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I have been digging out some of my old projects recently, and I went back and updated an old shifter design. Some of you may notice some of my old design in there, as well as some influences from past designs.
The shift lever itself is completely compatible with stock linkage, and can be installed without dropping the torque tube. What makes it different from any of my previous designs, or any that I am aware of, is that it allows for shortening the actual lever in 10mm increments from stock height to 30mm shorter. The pivot point can be adjusted from stock to any increase in ratio in 10% increments by using machined 2.5mm spacers (stock pivot distance is roughly 25mm). I measure that you may start hitting the torque tube at any pivot point beyond 50% reduction, but I will need to test this in the real world. It may be possible to add additional adjustment by raising the front pivot point. It would be possible to do this with similar shims by separating the bearing block from the clamp in the front--rod removal system as shown.
There are some other small updated, including replacing the stock shifter pivot bushings with uprated Igus bearings for increased isolation and less friction.
I am printing test parts today to check clearances and make sure everything works as intended. I will keep everyone posted as to progress.
If all works out well, i will machine a test level and toss it in the GTS-4 for some real world testing.
Here is the webviewer model for those who are interested in taking an in-depth look:
Just a curious question... Why would i want to adjust for variable heights of the shifter handle. Does it feel differently or solve any specific issues between the stock and the shortened shifter? I have the short shifters on both of my 5 spds and I do find the through is tighter but feels more notchier. Would this allow for me to find an in-between area of long smoother throw and shorter notchier feel?
There are two adjustments in this design. One is to change the overall height of the shifter ****. The second is for the lower pivot point. Increasing the distance between the two pivot points will reduce the throw. By using a stack of shims, each shim inserted will reduce total throw by 10%.
By shortening the **** and increasing the throw, you can create whatever the best shift geometry is right for your driving preference.
With existing designs, there are fixed throw reductions, and there is no ability to change this in the car.
After receiving some very helpful feedback (thanks Colin), I modified the front clamp to be two pieces. The bearing is now located 12.5mm higher than stock, so is centered at the 50% reduction point. Having it a separate part allows for installation of shims for even more aggressive throw reductions in the future if necessary. This design assumes that anyone who would drop the tube to install the front rod replacement bearing would likely want aggressive shift geometry.
Here is a picture with the modified bearing block, and 50% reduction shims installed and the shifter height dropped to a position 7.5mm below stock lever height (the overall height reduction is limited as the bearing has moved up 12.5mm - this would be easy to modify by including a shorter shifter lever with the front bearing upgrade.)
A couple last minute updates this evening before leaving the office. Prints should be done when I get in tomorrow so I can see how it feels in hand.
I removed alot of the unnecessary material from the bottom to allow for more clearance at higher pivot spacign.
I also re-designed the front pivot arm for reduced size to help with fit under the foam if the bearing block was spaced tall.
Finally, I removed 2.5mm of height from the bearing housing, so the default height with the front rod delete is centered at 30% reduction in throw, and I will just machine a stack of 2.5mm spacers for the bearing to match the shifter lever spacers. This way, the bearing block can be spaced the same as the shifter so much of the standard bind, experienced from standard short-shift designs, can be removed.
If I remember right there was a guy from mass. that was on to a design very similar to this and he never came back so this will be a sure winner,I really like this design if I could afford a milling machine I would have done this long ago,just keep going!!!
08-15-2016, 02:38 PM
New Manual Shifter Design
