Kent Trammell (theluthier)

1,434 replies · posted

Collab 2020: Modeling Heavy Equipment (Backhoe)

Accomplishing a BIG project TOGETHER

Starting in March 2020, I began a large stream project to model a comprehensive, highly-detailed Caterpillar 434E backhoe. Please watch the first stream (first 3 minutes of abridged version at least) for an overview.

It's a straight-forward project of building a complex model over an extended period of time. The spin on the project is that I want your help to accomplish it! If I build some parts and you build some parts, we will finish this thing much quicker. Plus the contribution format will include reviews, the potential of having your piece(s) assimilated into the final model. Not to mention large quantities of XP are at stake 🤑

NOTE: This is an involved project reserved for Citizen members.

Collaboration Details

The general idea is that I kickoff stages of the project via live stream, which is typically once per month. For the time in between streams, you choose a piece of the backhoe and apply what you learned from the stream to that piece. For example, the first stream covered initial block out. So between stream 1 and stream 2, your job is to pick a piece and block it out.

This is the repeating protocol for each Assignment Period (between-streams):

  1. Signing up for pieces of the model. I will be maintaining a Google Sheet to organize piece selection and grading. Following this URL will give you the ability to comment. The sheet is sectioned vertically and color-coordinated with a backhoe image. To sign up for a piece, right click on an empty cell below your desired piece section and click "Comment" (CTRL + ALT + M). Comment your name or username and I will fill it in officially as confirmation.

    Remember that it is OK for multiple people to model the same piece. But lets try to have at least one person assigned to each piece before doubling up.

    2. Project file structure. We're going to use Google Drive as a means to sync a single working directory among all contributors. See this thread about details and how to get set up.

    3. Submitting your piece for review. Exactly one week before the next stream is scheduled to be broadcast, your piece is due. In the "Attempt" cell of the spreadsheet, paste a download link to your .blend file via Dropbox, Google Drive, or equivalent hosting service. This will earn you at least 10 XP each week.

    4. Review. On stream I will review each submitted piece and decide which will be assimilated into the master model (in the case of multiple submissions of the same piece). The purpose of the review is to generate feedback for you work and advice for improvement.

    5. Assimilation. If your piece makes the cut and is assimilated into the master model, your name / username will be added to the object in Blender. You will go down in history as a definitive contributor to this epic backhoe model!

    Once the model is completely done, I plan to render a short demo reel showing off the model and crediting all contributors. It should be a rewarding conclusion to all the work we will do!

Assignment Prompts

I will reply to this thread after each stream with a [big] assignment post denoted by a  📣 emoji in the title. There I will clarify instructions about each Assignment Period.

Online Resources

Reference Images


This is THE thread

We will centralize our collaborative communication between the streams and this thread. Ask any and all questions pertaining to the Backhoe project here.

  • Hi guys Here is a image of my wheels 

  • sorry there 

  • sorry there 

    • crew

      Nice job sshanr , have you added a subsurf mod yet to see if you need to add any holding edges?

    • Okay sshanr, , now try and make the tire and treads one mesh.

      Also maybe 'even them out'. I mean your treads are going: left right, space, left right, space, etc. I think they should be more evenly distributed.

    • sshanr Did you watch the tutorials in the link I posted for you? Your part is essential dude, it's the wheels, we ain't going nowhere without them, c'mon we are only a few days away from the stream.

    • Not gonna lie I am terrible at tires. I love the "Tiled" elegance from spikeyxxx in the file posted from Kent's live stream 2. We could all learn a lot from this guy just going into edit mode and admiring the simplistic approach that remains easily editable and relies heavily on a few modifiers to look great.

      My brain is still figuring out how to think this way more and more.

    • @spikeyxxx what do you mean by

       I mean your treads are going: left right, space, left right, space, etc. I think they should be more evenly distributed.

    • sshanr Look at this:

      There are gaps (spaces, the green lines)) between the treads (in blue). With an even distribution you should have : blue - green - blue - green,...and not: blue - blue - green - blue - blue - green,...

  • blanchsb Ok Blanch, here's the link of my part of your part, it's called Blanch Part. Kinda of a hard part your part.


  • blanchsb 

    And this is the best I could do:

    Just the hard part, you can do the rest yourself:

    See if you can use it;)

  • crew

    ppfbourassa without seeing the bigger picture of whats actually happening, I think as for the second image I would dissolve the 3 edges shown removing the 2 verts circled, if you need to define the edge more I would edge slide the 2 outer edges closer as shown here:

    As for the other image, again without the bigger picture, I think dissolve the random vert, make some cuts with the Knife tool and slide the arrowed vert out slightly and dissolve the edge squiggled out. But again without the bigger picture and knowing whats round the corner it's hard to solve.

  • spikeyxxx and dostovel and adrian2301 and everyone thanks for the tips. I think most of the solutions work that have been posted. I am going to go with spikeyxxx elegant final solution. I also found a spare duplicate edge while repairing this one and blasted it away manually because it wasn't caught by the remove doubles this whole time........arghhhh.

    Here's putting it into practice. It was elegant but still required a lot of work. I think adding more topology to the circle to make it a 16 sided circle gave me more room to work with in this case. I'll have to remember when things are going to take harsher turns and change from one shape to another perhaps maximise the topology without adding too much and also make it elegant.

