Bormac's Nichimo Midships 443 WDS - An unexpected project

[silvertriple]

I scratched my head looking at the bottom rear arms...

Looking at them, they are not flat. And I checked it is the same on the other side.


Analysing a bit more, it looks it could be deformation due to the car sitting on wheels for long time. Very likely. In my chat one Exceed fleet owner was just bugging me to ask a question. I took the chance and asked him to check on his cars... And in the meantime, I decided to proceed to the design starting by the carrier face this time...


Within a few minutes, response came with pics : NIP arms are plan, so that is becoming easier. Anyway, without the confirmation, I would have modeled them flat, as looking at the other arms, having them different from flat would sound illogical...

Once this was done, I proceeded the same way as the other arm.


And this is another part being done...


Looking at what I'm doing next

[silvertriple]

I started next the motor plate. I decided to proceed this way as I thought it would be easier to do this way, and to have the reference points when dealing with the gearbox (not like I did with the Spirit FF).

One single sketch, all measurements in....


And that's it


I printed .4 mm thickness to check the measurements. I had one misread dimension and I corrected. This part is now done. What next?

[silvertriple]

Further analysis of the Front gearbox shows few additional differences than the obvious ones, but nothing that can't be changed with some sketch and extrusions...
That being said, one of the difference will require more work.

Two approaches are possible :

• option 1: rebuild it the hard way using the same sketch as the one I created for the Spirit FF gearbox

• Option 2: take the Spirit FF gearbox, cut it and add what is required

For the rear gearbox, although there is common design cues and some common definition data, I believe only the first option is valid. In the Spirit FF the angle is used to define some elements, and I checked, it doesn't work with the angle being equal to zero (that would have been so much easy otherwise ).

In terms of advantages both options have their pros and cons: for option 1, It would be nicer and a chance to have proper sketches. The option 2 is probably much faster...

I won't do it directly, I'll sleep on this, and tomorrow, it's initiation and demo track session at one of the clubs. I said I'll be there to help, so I'll probably work on this tomorrow afternoon or evening...

[silvertriple]

After a good day on carpet indoor track sessions, alternatively with the M06 and with the Lunchbox (trust me or not, but the Lunchbox is far from ridiculous on a track when you know the trick), I went back to my desk around 16:30...

Once Fusion 360, I first took a cutout of the Spirit FF gearbox design while making sure I would keep the right references when breaking it...


Then I created a Midships core gearbox (basically the key and common elements)... I could not directly do the left gearbox, because this is common to the right side...


Then I did a mirror and make the necessary correction to have my right gearbox...


Advantage of doing it this way is that I know it meshes, because it meshes on the Spirit FF.

Next will be to get back on the core, correct what needs correction (basically what I needed for the right side) for the left side, and then deal with the Motor extension...

[silvertriple]

As planned, got back on the core gearbox, and added the Motor extension. I basically draw the extension on the rear face of the gearbox, and extruded it from there, with some offset.


I just used the motor plate to position the motor fixation holes...


And I finished by an easy work to reproduce the front plate added to fix the motor without breaking the gearbox.


For the content of the front gearbox, there is few elements remaining to be modeled : the center differential (which is also the slipper clutch), and the setting system (which is the reason the hole on the motor plate is not a circle on the differential side...

But I'll probably tackle the rear gearbox first... I closed Fusion360 for today...

[silvertriple]

Started to work on the rear gearbox...


First as usual, my work is starting by observation


But this time while doing the observation, I had some sketch to compare with my caliper and assess/confirm commonalities and differences


As said yesterday, I can't really use the original sketch as the angle is not workable (even if I play with a non zero value close to 0)...
So this is going to be the hard way.

I started to put the key definitions on one single sketch that I intend to use for both right and left side with some amendments. After 2 hours of work, I have my main definitions...


More time will be required, I won't finish this tonight, but at least, I'm in the good path again

[silvertriple]

I had my sketch ready. The plan was to do common things, do a mirror, and then do things as per each side...

I started to do common things...


Then pursue to add more common things...


The mirror did not worked the way I wanted as I did not succeed to include the sketchs. I decided to pursue the left side to the end


I then apply the mirror and did the required modifications for the right side, and I have now a complete rear gearbox


I'm looking at what I'll do next : Chassis or Transmission?

[silvertriple]

I resumed my CAD activity at the end of my day of work yesterday. The idea was to go as far as possible within the evenning on the Chassis CAD model. I learned a lot while doing the Spirit FF CAD model, and this should easy the work here. Plan : define the main volume, shell it, add the cut outs and details and finish...

Started by a sketch with the main volumes definition.


Then I did some extrusions to get to the next steps, and a lateral cut for the front.


Looking at the chassis, the fillets are there before we can shell, the front details as well. This mean I had to add them before applying the shell.


At the next step, I applied the shell, and start to define my cut outs (here the front one is done).


Then the motor cut out... (I have sketched this one on the rear face, and when applying the cut out on the length, it sort of confirms the measurements are right )


Once you have that, next is to add all the details...




Last, I worked out the rear gearbox attachment, and I have te Midships/Exceed chassis...




For the Spirit FF, the chassis was slightly less complex, and it took me 3 days to get it done. Here it was more complex, and it took me 5 hours and a half to get there. Seems I'm getting faster

[silvertriple]

Today, I decided to start the top chassis. I won't finish today most likely for lot of non rc reasons.

As usual when tackling a complex part, the most important is the plan...
The top chassis is a combination of multiple bodies each with with chamfer and fillets, and that's exactly what we are going to do before shelling the combination. Once this will be done, there will be cut outs on the faces, and then set of sketches for fixations and various holes...

