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silvertriple

Bormac's Nichimo Midships 443WDS

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Still in vacation, so I took benefit to move forward on that beast...

First, I wanted to complete the wheels. The hub is different from the Spirit hub, so I had to model it. At some point, i noticed something : what I was thinking to be a chamfer with wear is actually something else. I had to remove my glass and look closer to discover nuts :-)... It's useless, but since I know it is there, and the fact it is super easy to do, I did it :-)
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After that, I had to take care of the tire. I'm still thinking about TPU for printing tire, and I saw some videos with some rubber resin printed tires, and the result seems very good... I keep that in mind for later, but in the meantime, applied a profile, a revolve...
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Then two sketch , 4 revolve and 2 circular patterns after, I got a tire...
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This tire was later reviewed as the profil was too flat...

I also inverted the steering rod ends, so it looks proper now...
oP4LKQZ.jpg

This morning, I started the roll cage, and I'm likely to post about it at some point tomorrow, as there is still one part to tackle... I did not finished today, as I got multiple interruptions within my day for lot of various reasons.

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7 hours ago, DaveBuildsRC said:

Will make a nice shelf buggy or planning to use it

Well, if you had read the first post of the thread, you would know that the Midships I'm modelling is not mine, but it belongs to @BORMAC, and I'm not sure what he will do with it.

On my side, the mix of Exceed/Midships I bought will be used as a basis for an Exceed: I'll keep the parts I'm not going to print because they are not printed, while the plastic parts will be kept on the side. And that Exceed, like the Spirit FF won't be a shelf queen. My cars are all runners. And once I have the stl files to be able to reprint things, I don't worry too much about breaking something :-)

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Yesterday, I started to work on the roll cage. While on the Spirit FF it was symmetrical, it is not the case here...

The approach I took was to set the symmetrical things first, then apply a mirror and finish each side more or less independantly.

For the symmetrical part, I started to set the seats points as bodies.
Then I created a sketch going thru each of them, with the target of setting a pipe between the different bodies. There was a bit of work to make everything right, but at the end I had it.
EngMTR6.jpg

The I applied the component mirror to get that on the left side.

Once done, I started the right part. One could have thought about a 3D sketch, but it is not the approach I took. I started by creating the seating point on the chassis side, then the pipes parallel to the chassis plane, it was quite easy to define as the lines are either parallel to the ground, either parallel to lines already defined for the bodyshell. Once that part was done, it was definitely easy to set axis from each of the end, and used those to set plans to get the inclined parts.
hr649hZ.jpg

I proceeded the same way for the left side, at one exception : I did hava already the plans in place for the last steps as I had them set from the right part.
UgkOaxD.jpg

Next I took care of the braces. While doing this I noticed a discrepancy of .40 millimeter on all the braces. The space available in between the two roll cage side is too big of less than half millimeter. I rechecked my chassis measurements, and they are fine: the designer probably relied on the flexibility of the plastic...
dGhufjG.jpg

Wing support and additional front part were added last night...

This morning, I built a wing... I'm not going to detail the build, but once you understand how to work with multiple bodies, it is fast.
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The wing was promptly added to the car...
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And I applied a quick paintjob...
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I will add a driver figure at some point, just because it needs it to be called finished. I will start to proceed to print dimensional tests within the next few days...

But first, I need to model the Exceed roll cage and wing...

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This morning, I started by using the slicer to prepare a set of test print and launched a print of the motor plate. The first test I did last week was non conclusive as the PLA was probably affected by storage issue. I had the dryer running all afternoon yesterday before I run some night prints, and that should be better today.

While doing that I started to model the Roll cage of the Exceed.
MTHMtm2.jpg

This exercice confirms the requirement for test print of the top chassis: At the end of the Midships roll cage, I noticed a discrepancy of .4 mm (39 in real, versus 39.4 in virtual) between the brace length and what I need on the model.
While working on the Exceed cage, the brace are this time too long (36mm in real while 35mm in virtual). Something is definitely wrong there :-)
I think I know what is the culprit, but will have to confirm this by the chassis test print.

Anyway, once my roll cage sides were modeled, the print of the motor plate was finished. I launched another print (Front Gearbox - 9 hours) and started to test my motor plate.
First with the front part allowing to fix the motor...
Ub8U9BA.jpg

Everything is good, next is to see with the motor plate, the real one.
I used screws and introduced them in holes.
OQFgohA.jpg

There is a non critical element incorrect - the center hole for the motor has the side on the transmission too short of .5 millimeter. The rest is fine. Not really an issue as this measure is not used anywhere else.

In the afternoon, I did nothing related to rc while the front gearbox was printing. It was finally printed about 20 minutes before the late dinner, and I took the time before the dinner to test it. I made multiple checks
TlP6xDA.jpg

First, the overall shape is perfect, and the centering points are perfects as well. The front part allowing the fixation of the motor is also lining up perfectly (that was the only element I took from the motor plate).
I did 2 mistakes : gearbox fixation to chassis is half millimeter behind what it should. And the top closing hole is half millimeter too high. All others elements are perfectly lined up.

