Home built bike stuff

Straws · August 12, 2018, 4:07am

One of the less frequented threads of days past but one I always liked.

I’m in deep on a di2 macgyver hole right now. I’ve taken a di2 climbing shifter and stripped it down to make what I saw here.

But I didn’t like his exact solution so I made my own. I grabbed a ps2 controller just like in the article but I used it a bit differently. I noticed that the buttons on a ps2 controller are all indexed differently into their shafts, so not only is a button in a cylinder (so that it cannot move off its path of travel) but it also cannot be mixed up with another button. Really no idea why they did that but whatever. You can see that in the photo below. They have different sized tabs in different orientations.

As you can see above I cut the pad into two pieces. I decided the two buttons I wanted and put those on the right relatively undisturbed while I experimented on the test pieces on the left.

I removed those two shafts completely from the surrounding plastic. This allowed me to glue them together much closer than they originally were as the di2 button are quite close (the giant housing on the shifter uses a pretty ingenious pivoting technique to spread the physical buttons apart). I used super glue and baking soda to create a more solid structure than just glue alone. Once I got to this point I realized that the buttons were just slightly proud of the plastic and that if I were to put them underneath a rubber hood they wouldn’t protrude at all. I took my test piece and sanded it down about 3mm leaving enough plastic for the retaining portion to still capture the button tabs securely without fear of breaking. That is pictured below, sitting atop the stripped climbing shifter.

Those were just two cylinders after I was done removing excess plastic. All that fillet between is super glue and baking soda.

I will permanently mount that button housing onto the shifter with aforementioned super glue and baking soda. It’s semi-permanent as it’s rather trivial to cut off with a dremel so I’m not worried about having to remake it down the line, other than the time commitment.

Also I have since taken a 9/16" sprocket and heated it up to create a punch for the hood but it is a bit tight. I’m going to experiment with a larger socket. I will update with final build and pictures tomorrow.

sleve_mcdichael · August 12, 2018, 4:34am

Super glue and baking soda

russ · August 12, 2018, 7:45am

Idkifi understand exactly cause I’m drunk butits probably foreaseofasssembly at the factory
Lessto messup in the assembly line e

turpentine · August 12, 2018, 1:12pm

I’m really anticipating this frankenbuild.

igor · August 12, 2018, 1:17pm

Oh my that is cool. This makes me want a di2 setup simply so I can glue Nintendo and Sega buttons to shifters.

Straws · August 12, 2018, 5:55pm

I have to imagine that’s the only reason for it.

dfl · August 12, 2018, 6:08pm

When you have this done, we need to have a Bay Area Tarckup just for IRL show and tell.

EDIT: also for tarckup for tarckup’s sake, but show and tell first.

Straws · August 13, 2018, 12:52am

I’ve now removed the cover for the master cylinder from the lever body. It’s pretty thick so I cut a hole into it to put my shifter in which will help decrease the protrusion of shifter body. I have cut the hole and am gluing the shifter in with black shoe goo so once again I can remove if necessary. I know the hole is much larger than it needed to be but I changed my mind halfway through on where I wanted it to be mounted and then changed it back.

I’ve been thinking of trying to get all this shit 3d printed into an entirely new master cylinder cover. I could also 3d print the buttons and everything so if someone were to print their own they could easily do it without needing to get a ps2 controller and all that jazz. The internals of the climbing shifter are fucking tiny.

Now mounted to the shifter.

Eddbread · August 13, 2018, 6:34am

I look forward to developments

Rusty_Piton · August 13, 2018, 1:25pm

This is some glorious, next-level bike nerd shit. I applaud you Brian.

ergott · August 13, 2018, 11:37pm

Wow

tehschkott · August 14, 2018, 12:52am

Add third button that plays el cucaracha or GTFO

Straws · August 14, 2018, 3:50am

Today was productive. I cut the holes in the hood for the buttons using a 9/16" socket that I heated up with a torch. Once I got that on it was time to start wiring up this sucker.

The gaps are bigger than I wanted due to the hood stretching from the extra bulk underneath. When I 3d print a new unit I’ll get a new hood and try again.

The plan, if you haven’t read elsewhere, is to mount the 3-port junction box under the saddle and have everything end there. I’m only using one junction box because it’s just the shifter, the battery, and the derailleur. The problem with this is that the shifter wire is only like 12" long but I need it to go like 48".

