Marui Samurai - Another SilverTriple's journey...

[Kol__ 3909]

On 4/11/2022 at 10:20 PM, silvertriple said:

It looks a bit complex, there is a lot of measurements, but that's it...

That is epic, hats off to you sir

[silvertriple 4121]

Today I started to execute the plan, and attached the frames with my measurement braces...

First, beside the gearbox attachement, the chassis is symmetrical

Then I  used triangulation to define the attachment points, and less than the time needed to print 4 hex hubs for the Nichimo, I had my points defined fully.

I had a doubt on my gearbox measurements. This confirms it was wrong. I had 1mm deviation on the measure of those. This was the difficult part to measure as it was the holes with hex. I'll correct my gearbox file accordingly.

Now for  the small story. Measurements is one thing. But when you have more than one car, you may think it would ease to precise things. Well, it may help to decide, but once you measure on multiple cars, it includes production deviation in the story. The roll cage I built in Fusion 360 was measured on a NIP part. And the wing is fitting on the two Samurai that are not yet in parts. But, when I did measurements on the car for the top of the roll cage and for the front of the roll cage, I had the first measure with 1.5 mm range of deviation, and the second with 2.5 mm range of deviation... On the motor plate, I should have measured it slightly differently, that's all.

[silvertriple 4121]

My son finally finished his Super Hotshot... (yes, the driver has closed eyes, as my son decided that since he's driving the car the driver figure will be afraid and keep eyes closed :lol:)

That means that my tools are available again :-). In other words, it's time to start the Samurai :-D!

I started to put the elements on the table...

Oh, no, not those ones. I put on the table the parts I'll use for this build. I got the chance to find some clusters of new parts and some NIPs, and the chassis and gearboxes are from @optimaforever (aka OptimaHouse), and the wheels and wing are my own design printed SLS nylon. The bodyshell is the one that was delivered with the first Samurai, and I got a free wing from TBG which completes the bodyshell. Tires will be Hotshot tires (I like them, they usually last longer than others). I may still have to print some stuff but we'll see along the build.

The build starts by the rear gearbox, and the rear diff.

I used sand paper to smooth the nylon a bit on the surface that goes in contact to the motor plate, and for the left side, it is a bit difficult due to the element protuding to go inside the motor plate...

The diff is smooth in there, which means the adjustment is perfect.

Then next step and the problems start: it's about the center diff. When I received the wrecked car, it had the central diff moving up and down sometimes not meshed...

Now I know why. One of the center differential collar is missing. It was not there, simply.

I could have something like this on the Hunter/Galaxy parts bin, but that would mean make it detrimental to another build. That being said, there was missing spacers for the Hunter/Galaxy (they use quite a lot of spacers ID3/OD4) and when I search a solution, I found one feasible solution. It's good time to do experimentation :). I have a pipe of 250mm, ID3/OD4, and recutting it should do it.

The time to search the proper tool, to cut it, to finish it and to shave (it's actually 4.1mm instead of 4), and voilà, I have my collar.

Looks like it is time to close the gearbox... I may have opted for nylon locknuts, but I took the screws (hex) as per the part lists, and I should have took additional 2 mm provision to add locknuts.

The gearbox meshes perfectly, and @optimaforever did great job when designing it.

I took the motor that was delivered with the Wild One for this build. the wires should be long enough to put the ESC at the place designed for the MSC servo. I mounted a 18T pinion. I will need to calculate what is the ratio, as I may change this for a brushless later on.

I finally closed the pinion side with the nice pinion cover...

[KEV THE REV 2437]

Great work all round 

[silvertriple 4121]

Next is about the front gearbox...

First, the differential. The red parts are again from OptimaHouse. The ball bearings fits perfectly. I had some difficulties to get the e-ring snapped in, but that's because of Marui's design. I used the sheet I used for the pinion mesh to get the e-ring lit up to ease the snap on with the tweezers.

