The Rocketman Posted October 22, 2019 Share Posted October 22, 2019 Now if BMW is going to build a really expensive bike like an RT, you think they wouldn't skimp on parts, right? Wrong....the entire bike is only as strong as its weakest link. The mechanism that keeps the gas cap propped open (that little 'click' sound when you open it) is controlled by this cheapo piece of plastic (the red one below). A roller pin goes into 2 microscopic holes at the end of the red thing as a pivot. My original one broke last year. Sure, BMW won't sell me the plastic part, nor tell me where to get it. They'd much rather I buy a brand new cap for about $250. So I took a shot and bought a used cap on Fleabay from a 2015 K1300S, and it happens to use the same piece (dumb luck). Now, after a year, the replacement one broke last weekend. If anyone else here has experienced this with any year bike, please let me know if you've come up with a better solution. Yeah I can leave it off, and then the lid would just flop around when open, which is no big deal. I just like when things work the way they're supposed to. Link to comment
wbw6cos Posted October 22, 2019 Share Posted October 22, 2019 Do you think a machine shop make that out of metal? Would it last longer if it was made stronger, right? Link to comment
The Rocketman Posted October 23, 2019 Author Share Posted October 23, 2019 I would assume so. Just needs to be strong enough not to break, but flexible enough to spread a little to get the roller pin in. Just hard finding someone to make a one-off piece without it costing a fortune. Was hoping someone already did it, so I didn't have to re-invent the wheel. Link to comment
Hati Posted October 23, 2019 Share Posted October 23, 2019 Wouldn't this piece be an excellent candidate for 3D printing? Link to comment
The Rocketman Posted October 23, 2019 Author Share Posted October 23, 2019 I did discuss that option with a 3D printing friend of mine. Just not sure if the materials used would be so brittle as to break again. I'm not familiar with the stuff they use. Link to comment
Hati Posted October 24, 2019 Share Posted October 24, 2019 Add to that fuel resistance as well. Surely there are plastics for printing that can handle that. Link to comment
EvilTwin Posted October 24, 2019 Share Posted October 24, 2019 If it doesnt have that detent, then it just moves freely? Doesn't sound like the end of the world. You could conceivably make that out of a small piece of aluminum bar stock and use some thin screws that are threaded into tapped holes. Does the roller have retractable pins that let it snap into the plastic holder (like the pins on a watch band)? Link to comment
The Rocketman Posted October 24, 2019 Author Share Posted October 24, 2019 The roller is solid, in that the pins on the end are not spring loaded or retractable. The ends of the red legs bend slightly to insert to roller pin into the holes in the end of the red legs. And no...it would definitely not be the end of the world if the gas gap didn't lock in place while opened. This mechanism has no effect when the cap is closed. Link to comment
EvilTwin Posted October 24, 2019 Share Posted October 24, 2019 It still might work with some aluminum since at that thickness it can be bent enough to open up and accept the roller and then bent back so that it is trapped. Thread in some screws from the bottom with the heads clipped off and use epoxy or some type of thread locker to keep them from moving. It could also be made out of plastic. I have some I used a while back for a boat project that machines pretty well and is reasonably stiff. Either way it's doable, but might take one or two attempts to make it, but what else do you have to lose but a little time. Bob Link to comment
basilr Posted October 25, 2019 Share Posted October 25, 2019 Try JB Weld. Then grind it to shape using a rotary tool (Wizard) and drill a hole. I haven't had to fix my gas cap but I have rebuilt small broken posts such as on our food processor and it still works 18 years later....it's a Braun. Link to comment
EvilTwin Posted October 27, 2019 Share Posted October 27, 2019 On 10/25/2019 at 1:10 PM, basilr said: Try JB Weld. Then grind it to shape using a rotary tool (Wizard) and drill a hole. I haven't had to fix my gas cap but I have rebuilt small broken posts such as on our food processor and it still works 18 years later....it's a Braun. That sounds like it could work too as long as the jb weld sticks to the plastic. Worth a shot. Link to comment
dirtrider Posted October 27, 2019 Share Posted October 27, 2019 Afternoon The Rocketman You can probably trim the plastic plunger piece back then bend up a simple metal shoe to go under the plunger crossbar (spring pressure will hold the shoe in place). Drill a couple of holes for the plunger posts to poke through & a couple of smaller holes for the roller axles to snap into & it should be good for life. I would probably use a piece of thin stainless as aluminum would be too weak hold the roller axle in place & steel or tin would rust. Link to comment
The Rocketman Posted October 28, 2019 Author Share Posted October 28, 2019 DR, your attention to detail is second to none. Link to comment
The Rocketman Posted November 8, 2019 Author Share Posted November 8, 2019 A machinest friend is giving this an attempt..... Link to comment
The Rocketman Posted November 19, 2019 Author Share Posted November 19, 2019 We may have a winner...... 1 Link to comment
Hati Posted November 19, 2019 Share Posted November 19, 2019 What are the chances of making a bunch of those Rocketman? Link to comment
The Rocketman Posted November 20, 2019 Author Share Posted November 20, 2019 Don't know. When I pick it up I'll ask my friend if he's even interested in making any more, and if so, how much he'd charge. 1 Link to comment
aggieengineer Posted November 20, 2019 Share Posted November 20, 2019 On 10/27/2019 at 1:40 PM, dirtrider said: Afternoon The Rocketman You can probably trim the plastic plunger piece back then bend up a simple metal shoe to go under the plunger crossbar (spring pressure will hold the shoe in place). Drill a couple of holes for the plunger posts to poke through & a couple of smaller holes for the roller axles to snap into & it should be good for life. I would probably use a piece of thin stainless as aluminum would be too weak hold the roller axle in place & steel or tin would rust. That is definitely worth saving for future reference. Much less labor-intensive than working with a billet. Many ways to skin a cat, as they say. This is a good one. I hope, however, that this is an infrequent problem. Link to comment
The Rocketman Posted November 22, 2019 Author Share Posted November 22, 2019 Got it back earlier. The cost was free and was done as a favor by a friend. He said it was very labor intensive and time consuming, and is not interested in fabricating any more. Hopefully these photos of the assembly will show you how its held in place for future reference. One screw holds the bracket down, and the roller pin slides against this bracket to lock the cap in place vertically when its open. 1 Link to comment
Indy Dave Posted November 24, 2019 Share Posted November 24, 2019 Just wondering if there is a slight alignment issue causing the plastic to break? Link to comment
The Rocketman Posted November 26, 2019 Author Share Posted November 26, 2019 I don't have a clue but this is the second time this has happened on 2 different caps. Link to comment
RoadRunner Posted February 9, 2020 Share Posted February 9, 2020 Replaced mine with a keyless cap. Link to comment
The Rocketman Posted February 9, 2020 Author Share Posted February 9, 2020 Makes the most sense if it ever happens again. Doubt if anyone is going to try and steal my gas. Link to comment
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