, I did not succeed to introduce any 0 value in my parameters yet... But if I succeed to get it work, it opens another world of possibilities... I may then think about all sort of funny ideas

[silvertriple]

Well... A bit of reasearch, and a new feature appears .

Conditional parameters don't exist in Fusion 360, and it is not even possible to enter a parametric value with a 0. Had to find a way. A bit of search showed there is an interesting function: Sign(x) is answering 0 if x is a negative value. I decided to see if I can create rings for modern tires based on a parameter set to 1 if modern tires or -1 if original tires.... And it worked after a few tries.

Here is my wheel when the parameter is set to 1 for modern tires


And here is the wheel when the parameter is set to -1


And it's not perfect as there is a warning left in the case of the parameter being -1...

*EDIT* I had to change the rear extrusion to .1+Sign(ModernTire)*3.5, do a +.1 extrusion and a -(.1+sign(modernTire)*3.5) extrusion to get it right...

[silvertriple]

There was a last step to do on those wheel design work: be able to set the right type of driver for the stl I want to print. It was relatively easy to do, as soon as you understand what you can do with the sign(x) function.

With the Hex driven parameter set to -1, it is the Marui Samurai original friction driver which will be used. And with the same parameter set to 1, it is going to be hex driver. There is warning, but it's not really an issue in this context, as I do not make anything after that in this area (precedence has some importance in the history for this).




You can see the parameters in the screenshot if you are going thru a similar model project for a multi-purpose wheel set
And yes, that was fun, I spent a lot of time on this, but I can certainly say I have quite a good idea on how to use parameters in Fusion 360. Yes it may take a bit more time than to do directly on the sketches, but it is really rewarding at the end . Have fun.

[silvertriple]

Extracted few stl from my Fusion 360 project to do some tries, as I got a roll of PLA+ Silk Silver filament yesterday. Fine tuned my settings, and launched a print of wheels in draft quality to see the results before eventual refinements of the design, and final choice of wheels.


The aspect of the print is quite promising already

[silvertriple]

The print lasted about 14 hours for 3 wheels that I intended to test to validate the work. This morning, the print was finished, and I could see the results.

First thing I noted is the requirement to review the slicing to go for tree support rather than normal support, as the normal support are difficult to remove between the rings... That being said, I'm not sure the rings are required (I'll probably let them in the final design possiblilities, though)...


Next was to do some tries. I have two obvious combinations to test:

1. Kyosho Scorpion re-re rear tire at rear and Schumacher T693 at the front.


Here is this set on the Samurai. This is the most approaching combination in spirit from the original Samurai wheels set




2. Hotshot tires. This could work with any 2" tires combinations with narrow front and normal size behind


Here is the combination on the Samurai


I'm not decided yet on what I do at the end for my Samurais. Ultimately both set works. I still need to do some fine tuning on my rims design, but it's already in very good shape. I will review and finalize my design before printing a full set...

[Dadio]

To print the tire support rings without support is pretty easy , just put a chamfer on the lower side as in the picture , as its 45 degrees its less than the 50 degrees overhang that most printers can cope with without support , holds the tire just as well .

its a very easy trick .
Those wheels look really nice in that filament , silk filaments do usually have dreadful layer adhesion though so its going to be interesting to see if they hold up to driving , they probably will , I've printed wheels for several cars in PLA and never had a failure .

[silvertriple]

To print the tire support rings without support is pretty easy , just put a chamfer on the lower side as in the picture , as its 45 degrees its less than the 50 degrees overhang that most printers can cope with without support , holds the tire just as well .
Bolink Digger 2.2 Rear Wheel v2 v2.jpg
its a very easy trick .
Those wheels look really nice in that filament , silk filaments do usually have dreadful layer adhesion though so its going to be interesting to see if they hold up to driving , they probably will , I've printed wheels for several cars in PLA and never had a failure .

Thanks

I did not thought about applying this when doing the design (I was maybe too focus on getting the parametric thing working )... This is part of the things I intend to modify. I also want to modify the spoke reinforcement and reduce the size of the external ring, and few adjustment on the parameters for the axle diameter and the driver diameter... And slicing will be revised: the target was to test and not the quality of the print.

And for the Silk Silver PLA+, it looks nice. Not sure how they will work out on the field. That's part of the things I want to try. And in any case, if the model work, I can also get it printed in Nylon (SLS or MJF) and eventually painted thru the online printing service (both Weerg and Materialise are proposing options for this).

[Dadio]

The next thing I want to try is electro plating 3d prints , looking at it on YouTube it seems to be relatively easy and would be perfect for these wheels .
I've never even tried the parametric stuff your doing , I think you learning Fusion much faster than me

[silvertriple]

The next thing I want to try is electro plating 3d prints , looking at it on YouTube it seems to be relatively easy and would be perfect for these wheels .
I've never even tried the parametric stuff your doing , I think you learning Fusion much faster than me

Well, discussing with Ryo, it seems I do not have the basics for the rest: I directly went to the advanced functions and may have some difficulties to catch up on the really simple things: I may eventually restart what I've done for the Nichimo at this stage, as I'm not sure I'm on the right path for this one . It's a learning curve in any case...

[Dadio]

It's learning three things simultaneously , computer aided design (specific to 3d printing), slicer software and 3d printer hardware . JUST HUGE LEARNING CURVE !

[silvertriple]

It's learning three things simultaneously , computer aided design (specific to 3d printing), slicer software and 3d printer hardware . JUST HUGE LEARNING CURVE !

I completely forgot the 3rd one, but yes, true. I had a lot of discussion with my brother on that aspect and it helped me a lot... And specially when you discover the default settings of the slicer for the machine are way off and generate additional issues to tackle...
By the way, I'm considering convert the extruder/hot-end of my Creality Ender 5 plus to something more suitable, as I really see things I'd like to be able to do and I'm not right now due to the limitation of the bowden extruder (thinking of TPU for example, where the length of the bowden tube is a nightmare to manage in terms of retractation)...

[Dadio]

It's a toss up between Bowden with a light print head but lousy retraction and direct drive that's heavier but tiny retraction , the thing that swung me to direct drive was the time it takes to do retractions , just try it on a long print in your slicer with a 7mm retraction or with a 0.5mm retraction , it saves loads of time , this means that a Bowden printing 80mm/p/s is not much faster than a direct drive at 60mm/p/s .
Also these days with the super light weight extruders like the Orbiter that I'm using a direct drive setup is not nearly as heavy as they used to be ! You'll probably have to design a mount yourself as the 5+ is not so popular , I had to design one for the Ender 5 as there was nothing exactly right on Thingiverse as I'm also using a Dragon hot end .