Floor board vibration

[F1 Rocket]

The forward floor board/bottom fuselage skin on my Rocket has a fair amount of vibration. Not normally an issue with the Velcro attached carpet I have in that area but it?s very noticeable when pulling some G since I tend to dig my heels in a bit. I?m curious what others have done in this area.

[fixnflyguy]

I have two friends with Rockets, both carpeted and I have not heard either mention of vibration. I have been in both planes myself. I have an RV-4 with similar construction, and it is a known fact that exhaust exit pulses can present vibration or drumming depending on the exit pipe angle. I have a 4 pipe system that is smoothest with all 4 pipes turned inward a few degrees. I put a layer of 1/8" high density fireproof silicone mat with a .025" stainless sheet bonded on top under my rudder pedals to stop vibration and heat and I have no carpet in mine, simply because I like my heels to slide on the metal.

[F1R]

Are your exhaust tips cut off at 90deg & pointing straight back? or are they angled downward slightly and cut off at an angle?

Dr. Dan Horton might be able to reference some research/ tests & or photos to illustrate what has been proven to reduce floorboard pulsation.

An SS skin on the bottom of the floorboard area would serve as a fire protection and properly done with a sandwich of vibration damping material, should calm and quiet things down.

I like the SS heel pads as described above for the inside.

I expect the F117 Engine nozzle theory might be useful to consider for your exhaust tips. Not so much for heat signature reduction , but for noise and vibration reduction.

https://aviationweek.com/aerospace/p...zzles-exhausts

[rocketbob]

Danny give me a call some evening. I have some exhaust turndowns I can send you to try. They were made by Vetterman.

[F1 Rocket]

Originally Posted by rocketbob

Danny give me a call some evening. I have some exhaust turndowns I can send you to try. They were made by Vetterman.

Hi Bob,
Please send me your phone number via PM.

[gereed75]

Might be work than your looking for, but I epoxied a foam core onto my RV-6 floor and then epoxied an aluminum sheet onto that creating a very stiff composite floor panel.

No vibration, exhaust pulses, nor heat and it provides a smooth floor without the mess of a carpet. I think it also gives the cockpit a more solid feel than most rv’s have.