I will continue to proceed into the test with the rear gearbox. I mainly need to validate the fixations points, are other elements are non critical (as long as the one printing the gearbox would print both side rather than just one). I launch the print before going to sleep tonight. Next in the pile will be the chassis and depending of the result the top chassis...

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I did not took pictures during the test of the rear gearbox. I spoted instantaneously 2 big mistakes and one smaller:
- the top of the gearbox was off of 1.5 millimeter, which explain partly my rear input rod issue colliding the top chassis
- the rear extension that aims to fix the roll cage was off because I measure the tangent and applied the circle center there (it was likely too late when I did that last sketch).
- another half millimeter with the gearbox fixation points (too high).

All were corrected, as well as the other mistake identified during the previous tests before extracting a stl to print a chassis. It's on going and will take about 24 hours print (it's 9 hours this is ongoing).

With the corrections, done, I had multiple checks here and there to get other things corrected : it's easier to spot a mistake when you have a data point saying you this is wrong (and the roll cage was showing some issue).
I checked the top chassis and corrected the hole position. Symmetry and half millimeter wrong means 1 millimeter wrong at the end. The result is that now the roll cage of the Exceed seats perfectly on both top chassis. The roll cage of the Midships rely on its flexibility to join the braces. Not sure why they do it this way, maybe they found out having it under tension makes it less prone to break at the first roll over...

I finished the roll cage parts of the Exceed
bhjmVeg.jpg

And since I had already the wheels (they are the same as the Spirit FF ones), I just added them.
vRwCSVJ.jpg

I still have a wing to model, and for the bodyshell, a gentleman send me some picture, but it maybe too difficult (I may have to get a TBG bodyshell to model it - it's not as critical as the plastic parts or the Midships bodyshell anyway)...

Still few parts to validate :
- top chassis,
- arms

Still some areas of work : 
- center diff to make it printable
- define a possible lock for the center diff (I had some demand for this)

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It is still printing... So I did move forward on what was lest on the table possible to model... The Wing and the roof.
kwxtArP.jpg

Other parts I had already (resistor cover and its support). Now, I need to find an Exceed body shell, even in bad state for next step...

In the meantime, I decided to retry to put both cars in the same file. There was an update of Fusion 360, I noticed that as I needed to reset the rights for accessing folders on my computer, and before that each time I tried, it did not work and I got a massive crash. Both cars file are read only now. I created a new file where I put a link to both the Midships and Pegasus Exceed...

And tada :-)
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You may have already noticed I like to work on vintage cars by chassis series (Hunter and Galaxies grouped together, Ninja Coors and Shogun). Having the 2 cars CAD models in the same pictures is just a great achievement and nice reward... But now, I really really really need to find an Exceed body shell :-)

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Short update, no pictures.
Long print when fine.
I had a doubt on the length, it was confirmed. The cause was a cumulation of 3 mistakes, and one of them was a 1.5mm mistake in one of the non printed parts of the Spirit FF (NB: Carbon Fiber battery door), the other was the fact I did model with the right length, but the top part of the chassis was not taking into consideration the angle of the gearbox attachement.
I spent my evenning to correct the chassis parts, and will review the roll cage tonight. I'll have to do the same for the Exceed...
I've relaunched a print of the chassis, as I want to be sure of my work when sending the Midships and parts to @BORMAC...
 

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Second 23 hours print of this project, I really want to make sure my dims are right before I can send the car and parts back to Jason.

This time it is much better
FtX9IY8.jpg

And I put the gearbox in the chassis with the propeller shaft to make sure about everything... It fits :)
y4kpwkO.jpg

I made very few minor adjustments. The Midships chassis parts are now good to go. The Midhsips bodyshell still requires few adjustments.

On the Exceed side, I still need to review the chassis, and the roll cage as well (it seats on the Exceed top chassis I may replace following the change I did on both Midships chassis parts (for which some measurements changed) - I'm going to take the time to think on the way to proceed before doing anything there).

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Progressively revalidating every single component...
I even found mistakes on the Spirit CAD while doing the analysis (minor, but still).

Remains in the todo list before being able to send the car down under :
- rework the Midships bodyshell. I've put Jason in contact with another friend in Australia with a Vac-forming machine, and we will try to do something here starting from the bodyshell model. I need to get it right, I know more or less what to do to make it much better, but that will require some of my attention...
- rework the Exceed roll cage. I replaced the chassis component in the Exceed file, and the roll cage needs to be modified accordingly. I may have to rebuild the sides, but even if it is the case, It should be fine, I have a roadmap, and it is just to follow.

After that, I will need to work out the transmission. 
- As mentioned earlier, the central diff is not currently printable. I need to change a few things to get it printable (multiple areas were thickness is .5mm or less).
- I will also review the front and rear diff to make them easier to print.

