A new project - Nichimo Spirit FF - The first of a kind

[silvertriple]

Have you used any professional printers yet? I have used shapeways a bunch, decent stuff. I know a lot have used immaterialize with good luck as well. I just sent off some files to JLCPCB to test out, they have crazy low pricing especially on resin prints, but even the PA12 was 1/3 to 1/2 the cost of shapeways. Might be worth looking into them if you havent used them yet.

I already used IM which is quite cheaper than Shapeways already (and that is even without considering options to reduce the costs - see my Hunter/Galaxy thread for indications). And I'm considering also other services. I have to prepare my parts to do an estimation in many places before deciding about the final option...

[silvertriple]

I decided this morning to finish the roll cage and complete with all red plastic parts as I do consider printing them in SLS dyed red, so there is no color mismatch on the car (maybe I'm a bit perfectionist)...


Then I decided to play around with colours in Fusion 360...


It looks so much better now . And do you know what, I started to like this ugly car
The servo mounts confirm the design is right for the speed servo holes


I did all the part fixing the pillow balls on the suspension arms



I still have a few remaining red parts :
- battery door - 2 components
- Steering joints - 1 component (x4)
- Front Sway bars joint - 1 compoenent (x2)
- Transmission axis - 1 component
- front and rear sway bars attachment - 2 components

Once all of this will be done, would remain in plastic parts to be modeled
- Front Wheel - 3 components
- Rear Wheel - 2 component plus one identical to one of the front components
- Servo Saver - 3 components
- Steering Servo horn - 1 component
- MSC components - not sure I would bother about this...

[silvertriple]

Today, I wanted to tackle some additional parts...

I started by using a plugin to model the internal gear (with FMGear, it's really easy).


Then I decided to tackle the battery door and the rear sway bar. And yes, I did put some red on an original black part, but I do like it this way. And I did the sway bar, just because it was easy to do...


Then I worked out the Servo Saver (4 components which were originally black, but it will be red )


For the front sway bar links, I decided to model the sway bar first, then to build the pillow balls and then to do the link. Somehow, it's a great pleasure to estimate an angle, to put everything in place and then to measure the distance between the balls and to have it almost identical to the one you have when you look at the caliper


I then worked out the steering rods... Same principle : pillow balls first, then identify the center point, use an axis through the two point and build a construction plane at angle...


For the last link, I got the servo from a very good friend in the design (as well as his motor), and positioned them in the chassis.


Next, a servo horn (red because why not ) and again a pillow ball (different from the others) to model before being able to get the link done...


Status as of today for red parts :
- battery door - 2 components - Done
- Steering joints - 1 component (x4) - Done
- Front Sway bars joint - 1 compoenent (x2) - Done
- Transmission axis - 1 component - Done
- front and rear sway bars attachment - 2 components - Done

Added :
- Servo saver (4 components)
- sway bar front and rear attachement (2 components)

When I started the project, there was the box of the car with the components, and I took a small box where I did put the small component which where due to be modeled within the day... At some point, I had another box in which I started to put all the parts modeled. I have now a bucket (15 cm diameter, 10 cm height) in which there is the remaining parts to be modeled. One thing is I'm quite I can even put the metal component I've not modeled in, it would not be full... That means I'll see the end of this modeling exercise at some point...

[silvertriple]

I think I lost my evenning trying to sort out the bevel gears... To finish by a suspicion that the mod is different from motor pinion and internal gear: it's far too big to be a .8 it should be 1 or 1.2 on the bevel gears. The good thing is that it is more robust, the bad thing is I spend my evenning doing something ready to go to the bin

(and don't ask why I'm doing this while the gears are all ok for this car )

[silvertriple]

Today, I worked to understand the exact elements I should use to set my bevel gear in CAD... Decided to work this way, as obviously I was not making it right last time...

I decided to put the gears profiles in the gearbox to understand the exact elements about the gears...


Next step was to include the cone angle from a bevel gear calculator (which is not depending upon the mod or the gear face width, but just of the number of tooth of the pinion and the gear).


I do have now the few key numbers I need to use to design my bevel gears
- Pinion teeth (14)
- Gears teeth (34)
- cone angle 22.38°

(for reference : the bevel gear calculator is here : http://otvinta.com/bevel.html)

The bevel gears are mandatory to finish the modeling of the few remaining plastic parts (especially considering I'd like to get them printed). Next step if for tomorrow.

[Dadio]

The only time I tried bevel gears i did it by making a cone and drawing the gear profile on the edge and sweeping , then making a circular pattern of the teeth , but then I was just making a mad hatter's watch for cos-play , nothing like this and I couldn't find a bevel gear add on in Fusion so I just did a very rough gear set to turn the hands . In short "your on your own " best of luck

[GoMachV]

I did bevel gears once but I cheated even worse. I found the closest ones I could on sdp.si (I think…. Might have been somewhere else) and grabbed the cad file they provide. Modified the cad file for my own use.

