tyrion

I mean rear derailleur. Indexed. Make it out of polyester or alloy, just make it nice and clickey and precise. A system where you just plug in the numbers of the RD and you can get a good thumb shifter printed locally.

Does this make sense?

70sSanO

I’m waiting for programmable electronic shifting.

Buy one RD and swap out pulleys for different chain widths, and run whatever you want.

Can’t be that tough.

John

Ironfish653

Trying to figure out what problem that you guys are trying to solve?
There’s a lot of cross-compatibility between 7-8, 8-9, 9-10, that unless you’re after an 11-so thumbie, or a one-off system like Tiagra 4700,they probably already exist.
I’d venture to say that Paul’s or VO probably has you covered.


Same goes for an Omni-speed electronic RD. What kind of benefits would it offer over a mechanical RD on a 7/8/9-speed system, especially for the cost?
I imagine the list of people who are looking for 7-9sp Di2 is pretty short.

Germany_chris

https://archercomponents.com

there ya go

70sSanO

1x only.

John

70sSanO

Didn’t mean to hijack.

I’m not well versed on 3D printing to understand the advantages. Especially cost and design; unless someone uses a company’s intellectual property to replicate the item.

John

ClydeClydeson

Campagnolo used to sell convertible shifters, back in the early days of indexing. IIRC they sold a replacement plate for the inside of the shifter that had the detents spaced for the desired drivetrain config. Also, they didn't work to well.

A simpler solution would be a single shift index mechanism with a replaceable outer cable spool to change the nominal mm/shift. Another idea is custom cassette spacers to more closely match the whatever shift spacing happens from your shifter and derailleur.

70sSanO

I’ve done plenty of re-spacing cassettes and it is primitive at best. It also requires heavier full cogs instead of lighter spidered/carrier cassettes.

John

Edit added: It does allow for customizing a cassette as far as cogs and gapping. I have one 8 speed 14-36 cassette with a 14t junior 1st position cog.

tyrion

I don't know much about 3D printing but the flexibility is what interests me. There are 2 components to this: a smooth, "clickey", satisfying mechanical design that can take whatever cable pull numbers the derailleur wants.

You could choose the the mechanical design that works best for you and your hands, and just plug in the numbers dictated by the RD, and click "print me one of those".

70sSanO

I’m sure someone with real knowledge can chime in, but I would think functional assemblies that require differing material properties, such as springs, might be tough to 3D print as a complete functional assembly.

I would also think that there would need to be some design parameters (CAD?) that precedes any printing.

John

Germany_chris

True and flat bar only..

TBF front derailleurs don’t much care about mixing brands. Since that shift system is open source and fairly recent I’d bet a front shifting system is coming. The larger question is whether they’ll build a drop bar version since “gravel” is all the rage.

70sSanO

Archer has a drop bar shifter system: DBR remote.

John

zandoval 

A 3D printed Thumb Shifter would be nice. Even if just a friction shifter. I see the only problem being the 3D print material. For little home printers using PLA the material would be to soft and temperature sensitive to used over a prolonged time. Professional printers that use Resins and other materials are expensive. As far as the design... Hey... It's just an engineering problem... Fun Fun Fun...

Ironfish653

You'd really have a separate 'model' stored in the software for each variety of speeds and cable pull; like "Shimano-11" or "SRAM-10". You might be able to have it incorporated into the design software, but it wouldn't be native to the .stl files that actually run the printers.

Most 'hobby-grade' printers really can't get the resolution to print a complete, functional assembly in one shot; at least not with the kind of tolerances you'd need to make an indexed shifter work. You'd need to do each component separately, then assemble. Then you have an all-plastic shifter. Just like on the cheapest of BSO's
Microshift makes thumbies for Shimano 7sp-9sp, and 10-sp/11-sp (MTB) that are pretty nice, and reasonably priced. If you really want to go full-zoot, you can put 10- or 11-sp Dura-Ace barcons on Paul's Thumbie mounts. Doesn't get much nicer than that.

