/diy/ - Do It Yourself

[Anonymous No.1349607]

hey guys,

I'm an idustrial designer and huge bike fan.
I love to do a custom cnced chainring.

the thing is I can't asses the cost.
I can create the 3d files no problem but I have no clue if running the cnc mill is actually expansive.
milling the ring would probably take considerable time.

the production ones are usually cold forged and then finished with a cnc mill.
would it make sense to make a rough laser cut of teh chainring befor cncing it ?

[Anonymous No.1349610]

bonus question:

can somebody tell how to chose an alloy and heattreatment ?
I know the basic difference between 6061 and 7005 and that T6 is the most common heat treatment but about things like 7050 T10 ?

[Anonymous No.1349628]

>>1349607
Idk much about machining costs, but what do you ride? I'm saging only because this is an unrelated post

[Anonymous No.1349739]

>>1349607
>milling the ring would probably take considerable time.
Yes, and it will be a huge nightmare to fixture it.
>would it make sense to make a rough laser cut of teh chainring befor cncing it ?
Laser costs per inch. Water-jet is more cost effective, but it's not going to lower the cost much.

Flat parts like this are going to be annoying because the inside features and hole pattern have to be machined first. And then that hole pattern will need to be used to bolt the blank to a subplate that can be held by a vice in the mill. That way the rest of the features that need to be machined can be done in a second (and probably third) operation.

Do you want to spend close to $500 for a fancy super-unique chainring?

[Anonymous No.1349748]

>>1349607
A CNC router might be the way to go for that part.

[Anonymous No.1349899]

>>1349739

fuck that's what I was afraid of.

if it was 100 t o150 I would consider it, but only just because I've been wanting to do it for aw while..

>>1349748

can you elaborate ?


>>1349628

I want to make a very ridiculose gravel bike build.

I could possible get my hands on a nx eagle group for oem price and wanted to "force" that into a rather quick steel gravel bike.

I'd love to put something weird like a 46t / 44t narrow wide oval directmount ring up front just for the heck of it.

something quick , like 35 or 38 mm tires

and a cockpit setup that equaly weird but that I personally love.
a flatbar with lots of sweep , almmost northroad style. mtb brake levers and the nx shifters + mini aero bars.

a custom paintjob on the frame and fork should be self explanatory.

[Anonymous No.1350360]

>>1349610
bonus answer:
you buy the sheet already tempered
It takes an oven with fairly precise temperature control, because unlike steel, Al alloys are heat treated not far from their melting point. Fairly hard to do on a one-off part.

[Anonymous No.1350363]

>>1349607
you would have to design the laser cut semi-finished product with anchor points for the milling operations, remember that the mill needs to hold the work down somehow.

btw pic looks like it's made from 2 sheets

[Anonymous No.1350364]

>>1349739
how the fuck is a water jet more cost effective? Ever seen the difference in speed and energy consumption?
The only reason you choose a water jet over laser is because the laser would fuck up the material with heat.

[Anonymous No.1350403]

>>1350364
>how the fuck is a water jet more cost effective?
Go get quotes for both on the same part.

Maybe it's just the shops near me and their resulting demand/backlog for both machines, but water-jet costs less per inch in my experience.

[Anonymous No.1350459]

>>1350364
You're probably going to have to use a water jet cutter. Lasers cutters don't do metal. Not even soft ones. Milling is normally done on softer materials like aluminium. When people want to use do a thick hard piece of metal like what chain rings need to be made of they use water jet.

[Anonymous No.1350523]

>>1349607
so... you've never actually owned a bike? i imagine you would know what the chainrings are made of if you actually rode a bike. the whole drivechain needs to be replaced every 1000km. you've honestly never researched and bought parts?
you would need to temper the teeth as well.

>>1350459
laser cutters do metal you stupid faggot.

>>1349899
the $100 figure is actually accurate. just grind the tooth angles yourself. you'll need to touch them up and round them off and polish after cutting anyway. consider getting a jig cut for a rotary tool to finish the teeth for your chosen profile. different chains and gear setups have different profiles to allow flex and for the chain to jump properly. make it in steel first.

a cheap option would be to use an acid bath and resist. this guy runs through the process.
https://www.youtube.com/watch?v=jEnNMTMZadw

if you were thinking of being able to just send a design to a shop and get a final product then you're looking at a few grand for a rapid prototype.

[Anonymous No.1350832]

>>1350523
>the whole drivechain needs to be replaced every 1000km.

[Anonymous No.1350848]

>>1349899
>if it was 100 to150 I would consider it,
I would charge you 125 for the parts, but have a limit of 10 because I can't do all that fixturing, material cost, and tooling overhead for nothing...

[Anonymous No.1350874]

>>1349607
I'd quote that 75$CAD/each for 20 minimum qty. Lower price for more. People in this thread don't know the fuck they're talking about. 6061-T6 Aluminium would do the job just fine. Anodised. You're not going to do 20000miles per year on that bike anyways.
-Take a flat sheet with final thickness already.
-Do the bolt circle. (1:30 cycle each, 8min. prog/setup)
-Make a jig to hold the part by the holes.(20min.)
-Programming from an already drawn 3d file (20min.)
-Setup (3 tools to measure, 1 zero to set) (10 min.)
-Cycle Start / flip / cyclestart (12min ea.)
-Send to anodise.
-Mill a template for the logo, Sandblast the oxide away for the logo.

(I'd probably tell you to modify the radiuses near the bolt circle, make 'em .094)

[Anonymous No.1350884]

>>1350832
>i dont own a bike
yes, chain, derailleurs, rear and front sprockets, bottom bracket cartridge.

[Anonymous No.1351027]

>>1349607
>I'm an idustrial designer.but I have no clue if running the cnc mill is actually expansive.
So you are NOT industrial designer.

[Anonymous No.1351060]

>>1350832
Yes anon, everything the chain touches on a bicycle is considered sacrificial. They get worn, they break, they get replaced - usually on the cheap. I'll tell you another secret, it's the same way on motorcycles.