[silvertriple]

Well, first, I want to be able to print part of the transmission : internal gear, bevel pinion, bevel gear and differential housing. The diff internal gears are made of metal, and they are likely safe. But the plastic gears, I don't think so, especially considering :

• I saw some broken internal gears

• I can see some trace of usage on the bevel pinion which let me think it would break at some point

Now, I had some discussion with @optimaforever on the way to proceed (and also looked at some videos on YT), and he is working by projection of the tooth of a pinion in the same mod at the proper point, lofted to the cone and cut to the right dimension. It should work. I did tried on wednesday, but I did not have the proper seating points (there was not a single way to measure the facewidth)... I decided to assess those elements properly so I can have a clue of what my bevel gears should look like without being cut for esthetic purpose, and I will apply those cuts once I have a working model...

At least it looks simple in my mind

[Dadio]

I think with this I'd find a close matching current part , there are plenty of cars with bevel pinion and crown gear and adapt the gearbox design to fit them , it would be cheaper and easier to get off the shelf metal gears and adapt the design of the gearbox to match than have the gears 3d printed in metal . When I drew up the 834b dogfighter gearbox I designed an adapter ring gear to use a 2014 scorpion diff as the genuine dogfighter diffs are rare as hen's teeth .

[silvertriple]

I think with this I'd find a close matching current part , there are plenty of cars with bevel pinion and crown gear and adapt the gearbox design to fit them , it would be cheaper and easier to get off the shelf metal gears and adapt the design of the gearbox to match than have the gears 3d printed in metal . When I drew up the 834b dogfighter gearbox I designed an adapter ring gear to use a 2014 scorpion diff as the genuine dogfighter diffs are rare as hen's teeth .

I had this in mind as well, but one of the main issue with this approach is that it requires to have a lot of inventory at hand to check the possible correspondances: there is no proper database online to check this easily, unfortunately...

That being said, after some work done, some work undone, done again, undone again and done again, I finally had bevel gears having the right mod and the right dimensions...


The mod is indeed 1.


I did check quickly by positioning those they would fit in the gearbox before doing the adjustments...



I stooped there last night, and restart this morning with the firm intention to get the gears and the diff case done this morning...

After some confusion (360), few mistakes, user issues, I finally have both pinion and gears correct, with their proper dims and seat...



And I did the differential casing after this




Next are the bevel gears inside the differential...

14 and 10 teeth... But why

[silvertriple]

A bit of work later... I have the differential bevel gears, which are in .8 mod...


And it sits perfectly in the diff case...


Last thing was to repatriate the work done in the Nichimo overal project, position them correctly and...


It's still missing bearings, spacers, and axle, but the transmission parts are in (red because why not )...

[Dadio]

You always see the sun gear being bigger than the planetary gears , if they were equal the gears would either need to be tiny and weak or big and the diff would be very wide , plus the sun's bigger than a planet so sun gears have got to be bigger see
Glad your designing the gears not me , looks like a job well done

[silvertriple]

After the complex things, time to complete the transmission...

First out diffs, bearings, axles and dogbones...



This morning I added the missing bearings and spacers in the differential and the gearbox.


That allowed me to identify a demi millimeter issue in my diff case (it was too big), and the fact that the bevel gears needed a half millimeter offset in the diff...

And yes, my dogbones are having a design issue, but it's not going to get printed so I don't really care...


I modified the battery holders to allow the usage of 138mm battery packs...

Remains to do :
- front knuckles pivot balls
- radiator
- shocks
- hub and wheels
- bodyshell and wing

At this stage, I did not include any joints neither did considered motion... But considering I'm close, that could be interesting

[silvertriple]

Started my afternoon with the radiator on my desk... I simplified it a bit.


For the small story, there was a radiator bag in the box of the Nichimo Spirit FF and Vantage FF...
It included 3 parts. The radiator, the plate going between the chassis and the skid plate where the bumper is seated, and the motor plate. "Radiator" this is supposed to ease the motor heat transfer... Let's have a look.


Knowing that heat convections makes hot going up and cold going down, I'm not sure how it worked . I guess I will have to take an infrared thermometer to find out if it has this function as well, as my own knowledge tells me this is more weight to get the FF architecture work

As i was in mood to do more today, I decided to tackle the wheels...


Front first and then rear...


The original rims are in two parts. I made them in one single part, kept the holes for decoration, but adapted them to 3mm screws as the original 2.6mm are difficult to find, and adapted the wheel hubs as well... The size of the rims should be fine with Tamiya oval blocks or supper gripper, or Kyosho Turbo Optima re-release tires (I just have to make it slighty narrow front and rear - about 4mm each).

Remains to do :
- shocks
- front knuckles pivot balls
- bodyshell
- wing
- tires

[silvertriple]

Decided to add some red again... Red contrasts well with black and that makes it more punchy...


Next was time to add some gum on this thing... Profile over a prokected intersection of the rim and a revolve later here is what I had...


Then played a bit with a tangent plane, some figures (too much to my taste), some extrusions, a profile to recut what was too much addition and tada, I had a front tire...


And the next one was much more easy...


I'll apply the same principle for the rear ones, but tomorrow...