Leisesturm

Probably easier to force standardization around a single pull and spacing parameter across all manufacturers. Either one standard for Road and another for Mountain, or just one for anything that shifts chain on a bicycle.

tyrion

I see this as a function with 2 params: first param is the structure of the shifter (bar end, thumbie, etc.) and second param is an array of numbers that specify the cable pull.

zandoval 

There are more than a few parts I have considered working into 3D printing but there is a big limitation with the durability of the materials you print with. Now if we could get an affordable table top CNC... Wow...

Please Santa... I'll Be A Good Boy...

DorkDisk

Thumbshifters are very basic; indexed ones have a piece of metal, called an index plate. with holes in it that a ball bearing drops into, which give it the "clicks." BITD some used to make custom index plates. Microshift makes these available so the user can swap the number of clicks. Microshift has two types of shifters: big barrelled for dynasys and small barrelled for 1:1. Both have index plates for different indexing. Additionally, the shifter mounts can be swapped for bar end or flat bar. Some more info.


index plate for 9sp 1:1 shifter to 10sp road

UniChris

That's what 3D printing is bad at, and conventional manufacturing technologies are good at.

Probably better a selection from stock conventionally manufactured parts, at most 3D printing some hand-specific aspects. But the cheap 3D printing technologies (for parts that aren't tiny) are pretty weak compared to injection molding, too.

Also turning "preferences" into CAD data isn't necessarily simple. Or reliable in capturing what they users actually want/need. You'd almost do better letting people mold some kind of epoxy putty or something.

Probably better done with a range of insertable stock mechanical parts.

Or at the outside, having a special purpose machine that cuts just one aspect of them on demand. Kind of like cutting keys from a data input moving the cutting wheel in and out, rather than a probe moving along the original.

UniChris

That actually makes sense.

If it actuator were built like a better version of an RC hobby servo, it would be a simple matter of software to effectively give each sprocket its own dedicated barrel adjuster type control.

You could even support a chainline angle trim that would alter the position for a sprocket very slightly depending on which ring you were in.

And could tune an initial "overshift" on change that would then back off to a "run" position.

rosefarts

I know because I have it.

I run mine 1x because I’d go 1x on my bike regardless of shifting mechanics.

I think Archer is compatible with putting two motors/batteries on the bike, one up front and one in the rear. I read about it somewhere on their website when I was purchasing my system. I’m not sure if they integrate all speeds into one shifter or if they make a left side.

Germany_chris

Those really do look integrated

rosefarts

To the original question. How strong or durable is 3d printed poly or whatever they use?

Seems like a program could easily be made, a single shifter shape and a database of what pull for each brand. Not unlike what you can do with microshift but without a complete product.

Seems like they’d break and wear too easily though.

Edited to add,
I run 1x11 thumbies on my MTB and like it so much I might get thumbies x12 on the next bike. Microshift holds up to wrecks. Will a plastic one?

Cyclist0239879842

I had hoped I'd find others that were interested in 3d printed shifters on this forum. Part of the reason why I joined, actually. I just open-sourced a 3d printed bar-end shifter design a couple of weeks ago that is, indeed, equation driven. Not quite what OP was asking for (thumbies) but pretty darn close! I'd consider making thumb shifters sometime in the future.

My design goals were: 3d printed, durable, indexed, easy to install/uninstall, and equation-driven. As others have mentioned, PLA (the plastic material in most household FDM printers) is not an ideal material for long term durability. But it seems to be holding up really well. I have a little over 500 miles on them installed on a touring bike. I'll add another 2k by the end of the summer. I really had to rethink how detenting is traditionally done in these shifters.

The files were built in Solidworks and the detent-spacing / cable-pull variables are stored in an external text file. I've printed one for my 9 speed shimano RD and one for my 10 speed campagnolo RD. I'm still low on the post count but happy to link to the files for anyone that's interested. I also did a write up on my site that covers the design process. For those wondering, it took about 60 hours of CAD time, 50+ prototype prints, and many hours of riding to dial in the fits...particularly the detents. I'm proud of them.

holytrousers

if one doesn't make big profit out of them, what would be the problem ?