    The final solution looked like as if the entire circumference was "inset" in a sense and then a couple of holding edges added to the top of the shoulder in a way that moved the 5 sided pole inwards.

    I'm interested to see what all y'all think now that I have tried my hand at it again for the umpteenth time and lessons learned. I'll do a short recap below

    Problem Before: 

    Not enough geometry to work with (I think).  8 sided circles not working when rectangle sections needed more holding edges that the circles could provide

    Using Bevel and Weights (not industry standard way of doing things for this project). 

    And 5 sided pole seemed to be interfering with the subdiv modifier producing a crisp look and feel.

    1 stray long edge duplicating an area that was already covered by 2 edges along the cylinder cross section.

    I hid the Bevel Weighted Edges but they are still active. Notice how the light pinches at the top shoulder on the right of the image

  • Solution After: 

    Made use of spikeyxxx elegant solution which covers most of the comments below:

    Added more geometry to circular cross sections. I think I really needed this many due to the "holding edges" needed for good corners.

    After adding more sides to the circles (gone from 8 to 16 edges) used Shift+Alt+S on individual circle loops to turn them back into perfect circles (the Edit Loop Tools: Circle macro was moving the circles around on me and causing headaches)

    Dealt with pesky 5 sided poles to get them away from harsh edges (made use of inset in ways I haven't done before haha) and I was able to keep the shoulder I was concerned about losing at the side of the cylinder (this was really the big pain point).

    Found 1 stray edge that was going the length of the cylinder and connecting in places it shouldn't. Deleted it.

    Actual Verts: with 5 sided pole moved to the cylinder. This was actually quite tricky for me to do properly even with Spikey's example.

    With a glassy matcap and subdiv  "On Cage" preview on to show how light catches it:

    Much more elegant look with the light smoothly transitioning around the circumference.

    • "...and there will be no pinching on this DOG!"

      Looks fantastic now!

      Maybe we could 3d print the 434E when it's finished...

    • crew

      Looking smooooth!!!! 

      There are times when more geometry is needed even if our minds are programmed for less.

      With the loops tools circle thing, can be a bit unpredictable sometimes, gives bigger circle than expected usually, and you do have to be sure you only have right verts selected, ALT + A is good practice before using it.

      Great result, this is what collaborating is all about.

    •  We'd need a BIG 3D printer LOL. I don't want any less than True to Life Size

  • crew

    All this progress being posted has me playing catch-up! Here's where I'm at after working a couple hours the past two Thursdays:

    Still a long way to go. There's so many details and pieces to model and interconnect. The diagram website is an absolute life-saver. I never could have figured out these intricacies with photos alone.

    Like you, I'm running into similar subsurf pinch problems as blanchsb, especially cylindrical shapes into rectangular shapes. I'll be sure to discuss such junctions in the next stream.

    Keep up the great work! The progress everyone is posting is inspiring 🙌

  • Next Question for the community regarding a potential "Clearance" issue (not a sale haha).

    This should be easy to answer but somebody is going to have to "Give".

    If the loader arms are centered on the Bucket Mounts we will end up with very little room for the wheels to turn.

    We either need to move in the Bucket Mounts to the Center More...........or Move The Wheels Out More.

    Thoughts from the Pound?

    • crew

      Looks a bit tight from  that  angle.

      I think we have front and rear wheel steering on our DOG  wouldn’t need to much space but I did notice the tyres are slightly wider than the hubs but who knows which is the correct size

    • Even though the reference never wins real life, it looks like the tires are correctly placed.

      We don't get a great view in the references on the main file for the Loader Bucket so I'm thinking they probably need to go towards the center more.

      ppfbourassa what do you think? It shouldn't be too much trouble to move your loader arm mounts in a little, correct?
      I centered my assembly against those, so if we all decide that is the way to go then just tell me how much you move towards the center and I can do a straight shift on my assembly by the same amount.

      Also the engine enclosure Aft-Side (towards the cab) is looking a little too wide I believe.

      P.S. That wheel well and axle-interface assembly looks amazing with x-ray turned on from above. I'm gushing. Can't wait to see all of this stuff with some silky smooth subdiv going on.

    • Yeah, these are the separate objects, and when I cut holes it should be possible to slide the holes around easily.

    • I am a bit confused about the tires...

      Using a reference box with some known sizes (total height, stabilizer width, wheel base distance) and given the fact that the tires for this model come in 24'' and  28'', I get something like this:

      Something seems off, compared to the reference picture...probably due to the focal length of the camera...

  • theluthier I have submitted a file to Google Sheets 

  • I may or may not be working on a little sizzle reel for the upcoming stream. So theluthier could I get a link to your digger arm (when it's ready?)

  • I was learning how to use decal machine and added the logo successfully to the loader arm for fun using the addon for my First Official Decal. Looks like the DOG gets top spot on my Personal Decal Save Library now!

    Tried a render out.  That was a pretty fun exercise:

    • It looks like a toy

    • Yeah sshanr They are technically grown-up toys haha!

      Don’t pay any attention to the DOG image on my submission, that was NOT a decal by any means I was just trying to figure it out last minute and ran outta time.

      theluthier One thing I wonder if you could cover during the live stream would be how to add a circular cut-out on a rounded surface that will not cause the main rounded surface to “deform” weirdly with subdivison. There are a lot of Grease Fittings on my loader arm parts and most fittings will screw into threaded holes that would go from the outer part curved surfaces all the way to the pins “pivot points“ for rotation, the curve surfaces are typically the areas of least metal thickness and make for good locations to drill out material. High areas of friction require regular greasing applications to preserve their integrity So grease fittings or “grease ports” are placed for ease of adding lubricant to high friction areas with a grease gun.

