Marui Samurai - Another SilverTriple's journey...

[silvertriple 4121]

There is some stl for the tires on Thingiverse, I imported and could not resist to look at my wheels with tires

[Ray_ve 1204]

4 hours ago, silvertriple said:

There is some stl for the tires on Thingiverse, I imported and could not resist to look at my wheels with tires

If only it was possible to 3D print rubber . Great modeling of the wheels!

[silvertriple 4121]

1 minute ago, Ray_ve said:

If only it was possible to 3D print rubber . Great modeling of the wheels!

It is possible, but my printer is not able to do that. It's part of the next tooling investments planed: you need a direct drive extruder on the printer, which is not what I have right now.

[Ray_ve 1204]

2 hours ago, silvertriple said:

It is possible, but my printer is not able to do that. It's part of the next tooling investments planed: you need a direct drive extruder on the printer, which is not what I have right now.

I've seen it once at a big manufacturing site. The industrial 3D printer was the size of 2 big closets but the results were beautiful.

[Lee1075 282]

Just watched a YouTube video on rubber (ish) resins for SLA printers, looked very promising.

[silvertriple 4121]

On 1/30/2022 at 10:41 PM, Lee1075 said:

Just watched a YouTube video on rubber (ish) resins for SLA printers, looked very promising.

Arghhhh! Now, I need to replace my printer by two :-D

[silvertriple 4121]

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 4121]

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)

[silvertriple 4121]

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 4121]

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 4121]

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

[KEV THE REV 2437]

Looking good so far

[silvertriple 4121]

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...

[Ray_ve 1204]

Very nice job on those wheels! Congratulations on those, they look great!

The wife is at work this afternoon, so that's a good time for me to get the cardboard box labeled Samurai, and see where I left off last time...

[KEV THE REV 2437]

4 hours ago, silvertriple said:

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...

Nice work.  They look great

[GeeWings 2860]

They look excellent @silvertriple, great work.

 

[silvertriple 4121]

Was thinking tires again...
There is some STLs for the tires in Thingiverse. And yesterday I come across an interesting post on one Facebook group about tires printed with Varioshore foaming TPU. It's a TPU with foaming agent inside, and it results in different density depending on the temperature you print it. And it have some advantages compared to standard TPU: in particular, it could be printed with a bowden extruder. Another one is that you could potentially target the right shore for tires including (and that what's interesting) infill which would remove a lot of the support issues... I may want to try that for Samurai tires. I'll probably have to order some Colorfabb Black Varioshore Foaming TPU at some point within the next months...

[silvertriple 4121]

 I launched a final printing for my Samurai wheels. I've opted for on set of oval blocks at the moment (I could always change my mind if I find something better later). I did a few change in my cura settings :
- Infill 30%, Grid (which I think should be ok, as some are using Lunchbox with printed wheels and an infill at 20%)
- Monotonic Top and bottom
- Ironing, concentric
- Support in tree mode, everywhere
- Layers of 0.12 at the exception of the first one. The wheels are grown up from their rear face.

For a set of 2 rear and 2 front in 50mm diameters, it is going for about 23-24 hours print. The current progress is about 61%. And the result in terms of quality appeared to be promising as per what I  can see already on the spokes of the front wheels (and yes, there could be always ways to have better quality, but this will be probably good enough).

[silvertriple 4121]

 

Here are the new printed rims. The quality is really better than previous set.

I may want to adjust the retractation as there traces of under extrusion in the areas post a move, but beside this it is quite good.

I will try with tires on a Samurai  next

[KEV THE REV 2437]

Very nice 

[silvertriple 4121]

Four wheels, oval blocks

Two minor details to review in my stl and they are good to go...

[silvertriple 4121]

This got me thinking the whole night. It's good, but it doesn't respect one thing of the Samurai design. Something disturbs me when I look at those pics.
The rim diameter size difference of the original wheels is about 4mm. Front tires are lower profile than rear ones. That gives a very specific look to the buggy (it would be the same with a Kyosho Progress, I believe).
4mm is nothing and a lot, ultimately.
Yes I could choose original diameter and squeeze smaller tires on both Front and Rear (aka Dadio's method... But I won't be able to do that with the oval blocks which are the closer in spirit from the Marui Hyper Traction tires I can find... I can't do that but what about adding a millimeter to the external ring of the front rim so it looks bigger?

Let's see... I still have the front wheel originally printed. it has a bigger external diameter, but I found it too big, so I reduced it for the second set... I took them in pictures, and here is:

I think I got my perfect solution, now :-D

[silvertriple 4121]

Added one parameter, reviewed the slot internal diameter and it should be perfect now...

 

Edit : tweaked it so it become less obvious that the external ring is bigger...

I think I'll need to reprint those

[Kol__ 3909]

Awesome work mate, what sort of cost and time is involved in making a set of wheels like this?

[silvertriple 4121]

5 minutes ago, Kol__ said:

Awesome work mate, what sort of cost and time is involved in making a set of wheels like this?

Well, I almost started from scratch with Fusion360 when doing this, so it increased a lot the time I spent on this... It's few evenings I spent on this during those last two weeks (I stopped counted time, and did restart my work at some point as I completely messed up in Fusion 360 and it was much better to work this out from scratch). But I would say the design of each wheel was about 3 hours each when I decided to redo it from scratch... Then the tweaking is requiring prints, and prints are material and printing time...

For yesterday's print, the four wheels is about 120 g of PLA+ including supports, and the cost of 1kg of filament is about 25€... So, in terms of material, it is less than 5 euros, and in terms of printing time it is about 24 hours...