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Another Nichimo project... or may be two, actually :-)

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Hi everyone,

After the Spirit FF which have a lot in common with the Vantage FF (I got the data for it, so it should be possible to do it at some point), and both Midships and Pegasus Exceed, if I want to complete the chassis collection, I have 2 which I need to tackle...

Fortunately, one guy proposed me two cars recently, and they were the two missing cars missing in the Nichimo buggy range :

A Cosmo Shooter - 2WD  - kit n°6, with its box, and complete (the driver is in one of the boxes)

A Luminous - 4WD - kit n°5 without the box and the bodyshell, and a broken steering servo...

I check the instruction manuals, the construction is modular, and even lot of pages in the manual are the same... My target is to model both chassis, and add them to my virtual Nichimo collection :)

Workplan :
- tear down
- CAD model of common things
- CAD model of 2WD specific parts
- CAD model of 4WD specific parts

I can already tell there is lot also in common with the 4 other kits, even without having tore them down...

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these cars come from a great era in RC, where there were lots of different ideas being tried. But the motor being up that high is an odd choice though

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There is lot of odd choices on the Nichimo : some are interesting ideas, but some are how to say... Engineering wise, they had ideas (a lot), but they probably over did it... Have a look at my two other threads on Nichimo cars if you want to dig deeper :-) 

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I can confirm the Luminous is indeniably a Nichimo : there is a **** lot of screws to get it down to parts...

I will need to do the same for the Cosmo Shooter, but I will proceed to the cleaning of the parts of the Luminous first. It's much more confortable to model clean parts :-)

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While the gearbox print test is in progress for the Super Wheelie/Big Bear, I did some cleaning on the Luminous parts...

Ultrasonic cleaner, water and dish soap, 50°C, 30 minutes bath with 10 minutes ultrasonic waves activated...

Parts look almost like new... I've not cleaned anything on the transmission parts (for most, I don't need to model them as I have the front and rear diff from the Spirit FF and the LSD (limited Slip Differential) from the 443WDS)...
That should allow me to work on the Luminous CAD model very soon...

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When I went back from the office, the Luminous were sitting next to my computer with the caliper...

I started by the rear gearbox...
Measured the overall length, positioned the center hole, then the diff hole, and derived the rest from there... The distance between the two key holes is the same than on the Spirit FF and Exceed front gearbox, unsurprisingly...

Once the right side was done, I did a mirror and worked out the left side

Once there, I had a few checks, and I noticed that the shell thickness is variable : it should 12.25 mm deep in the center (1.75m thickness) while the rest is 2mm thick. I check on the front gearbox, and it is 12mm deep in the center (like on the Spirit and Exceed, so it should not be an issue, really - just have to make it proper in shimming). I still need to make everything that close the gearbox and complete it, in both 4WD and 2WD as while thoe part are common, some are distinct between the two models in the gearbox...

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I spent the night sleeping with an issue in mind, I didn't now where it was when going to bed...

Today, I checked. The diff had not enough clearance based on what I see with the diff in the gearbox : the diameter had to be bigger inside, and the thickness is not in cause. This means the diameter is wrong. And the diameter is made from the center position and the extreme point which is 100% sure. My center position is wrong then : and the mistake is because a sign in the calcul of the position of this hole. The spacer is shorter in the gearbox than for the Exceed, that should have ring the bell...

Anyway corrected the sketch and had a look again... And it became clear that my tangent arc is not right, as we have likely a double curve as the diameter is bigger, which means as well the tangeant on the circle is taken lower...

it's the same, but different :-). I'll have to get a print to see if I can reproduce the exact spline on the top, but it's not too much important...

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Did not post much those days... Lack of motivation it seems, plus a bit too much of work in the office...

Anyway, yesterday, I worked on the front gearbox left side...
I started by putting all the key measurements in a single sketch, did a few extrusions, chamfer, and lofts, and I had my part ready to shell...

On the other side, I had this...

I first worked the inside...

Then move to the other side... The suspension supports remain to do...

And that was quite fast to do...

The right side was started with a mirror from the left, were I did rework whatever was required using extrusions... 

And here is:

I'm not sure what I tackle next yet...

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Nichimo Luminous and Cosmo Shooter arms are prone to deformation including for display usage, and this even if the wheels are not touching the ground... All of them are deformed. I did model them without the deformation, and that is where we are all superior to any scanner which would have included the deformation without even considering that as an issue...