      Jonathon posted a video that I believe is relevant but it probably means most of my low poly parts will need an applied subdiv to use the trick a little better? Or maybe you could just show how to do one during the live stream. You’re probably going to have to figure that out as well. We will also probably want to use the “same” size grease port fitting across this DOG too so maybe having one built with help anyone else who has need to use them?

      Jonathon’s video on youtube is posted below.

    • There is also this video that I believe is relevant:

    • crew

      Your loader arm is looking great, Shawn. I'll be happy to cover the circular cuts in rounded surfaces bit. Could you snap a screenshot of the "grease port" that you're describing so I can approach it most relevantly?

      but it probably means most of my low poly parts will need an applied subdiv to use the trick a little better?

      Unfortunately applying a level of subsurf is often the only option, depending on the level of curvature. Looking at your arm pieces I don't see much I'm curious about the specific area you're referring to.

    • blanchsb , that's exactly the link I just wanted to post now 😀! But I'm just 16 minutes too late 😉 .

      I've also found this video usefull, since the guy here cuts an svg-path into a sphere where he uses a "Curve Modifier" in order to minimize distortions of the path before projecting it onto the sphere with the "Shrinkwrap Modifier".

    • blanchsb , I've used Inkscape in order to trace the "Dog" logo for the wheel hubs, since the orginal "Cat" logo is 3-dimensional, too. The only problem is using it with a "Mirror Modifier", so I applied the modifier and rotated the logo manually.

    • theluthier this also begs the question: Would this be a good use case for using the coveted MultiRes (this isn’t a “skinned” mesh I suppose but I wanted to know if it had a use case here Since I don’t have much geometry to work with, I have never used multires.......ever).

      yeah I’ll try to get the grease port fitting posted here after work today. I’ll also show where mine are going to be needed to be installed based on jjakeblended ’s find of the schematics (and my own special access). and as a complete side note, how do I “quote” someone. I’m on my iPad right now and not sure how that works.


      1. I’ll definitely watch that video later. Thanks!
      2. I am using Afinity Designer to make the DOG logo (I think dostovel logos should be the officials but I drew that up around the same time and I may want to do a special background on the loader arm logo  because for the cat logo it has a unique shape there. Using the decalMachine add-on is super handy putting this on original/mirrored objects and once I figured it out it was extremely easy to use, plus it has the feature to add 3D detail and makes use of paralaxing. I think I’ve purchased most major add-on’s and am itching for opportunites to use them to learn how to add them to my workflow. I know the mirror modifier has a flip U or flip V feature as well that seemed to work really well for me.

    • crew

      Would this be a good use case for using the coveted MultiRes

      If anyone covets's me haha. Theoretically yes, multires could be used to add smooth subdivisions AND fine tune pinching via sculpting. It's a clever approach in fact.

      But It's not a common solution and slightly complicates the setup. Imagine doing this for *all the pieces on this backhoe* 😵

      Typically you can get a simple subsurf modifier to do what you want with enough finagling, at least to a satisfactory level. Only in the most bothersome situations would I add a multires modifer to manually smooth out pinching.

    • Had to Google the word 'covet' and found this: 

      "Thou shall not covet" is the most common translation of one of the Ten Commandments!

      Funny how educational learning 3D actually is;)

    • Lol. It is technically coveted because Kent wants it to work on 2.8 badly. I hear there is a semi-stable release on 2.83 on the rumor mill. spikeyxxx is this true?

    • blanchsb if I'm not mistaken, this did not make it in the 2.83 release, but Multires is supposedly working again in 2.90!

    • Superfresh info about Multires:

    • On the left 2.83 Beta vs on the right 2.90 Alpha (compiled today):

    • what is better  2.83 or 2.9

    • theluthier okay here is the examples of the grease fittings and adapters that get installed into my curved surfaces that have pinned hinges. (Now I'm thinking of the children's song "I'm all made of hinges")

      and here's some info on the specific grease fittings posted below. The 90 degree fittings are mostly used when I zoom in on the diagram for the loader arms.

      There's also going to be a bunch of hydraulic fittings as well on all of the hydraulic parts that will share the same modeling lesson/technique. Hope that helps for the lesson.

    • That is perfect!  I've actually been looking around for a decent close-up view of some grease fittings; these drawings are even better.

    • Perhaps another pain point that everyone will probably appreciate being covered is how to line up circular parts so that they are concentric with others.

      I know blender is not really a CAD program and the snap to an object’s circle-center circle ⭕️ is not a built in feature like other professional 3D cad software.

      theluthier  Maybe a quick tip on how to align parts that are all concentric to each other would be helpful for the DOG Pound? What do y’all think?

      There are a lot of hydraulic/mechanical fittings and hinges on a lot of these parts that are all going to need to be lined up. I know eye-balling-it is the artist way for a lot of things but the engineer in me cringes to do that over and over again haha, maybe it’s just me and I’m being overly critical of my own workflow though.

      One rather hard exercise I have found is lining up 1 object with 2 other objects without deforming the mesh terribly. Say there are two hinges, one at each end, and you need to line up both ends to other hinged parts of the assembly.