Then I closed the differential. This part is a structural weak point. It was not really thought for maintenance. There is already some cracks on it. But it still together (had one brand new, just in case). I thought about replacing the screws, but kept the original one as the casing is so thin I'm not sure it would survive.

Next I had the servo. I was thinking about a low profile quick servo. But for some reasons, I had to take what I have at hand. I'm likely to replace it when I find a proper servo (the kind of I was expecting to get at some point, was delivered to another address, reimbursed by aliexpress, and got delivered with the wrong reference, but as reimbursed, I could not send them back - but they are of no use, as they are 360° servos instead of 180° and they do not work the same way  )

The servo joins the rear front bulkhead part. The chain is positioned before the servo, and it is quite cumbersome, actually

Then adding middle bulkhead and front diff is just a formality. You just need to pay attention to the chain orientation, and that's it...

Next are the bottom arms, that includes torsion bars, acting as spring for the front suspension.

Remains to add the top arms and to close the front bulkhead with the front part...

I continued with the front knuckles...

And then I checked the balls enclosing to notice that I absolutely need new ones, which means it is the end for today, as I need to do some print for next part and I will use some red PLA, just because red goes nicely with the black :-) ...

[optimaforever 87]

[silvertriple 4121]

Today, I started my day by fetching the printed parts on the printer bed. (I found the suspension cups on Thingiverse, and I knew they worked as Dadio from rc10talk mentioned it).

And soon, I had the front train completed...

Next step is about preparing the left chassis frame with the chain guide, the spacer between the rear arms and the front MSC servo support also acting as spacer. I opted to used the red parts from OptimaHouse as it will be nice touches of red in the black chassis :-).

And we join this with the front train, and we add another (red) spacer...

And next comes the right part of the chassis... And it's better to check you have not forgotten anything before you put the screws in.

At next step, a small issue arise. It's time to put the tensioner for the torsion bars. I used again the part from OptimaHouse, but I had a small issue. As per the manual, You are supposed to use 3x8 tapping screw with a washer. The parts of OptimaHouse are made for M3 screws. I used a M3x8 screw, and the hole is too short, or the chassis not thick enough at this particular place. I solved it with a flanged M3x6 screw, and reported it to @optimaforever so he can take note of this. Among his parts, that's the only minor issue I faced (and it is really easy to solve anyway).

Next is to add the floor for the RX... Quite strait forward.

The gearbox is joining the chassis. Everything is lining up perfectly

Time for the sprocket, and the chain tensioning...

While the front did not require spacers for the axes, it looked like they will be required for the rear. I stopped my build there, designed the parts, and launched the printer. It was time to lunch, so next part will be in a next post... :-)

 

[silvertriple 4121]

Lunch was good, and parts were printed. It did not took much time to print, probably more time to heat the printer than to print, actually. I printed 8 spacers, just in case I need to put them on the front as well (as per the instruction manual, we are supposed to put on on each side of the arms). It seems than one is enough. I put the remaining in my Samurai box, they will be useful for next Samurai.

Arms are joining the chassis next.

And the nerf bars finish the fixation of the arms at the bottom, while the bumper is added at the front.

The shocks were not clean yet, and they were full of old Marui oil (black one, not really nice to clean)... I spent quite a lot of time to get them clean inside, and to make them looking good outside. About too much time later, I had nice clean and smooth shocks.

The instructions mentions a black rubber tube: the most approaching stuff I had was the black tube around the new 540 silver can from the Tamiya Wild One. I cut it, and it may work, although the inside diameter maybe slightly too small... I may need to think about a better solution

But first is the front shocks... Issue again, with missing parts. The collars marked D on the plan are not present. Instead there was some silicone tube. I have two other Samurai to do some measurement, let's go printing parts :-). Measured, modeled, sliced, Print. About 30 minutes total. I printed four, as I checked the holes in the cylinder of the shocks are the same at the front and the rear, so it should work as well for the rear.