I started by the front

Then made a copy paste as new to change the few measures required to be changed plus review the following operations to make a rear arm. That took me about 5 minutes...

C-hub and carriers were easy to do with a limited number of sketch for each...

On the suspension it remains the upper arms and steering arms to model, as well the pivot balls and joints...

Speaking about suspension, I made the shock tower which comes on the front gearbox... It's a bit complex, and required a bit more than 10 sketches to get there (I might have done less, maybe, but I've been lazy :-) )

The fact is this part allowed me to check and review the position of the shock tower fixation on the gearbox, which was the only doubt I had...

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The chassis itself is a nightmare to measure, in all the directions, with a similar type of complexity as the Marui Samurai chassis... I had some checks, and what I thought initially to be a common plan was not...

In terms of approach, I decided to do one single sktech to fully define the profile, then did some extrusions from there and, applied the chamfers, cut from other plans and so on... Few pics with the different steps :

Once there, I got the holes applied...

And the next step was to deal with all the features on both sides...

Once the left side was done, next step was to make a mirror and to do the difference appliable to the right side (which will be retaining nuts for the transversal long M3 screws).

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With the two chassis halves in hand, it is time to make some joints and check everything is lining up...

A few minimal corrections here and there, and here is what I have

I have a small 1 mm doubt...
But having done checks on the gearbox, it seems that it is likely this way in the car... I checked the joint freedom degrees, and it is largely inside what is possible, so there is fair chance this is correct... (but I can't help thinking that it could have been much better to have this lined up)

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After my last post, I worked out the Bumper...

And it was very quickly added to the chassis...

Then I had a look in the box where I store the parts
On the left side, plastic parts already modelled. on the right side, whatever remains to do. If we consider that I have about 6 parts to check for the transmission completion, and for the shocks it is likely the same as on the exceed/midships, we are not far from the end of this chassis modelisation... and the Cosmo Shooter is sharing a lot of those components... This should go relatively quick, especially considering than the wheels are the same as the Midships plus a additional part for the Midships, and the front wheels wiould require some very simple modeling... Time to completion os not that far.

I continued progressing with the remaining part after that picture...
The motor plate is probably the easiest part to measure on this car... And the sketch 100% matches on the real thing (although the picture is difficult to take with only one hand).

The battery holders are in place as well

And last part I did was the receiver plate

Most of the difficult parts are done, now, it should go quick for the remaining elements...

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The advantage with the modular conception of the Nichimos and the fact I model already 3 of them, is that I have already a lot of parts already available...

The rims and tires are the same as the Midships... But there is an additional disk for the Luminous (not a good idea IMHO, I may have a look at what it gives with gold wheels without the disk)... I added the menstion Super Pin Spike on it, which I did not for the Midships...

I did the upper links to complete the suspensions...

All links works perfectly, except on the rear where I could only make them working with a cylindrical movement (probably for less than .1mm)... 

Once this was In, I added the axles (same as the Midships) and the wheels...

today, after my day of work, I tackled the last cumbersome part of this chassis (whatever left is super easy :-) ) : the rear cage, which is again a measure nightmare... You have to have all the parts around to set the sitting points right. I first started by the part which is common to the 2WD chassis (I took a copy as new of it, to avoid doing it again)...

Then I completed the parts, and added the brace, body mount and wing mount...

Lastly, I added the switch and resistance holder...

At this stage, the plastic parts of the chassis are done. I need to include :
- the transmission, for which most of the parts (about 95%) are common to the Midships/Exceed
- the shocks (the rear are common to the Midships, and the front are easy to deal with, as there is only 3 parts to modifiy (spring, piston, and body)

And for the bodyshell and wing, I just have the wing, and no bodyshell... I may try to create one just like for the 44B Racing Baja, but that will be very much later. The program for tomorrow is the transmission and shocks, and if everything goes well, on friday I will tear down the Cosmo Shooter to be able to model the 2WD parts...

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This morning, before my working day, I just took teh time to create a shock file, include the rear shocks of the Midships, and do a copy as new to derivate the front one with the very few dims requiring modification... And added to the chassis...

That was quite quick, after that I closed Fusion 360, and reopened it after my day of work to deal with the transmission... I had to modify the center shaft and that's all for the front gearbox.

