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Feb 22, 2015, 02:11 AM
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dshy's Avatar
Lots of details in that cross brace, nice model. I'm modeling out the brakes on kobayashi and my topology got a little messy where I needed to make a little shoulder similar to the bottom section of your part. Slowed my progress to a halt, might have to take a new approach now that i figured out all the shapes I need to make the part.

How's the gpv-1 project going?
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Feb 22, 2015, 09:39 AM
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katana2665's Avatar
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Quote:
Originally Posted by dshy
How's the gpv-1 project going?
Getting there...



Working on the other pieces now. As for your model, I find that it's easier sometimes in Max/Maya to just build two sections of vastly different topology and then just insert one into the other. While not technically accurate, it makes it less problematic than trying to figure out how to change the edgeflow to suit the new direction in geometry.

They use this method exclusively in video games where say a shoulder pad has to be 'attached' to the main figure. In some cases it allows the shoulder pad to be easily replaced by an updated model, thereby preserving the base model. In other cases, it's to save on wasted polygons.

Just depends. When you render your model at a higher resolution, you usually won't see the break if the materials are the same.

Another thing you can do, if you have the tools ids to model the two pieces, bring them into ZBrush to combine them and then into Topogun to redo the topology. That's my method for difficult pieces.
Last edited by katana2665; Sep 03, 2017 at 08:46 AM.
Feb 22, 2015, 07:33 PM
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dshy's Avatar
Looking great!

Do the printers care about quads? Ngons? Edge flow? I usually box model with all the game constraints in mind, but if I can just bash everything together that will be way easier. For CNC routing/milling I would suspect the mash up method would fail/not work?
Feb 22, 2015, 08:22 PM
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katana2665's Avatar
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Printers just need airtightness and the right file type. (.stl/.obj) scale from the animation programs are not as precise as cad...you can see for yourself if you download the Makerbot free software and import a file. What you will see is a rough surface of tris and the scale is different.

The model needs to be a single mesh. So in this quick example from 3ds Max...we have two objects, both airtight, occupying some of the same space.

Maker bot recognizes them as one mes (denoted by the yellow outline.
Last edited by katana2665; Sep 03, 2017 at 08:47 AM.
Feb 22, 2015, 10:04 PM
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dshy's Avatar
Thanks Chris!

Are the facets an artifact of the obj export? I know obj has issues with normals. Is it possible to just soften the normals? Or is it a question of export density? If you make the sphere millions of polys it will export smooth?

Thanks again for your effort and time explaining and for of coarse sharing your efforts.
Feb 22, 2015, 10:09 PM
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katana2665's Avatar
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You're seeing the polygons because it was a low rez sphere. The cube is only two tris per side.

Increasing the density of the mesh, smooths things out, but increases the file size.
Feb 22, 2015, 11:15 PM
dammachines
Quote:
Originally Posted by katana2665
Printers just need airtightness and the right file type. (.stl/.obj) scale from the animation programs are not as precise as cad...you can see for yourself if you download the Makerbot free software and import a file. What you will see is a rough surface of tris and the scale is different.

The model needs to be a single mesh. So in this quick example from 3ds Max...we have two objects, both airtight, occupying some of the same space.

Maker bot recognizes them as one mes (denoted by the yellow outline.
Chris,

If I understand what you're saying here about having two models occupying the same space I would say how this is handled is dependent on the slicer. I use Cura with my Ultimaker, and early on when I was modelling the MX Helmet that I posted in a thread a while back I added the visor by just adding the visor model to the top of the helmet model. When printed, it attempted to both close the top of the helmet (inside the model) and add the visor above. It didn't print well at all.

I ended up having to edit the mesh (I'm using Blender) and manually connect the vertices to create a single model to get it to print correctly. I still have the "bad' stl file here, I haven't tried it in Netfab yet, but since it's used on professional printers (well the higher end version of it are) it may handle the file differently.

Dave
Feb 23, 2015, 01:52 AM
RC Motorcycles are fun Bobby
King of the hill's Avatar
Quote:
Originally Posted by katana2665
Getting there...



Working on the other pieces now. As for your model, I find that it's easier sometimes in Max/Maya to just build two sections of vastly different topology and then just insert one into the other. While not technically accurate, it makes it less problematic than trying to figure out how to change the edgeflow to suit the new direction in geometry.

They use this method exclusively in video games where say a shoulder pad has to be 'attached' to the main figure. In some cases it allows the shoulder pad to be easily replaced by an updated model, thereby preserving the base model. In other cases, it's to save on wasted polygons.

Just depends. When you render your model at a higher resolution, you usually won't see the break if the materials are the same.

Another thing you can do, if you have the tools ids to model the two pieces, bring them into ZBrush to combine them and then into Topogun to redo the topology. That's my method for difficult pieces.
Top idea with the adjustable wheel base and rake and trail K ! , if a bike in 1/1 mishandles it's nearly always caused by a wheel base / rake and trail / weight distribution data not correct , so this would apply to all scales in RCB's too . I know that Honda HRC take this data so seriously - one of the reasons why their race bike's consistently have the best handling and tyre wear even though they have some of the highest horsepower figures . I remember Mick Doohan saying once hid did 150 test laps to perfect the yoke angles and swing arm positioning on his NSR to get it right !
Feb 23, 2015, 02:16 AM
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Chris Nicastro's Avatar
The GPV has adjustable Rake, Trail, WB, Swing Arm Pivot and Chain Tension as well as full suspension and ride height.

Its the real deal in a small bike.
Feb 23, 2015, 02:51 AM
RC Motorcycles are fun Bobby
King of the hill's Avatar
Quote:
Originally Posted by Chris Nicastro
The GPV has adjustable Rake, Trail, WB, Swing Arm Pivot and Chain Tension as well as full suspension and ride height.

Its the real deal in a small bike.
Didn't know the full spec's of the original kit Chris , but I should have known - if it was one of your bikes then every detail would have been conceived originally - .
Feb 23, 2015, 06:23 AM
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katana2665's Avatar
Thread OP
Yep. This is Chris N's carbon race kit...it had a lot of adjustment. I did the chain tension device yesterday, which was a clever offset concentric piece with a indicator for tension.
Feb 25, 2015, 11:32 AM
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katana2665's Avatar
Thread OP
A more consuming and difficult piece. My hat off to you Chris for getting those nice smooth radii.
Last edited by katana2665; Sep 03, 2017 at 08:47 AM.
Feb 25, 2015, 11:01 PM
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katana2665's Avatar
Thread OP
Rear Sprog. Still have to tweak the teeth.
Last edited by katana2665; Sep 03, 2017 at 08:48 AM.
Feb 25, 2015, 11:14 PM
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Chris Nicastro's Avatar
Good job on the swing arm thats a tough part to model. Even harder to produce! Did you lighten the part with pockets?

The factory hated that part and the shrinkage was a big factor.

The sprocket you worked from was the early one. The later update increased its strength. The tooth profile is off I can see that. I put a conical extrusion on the back surface and used the lightening pattern to blow it out. Then add half degree of taper to the walls for tooling with the parting plane on the front face. Use the chain to take some dims from.
Feb 27, 2015, 01:46 AM
PROFESSOR TRUTH JIMMY ICE
Akura2's Avatar
Quote:
Originally Posted by Chris Nicastro
I put a conical extrusion on the back surface and used the lightening pattern to blow it out. Then add half degree of taper to the walls for tooling with the parting plane on the front face. Use the chain to take some dims from.

Whut?


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