And I have a front shock

For the rear, I forgot to take care of the specific screws required by OptimaHouse chassis, and they will be delivered at some point. Not sure when. We'll see. In the meantime, I used some temporary ones to avoid loosing dog bones every time I touch the chassis :). And by the way, the printed collars made for the front shock work as well for the rear.

I stopped there. I needed to think about a way to fix my ESC. One of the two other Samurai had an ESC glued on the battery pack, and it is not really practical. I think I have a better solution :-), but you will see this probably tomorrow :-)

[silvertriple 4121]

After a morning spent on a track indoor session, i got back to work after the lunch. But I had prepared my plan yesterday, as it required some printed parts...

I was teasing a way to fix my ESC: there is a natural room for it in the place of the Speed controller servo. I started to design a very simple part for this.

Once printed, I did check it: it requires to cut the plastic of the setting jumpers of Hobbywing Quicrun 1060, but beside this it worked. But it look like unachieved. There was something missing... I had a servo model somewhere, let's use this to do something : what if I put a fake servo head on top of my ESC support : that would look like a servo :-D

and then, I decided to go for a wireless MSC in addition to the ESC and it's fake servo supporting it. Which means I need to do something to support the MSC :-). Fusion360, measure, model, print, try.

A modification later, I had my support and I even added a servo horn on my fake servo (it even rotate at will :lol:).

Next was to put the wireless MSC in

And it's driving servo

Once here, I added the RX as planned. There is not much choice actually as the chain is taking some place...

I used my dremel to clean the resistors radiator. It's not perfect, but it is much better than what it was before. it's fixed in sandwich between the rear plates with the central wing support. 

And this joins the rear of the gearbox next

Next step is about the roll cage. 6 screws are added at that step, in 3 different lengths.

I added the wing to check it was fitting properly (well, I check on the two others, there would be no reasons for it not working but I still had to check.

Before I get to the roof, I need to paint the driver figure. And unfortunately, I do not have enough barbecue picks available to add it to current batch in progress... Which means I won't finish the car this week.

In the meantime, I did try to assess the weight.
Currently, it is still under the kilogram. I'm not sure how Marui measured the 1060g, because wheels alone, I believe we are way above that value. Maybe without wheels, but then the value should be lower than 1060g...

Any way, I had a doubt with the matt black chassis, to the point I even considered painting it, but at the end, with all those red touches, it's really nice...Looking forward to next week-end when I'll be able (hopefully) to finish this car...

[silvertriple 4121]

I did not post late on Sunday evenning as I have my stuff to prepare for a work travel, but before going to bed, I worked a bit to prepare a driver figure before painting it.

I got a few Marui multipurpose driver figure reproduction  from OptimaHouse.

There is one thing bothering me on the helmet.  The face is separate and will allow for a nice paint of the face, and should even allow to put some black around the face. But the Helmet doesn't have the front opening. To make it more realist, I decided to make holes to have proper aeration for my driver, and they would look more natural for what I want.

On Monday I went for a 3 days business travel (my first since the start of the Covid era). As a result, I'm in an hotel room, and the only thing related to RC I brought with me are my caliper, the printed measuring tool and the Samurai chassis frames and my personal laptop with Fusion 360

I spend some time to look at the chassis again... When you look something long enough, you would see different things, to the point it become obvious... I saw clearly some tangent lines...

And another one, then another one, and another one... When you get more than one clearly visible, it sounds like it is no coincidence. I believe Kurihara San liked tangence, and used them to define some elements of the Samurai chassis...

I took the assumptions, added a few perpendicularity and parallels, and I draw some elements in a sketch based on the projection of the holes defined previously...

Next steps will be to extrapolate the chassis from there and the different offsets, and angles....

[optimaforever 87]

Impressive report / modeling job!!!

[silvertriple 4121]

I was back home on Wednesday evening.
I tool the time to take care of the driver figure paint job, at least for the helmet...

On Thursday, I did a few five minutes job in between meetings to deal with the driver body(s) (I used a paint marker rather than a brush, it's just very much quicker - and yes, there is also some Hunter/Galaxy driver that were worked on simultaneously).

