Projects Let’s Redesign A Brake Pedal Arm or Not?

are you still going to be on the right side of the column looking down upon it?

 

@nobby currently it’s left of the column. When I get profile layout squared away (all bugs worked out) I’ll be laying out for a Z bent from a plan view perspective to get pedal over to the right.

 

yes, this is the hot-rodding for sure.
I am going to try doing a cam at the fulcrum for a modern flick out brake light switch
atop of which has the return spring.
its amazing how many of them have the flickering brake lights

 

Not exactly sure what you mean by getting the pedal pad up higher on the toe board. It looks as if you moved the pivot forward, Point 1 in the picture would not hit the floorboard. I would remove the the pedal ***embly from the pivot and slide it forward till you can make surface 5 fit flush to the bottom of the floorboard . Then I would put a spacer between surface 5 and the floorboard. I'd look at where the pivot hole is now located and try making a temporary pivot. As for the pushrod, if it hits, I would flatten 4 slightly or put a notch in it with a filler piece. My concern is that the finish location for the pedal will be too high for driving comfort. I'd sit in the vehicle and locate exactly where the pedal feels right and work back from there to the location of the pivot point.
I think you are doing a lot of nice work to fab this up, so please take my comments constructively.

 

I stand corrected Pete, your correct in what you said. In fairness to me I did not absorb what you meant by pointing back vs up at me. Now, for the last two day’s I’ve had how a modern brake pedal arm works on my mind and how it’s fulcrum makes for a nice horizontal action for the driver of a vehicle.
There’s a reason why I cut a cardboard arm out. It’s so I can look at it and take in what I’m not seeing despite what help is being offered to me. See, thing’s don’t alway’s translate well for me in written form. That said, had you said John the way your layout is right now will cause you to have to push down ward on the pedal vs forward on it. I know, same thing but different wording.
There’s a reason why the ***le of this thread has the word’s “let’s”. Thanks Pete.

 

Ya, I just posted about that just below your reply. Thanks for sticking with me on this.

 

And a Thanks to Rich B. This photo was the kicker that had me hold the still intact pedal arm forward and see what would happen.

 

@Pete Eastwood @ekimneirbo tacked in temporary pivot and mocked up floor to set just as it would when cab is dropped into place.

Before and after. Better?

 

No turning back

 

Got master down 3/4” and forward 2”. Going to try for another 1/4” forward. Ever bit help’s cut down push rod length.

 

Sorry, my question about pedal angle, wasn't about location left or right. It was how the actual rubber pedal will be located at what angle to the arm. But I'll just wait and see how you do it.

 

@1971BB427 I’m unsure at the moment. Most likely a tap off to the right.

 

I wouldn't sweat the longer pushrod length as longer will give less angularity to the master cylinder which can be an issue depending on the relative heights of the pivot points. Of course longer will require it to be of suitable material to avoid flex and must be controlled such that it isn't able to fall out.

Suggest you put your foot, or maybe just your shoe on a temporary or imaginary floor to gauge what if might be like in use.

Chris

 

I forgot to mention, well it came to me rather later; SoCal do a lengthened pushrod for this purpose, so if you want plug and play, or maybe just inspiration?

Chris

 

If strength of the pushrod is a problem, maybe a larger size tubing with short/smaller stubs at each end. You could thread the inside of the tube so the stubs could adjust length. A piece of thicker wall chrome moly tubing should easily work. I might have some if you can't find any.

 

Back on it today. Work is slow (some of you know why) but I’ve decided not to get that extra 1/4”. Bail clip has clearance, why make it worse. More than enough push rod available in this unit I picked up. Look’s like 2” shorter than what it is posted below will be the end length.

 

Cleaned up the frame and finished scribing in bracket. Also checked that push rod will be square/in line to master from the brake pedal.

 

Johnny
Ain't those aluminum trailer stands the neatest things to have around!

 

Yes Sir

 

Those brake pedals always need some tweaking. It nicer driving if you can get the pedal on the right side of steering column and so you don’t have to pick your foot way up. If you can get the steering clear of the feet even better.
Lots of compromise and ingenuity and CAD
Cardboard aided design.
Looks good.

 

As long as you don't put much weight on them.

 

**** me added a strip of metal to give inner edge more riggedity.

Before and after.

 

To close the day out.

 

Pretty soon

 

Not in the cards for this one. This thing came with one of them mini vacuum boosters but I told her I wasn’t going to use it.

To think of it, maybe it’s because of that booster is why it got set up the way it was???

 

It appears your pedal shaft is tacked to the boxing plate. A much stronger set up would be to use a longer
shaft run all the way thru to a hole in the outside frame rail, welded to both, with a additional collar
added for additional strength.

 

@Blake 27 stay tuned.

 

Not much building today. Just lot’s of time doing boring stuff to make sure pivot point will be good. Then there’s my redesign of the pedal. However I jumped the gun and had all ready changed the radius of the arch to 13” radius from the 10” it was originally. But I got it back.

Also moved mock up pivot forward 3/16” from where I placed it last week. Lower pivot looks good and there is still pedal above the toe board when fully depressed.

 

Here’s a thought. If motorcycles can use bellcranks on brake pedals why not me on a car? I like that a lot better than Z-ing the pedal arm.

Example

 

About the best you can do in the pedal arm itself is a slight off set bend.
Z a pedal always has too much flex. Bell crank or extended axle between the plunger and the arm. There’s usually some extra brace from the frame to bolt too.