      Maybe this is too late to discuss this though. Just figured I’d throw this idea out. I spent way too long trying to solve this particular problem on my own and told myself “there must be a better way” and “I’m missing something”

    • crew

      I feel it ,blanchsb , sometimes I can be like how can it be done after what seems like an hour , and then I see a tutorial or someone explains it and I'm like 'I knew that already'.

    • crew

      blanchsb I'd be happy to discuss that situation on the stream. While I think I know what you mean, could you post a screen shot of 1 or 2 situations as you described? Indeed it sounds like a common task and thus helpful for the DOG Pound.

      EDIT: I just noticed the grease fitting images you supplied. Would it be helpful if I modeled that specific (most used) fitting during the stream?

    • While I think I know what you mean, could you post a screen shot of 1 or 2 situations as you described? Indeed it sounds like a common task and thus helpful for the DOG Pound

      Yeah I can do that: 4 different parts the must align in similar ways. Hard to explain but hopefully the picture below makes sense. I wish there was some sort of concentric snapping between two objects that have circles. Would make it a little simpler to align them all.

      one of my biggest pains was aligning the hydraulic main body from one pivot location on the right to the other location in the lower left  (It is the note in yellow, regarding the part in pink/purple) and making the “rod” also align perfectly (the yellow part inside). Somehow these Two parts got out of alignment with everything even each other and it took me forever to figure out how to align them all again

      EDIT: I just noticed the grease fitting images you supplied. Would it be helpful if I modeled that specific (most used) fitting during the stream?

      I feel like I am making all of the demands for what to cover in the live stream 😂 . Sure if there is time left over I’d love the additional coverage. Or I can make the grease fitting and post it to you and you give me feedback And once it is satisfactory then it can be given to the group. With the time constraints though: I’d rather see how to make good holes on the curved surfaces and how to do the hydraulic lines easily to be honest.

    • blanchsb that is indeed tricky! When I was in a situation like this (actually also with hydraulic cylinders), I made a small 'rig';

      using Empties at the ends of the cylinder, parenting (or using Copy Location and Copy Rotation Constraints,,,) the two parts of the cylinder to the Empties and a Damped Track Constraint so that I could just snap the two Empties to their positions and the cylinder would follow...Somethiong like that, can't remember exactly;)

    • Ooooooooo! I wanna see how to do that! Kent there you go. Empties for the win.

    • blanchsb maybe (hopefully) theluthier has a better way of doing this! But I've got it working and the cylinder is the hardest part, when you can do that, the rest is a breeze;)

    • I’m not picky spikeyxxx anything is better than how I was doing it. Haha

    • blanchsb and theluthier I remember now how I did this, actually used Empties and Bones, sort of like this (the set-up is symmetrical):

      I'm not a rigger and waylow will probably laugh at how 'clumsy' this is, but, in trying to avoid circular dependencies, I ended up with this;)

    • Interesting.......kinda hard for my brain to follow just looking at it since I have never done this but I will try to replicate it on something simple and reply if I have questions. Thanks spikeyxxx 

      I feel bad for Wayne trying to play catchup (but feel free to play with kechup/ketchup/catsup) on this forum posting haha.

      P.S. I am a Heinz Ketchup guy myself.

    • blanchsb each Bone is at the position of one Empty (Copy Location Constraint) and pointing at the other Empty (Damped Track Constraint).

    • crew

      Forgive me blanchsb and spikeyxxx...but I'm having a hard time understanding the difficulty at hand 😅 Clearly you two get it though, so it's just me not understanding.

      With constraints involved, it almost sounds like you two are talking about how the model correlates to the final kinetic functionality of the mechanism (?)

      Perhaps I'm not clear about what needs aligning to what. Based on the screenshot I'm seeing circles being connected by straight lines which is..well..straight forward.

      If you could record a video of your screen and your voice describing the issue, that's probably the best way for me to understand.

      I'm sorry! I feel so dumb 😫

    • theluthier don't feel dumb!

      Basically you have a hydraulic cylinder like this:

      and you need to snap point P to a certain position as well as point P.001.

      Try this without looking at my solution...

    • spikeyxxx not only explained it well with one sentence but provided a clear picture! What a stud.

      theluthier Let say that P and P.001 were not aligned in the first place and now your job it to align them. P must point at P.001 and yet P.001 must also Point at P. How to do that without a circular argument makes my head hurt haha.

      If I need to move P around to re-position it Then I want P and P.001 to keep looking at each other.

      This is what knowing this will solve for me:

      Basically I have to line my assembly up with:

      1 Align with Itself (I have lots of objects that pivot and join together on both ends within my loader arm assembly) AND 

      2 Align with the Loader Bucket on one end AND 

      3 Align with the Chassis on the other end. 

      If I modeled everything together I could completely control all of that but at this point I am depending on ppfbourassa's changes and the changes from adrian2301 for the chassis. Currently I have #1 and #2 under control but I am having a hard time getting my entire assembly moving to align to #3 while maintaining that relationship to #1 and #2. It's been turning into a little of a nightmare haha. If ppfbourassa or adrian2301 moves their pin holes because they needs more room then I need to be able to adjust my assembly accordingly to match them. My part is the middle man and should probably conform to the others

      spikeyxxx  is on point with perhaps bones/empties/contraints. I am not so much concerned about the animation as I am about keeping things lined up if there are any more changes.

