Form's OFNA linkage setup

[Form]

I did a version of the OFNA linkage mod and was not satisfied with the results. The throttle linkage was bending a lot and that introduced some lag when pressing the throttle, plus it was not that precise in general due to the bendy throttle mix arm.

Here is my new take on the OFNA linkage mod:

http://www.youtube.com/watch?v=7-p2w659bXo

There's only one bend in the throttle linkage and I made some kind of "brake stopper" which you'll see in the video, works pretty well!

The throttle mix arm is this: http://www.ghhobby.com/proddetail.php?prod=2604

I hope I can inspire somebody with this!

Here are some pics:

I ordered some Team Associated balls that came with a screw but they were not the right size… so I dremeled the ball until it fit in the OFNA cups. It fits even better than the OFNA balls and does not stick. I used some threadlock on the screw so it doesn't come off.

I re-made the linkage to the throttle and bent the metal bar so there would be zero slack:

The Team Associated ball is also lower, so it pushes more "directly" on the mix arm:

Gratuitous shot of my hands:

 

[Shaun]

awsome job!! the ofna mod is next on my list!!!!

 

[frddyj]

Awesome how to thread you made for us to see so + rep to you Mike.


did you have to grind the linkage ball on the throttle mixer to get it to swivel without binding?

 

[Form]

Awesome how to thread you made for us to see so + rep to you Mike.


did you have to grind the linkage ball on the throttle mixer to get it to swivel without binding?

Yep, as I said the ball was too big for the OFNA cup so I had to grind it else it would not fit at all. In the end it has a better fit than the OFNA one, without any binding at all.

 

[ikesavage]

Nice vid but movement on the linkage is a bit to quick to see how good it works. I see your brake stopper at the end next to the mixer but not real sure what its doing?
Heres a pic of my set up working on the brake set up next

http://viewmorepics.myspace.com/ind...mID=656681&imageID=4931782#a=656681&i=4931970

 

[Form]

Nice vid but movement on the linkage is a bit to quick to see how good it works. I see your brake stopper at the end next to the mixer but not real sure what its doing?
Heres a pic of my set up working on the brake set up next

http://viewmorepics.myspace.com/ind...mID=656681&imageID=4931782#a=656681&i=4931970

If it's too quick to see then it must be good heh! jk I'm 100% positive this is better (more linear response) than the "traditional" OFNA throttle mod (4 bends in the throttle rod to go around the "roll cage") which introduced a lot of lag because the rod was bending before kinda getting its original shape back.

Also I move it pretty slow at times in the video, I don't see why you say it's too fast to see… anyway.

The brake stopper actually only prevents the brake rod from being pushed too far when giving some throttle and braking the other way. Not necessary but this way the brake is completely 100% OFF when the carburetor opens, even if the brake linkage sticks a bit and pushes the other way.

P.S: Just added two pics of the completed linkage… I just realized there was no final result pic with all the stuff on there!