Thread: Project $ 3 K Is Underway

Tweet

Don---I thought that you new that spring loaded ball plungers were commercially available, or I would have mentioned it to you. I use them all the time in machinery I design, so ya know how it goes ---I have known about them for years, so I assume that everybody else does too. One word of advice----get one with a really strong spring. From the pivot point on your shifter to the detent ball is only about 1 1/2", yet the shifter lever will be about 18" long from the pivot point. That gives you a mechanical ratio of 12:1, so you should have no problem overcoming a really strong detent spring.---How are you going to design the lock-out gates???? The spring detent ball will hold the shifter in position for normal driving, but without a lock-out gate, the shifter will still move if it gets bumped with a knee, or under real hard acceleration. This could spell disaster. The Gennie shifter must be manually rocked to one side to disengage the lockout gates, thus require no push-button. The Lokar units have a sprag which is engaged with the lockout gates at all times unless you manually depress the shift button to allow a shift. (actually they have no lockout gates between drive, drive 1, and drive 2, which makes sense, but they don't have a lockout gate between drive and neutral either---as many street racers with blown-up engines can attest to).

Brian: No, this was the first I had ever seen these. I was going to build my own version of the same thing. I bumped up to a 3/8 diameter sized one, with 5-10 lbs of push on it. I have nothing to judge that by, but it seems a good starting pioint. Plus, combined with the internal one in the 350. it should be ok, I hope.

That's what is great about these forums, there is such a large pool of info and experience to draw from.

Don

Brian: No, this was the first I had ever seen these. I was going to build my own version of the same thing. I bumped up to a 3/8 diameter sized one, with 5-10 lbs of push on it. I have nothing to judge that by, but it seems a good starting point. Plus, combined with the internal one in the 350. it should be ok, I hope.

That's what is great about these forums, there is such a large pool of info and experience to draw from.

Don

Don,
could you post some good pics plz. im having a hard time tring to figure out how to lock into at least park and drive... the way i set mine up it changes gears very easy..

Thanks
Harmon

Originally Posted by CHEVYBOY

Don,
could you post some good pics plz. im having a hard time tring to figure out how to lock into at least park and drive... the way i set mine up it changes gears very easy..

Thanks
Harmon

Harmon: I am sharing that same concern you are mention, so I may actually add some sort of small, second lever at the bottom to act as a reverse/park lock out. I can just see me swatting a mosquito at 80mph and hitting the shifter instead.

I just want to be sure it isn't a pain to operate in daily driving. I will let you know how the detents work first, though.

Don

Originally Posted by Itoldyouso

I can just see me swatting a mosquito at 80mph and hitting the shifter instead.
Don

If you put down the beer...............that won't happen so much!

Isn't that how you know something is about to happen to a redneck, when he says "here, hold my beer and watch this."

Don

Thats when you" wake up BaaBaa Cause he ain't gona beleave this"

Alright guys---listen up. You've all seen the ball in the end of a Heim end (thats a sherical rod end to those who didn't know.) So---instead of a plain pivot bearing or bushing at the point where the shift lever pivots, use a "self aligning ball bushing"--thats another part that is commercially available, thru McMaster Carr.--What does that do???---Well, it lets the shift lever swing a bit from side to side, as well as back and forth.---Why would you want to do that???---Well, if you put a fairly stout compression spring over the bolt which goes thru the pivot center, between the side of the shift lever and one side of the housing that holds the bolt in place, it will crowd the shift lever pivot up tight against the other side of the housing. This will get rid of the side to side movement, UNLESS YOU DELIBERATELY PULL THE SHIFT LEVER TO ONE SIDE. Now, on the side of the shift lever opposite from the pivot, you have two things---one is the short lever that connects to the linkage which goes over to the side of your transmission. The other---(here's the trick part) is a lock-out pin. In this case the lock-out gate is simply a radial slot in a peice of metal plate attached to the part of your lever support bracketry that doesn't move. The pin attached to the short end of your shift lever is only long enough to engage the plate by about 1/8". Under normal conditions, you can not move the shift lever, because the movement of that pin is restricted by the length of the lock-out slot. (or lock-out hole). If momma or the kid, or your big old knee hits the shift lever by accident, nothings going to move. If, however, you want to shift gears, you grip the knob on the shift lever and push it sideways, just a tad. (opposite to the side that the lock-out pin is on.) Since the shift lever can rotate sideways against the spring, it will cause the side opposite from the pivot point to swing the other way, thus pulling the lock pin out of the gate---you shift to whatever gear you want it to be in, then release the shift lever, and if you've built the slots in the lock-out plate correctly, the lock-out pin will go back into a hole at that point, and the spring will return the shift lever to its normal position (not cocked sideways).

Or----(there's always an "or")---you can do it like Lokar does. There shifter will only move back and forth---no sideways movement at all. Instead of their lockout plate with slots being arranged to one side of the shift lever, it sets directly in line with the lever. There is a spring loaded sprag (which is just good old engineering talk for a peice of metal that engages the teeth on a gear to prevent it from rotating) fitted into the lower part of the Lokar lever. This "sprag" is kept in contact with the "teeth" on the lockout gate, so that the shift lever can not be moved. When you push down the button in the top of a Lokar shifter, this in turn pushes a flexible peice of cable, (Lokar shifters are actually hollow centered like a tube). The other end of this flexible cable retracts the sprag from contact with the teeth on the lockout plate, and allows the shifter to move.---Simple, Huh???

I'm not getting it Brian. Can you do one of your drawings? I have no play in my shift lever, it only goes up and back, no side motion whatsoever.

If I can see a picture I might understand.

Thanks, Don

Damn, Don---I was afraid you were going to ask that!!! Ah, well, anything for a friend. Its going to take a while, and right now my wife's got me stripping wallpaper (arghhhh)---I will do a model for you later today.---Brian

And I thought I was the only one on here with a "HONEY DO LIST"

Sorry Brain, I'm a little thick. No rush on the drawing, the car isn't going anywhere this weekend.

Don


Do I get to pick what colors you do the graphics in?


Hey Brian, haven't heard any updates on how your friends Chevy coupe is coming (the one you were pretty much building for him) How is it doing?

Okay Don---this is going to get kinda involved. This first model is a ball bushing. It is a 2 peice unit consisting of an outer housing (purple) and an inner bearing (yellow). The gearshift (we are going to show a plate style shift lever for simplicity), has a hole bored thru at the pivot point, and this purple bushing gets pressed into it. The purple outer housing is 1/2" thick, and is a hard press fit into the shifter, which is also 1/2" thick. (Sizes are arbitrary). The yellow ball inside the purple housing is free to rotate. The hole thru the center of the yellow ball is 3/8" diameter. The purple housing is 1 1/8" outer diameter.---Stay tuned----