I will have to order some bodyshells to TBG, and that will include an Exceed one, with both the target of modeling a car and second to cover the printed car (once that happens - because at the end, this will happen - not sure when, though :) )

Last I want to do a fully exploded view of the transmission, juts for fun :-)

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I worked out a mould from the body shell. it's not perfect, but it is approaching from the bodyshell. 
NATzwWr.jpg

I send both Fusion file and the pictures to get the feedback on this. Maybe this could work... Let's see what @yogi-bear will say :)

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As mentioned, I sent the Fusion 360 file of the Bodyshell a few months ago to my friend @yogi-bear located in Australia, like Bormac...

This morning, when I woke up, there was a mail in my mailbox with some pictures... The pictures worth thousand words, and it certainly sounds like an another achievement reached...
B3kNJqb.jpg
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R7Ge0SM.jpg

Obviously, there is still some work, as this will require dimensionnal validation before adjustments, reprint and finition before retrying (need for some filler and sanding, for sure before next attemps)...

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Today, I got some pictures from my friend @BORMAC... He allowed to share them. It was about the Midships bodyshell attempt... @yogi-bear is probably awaiting eagerly for this post :-)

Just a few reminders before the pics :
- this is a dimensional test, which means the mould was taken straight out of the printer and the vac forming was done without any additional preparation
- the idea to try to do a mould came long after the original bodyshell was sent to Australia, and when I did the model, I had no intentions at all of this sort, which means I paid attention to get the general idea of it without making too much attention to get very close of it (not like all the mechanical parts). Additionally, I made it using plain solid, and this likely did not help at all, because having some limitiations in the exercise...

DKHrtXa.jpg
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svRcErd.jpg

There is some good and some bad. The bas is mainly the front part which is off... At the time I did this model, there is a lot of things I did not know how to do yet. I would do it differently today... The good is that it shows it is possible to do something, and I could do better... There is still some work. Jason told me this is not a fail for him, but on my side, I see where my model is off and that is where I'm unhappy... On the other side, this allowed me to learn so much that it is somehow very good, so it is very positive. The Midships was my second car model, and from there I came a long way, and what you can see it this post is the result of lot of discussions with a few people, and they all participated to make this possible... Thanks to all of them, :) and specially to @yogi-bear who made this possible...

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all things considered, this came out extremely well. Do you think you need to start again, or can you just adjust the existing 3D model? Also for the next version I’ll apply a spray putty coat. I’m guessing that would be about .3 mm thick, to help smooth the surface so the final product is a lot nicer. I need to try that wing too, but overall and excellent result I think.

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9 minutes ago, yogi-bear said:

all things considered, this came out extremely well. Do you think you need to start again, or can you just adjust the existing 3D model? Also for the next version I’ll apply a spray putty coat. I’m guessing that would be about .3 mm thick, to help smooth the surface so the final product is a lot nicer. I need to try that wing too, but overall and excellent result I think.

Honestly, I did not look at that yet... I spend the afternoon trying to fix my printer following an user mistake, and it still not back to work (long story short : started a print with wet PLA, filament broke into the bowden tube, had to change the tube and the nozzle, and now I have to redo the offset properly (which I thought it was, but still is not))...

I'll let you know once I can have a look. Not sure how much dependencies there is on what I need to modify (which is almost on the first sketch)...

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55 minutes ago, silvertriple said:

Honestly, I did not look at that yet... I spend the afternoon trying to fix my printer following an user mistake, and it still not back to work (long story short : started a print with wet PLA, filament broke into the bowden tube, had to change the tube and the nozzle, and now I have to redo the offset properly (which I thought it was, but still is not))...

I'll let you know once I can have a look. Not sure how much dependencies there is on what I need to modify (which is almost on the first sketch)...

yeah, wet filament can be a big issue. I sprung for a dry box a while ago and that has helped a lot.

No rush on the body either, I've got plenty to keep me busy :D My next attempts will involve casting with resin and silicon instead of plaster. The plaster is cheap, but it's not going to last for very many copies, and it's not good for the vacuum system either. So I am going to start trying the idea of the harder inner core/support with a semi flexible silicon outer shell thats around 10 mm thick. That will unfortunately raise the cost to make a mould though. To start off with, I have 3 of the retro racing bodies I'll try this with, as they were quite hard to get off the plaster cast.

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9 hours ago, yogi-bear said:

yeah, wet filament can be a big issue. I sprung for a dry box a while ago and that has helped a lot.

No rush on the body either, I've got plenty to keep me busy :D My next attempts will involve casting with resin and silicon instead of plaster. The plaster is cheap, but it's not going to last for very many copies, and it's not good for the vacuum system either. So I am going to start trying the idea of the harder inner core/support with a semi flexible silicon outer shell thats around 10 mm thick. That will unfortunately raise the cost to make a mould though. To start off with, I have 3 of the retro racing bodies I'll try this with, as they were quite hard to get off the plaster cast.

yeah... I have a dryer... But I forgot to heat it up... My bad mistake...

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