In the evenning, I put my driver together

Then it was required to put it in place. I noticed that my "wireless" MSC support might be slightly higher than the original one, as the driver figure is not entering as easily as on one of the original Samurai. 

To ease the entrance, I decided to cut the non Samurai part, and it was a mistake, as my driver lost his left arm in this accident :-(. I took another body, and found a possible angle, so I painted it quickly (with abuse of the hair dryer).

Later on I had my driver figure fixed to the roof (not fixed yet to the roll cage). I trimed one of the body shell. I need to trim the wing as well, but the wing won't be used to run, as I intend to use the nylon printed wing for this...
I took few pictures, and for that I added my wheels :-)

Obviously, there is still some work. I need to get thru the paintjob for the bodyshell and decide what I do for my wheels and wing.  I also need to fix the roof, and I also noticed that I need to rework my shocks as I suspect 2 of them having the small o-ring travelling with the piston (I may not have used the proper o-rings). I already set the steering on my remote, and the car ran slowly in my house, during which I noticed that the front tires touch bumper when they are fully turned. I may have to think about a smaller bumper for this single reason...

Last element: I put the validated Samurai parts on Thingiverse today (at very single exception of the fake servo, as I can't share the servo head, as it is the work of someone who did not published his stl). You can find all my parts here : https://www.thingiverse.com/silvertriple/designs

[silvertriple 4121]

On 4/28/2022 at 8:22 AM, optimaforever said:

Impressive report / modeling job!!!

coming from you, this sounds like a great compliment (specially the second part :-) )

[silvertriple 4121]

Still had a lot to do. I intend to change the motor of this Samurai at some point for something more fancy, but in the meantime, I decided to hide the 540 silver can...

And for that, I designed a motor cover which goes nicely with the gearbox, as it uses some of the Marui design principles...

Tadaaaaa!

It works, but if you want to run the car with it, you should move the shocks pivot ball on the 550 motor size position, as the cover extend the motor can (and I put it in my Thingiverse designs as well as few other things)...

[KEV THE REV 2437]

Nice work  . 

[silvertriple 4121]

Beside the Hunter and Galaxy, I also worked a bit on the Samurai...
First, I suspected 2 of the shocks having an issue with the o-ring. It looks like the o-rings I used are too large. I decided to open them to inspect them.
Front shock was fine, but that was not the case for the rears. the o-ring was actually moving. I tried with o-rings with the lower tore diameter, and it makes it even worse. At the end of the day, I had spring and no longer shocks. Maybe the material of the o-ring is not proper. I raided the spare parts of my son's Super(Hot)Shot as it was the easiest to access to get 3 red Tamiya o-rings of the proper diameter. I will try to change them tomorrow evening.

In the meantime, I reorganized the cables in order to reduce the mess on the right side next to the pilot. Once done, I fixed the roof.

My driver is now in good place :-)

Remains to do on this Samurai :
- resolve the shocks issue
- bodyshell paint job (I'm thinking to pearl white with red accent, and there will be probably two body shells and with different designs). For the wheels and Wing, I'm contemplating the idea of spraying primer and then pearl white (TS) on top of it, eventually with red accents on the wing... Time will tell, it's still under thinking.

Any case, the car won't run until I have an underguard to put on this chassis. But something is telling me it is going to arrive soon...

[silvertriple 4121]

I did not made updates on this thread lately...

First, shocks issue was solved with Tamiya red o-rings. They works much better, and the don't leak anymore.

I received the under guard from Optima House recently. I had the time to mount them during an evening, butt did not bother to take pictures at that time as it was a bit late... It's nice, well done and mounting perfectly (I check on one of the original Samurais and it works as well. I did not checked on Dadio designs chassis, as the Samurai parts for other builds are in a box under a lot of other boxes, but will do as soon as possible.

