224 replies ·
posted June 11, 2020 4:10pm
This thread is dedicated to the wheels and the rear axle of the backhoe project.
The gearbox is now one connected mesh, but not yet all quads. Nevertheless, the "Shrinkwrap Modifier" does a good job:
This is now also one mesh:
The wireframe is from the skrinkwrap target which is just a copy of the old separate main body. I worked with vertex weights and different projection methods ("Nearest surface point" and "Project" along local axes). Maybe some smoothing will be necessary after applying the modifiers. File is here.
There is a 'strange' quad here:
and a 5-sided pole directly at the 'transition area/point'.
I played around a bit and came up with something like this:
Got rid of the first Shrinkwrap and reduced the Subsurf to 2 levels and then it looks like this:
But your biggest problem is this extra Face that shouldn't be there:
Thank you, @spikeyxxx, this looks much smoother than before! The first "Shrinkwrap Modifier" was just for keeping the original shape as much as possible. Don't I come too much off from that shape if I delete that modifier?
You will deviate from that original shape a bit, but see how you like it. Remember that these are cast iron shapes, with maybe some of the shapes welded on. That is a different look than the thin, pressed metal plates that form the outside of a car. And Shrinkwrap might ruin that effect.
Also using the Shrinkwrap Modifier with Vertex Groups or even Vertex Weights is very dangerous. I used it on my ' Bee-hicle' project, but it was a frustrating experience of applying the Shrinkwrap and re-adding one, several times. Don't get me wrong: it can be done, but like all magic: it comes with a cost...
You're absolutely right, spikeyxxx , with being very carefull with vertex weights. I'm currently experimenting a lot in order to avoid any steps due to shrinkwrapping or, if I can't (easily) avoid them, bring me at least into a good position for final polishing after having applied the modifiers.
The gearbox consists now only of quads, but the shrinkwrapping still needs some tweaking, especially at the yellow pads on both sides of the gearbox:
And this is my rear axle now with the all-quads gearbox:
This is now one continuous all-quads-mesh:
Another part connected to the left:
Only the gearbox side ring still has to be connected
That is looking really good duerer! Both the shape and the topology.
I love this slight 'bulge' in this 'new' part when it goes from 'square' to circular; gives it this almost organic look of cast iron.
Thanks a lot, spikeyxxx 😀!
I had to dissolve many edges at the green-blue part on the left side and bring the circular shape back to perfect circles with "Loop Tools". The edges (marked with a more saturated yellow) are beveled. I duplicated one edge area and used it as snapping target for the resting three in order to get an even look.
At the magenta bolts holder, I made the edge loops run down straight from the holes to the axle bottom instead of directing them into the corners nearby because this caused a lot of edge stretching so that some faces were overlapping which was clearly visible.
The holding edges at the corners of prodtruding parts are always a challenge, escpecially when they run into curved surfaces. I have a mix of solutions which all aren't 100 % perfect (I don't know whether this is possible at all?) but some slight pinching is only visible if you come very close and I can at least live with it. Maybe you can have a look at it when I post my finished file?
The holding edges at the corners of prodtruding parts are always a challenge, escpecially when they run into curved surfaces
How true and I think you solved that quite beautifully!
Here's an example of what I did:
When using one of the extreme Matcaps you can see some stretching, not even a lot. But now look at the mess I made of this in Edit Mode:
I'll be happy to take a look when you're finished, but what you've got so far looks great, I can tell that from the screenshots already.
I use the "Shrinkwrap Modifier" in order to project the outline of the cutting surface of the part that I want to connect to an object and do the same with a scaled up version of that outline as holding edge loop. Round objects are easier to connect since they don't cause as much stretching as objects with angular cutting sufaces.
I added recesses for the gearbox bolt nuts, but it's not yet all quads:
Didn't notice this before, but there is some pinching here:
might be easy to solve, by merging those three close-together edge loops at the bottom.
Something like this:
Might not work in your case, but it's worth a try.
Don't stress out too much if you can't solve it, with the right shader (dirty, greasy, damaged, painted iron) you'll be able to hide it;)
Thank you, spikeyxxx, for the hint 😀!
And it worked very well (!) 😀:
Now, the gearbox side rings and the green-blue part are all quads and without any 6-poles:
The green-blue element to the right of the gearbox is a mirrored in global Y duplicate of its axle left side counterpart.
Current status of the rear axle and its gearbox:
Hey Ingmar duerer that is looking just amazing.One thing I noticed that probably should be addressed at some point is that your assembly when linked is shown all over the place.
I'm currently cleaning up my file removing all parentships. This should solve the issue.
The hub and the first attachment ring are now one continuous part as on the real backhoe:
The "Dog" logo is also now connected with the hub in a retopologized version:
No way...that's impressive! I definitely appreciate the work this took but I would have left it as separate intersecting parts...You'll be a topology wizard by the end of this project, if you aren't already.