    • blanchsb indeed, this is not about animation, but using a rig to model things correctly...Thinking outside the box here.

    • crew

      AHHH OK you both have cleared it up for me! Thanks for the patience, guys.

      I think Spikey's damped track constraint is the best method. I'll certainly go over this tomorrow 👍

    • crew

      So....... I know a little about mechanics and engineering, I'm no expert but here goes:

      The idea of the hydraulic piston is for Part A to be pushed and pulled in and out of Part B, In this example P.001 would be aligned with the chassis, but the rotation is free, meaning there is no force rotating P.001. The rotation of P.001 happens  when the arm is lifted or lowered by a separate piston. If P is attached to the bucket, the push and pull of this piston is to rotate the bucket, so with the piston extended, or pushed, the teeth of the bucket would point towards the ground, and when retracted, or pulled, then the teeth would point towards the sky. 

      So this would suggest that P.001 would be constrained in location only, or aligned with the chassis, but free to rotate. The other point to consider is that parts A and B must always be aligned exactly on the same axis. The rotation of the bucket at P is dependent on the position of A  in relation to B along this axis. So this piston controls rotation at P or more precisely the rotation of the bucket. The rotation at P.001 is controlled by the movement of other parts, or the lifting of the arm by another piston, But the location of P.001 in relation to the chassis will always stay the same. Part B would move along or over Part A.

      So to do this in Blender:


    • I figured it out spikeyxxx  adrian2301 theluthier . Thanks to Spikey for the clear explanation. I mainly want this as a part of my assembly to assist me in moving my parts so that I mate up to the Chassis and Loader Bucket and also maintain my assembly's relationships for each part to one another. This will help me roll with the design punches if anyone needs to move any pivot points. Maybe I do want Wayne's input as well since I am 1/64th Aussie. waylow  feel free to tear my thought process apart.

      Enjoy the video and give feedback (best watched at 1080p). My voice is extremely alluring and should keep you awake for maybe 30 seconds of the 2  minutes,  haha.

    • crew

      HI Shawn, 

      Sorry if any of this is off the mark - I haven't read the full thread so I'm a little confused as to what's going on haha.

      But I have flagged it with Kent that I think we need to rig this project when it's done ;)

      You are on the right track (pun not intended) but you can keep everything inside the 1 armature rather than using an armature and 2 empties.

      Swap your empties for bones and then parent them in the same way (rather than copy loc constraints).  Everything else will be the same - except you will probably need to avoid parenting one control to the other (as you are likely to get a dependency cycle - but I will have to take a closer look at things to be sure, I'm just thinking out loud at the moment).  If you do get a dependency cycle you can then unparent and use the copy loc.

      Keeping all the controls inside the 1 armature will make it useable for animation ;)

      As for the stretching part - I'm not exactly sure how it needs to work but try the stretch to constraint and turn off the volume preservation so it stretches the geo along the length of the bone.  (otherwise you will get cartoony S&S)

      The stretch to is very similar to the damped track but it also stretches.

    • Sorry if any of this is off the mark - I haven't read the full thread so I'm a little confused as to what's going on haha.

      But I have flagged it with Kent that I think we need to rig this project when it's done ;)


      Ladies and gents, the game is afoot. shall be eventually.  One thing at a time I suppose.  :D

    • crew

      So was that you in the video blanchsb , haha

      Perfect, I would presume the empties could be parented to the part it is attached to.

      3 Align with the Chassis on the other end.

      the changes from adrian2301 for the chassis.

      I have worked hard on trying to work with everyone's parts to get the chassis to a point now where I don't anticipate having to  make any more changes to the chassis, apart from maybe detailing, but the position of the key points such as where the loader arm attaches the chassis, I'm confident won't change.

      I'm still a bit confused on the part you talk about stretching.

      I've borrowed your image, I'll give it back I promise, 

      Ok Consider Piston 1 is your example in the video,  point 1 is attached to the chassis and location is fixed but rotation is free. Also point 2 has a fixed location in relation to the main arm. So if the empties in your example video were to be parented to the chassis and arm respectively, when lifting the main arm, which is fixed at point 10 to the chassis, piston 1 would extend and rotate at point 1 and 2, perfect so far in you video. Piston 2 has fixed LOC at Point 5 and 6 in respect to part 2 and 3. Piston 2 when extended pushes part 3 which then rotates the bucket at the pivot point 8. Part 4 is there to stop it just flopping around.Part  1 and 2 are there to stop piston 2 moving in the wrong direction. So imagine the main arm raising up at the bucket end and pivoted at point 10, Part 1,2,3 and 4 will all move as they are all connected. All the pivot points from 1 to 11 will be rotating at different degrees and directions, while the main arm is raising but will always be constrained on the location to the respective part. Point 1 to the chassis, Point 2 to the main arm etc. etc. Where the piston is free to extend as in your example video, the only consideration going forward would be a limit to how far it extends and retracts. This I would suggest be controlled by limiting the rotation of point 10 for piston 1 and point 8 for piston 2. I'm going to stop there as I'm beginning to confuse myself.

      But I'm not sure where stretching will be necessary.

    • The stretching is only necessary because my parts' pivot points at the Chassis connection are not "perfectly" going into the holes that are there. They are slightly off when you zoom in (circles 1, 10, 11) I would only need to stretch "Part 1" and "Part 2" to get them to line up.