I had to finish this car. I trimmed the bodyshell and the free wing weeks ago (I ordered 3 Samurai body and wing and received 4 wings, one was free, and it goes with the body I had already). I had something simple in mind, and I wanted to honor all the parts mounted on the car, so I asked my friend [mention]optimaforever[/mention] an OptimaHouse logo to be able to make some masks and put the logo on the shell (maybe this will be a first for him to see his logo on a real car :-) ).

This afternoon, it decided to procrastinate a bit on the Nichimos CAD models and to finish the Samurai. I won't detail the process, but will just put pictures of it...

And finally...

I'll let them cure for some time before making pics of the finished car...

[optimaforever 87]

Impressive masking job, can't wait to see the whole package  

[silvertriple 4121]

I took some pictures yesterday evenning before going to sleep :). I could not wait more to see the final result... I wanted it to be simple and effective, and I'm very happy with the result.

The wing will be used only on the shelf, there is a Nylon PA12 SLS printed wing for the runs. I need to find a can of TS-45 for this.

[silvertriple 4121]

Changed the faulty servo broken at Belley... 2 hours work
Did not unmount everything : 
- removed the sprocket first
- removed the underside guard and bumper
- removed the roll cage in one part
- removed the front spring tensionner, and middle part
- unscrew the front cell
- changed the servo
- remount everything

My Samurai is back on track. This car has never been thought for maintenance, for sure
 

[Ray_ve 1204]

Love the underguard design, it is very much in pace with the Big Bear/golden eagle with those fins at the bottom!  

I really need to do more work on my samurai, have not found the time lately....

With all these moddeled parts, you can almost run that car forever! 

[silvertriple 4121]

4 hours ago, Ray_ve said:

Love the underguard design, it is very much in pace with the Big Bear/golden eagle with those fins at the bottom!  

I really need to do more work on my samurai, have not found the time lately....

With all these moddeled parts, you can almost run that car forever! 

Definitely, between what Optima House propose (there is more than what it is on his i.materialise.com shop, you just have to contact him thru his Facebook page to get more informations about that), and what Dadio designs propose, you could definitely make a nice runner, as long as you have the metal parts going with the car...

[silvertriple 4121]

Last time I ran cars at my club I did broke only a servo... Someone said I did not try hard enough !

I did a quite violent run with the Samurai this morning...

The nylon wing did not survive the run. The rest of the car is safe, and the chassis is intact. Although I did encounter an additional issue with the pivot ball leaving the rear right arm a few laps after the previous fly, and having the car stopped with a dogbones lost on the ground... The OptimaHouse parts are validated, they all survive this run.

Beside this I also had a non functionning servo on the Spider TF3, for an unknown reason as it was working perfectly fine last time... For this time, my son did not broke anything. Not too bad, actually. We left at 12:00, while the temperature was already above 30.

[silvertriple 4121]

Since those were missing in the CAD collection, I modeled the Samurai tires...


They are quite similar to the Ninja tires in the spirit, somehow, but require a heavier timeline in CAD software... Ultimately, it did not took much time to complete those.

[silvertriple 4121]

I got recently some Samurai left over parts. Among those there was two motor plates...
I needed to rework my motor plate, as it is the basis for the gearbox. After doing measurements, I decided I would proceed differently and redo it from scratch.

I took a picture, applied a Canvas, calibrated it and did it from there... I don't like this way of doing, but it gets the things right.

Then I took the time to look at my two plates. There was two versions of the gearbox and as well two version of the motor plate. Except one hole (circular on one side, and slot on the other side), everything else match.

I  did stop working on the chassis when I noticed some measurements of the gearbox were wrong. And until I got those two motor plates, I was not able to measure anything as the Samurai n°2 and N°3 are not in parts yet... And the Number 4 was missing most metal parts. At this stage I succeed to get axles, outdiffs, motor plate, roof, and some other small parts. I still need to find a shaft set, big bevel gears and a central diff so I would have everything to work out a N4.

In the meantime, the motor plate being right should allow me to restart back on the Samurai model, starting from the gearbox (which I need to redo - not sure a replace component would work for this). But before this, I'll print a motor plate for a safe check.