For the rear gearbox, I had the center diff and rear diff, but both shafts from the Midships required modification. It was also the case of the center shaft.

Once the diff to diff part was done, I focused on the rest... pinion and spur gear... And I discovered an expected issue.

The potential .5mm mistake was marked in my notebook, and was quickly corrected.

Once that was done, I added the servo saver and steering rods...

And I also added the dogbones and review the camber sligthly... And it is done.

Tomorrow I will have to tear down the Cosmo Shooter to get the last parts to model for this set of chassis...

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As soon as my work day was other, it was week-end :-)
And operations started with the objective to move the Comso Shooter in Fusion360... My target is to have this car chassis done before the end of the week :-)

The Luminous is in much better state than this Cosmo Shooter...

The front cell is actually a steering servo box.  And the front shock tower is also different from the Luminous... There is part you don't see here which is also different : the part that is used to support the 2 servos on the Luminous is replaced in the case of the Cosmo Shooter by a single servo support... I did not unmount it, it was a nightmare to do : I did not want to remove all the screws tonight (I will have to do this for sur tomorrow as I will need to get the transmission down.

I decided to start by what I thought could be complex...

But it turned to be very simple : lot of the elements are shared with the 4WD front gearbox so it is really easy to derivate it from there...

And the right side shortly followed...

The front shock tower is using some of the sketches of the 4WD, and it was again super esay to do (having the basis means that once you've done the checks, you don't do measures anymore)...

I then started a chassis assembly with the common parts... i had already the rear cage variant, as the 4WD is the 2WD rear cage plus the wing support.

The servo support was measured in place (it's actually difficult to do this way, but many measure can be derived from the 4WD version :-)

And I also did the front axles and the wheels...

What's left to have the Cosmo Shooter completed :
- transmission : there a spur gear inside the gearbox I need to model. The rest is something I already have somewhere. For this spur gear, and the axle it is on, I have no choice I need to get the car in parts...
- the assembly itself

I don't know if I'll be able to work on it tomorrow. If so, it may take a bit of time to get the car in parts first. But if I have the time, I may be able to do it very quickly :-)

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Today, I had one thing in mind when waking up : finish the CAD model of the Cosmo Shooter...

Started by removing some screws to get down to the transmission... I had to untight some of the screws in the middle chassi to give some space to remove the gearbox...

And then few others screws later, I had the parts I need to finish the model...

That is simple enough : the gear has logically the same number of teeth than the spur gear of the LSD (limited Slip Differential)... I knew that, but I needed it in hands to be able to model it properly, and anyway, I could have guessed the length of the axis, but it is better to model it to check the model (again :-) ). It did not take long, however...

Then I focused back on the assembly, starting by the gearbox...

And after some work involving joints (many joints), we have a Comso Shooter chassis...

And then I put the two chassis together...

I'll have to do some test prints before I can get those two cars having other adventures...

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I generally love the box art technical diagrams and pics... Having a CAD model of a full car allows to play a bit with what you can show...

2WD transmission focus

4WD transmission focus

Limited Slip Differential focus. Those who have read my 443WDS thread may have already seen this... But I tried to make it different, so it is easier to see the round-squared bevel gears...

And finally a picture with all my virtual Nichimos...

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Last night, I took a time lapse...

And this morning, I had a few parts to test...

Let's start by the chassis...
Seems it's a match :-). Holes are in correspondance. Dims are right, and it's a profile match...

Then gearboxes... I want to make sure that key holes are in correspondance with the chassis, and that the inside of the gearbox is matching the original one. There might be things not matching on the profile, but that won't be an issue as not impacting with what is around.

Rear gearbox first...
Key holes are rightly positioned. The front top is not lined up but it doesn't impact anything. The full gearbox is currently dropin, but it can not work with the original other side. I may try to get the profil right, but It maybe a lot of rework, as there is no easy way to get the profile being done... The cap is right, and that was important to make sure about the transmission.

Front gearbox then...
Same situation are the rear gearbox. Every key holes are rightly positioned to ensure the chassis geometry. And the full gearbox is drop in with chassis...

I'm asking myself if I should try to match up exactly the original parts. It works as drop in assembly, but not as drop in part...
The 2WD front cell being based on the same measurement, it should be the same. Not even sure it is worth to test.

I'll have to think about this before making a decision...

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