      "Piston 1" is a piston so I can move it and the outer and inner will slide just fine since they are two parts. "Part 1" and "Part 2" are single parts and currently will probably not line up exactly on both locations (loader bucket connection and chassis connections). So I would have to go into object mode and rotate to "eye-ball" hopefully something close, then go into edit mode and stretch the edges, then go back into object mode and rotate again, and rinse and repeat. Then do the same for the next part. Have the objects point at each other is really what I needed to be honest.

      I am trying to think outside the "we'll just edit the meshes until they conform to the change and remodel if necessary" box. If this were a production pipeline and let's say you did need to move 3 inches back, how would I roll with those new changes? Constraints seems to help A LOT to overcome this hurdle.

    • Yeah that was my sultry voice adrian2301 I was not trying to imply that you were making drastic changes or being careless. The chassis is looking awesome. I just didn't have a chassis to "line up with" when I first made the loader arm assembly. So now that I have put a lot of work into it and want to "mate them up" AND not deform my straight parts and the Engineer-in-me wants it to line up exactly haha.

    • With the Copy Location AND Damped Track Constraint I can totally line up my straight parts and manually stretch them along their local axis in edit mode until they go where they need to go. That constraint workflow completely makes my life A LOT easier.

    • crew

      blanchsb sorry if it came across wrong but I hadn't thought you implied anything, I am happy to make adjustments as and when. Not having any clear images of the chassis, I am modelling the chassis based on other parts and the images only as a guide. Now we are all on a more detailing stage the process is getting easier for me. With the next update of the main file from theluthier this week I will be able to move the location of the holes slightly to match your parts. The engineer-in-you would probably agree that if we had detailed drawings with measurements like circumferences of a hole or the precise location of said hole.  I hope this clears that up, I was assuming everything was all aligned perfectly. Now I understand the 'stretching' issue we can hopefully overcome this by moving the holes to line up.

    • adrian2301 to be honest I feel like it would be my job to line my parts up to your chassis since my parts are quite movable. Leave yours where they are and I'll make the fix for the next submission round. It is really a fine and challenging exercise for me. I'm not complaining at all because I am learning sooo much that I wouldn't on my own. This team interaction is quite fun.

      Maybe ppfbourassa would need to line his part up to mine since the bucket sits at the end and relies on the arms for movement.

      I think this makes the most sense to me.

    • Yeah, I tried to keep my holes flexible. They are all cut into flat sheets, so it's easier to slide around than yours where the whole piece kind of revolves around the holes.

    • crew

      blanchsb to be honest the chassis has pretty much been guess work, trial and error. So don't rely on the holes being where you need them, I think we will all have to work together to fix it.

  •  Sorry for the radio silence, guys!

    Here's this month's detail work.  I'm a little anxious that it might be visually underwhelming, and I'm glad Kent set a minimum of 25% completion, because there was a whole lot of work to do for what might not look like much visual progress since my initial block:

    Because of the design inconsistencies I mentioned last month, I ended up having to reblock all the major components from scratch - AGAIN!  I had hoped I could just use the first blocks that I made and maybe just simplify the mesh and reshape them, but no dice there sadly as the correct pieces were ultimately just too different.  It soaked up a lot of time to build all that again, but on the plus side I am much happier with my topology this time around.

    The only components from my first month that I was able to actually reuse were the hydraulic cylinders.  But, I did give them a work-over to clean up some topology issues especially around the vertical "round" parts - I had not made a very good intersecting cut with my first blockout - and I retooled the surface to make it more closely match the cylinders in my reference photos.

    But at any rate, with all of this work, basically almost all of the major and minor hard-surface parts are done for this part.  But, there's still plenty of work to go.  I estimate that at least two-thirds of the remaining work I have to do is going to be hydraulic apparatus - hoses, pipes, and fittings, and the small brackets that hold all of them.  There is a LOT of it.  It's like someone just dumped a whole basket of snakes into the back of the backhoe.  Really big snakes.  But, I'm confident it's nothing I can't handle and I'm looking forward to it!

    adrian2301, I know that you've made a lot of progress on the frame, but all I have is the original one that came with Kent's stream 2 download, so I don't know if you've changed anything around this part or even if you've been waiting for me, so I only have this request with regard to your frame:  if you can, I'd like you to raise the lower-most "slide rail" (that's what I've decided to call it) just an inch or so, enough so that it clears this part:

    You can see where it intersects the small "ledge" that sticks out the back of my slide-frame there.   Raise the whole rail if you can, because each of the two rails AFAIK should be the same height top to bottom. I think you should be able to raise it just enough to clear that, without intersecting the hydraulic cylinder above; if there's problems, I can address them afterwards.  That's the only change needed on my end!

    theluthier I think you'll probably need to move your digger arm so that the bottom hinge pin lines up with the holes on the swing-frame, and that's pretty much it.  There shouldn't be any design changes needed from either of us by this point.  The bottom end of your boom's piston should clamp on to the upper hinge pin.  You can probably just rotate and move the piston itself rather than the whole boom to make it fit.  Unless you want the "latches" on top of the swing-frame to be engaged with the small cross-pin there - it's up to you, and you can just rotate the latches as needed if so - if I need to do any remodeling of the latches to get them to fit right just let me know.  The latches are only supposed to be engaged when the digger arm is "stowed", so if you're modeling the arm to be extended in any way I suppose they would stay unlocked.

