SubD footpegs


(Gustavo Fontana) #1

Hi All,

I made these Sub-D footpegs yesterday for my bike. They are called adventure pegs. Basically is a larger platform (wider and longer than standard motorcycle pegs so you can stand on them with MX/trail boots. Arevernd also have a lot more grip (metal cleats).

I first modeled the original pegs and mating geometry to the pivot using sophisticated 3D reverse engineering (calipers and eyes). Then I made the larger metal pegs in Modo, also remodeled the pivot geometry so it’s all in once continuous solid. I converted to Sub-D using the SubDFromMesh test command and I added the pivot cylinders as more accurate nurbs boolean.

I was hoping to 3D print the in sintered metal, but that costs $2500 for one set! ( fancy CNCed pegs like these retail for $250). So I’ll see if I can find someone who could machine these for me (a bit tricky since it will require multiple setups).

I have some issues on conversion that I will come back and report here (mostly related to bad ngon OBJ imports). But overall I like this workflow. and I can’t wait to get even better with all-rhino modeling instead of the Rhino<>Modo dance.

these images are realtime screenshots using a tweaked anodized aluminum material from @andy, an HDRI with/skylight and groundplane on (a similar material to the aluminum).

in aces you are wondering why one of them has a protusion at the bottom: this is a stopper for the bike’s kickstand so it maintains a distance from it when it’s released. you can see the existing Yamaha pegs here:

Cheers,

G


#2

Total and complete luddite question, but could you put some sprues on there and print it in wax, and sand cast it with aluminum?


(Gustavo Fontana) #3

that’s a great idea Sam! I just looked into in and Formlabs makes a castable resin: https://formlabs.com/materials/castable/

I just asked friend and colleague Joel, h’s building ea furnace to melt stuff. He adviced to go for investment casting instead of just sand so we can get better detail and have no issues with the undercuts. here’s a project in instructable swith similar level of detail:

So we are going to give it a go. thx!


#4

Looks nice!
The metalworker in me was quite surprised though, when those commercial foot-pegs on your photo were cast from ordinary aluminum alloys. Wouldn’t that soft stuff (and likely sintered metal too) bend at first opportunity and wear like an eraser when touching the ground?


(Gustavo Fontana) #5

Hi Holger, If they were rigid yeah, but they have a spring/pivot action that makes them fold in when you drop the bike. The existing pegs are also a metal casting and they have survived many falls/drops (a friend told me :stuck_out_tongue:)

Here’s how it works: https://goo.gl/photos/mq9HPqtR45vxXRxu7


#6

Looks like Gustavo’s bike is an off-road machine, so I don’t think he’ll wear aluminum pegs out too fast. Some road bikes with cast aluminum pegs have some sort of steel button insert underneath for sliding contact with the pavement… Otherwise, if you’re a real “peg-scraper”, pegs are just “consumables”… :stuck_out_tongue_winking_eye:

–Mitch


#7

Hi Gustavo,
thanks for taking the time for recording the clip! It has been quite while since my last ride but I still remember.
Hopefully you you don’t drop that nice bike too often – had thought more of wear from touching the street (while riding) and other stuff while handling the machine.

What I wanted to point out is that alloys and casting / postprocessing methods Yamaha uses for its default pegs likely are somewhat more advanced than those one usually will have available with single piece lost wax casting.


(Pascal Golay) #8

Ohhhhh. _Motor_bike…

-Pascal


#9

Stay away Pascal!


#10

After your last experience you may rather take one of these:

:wink:

c.


(Pascal Golay) #11

What, no seatbelts??

-Pascal


#12

Well no. To stay safe and on topic, you’ll only get the SubD version without any weels :smile:

c.


(Pascal Golay) #13

Perfect, I’ll set it up in my garage - thanks. It’s ok, I have a helmet.

-Pascal