Pedal Buzz - 3D printed solution?

[Leucadian]

Ever since the car was converted to DCOEs I've had a intermittent buzz in the pedal when my foot is off the gas and on the brake.  Right now, the carbs are soft mounted, and the pedal linkage is a single piece of bent hex stock, fabricated by Ronin Auto, the connects the linkage to the pedal.  I suspect the hard mounted nature of the hex stock is what's causing the buzz to be transferred to the pedal.  The gas pedal itself is new and the floor nubs are in good shape, so there's no play at the pedal/floor connection.

 

 

I have access to a resin based 3D printer in my office, and I was thinking of printing a spacer that would close the gap between the pedal arm and the pedal slide, shown in red below.  Or, I could find an additional bushing that's larger than the one that is currently on the pedal linkage.  I'm a little worried about reducing the amount of play between the two elements and causing the pedal to bind.  

 

 

Seems like there might be an easier fix.  I've read in another thread that adjusting the idle can eliminate the sympathetic vibration in the pedal, but the buzz only occurs at decel.  Maybe a rubber bushing between the pedal box linkage and the hex bar connection to isolate the buzz?

 

The car runs great, and I haven't had any issues with the carbs coming out of synch, so I'd rather try and keep my carb linkage setup as is, and just fix the buzz.  Open to ideas!

 

 

 

 

[TobyB]

Preload everything with springs- 

then all the parts stay in contact, and as a 

bonus there's less lost motion.

And on top of that, if one spring fails, there's backup.

 

Lots of older stock linkages do just that, and sometimes

it's not obvious how they (cunningly) load everything up.

Those spherical bearings can rattle, too- good ones are slightly 

stiff, which isn't good for throttle linkages, so most use 'unlined'

bearings, and they have a little free play.

 

I wish you luck keeping those synced...

I never had much luck with the double- push linkage

that came with my car.

 

t

 

[Leucadian]

Sage advice sir - I'll see what I can do to preload the pedal box arm against the rear of the pedal slide.

 

I'll see how long the push linkage keeps everything synced, it's only been a few months...Worst case, I'll swap out the whole linkage for the @halboyles system.

[Son of Marty]

One of my problem with the double post on the manifold type linkage is the engine rocking will push and pull on the throttle levers, where the factory type with the single ball joint resists this input. And as Toby said they are hard to keep in sync.

[Mike Self]

Does your accelerator linkage at the pedal end have its plastic ferrule on it?  That will help some, and if you clean off the back side of the pedal and apply a piece of Slick Tape, it'll insulate linkage from pedal even more.  PM me for more information on slick tape.

 

mike

[Leucadian]

10 hours ago, Mike Self said:

Does your accelerator linkage at the pedal end have its plastic ferrule on it?  That will help some, and if you clean off the back side of the pedal and apply a piece of Slick Tape, it'll insulate linkage from pedal even more.  PM me for more information on slick tape.

 

mike

 

Thanks Mike.  It does have the little ferrule.  I've got some slick tape, so we'll see if that helps.

[2002Scoob]

I 3D printed a bushing for my buzzy pedal a few years back, works great. Did it out of CPE.

[2002Scoob]

+1 for ditching the double push linkage as well as the soft-mounts on the carbs. 

 

you can convert a double push to a single center - push if you've got one of those adjustable sync lever dealies that goes between the carbs. It's what I did a while back and works much better. 

[Leucadian]

1 hour ago, 2002Scoob said:

I 3D printed a bushing for my buzzy pedal a few years back, works great. Did it out of CPE.

 

Was it a larger bushing to fill the extra space in the pedal slide?  

 

I just ordered a synchrometer to check to see if things are in sync as I think they are (based on everyone's input, they may not be)

 

I'll probably pick up the Hal's linkage and call it a day

[Leucadian]

Ended up printing a small spacer bar to close the gap between the pedal and the throttle arm bushing

 

 

Added some teflon tape as well for good measure, and now no more buzz!