    The blend file is in my OneDrive if anyone wants it - it's the "swing_frame_02" file. ppfbourassa  I'd love to make it into your reel if there's time!

    It's been so awesome watching the progress everyone is making.  I feel like finding that site with the part drawings is like my biggest community contribution since I've joined CGCookie. :)

    We're on a roll everyone, let's keep it going!

    • crew

      jjakeblended Nice job with the swing frame. I have downloaded your new file and appended it in with my updated chassis/ stabilizer model.

      This image shows my updated chassis/stabilizer, the lower rail is now higher due to an adjustment made to accommodate the position and height of the axles and tyres by duerer and spikeyxxx , by the way the axle looks great. 

      The rails are easy to move, and once I move them down an inch the cylinders should fit nicely above.

      The top rail will also need adjusting, again easy to move. The more difficult part comes  with lining up with the chassis  support without lowering the whole chassis to much to obstruct the axles and the front end is currently nicely aligned with the loader arm from blanchsb , but I will probably not have this done before the live stream, theluthier , but the production line is still operational. I am continuously adjusting the chassis as everyone submits there parts because I have very limited resources for the chassis. I have the collage and the images of the chassis from the treasure trove, but nothing to show the chassis in relation to the other parts, and I thought the chassis was going to be the easy part, and it probably is in regards to detail, but as for size and positioning it is like a continuous modification process.

      Overall I would say the position of the swing frame is correct according to references, however I have two questions for you jjakeblended

      Q1. The cylinders, are they the correct size or are they an estimation?

      They look a little long. As the swing frame moves left and right along the rails they will collide with the chassis.

      And Q2. The Slide Frame Main, Would you agree, where it attaches to the rails, I think should have a plate attached to act as a kind of hook over the rail?

      I would suggest that's the purpose of the three bolts, same for the bottom rail.

       Really looking forward to the live stream and the 'sizzle reel' ppfbourassa is putting together.

    • jjakeblended Holy italiano cannoli batman! The Crock just dumped a bunch of reptiles all over that dozer on 5th street!

      What dedication to remodel your assembly! I think a few of us had to do that too. Learned a lot along the way though.

      I’m thinking bezier curves or similar are going to be your best friend as you “charm” all of your cobras 🐍.  I’ve got a few snakes to deal with myself, but rather than a basket dumped in one spot, mine have had a week to spread out and they’ve slivered all over front (in symmetrical fashion no less! Talented serpents.....,)

      I think theluthier  could perhaps give some good tips on how to charm one of these snakes in the stream.

      They’re probably mostly going to be the same tube size so we may all want to collaborate on the same tube diameter too haha.

    • adrian2301 - to answer your questions:

      Q1 - nope, the length of the cylinders right now is kind of arbitrary.  Once I have your updated frame I'll be able to shorten them to the right size, no problem.  If I need to, I can also adjust the cylinder mounts rearward a little bit also without affecting anyone else's stuff.

      Q2 - you are right!  There are clamps on both the top and the bottom; I left them off for now for clarity while you're making your adjustments.  They're simple square plates, so not a pain to add once we've settled the compatibility issues.

      blanchsb My favorite way of doing hoses and tubes like these are by using paths; I used them to make a French horn for a project a year or so ago and they turned out great!  There is one problem, though.  From the very early beta days of 2.8, I remember reading that there were some problems getting materials to show up properly in Eevee on 3D shapes made from curves or paths - i.e., you'd end up having to convert them to mesh to add a material.  I have no idea if that issue has been fixed or not - I hope it has, because I'd much rather keep all of the hoses curves rather than making mesh out of them, in case I need to tweak shapes.  But, I'll cross that bridge when I come to it I suppose.  

      Also this month, I see people have already begun adding at least basic materials to their components, so that is on the menu for me as well.  At some point before the model is finished I feel like we're all going to have to decide on some "universal" materials - yellow paint, flat black paint, glossy black paint, bare metal, shiny metal, rubber, etc. to apply to our stuff so that the model will look consistent when it's finalized.  

    • jjakeblended I just added materials to a separate file to show a temporary render. The main file I believe the materials will be selected by Kent, but you're absolutely right. I bet we will be assigned to do our own materials and we will want to pick a color pallette to stick to for the yellows, greys, and blacks I bet. It looks like he has grouped a few things together by assembly for the materials which is nice.

      I just don't like rendering white or grey objects haha. It's easy enough for me to spend 15 minutes to a half hour to throw some mats together just for fun. I'm no guru but I am getting better at the node editor.

      What's the difference between Path's and Curves I wonder? I'm going to honest that I bought the Fluent Power Trip add-onto see if I can use that add-on for the hoses and then just apply the mods when I am happy.

    • blanchsb as far as I know (so don't take this for authoritative, ha) the main difference between paths and curves is that paths you can't use Bezier handles to control the shape of the "curve" between control points.  Neither is superior to the other I don't think; for laying out pipes or tubes with very specific courses (like my French horn) I just like to use paths because building them is closer to the behavior of building mesh, and I feel the resulting mesh is also more predictable if I do have to turn the path into mesh at some point.  For something a little more "freeform" like flexible hoses that won't be going in straight lines, using Bezier curves might be better.  I'll find out. :)

      Note that as far as Blender is concerned, paths are still a TYPE of curve, so they use the curve properties tab and the "Convert Curve to Mesh" operator, etc.

