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Are you likely to order a shifter replacement rod?

  • yes, for sure

    Votes: 5 41.7%
  • no

    Votes: 2 16.7%
  • perhaps

    Votes: 5 41.7%
1 - 12 of 12 Posts

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Discussion Starter · #1 ·
Moderators: please feel free to move this around. Since it deals with both Elise and Evora, I did not put it in either of those forums.

@agentdr8 and I have been working on a solution to the broken blue-ball and shift rod. He designed and 3D printed (in metal) and tested a solution that appears to be working well for him. One component of that fix is the hollow metal rod, threaded at both ends with two slots cut in it. I just finished my first attempt at this, with a full metal working shop, and it was frustrating and time consuming. Drilling and taping and threading 12mm items is more challenging than smaller ones, especially since the OD is supposed to be 11.7 mm rather than 12 mm.

I am getting cost estimates for having the metal shafts manufactured by a machine shop. All you should need after that are @agentdr8's 3D printed parts (mine cost about $250) and a little time assembling things. If you can weld, then the 3D printed parts cost may be more like $150.

Please indicate in the poll whether you are likely to want to order one of these rods, either to fix a shifter you already have, or just in case of a future failure. Then I will know what quantity to order, and what the price might be. Sadly, I don't have a rough cost estimate. Perhaps $100?

Thanks!

Jon
 

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If we're willing to pay more, can we get more exotic materials? If it weighs more than about 1lb, i would want to use either Al or Ti for my comp car.
Al (AlSi10Mg) is already an option for Shapeways, but for some reason, it's more expensive than either of their stainless steel (316L and 17-4 PH) offerings. The ball I machined by hand was out of 6061-T6, and it seemed solid when paired with both the mild steel and the SS 304 shaft that I also machined. I don't know how strong an Al hollow shaft would be though. Not sure where you'd source a Ti ball from.
 

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Moderators: please feel free to move this around. Since it deals with both Elise and Evora, I did not put it in either of those forums.

@agentdr8 and I have been working on a solution to the broken blue-ball and shift rod. He designed and 3D printed (in metal) and tested a solution that appears to be working well for him. One component of that fix is the hollow metal rod, threaded at both ends with two slots cut in it. I just finished my first attempt at this, with a full metal working shop, and it was frustrating and time consuming. Drilling and taping and threading 12mm items is more challenging than smaller ones, especially since the OD is supposed to be 11.7 mm rather than 12 mm.

I am getting cost estimates for having the metal shafts manufactured by a machine shop. All you should need after that are @agentdr8's 3D printed parts (mine cost about $250) and a little time assembling things. If you can weld, then the 3D printed parts cost may be more like $150.

Please indicate in the poll whether you are likely to want to order one of these rods, either to fix a shifter you already have, or just in case of a future failure. Then I will know what quantity to order, and what the price might be. Sadly, I don't have a rough cost estimate. Perhaps $100?

Thanks!

Jon
I'm a bit confused about the cost. You mean "perhaps $100" for part of it + $150 for the rest, so about $250?

If it were really just a ready-to-go solution for $250 I'd buy. But you mention welding too? If that is required I'd probably be out.
 

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I'm a bit confused about the cost. You mean "perhaps $100" for part of it + $150 for the rest, so about $250?

If it were really just a ready-to-go solution for $250 I'd buy. But you mention welding too? If that is required I'd probably be out.
I can clarify what Jon was alluding to. The 3D printed ball will be around $150 (not including tax, shipping, and their fees) from Shapeways. The stock shift shaft has a metal tab welded to it where the gear shift cable attaches. In order to avoid having users need to have a tab welded, I created a 3D printable clamp mount, and those 2 halves will be roughly $100 from Shapeways. Neither of those values will include the cost of the shaft itself, which needs to be machined (which is why Jon posted the poll), either en masse from a shop, or by hand.
 

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If we're willing to pay more, can we get more exotic materials? If it weighs more than about 1lb, i would want to use either Al or Ti for my comp car.
To follow up on this, I was able to locate a different 3D printing service that claims to be able to do Titanium via DMLS. Cost would probably be about double that of SS.

A quick search on Ti round tubing did not yield any in metric with 12mm OD and 6mm ID, but I was able to find solid round bar in .5", which could be turned down to .47244". Then the matter of center drilling for the reverse lock-out comes into play. I've never worked with Ti, so I have no idea on its machinability.
 

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Discussion Starter · #11 ·
@Agent_86 has 3 designs on Shapeways for his replacement ball. One is ready to be tapped/threaded. One attempts to have the threads 3D printed (not sure yet whether that will succeed) and one is a press fit, which could be glued in place. So @Tengai650 could try his fix once the parts are available to the general public. It would be interesting to see what he feels about that approach after having tested it.
 

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It seems to me that because the OEM setup is somewhat weak, a simple yet robust enough fix would be to use the unthreaded replacement ball and Loctite 638 with the original shaft.
The original shaft cannot (or shouldn't) be reused, even if it isn't broken. The reasoning being is that it's cross-drilled at the bottom, and the cross gate lever/arm is riveted in that hole. Even if you could get the cross gate arm out without damaging the shaft, you'd still have a relatively weak press-fit interface with that hole in the shaft. A better solution then would be to get a new hollow shaft, and only thread the top where the shift knob goes, and press-fit the bottom into the interference-fit ball design that @jon_bondy mentioned.
 
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