I first started by a partial projection of the bottom chassis where I started to plot all the bodies, with the intention of applying sketches on the face and do cuts using those sketches to bodies individually...


After few extrusions with "new body" rather than "joins", some sketchs, with cut extrusions applied differently depending of the bodies, here is what I had...


That's tricky, it requires to think your bodies the way you want to apply the sketches but it works... Another set of sketch later to complete the front with new bodies and cuts, I could combine all the bodies and apply the shell...


Looking at the comments of some in other forums, I was afraid it would not work, but it worked like a charm...


Next is cut-outs, fixations and holes and finition details...

[Dadio]

Just quickly catching up , i had arms on several cars warp ,looking good

[silvertriple]

Just quickly catching up , i had arms on several cars warp ,looking good

thanks
Did I said at some point the Spirit FF was complex to model? I think I was wrong, it was f* simple
Measurements on this one are a nightmare .
Since my last post, I spent the evenning trying to make sure measurements are right by including gearboxes in the chassis... At some point I had a doubt. I'm now quite sure the thickness of the chassis is variable
That's a nightmare!

[silvertriple]

Early wake up this morning... I had some time to do the top cut outs before starting my day of work.

I had only the top faces to deal with. I first draw the cutout for the servo head (yesterday I had the check for the measurements and a standard servo should fit under but it is super tight), and for the air cooling feed (this is were the air scoop goes).


Then I went thru my working (boring) day. And at the end, reopened Fusion 360 to add the other remaining details. I added all of them (except the ribs) in one sing sketch and here is the result.


The top chassis is now in. The next step will be about the Midships specific parts : roll cage and bodyshell. For this I will need to get the gearboxes and chassis together so I can join the parts on the same plan.
I opened a new file, included the chassis and gearboxes in, and add joints between the parts.


I will obviously copy the file once all the common elements are added in and before starting the roll cage, so I can actually get it ready for an Exceed model

Basically, what do I need to model to get there :
- central differential components
- central shaft
- metal motor cooler part (2)
- metal shock towers : the component is the same as the Spirit FF one minus one bent

What I have already thanks to the Spirit FF and common to the 443WDS cars :
- shocks
- dogbones
- knuckles (front and rear are the same, they are just inverted)
- sway bars (front and rear are the same)
- rear steering feed rod
- servo horn
- Bumper and bumper plate
- front arms
- front and rear differntial
- shocks (color is different, that's all, but I'll keep my CAD black and red because red )
- ...

It's on a good path, but now I remember how pain it is to joint all the parts together... I may procrastinate a bit before getting there (especially considering we are two weeks close from the club vintage event, and i have 3 cars to finish/start : the Samurai, a Kyosho Spider TF3, and a Galaxy RS for my son)

[silvertriple]

After my last post, I started to work out assemblies.

I added the battery door hinge to the rear assembly


I had the idea that making assembly will help me to check key measurements and design.
As expected, it helps, a lot.


The battery door helped to spot a mistake in the placement of a key measure (the second measure i plot in the first sketch was not exactly positioned rightly. It's fixed, now.

Then I added the parts that goes on the front gearbox and are common to both Midships and Exceed. The bumper plate holes are lining up perfectly and that is a good sign


In this file I'll add whatever is common to both cars. The front train components will be added in the front gearbox subassembly. The rear end components will be added the rear gearbox subassembly. Now they are joined together, I just have to update references in the main file. component that will be added in the chassis file are the central shaft, the servo and its horn, and the input steering rods.

I've created 2 other files, in which the chassis assembly is linked.
- one for the Midships
- one for the Exceed

They will include at some point : their respective wheels, body shells, wing and roll cage.

Exceed wise, a parcel arrived today. There was a mix of Exceed and Midships inside. I decided to pull the trigger on it for multiple reasons: the exceed roll cage will help for me, as well as the metal parts, shocks and other components if I decide to print one Exceed (I started to develop some love the ugly ducky look of that beast). The chassis, bumper and other plastic part will be eventually helpful for Jason as the chassis he got is in quite bad shape, with cracks that don't look good at the end. The bumper was a good indication, and that is the reason I was confortable to bet on this.


And I'm sure now to have everything to be able to complete the CAD model of both cars (except the Exceed body shell, but I'll order one at TBG at some point ).

[Dadio]

Been away for a week on holiday with only sporadic internet access so was great to be able to read this at leisure , building up the parts as an assembly is a great tool , it's so easy to spot the errors , what I'm doing now is a new project per car then designing the minor suspension parts as a file each then a new file for the chassis or gearbox and bring in the rest of the parts into that file using "derive" to build up an assembly .
As I said briefly earlier the suspension arms on my Zerda and Coyote were all warped from 30+ years load but fortunately they both have symmetrical arms so they could be flipped over and swapped left to right , don't think you can do this on the Nichimo cars though .
Think you really must build one for yourself after all this effort , keep up the good work .

[silvertriple]

I spend most of my afternoon in the car, as I had to deliver my motorbike to the dealer for servicing. I discussed with the dealer, he's a friend, and he is following my stuff on Facebook. He does restore old motorbikes, and he told me he liked my work... Very pleasurable to see that people, even if they do not react follow and like the work.

Back at home around 5pm, I decided to prepare the transmission work. For that I decided to put the existing parts into the the design. I created a differential assembly and put it in both front and rear gearboxes.



I had to model the front axis as it is longer than for the Spirit/Vantage FF cars and it has some specificities on the central diff end. The Spirit FF axis is however there for the rear.


I'll add other things later on.