    • crew

      jjakeblended I've adjusted the swing frame rails to fit.

      Just need to add the clamps and adjust the length of the cylinders.

      The Link if you want it .

    • jjakeblended FYI: Materials on Curves/Paths seem to work fine in Eevee now. Luckily, because repairing intersections or other tweaks are a lot easier when not converted to a Mesh;)

    • jjakeblended  same here I just added materials so you can see. 

      I've been tearing apart my cab again lol smh  I keep seeing new things. 

       @adrian2301  at the front, back and side views I keep seeing that the back lower part of the cab gets narrower than the front.  So I'm going to stop where I'm at because I keep trying to match the wheel cover thingy...yea I'm a girl and I know nothing about the mechanics of things...I really don't know what I was thinking lol

      Here is the Back view.

      And here is the front view

    • crew

      jjakeblended I was afraid other priorities had trumped your swing frame progress this assignment period! I'm glad that wasn't the case. You'd done an awesome job on your new and improved swing frame 👏

      I think [Kent] could perhaps give some good tips on how to charm one of these snakes in the stream.

      blanchsb I initially planned to cover hydraulic lines but other things have pushed it down the list. If time runs out tomorrow, definitely next stream 👍

    • crew

      OK ketre , The Fenders as they say in some parts, wheel arches in others, are not quite complete, as to say they need to be extended in the  x direction in towards the cab so I would ignore them as a reference for now I was going to wait and use the cab as reference. But your right the cab has got an awkward shape, it probably is shaped around the fenders, but  I wouldn't worry about trying to do that. I would suggest at the point where the angle changes just above the fenders, it should be more or less vertical or even angled inwards. See the blue lines I have added to this Image. It wont go any lower than this as that is approximate height  of the chassis. but I would go with this for now.

    • adrian2301 all right, here we go - I've got the "clamps" on the back of the slide frame, and adjusted the cylinders for the correct clearance:

      Here is my updated file - but, I already submitted my previous file to Kent on Saturday, so these corrections probably won't make it into the stream unless Kent grabs them at the last moment, ha!

      ketre you know what I bet would REALLY help you with that - and help a bunch of other people's components  too - is a decent top-down plan view of the whole backhoe, but for the life of me I just can't find one - not even on that website with all the part diagrams.  It's super-frustrating!

    • crew

      jjakeblended looks like a perfect fit. My changes to the height of the rails are not included in my submission either, I think it may be a bit late now to be included. But at least we are making progress, I'm sure theluthier will be aware of the progress being made by everyone.

      ketre found an image that may help with the cab as far as height in relation to the fenders.

      As you can see the base of the cab lines up with the bottom of the fenders. The front edge of the fender is lower than the rear as you would be able to see from my model of the fenders, this weeks submission will be part of the next updated file and will probably help you more. As far as we can tell from this image the Cab is the same length as the fenders, maybe slightly bigger at the front, but I think the Cab curves in a bit at the bottom. The metal frame at the bottom is probably custom made for transportation of this part and not actually part of the cab.

      Here's the LINK to the site where I found this image, maybe useful for other parts, but I haven't searched the site so may not find anything of use.

      There actually based in AUS, so if waylow is not to busy and wants to join our project, a tape measure could be useful. 

      Just an Idea, but maybe Dixy can give a lesson on rigging and animating this DOG at a later stage, as it has been mentioned previously with the pistons, with constraints and bones and empties and rigs and rotation and everything else. I'm confident in theluthier skills, but waylow knows his stuff when it comes to animating. I have been on the Animation Bootcamp course recently, and I have learnt a great deal from Dixy, and realise how hard animating is. Bootcamp is probably an understatement, but it is a fantastic course.

      I for one am really into this collaboration project and think we can take it further and have a whole fleet of construction toys all rigged and animated, is it showing that I don't want it to end. ha ha.

    • crew

      Indeed I'm regularly reading through this thread. As well as I can...I know I'm not the only one getting confused in here lol 😅

      The cab seems to be a particularly tricky piece of the backhoe. If there's time today I'd like to work on the cab during the stream.

      Just an Idea, but maybe Dixy can give a lesson on rigging and animating this DOG at a later stage

      He's already told me he wants to rig it when we're done!

    • crew

      Yeah the cab is a bit like the chassis, you can't see where it begins and ends, But hopefully the image above helps.

      Excellent that Dixy, waylow , want's to rig it. Do you think he might want to be apart of a live stream or just upload a course? The reason I ask is I'm learning more about animation and rigging but most of the courses are from previous versions of Blender, pre 2.8, so it can be quiet hard to learn such a complex and difficult subject.

    • adrian2301  the collaboratoon is awesome and so much fun theluthier  thank you, Ive been tearing my hair out over the cab...

    • Oh wow, all your parts look so great, I feel my step and battery box are so lame now . I go away for a moment and there's just too much to read, so I'll just imagine it all goes "I present my piece!, wow, very nice, any advice? yes! maybe like this!, thanks! you all rock!.... and I'm done, good job everyone.

  • jjakeblended wonderfull, how the shapes flow/fit into each other 😀.

  • I'm getting excited for the stream today. Going to hop on the waiting room now if it lets me.

  • Hey everyone I just found this on the cab  

    A close look at the cab