Speaking of "not" working.

K

Kurts05Z4

Member
I spent a day soldering some micro (tact) switches together and made the harness, mounts, and some really cool looking aluminum paddles as a retro fit paddle shifter set up. Worked fine except for one glitch... Point bounce. Nine out of ten times the shift was executed perfectly, up or down, either shifter. That one time though would have been a disaster on the road if the computer obeyed the command. Two and three gear down/up shifts! :o
So...Without a buffer circuit to filter out the point bounce, no go on the tact switches. :thumbsdown:
Anyone have a spare set of steptronic factory paddle shifters for sale???
 
Just rig up a mini PCB with a latch ckt. set for,,,say 1sec.

As in another thread, just thinking out loud :)
 
Interesting problem and one you'd probably rather not have...

Having just built my own paddle shift system I have some idea of the circuit and what I needed to do to make it work but am unfamiliar with the terms you use or electronic circuitry (although I do understand the problem of multiple shifting on the request for a single change.)

In testing my paddle circuit I did not notice anything in the steering wheel paddle 'switches' that damped anything, just simply grounded the respective wire for each press.

What is different between the micro switces you have used and the OEM shifter switches?
 
cj10jeeper said:
Interesting problem and one you'd probably rather not have...

Having just built my own paddle shift system I have some idea of the circuit and what I needed to do to make it work but am unfamiliar with the terms you use or electronic circuitry (although I do understand the problem of multiple shifting on the request for a single change.)

In testing my paddle circuit I did not notice anything in the steering wheel paddle 'switches' that damped anything, just simply grounded the respective wire for each press.

What is different between the micro switces you have used and the OEM shifter switches?
Click to expand...
The tact (tactile) switches I used are 6mm x 6mm x 2.5mm with an extended plunger.
http://rsk.imageg.net/graphics/product_images/pRS1C-4479149w345.jpg
They are basically a convex disc that flexes when pushed making the connection and returns when released. They are just a very small momentary on switch. I haven't seen the OEM switches so I can't make a comparison.
After a bit of thought, the multiple shifts may be attributed to the levers I made to actually push on the switches. If they contacted the switch off center it's possible they caused the point bounce.
If I had a lab scope I could run a trace and see if its the switch or the way it's pushed that's causing the issue.
 
OK - I see the switches now. Very similar to those inside the key fob for the 3 function buttons.

I guess you could remove your lever and try manually pressing the switch to see what happens.

Good luck - sounds a really interesting idea and some neat engineering
 
cj10jeeper said:
OK - I see the switches now. Very similar to those inside the key fob for the 3 function buttons.

I guess you could remove your lever and try manually pressing the switch to see what happens.

Good luck - sounds a really interesting idea and some neat engineering
Click to expand...
OK, graphed the switches and they are the culprit. One press of the switch gives you a .2 ohm reading followed immediately by a 8-15 ohm spike and then a steady .2 ohm reading. Sometimes two spikes. All within 5-10ms. Oh well, I guess that's what you get when they only cost $1.00 each! I'll play more with these later.

Since it's getting warmer every day and I want to play, I went ahead and bit the bullet and ordered an OEM set from Tisher. :thumbsup:
 
Probably as well. I was using my paddle shifts yesterday and they have a very distinctive movement. Not a 'click' whwn pressed but clearly designed that no matter how you pressed them you would not physically push it twice in error. You have to let the shift right back to its start position to be able to get a second change.

Good luck in getting them working. Personally I love the Steptronic with them in sport mode. The car comes alive.
 
That makes sense about the switch needing to be fully released before a second shift is achieved. If the computer allowed it (or just messed up) a double downshift would probably leave pieces of the trans on the road. I'm starting to get anxious now about getting them installed. I should see them by the end of next week since they had to come from Germany. Looking at the back of the steering wheel, there are six dimples where the mounting screws will go. Minor detail, just drill and thread the wheel for machine screws. The plastic spoke covers will be easy enough to modify too. Then the fun begins! :thumbsup:

I'm going for a top down drive today on my favorite twisty road, (89-89A from Flagstaff to Congress and back for the Arizona folks) 270 miles round trip with about 40 miles (80 total) of hairpins and REALLY twisty parts over four sections each way. A for a good workout for the car and me! :D
I sure wish I had the paddles today! :headbang:
 
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