Article: Follow up Friday - Down Pedal Assist In Depth!

[RiverDave]

You can view the page at http://www.riverdavesplace.com/forums/content.php?604-Follow-up-Friday-Down-Pedal-Assist-In-Depth!

 

[Monstrous]

Nice article...thx

 

[RiverDave]

Nice article...thx

Glad someone read it.. LOL I think we might have dug a little too deep for the average RDP crowd.. LOL I thought it was pretty cool though, because you don't see a lot of new products being developed for V-drives in recent times.

 

[Taboma]

OK, I found the article, read it and truly enjoyed it. Great job of explaining it Dave :thumbsup

Been over 37 years since I've pedaled my Hondo up and down the strip, to this day, the most fun I've ever had on the water :yikes

The force is strong to own another one, even over the strong objections of my aging back

I realize it's a bit late to be asking questions, but I am curious.

Do these air assist systems still provide a degree of pedal feedback ? (I felt the feedback helped me sense how the boat was setting up, heavy on the transom, light, etc.)

Is there still sufficient spring tension to allow your foot to rest or have a little pressure on the pedal ? Again partially for the feedback and partially to allow the plate to essentially follow what the bottom is doing.

Do you know if anybody experimented with a simple hydraulic master / slave set up, similar to a hydraulic clutch ? I'd think somebody must have tried it, but I've never read about it.

Again thanks, I enjoy these tech articles, when you posted this in the lounge it must have gotten blown out by the show and tell posts

 

[rivermobster]

I think the general consensus is its to slow to be a viable option.

 

[RiverDave]

OK, I found the article, read it and truly enjoyed it. Great job of explaining it Dave :thumbsup

Been over 37 years since I've pedaled my Hondo up and down the strip, to this day, the most fun I've ever had on the water :yikes

The force is strong to own another one, even over the strong objections of my aging back

I realize it's a bit late to be asking questions, but I am curious.

Do these air assist systems still provide a degree of pedal feedback ? (I felt the feedback helped me sense how the boat was setting up, heavy on the transom, light, etc.)

Is there still sufficient spring tension to allow your foot to rest or have a little pressure on the pedal ? Again partially for the feedback and partially to allow the plate to essentially follow what the bottom is doing.

Do you know if anybody experimented with a simple hydraulic master / slave set up, similar to a hydraulic clutch ? I'd think somebody must have tried it, but I've never read about it.

Again thanks, I enjoy these tech articles, when you posted this in the lounge it must have gotten blown out by the show and tell posts

Sorry for the delayed response Taboma! If you note the front assembly towards the pedals you will notice a gap between the air valve and the plate. The Pedal will operate in normal operation with the traditional spring tension until the air valve is engaged. After that the system engages. If we were to use 100 lbs of air pressure for a round number and the piston was 1 square inch, then it would reduce the tension on the rod by 100 lbs. I believe the cylinders are larger then that (1.5 OD with probably 1.250 ID? Just guessing from the pics) So we have to calculate the piston area which would be A=Pi *R(2) Area = 3.14 x .625 x .625.. It all adds up to about 122-123 pds at a 100 PSI assuming the cylinder diameters.

Because the system is an "assist" system and it is still all functioning in conjunction with each other as one giant part.. There's no difference between this and a solid rod going to the back of the boat. So Pedal Feed Back, and everything a traditional setup should do is exactly the same, with the exception of it being helped with 123 lbs of force towards the bow while in operation. So in short I think pedal feedback would be reduced a little because you aren't pushing as hard on the pedal, but it should still be there, because it is one linkage that is directly connected to the foot pedal. In a Hydraulic operation (with a pump) there wouldn't be any feed back..

I don't believe anybody has built a manual hydraulic setup yet, but there wouldn't be any benefit to it, other then ease of rigging (you could run hoses instead of linkages. It's all going to end up being some ratio that is pedal vs throw, vs throw vs plates, with whatever you want in between.

 

[Wombat]

Great read Dave, wouldn't mind also exploring a Hydraulic set up as well for my Sanger Flat bottom.

 

[Taboma]

No problem on the delay, just rolled in after a few days at Havasu

Appreciate the excellent conscientious technical response :thumbsup I enjoy your tech articles Dave !!

Your views on a hydraulic setup make perfect sense, lacking a hydraulic pump there's no gain except a more simple rigging. Rivermobster, I was thinking more for a river day cruiser versus a flat or runner bottom style or circle racer etc.

 

[Taboma]

Dave, although not exactly relative to this "Down pedal / cavitation plate" subject --- but close. In this post:

http://www.riverdavesplace.com/foru...NCE-Wednesday!!-upland-ca-909-982-8391/page96

There's a GT performance Hallett 210 with an interesting tab setup. I think what I'm seeing are large tabs, using hydraulic pumps (Appears there's two per side) yet controlled by a left foot pedal. I'd think given the relatively short hull length and huge tab size, they'd need to be fairly responsive.

Do you know anything about this particular setup ??

Thanks

 

[lenmann]

Nicely done Dave.

Your method of using the picture and then sequential text explaining what was going on is very effective. Being new to the whole v-drive performance boat deal, these kind of technical threads are particularly helpful to noobs like me.

Thanks,

Len

 

[stryderphoto]

Great stuff Dave, I learned alot from both the original piece and this follow up. :thumbsup