This was the dog logo before the retopologizing with 10.220 vertices:
So, after the necessary retopologizing, I only had to do a "Bridge Edge Loop" operation to the now 40 vertices of the outer circle (reduced from 336 vertices):
The logo now has 3.639 vertices.
The black parts alone count 2.303 vertices:
The retopologized logo counted 2.494 vertices before connecting the separate parts:
This is now the almost finished rear axle as a whole:
The "Shrinkwrap Modifiers" on the gearbox can only be applied after applying the preceding "Subsurf Modifiers" (Level 2) in order to get the correct shape:
A quick update on the rear axle:
File is here. Edit: A newer version in this post.
Looks like you're really close to finishing, amazing job!
Only thing is, some edges are really sharp like here:
Those holding edges are too close I think:
If you just slide them away from the edges:
It will look better and more consistent to the rest:
Maybe round it out even a bit more, when looking at reference:
Anyway: great job on such a complicated part!
You're absolutely right, spikeyxxx, with the too sharp edges. This is bothering me, too. But it's relatively easy to fix. It's a remnant from the time when I used the "Bevel Modifier" with activated bevel clamping which was triggered very early by areas with extreme dense geometry. The main thing for me is that the rear axle fits into the chassis and the connections to the front are correct. With everything in place, the edges can be softened without causing any problems on the transitions from the rear axle to the adjacent parts.
How are the yokes properly aligned (?):
I could be mistaken, but I think that the ones you have are meant for situations like this:
where the two axes are aligned, but offset from one another...
whereas a 'single' universal joint would be used to 'go around a corner'
Then, also, the alignment wouldn't be a problem...
This is what my drawings showed me:
This part is really confusing.
And this yoke is currently floating in the air together with the bars at both sides 🤔.
A very confusing drawing, but it seems to me that that 'yoke' part in the drawings is positioned more to the middle and that the ones that connect directly to the wheels are not even drawn here. In the top drawing there are these lines to indicate where the parts go and part 3 comes about where part 5 is...That position seems to be confirmed in the bottom drawing. (At least that is how I read it...)
The double yokes are on both axles in the axle and housings:
So, my alignment is already correct, but I still can't imagine how the bar connecting the yoke to the gears in the gearbox can transform its rotation around around the own length axis into two rotations perpendicular to that within the yoke structure.
Me trying to read these drawings:
To me it's very acceptable to go leave it as you have it; it's a "looks right, then it is right" situation. Even if it doesn't make 100% mechanical sense, there's little to no chance we will see it operating (even if rigged). We'll likely see these parts in an exploded-view shot for the reel which still doesn't matter in terms of 100% mechanical sense.
According to that drawing you are right duerer!
That would mean something like this (top view):
and when the wheel turns:
And the three gears in the hub case also play a role that I don't understand:
So, this is my proposal for the "Mystery Files" 😉.
I like these machines where everything engages with each other as in this fun machine here.
I'm also very impressed with the amount of reference photos you've found for your axle and its various pieces. You're quite the internet detective 🧐
As to those three gears: just Google 'planetary gear' and find for instance: https://www.youtube.com/watch?v=ARd-Om2VyiE
This is the Rumpelstiltskin effect: once you know the name of something/someone, you have power over it/him/her..
Or in modern day language: when you know what it's called, you can Google it...
Thanks, spikeyxxx, that looks super coooooooool 😀👍!
Thanks, theluthier, for the promotion as internet detective 🕵️♂️😀!
So this is my rear axle for assignment 5:
This is what I could do so far. I need some help for solving the shrinkwrap problems on the gearbox (marked in red) and the alignment of the yokes mentioned in the previous post.
File is here.
You've reached a shocking amount of detail. Super impressive work!
Off topic: Just found this incredible machine 😁:
LOL that must be a photoshop job, right?
theluthier you are absolutely right!
Look at the 4 repeating 'humps' of gravel and then look at the sky above them;)
I'm sure that it's real. Here's a bigger image version:
duerer look at those repeating clouds above the heaps of gravel:)
Okay, spikeyxxx, you convinced me. But this vehicle has even more wheels and it's real 😁!
Sure, that's real and a great achievement for modern technology, but it makes me think of how they were able to make bridges like this:
This can only be achieved by human hand. And that's why it looks more vivid 😀!
PS:This traditional stone bridge is a great modeling object, too 👍.
My final rear axle with "Shrinkwrap Modifiers" still in place:
File is here. The connections on the gearbox aren't perfect but at least good enough if you don't need a close view.
I've smoothed some edges, as proposed by spikeyxxx and collapsed the modifier stacks (with subsurf level 1) on the gearbox and its direct side parts (the latter two beeing one object in my file). Both objects now only have each one "Subsurf Modifier" level 1 and one "Shrinkwrap Modifier" for smoothing out slight grooves in the tube parts. File is here.