Simple, extend the wire. I found out that the etube wire is 2 pieces of 24 gauge wire. Easy peasy. Picked up a 25’ section of doorbell wire and I’m off to the races. Snipping that first piece of etube was a bit nerve racking, up until that point I could pretty much undue everything I had done, including gluing.

First things first really, I needed to route the new wire through the top tube before any soldering can begin so I coul get a final length (also so I don’t have to pull heat shrunk wire through a tiny hole), in through the hydro port at the front and then into the seattube. Problem is the seatmast is probably a 8" above where the cable pops out of the top tube and of course it’s not like the vent hole between the top tube and the seat tube is super huge or flush with the bottom of the top tube. I snipped off a piece of steel wire I had and heat shrank it to the end of the doorbell wire. I pushed that the now steel-tipped doorbell wire through the internal route port at the front until it hit the back of the tube. I then attached a neodynium magnet to a string and dropped the string into the seat tube and pushed that into the vent hole. Pulled the string to get the head of the doorbell wire into the seat tube. Once I got the doorbell wire into the seat tube the magnet was not strong enough to pull it through the bend. I taped a socket to an old spoke and with a zip tie made a tiny version of a dog catcher’s noose. I got the wire into the noose and pulled it tight. I then pulled the wire up out of the seat tube so I could have a final length at the front to cut and match to the shifter.

wire capture device! Pretty proud of this idea.

I haven’t soldered anything in years, let alone something this small. Additionally annoying was that the etube wire is a bundle of about 20 fucking microscopic wires and the doorbell wire is solid copper. Splicing two like wires together is always easier than strand to solid. Regardless, I did a few test pieces and then went to town.

I had to splice in the extension at the front then put the etube connection back onto the extension after it exited the seat tube. I then took two long etube wires and spliced them together to create the piece that goes from the derailleur, through the chainstay, into the bottom bracket, then into the seattube. The next piece was a small piece of remnants to make a very small wire for the battery (housed in the seat tube) to the junction box.

At this point all 3 wires are sticking up out of the seat tube. Everything along the way is heat shrunk and reinforced a couple of times as soldered joints are actually pretty fragile to vibration and bending.

I took the junction box mount and glue it to the bottom of the saddle. I took off the seat mast topper and drilled a hole through the top of it so as to route the cables. Poked the cables out of the top, made a temporary foam fitting sleeve for the battery so it doesn’t bounce around in the seat tube, and blammo, bike is mostly done.

Seat mast hole. Drilling a $150 cnc seat mast topper was somehow the least stressful part of this entire build.

and you can see the junction box mount here.

Tomorrow I’ll wrap the bars and be done! I think.

dfl · August 14, 2018, 4:39am

And here I was all proud that I was able to figure out how to get the pusher working on my Endpoint.

joyofvaping · August 14, 2018, 6:00am

Nice!

Splicing solid core to twisted wires can be iffy though

Straws · August 14, 2018, 6:00am

Honestly I can barely tune a rear derailleur. This is way easier than learning the nuances involved in normal shifting and brake tuning.

Blakey · August 14, 2018, 6:04am

Did you test the function of the system with the wire extension before you cabled the frame? From memory di2 is very picky about wire type, sometimes a straight up splice can wreak havoc with operation/battery drain etc.

This is very cool, can’t wait to see finished product.

Eddbread · August 14, 2018, 6:17am

Di2 scares me
(also excites me)

Straws · August 14, 2018, 7:14am

I didn’t mainly because the only required splice was the one from the shifter through the top tube which meant needing to be spliced before testing. Everything else could have been accomplished with a longer stock etube wire. Even the shifter could technically reach the junction box with use of the ew-jc200 but I didn’t want to do that. In the end if I need to I can buy a couple lengths of 1100mm wire and have it all sorted but I’m pretty sure it’ll all work out.

I might actually end up buying the bluetooth adapter and stuffing it inside the seat tube or also gluing it to the saddle. Just so I can have a monitor on my phone when needed. I don’t like having a closed loop system.

Cause, even though I can’t tune a derailleur very well, it’s nice to pull a cable and see what happens. You can’t do that with di2. If it aint working you’re kinda shit out of luck.

jimmythefly · August 17, 2018, 3:30am

Awesome! Thanks for reviving this thread.

RE: controller buttons assembly. I agree with Russ, that is probably poka-yoke.