Who is making plenums?

[DanH]

Bill, how much composite work had you done prior to technical research on diffusers, designing a plenum, building molds, and then teaching yourself the resin infusion process?

https://www.danhorton.net/Articles/1...sinInfused.pdf

[dwranda]

Originally Posted by Plummit

The statement ''Just build one" should have been followed by: "I'll be right over to help if you need it!"

-Marc

I envy guys that have a large local builders network. My tech counselor is an hour away and I only know of 1 other builder within 2 hours of me. He just started a 14A which I went with him to look at 3 hours away and he bought the kit. The nearest active EAA chapter is 2.5 hours away. Sometimes I feel like I am alone on an island, but then there is this oasis called VAF with the fantastic network of very smart and experienced help. There is NO way I would have attempted this project without it. That is why my donation was just sent in to Doug. Gotta keep this thing running!!

[BillL]

Originally Posted by DanH

Bill, how much composite work had you done prior to technical research on diffusers, designing a plenum, building molds, and then teaching yourself the resin infusion process?

https://www.danhorton.net/Articles/1...sinInfused.pdf

Sorry for a delayed response, I spent all day with Kevin Hortons spreadsheets creating some tables for my POH. What a excellent process Kevin has developed.

To the question - not much on composite work prior to launching into the project. A few patches and micro for voids in the gel coats. I made a what-went-wrong list of issues for each failure and changed the process to address. The first plenum was botched and massively heavy, so it became a buck, the 2nd & 3rd were resin infusion failures with epoxy that was too viscous. Lots of study and reading . . . The 4th one was pretty good and resulted in a well documented process.

Bottom line, it is not hard, it just takes willingness to do it and have a plan for what is going to happen after the epoxy is mixed. Small experiments are extremely helpful to understand questions, and build confidence. The PTM&W technical guy was very helpful.

I am convinced that the process you and Pete Howell used to make the layup on top of the engine is the one-off way to go. A hand layup might be a little heavier, but not much. The inlets were based on some rough drawings and made in pink styrofoam. If I had used your process, instead of making a mold, things could have turned out differently.

I can understand why plenums are not really available. There are three engine widths, plus the 540, and each plane has a different cowl. Not much volume to support capital investment, not to mention the effort of obtaining dimension for all the above. Sams plenum (according to him) is a copy of Dave Anders early one for his RV4. This is why it looks like it does.

A gallon of HTR, 4 yrds of 8oz, some pink foam and guts is all it takes. Then add micro, some body work, and cool paint. Anyone can do it. And . . free advice right here on VAF.

[crabandy]

Originally Posted by BillL

Sorry for a delayed response, I spent all day with Kevin Hortons spreadsheets creating some tables for my POH. What a excellent process Kevin has developed.

To the question - not much on composite work prior to launching into the project. A few patches and micro for voids in the gel coats. I made a what-went-wrong list of issues for each failure and changed the process to address. The first plenum was botched and massively heavy, so it became a buck, the 2nd & 3rd were resin infusion failures with epoxy that was too viscous. Lots of study and reading . . . The 4th one was pretty good and resulted in a well documented process.

Bottom line, it is not hard, it just takes willingness to do it and have a plan for what is going to happen after the epoxy is mixed. Small experiments are extremely helpful to understand questions, and build confidence. The PTM&W technical guy was very helpful.

I am convinced that the process you and Pete Howell used to make the layup on top of the engine is the one-off way to go. A hand layup might be a little heavier, but not much. The inlets were based on some rough drawings and made in pink styrofoam. If I had used your process, instead of making a mold, things could have turned out differently.

I can understand why plenums are not really available. There are three engine widths, plus the 540, and each plane has a different cowl. Not much volume to support capital investment, not to mention the effort of obtaining dimension for all the above. Sams plenum (according to him) is a copy of Dave Anders early one for his RV4. This is why it looks like it does.

A gallon of HTR, 4 yrds of 8oz, some pink foam and guts is all it takes. Then add micro, some body work, and cool paint. Anyone can do it. And . . free advice right here on VAF.

My second plenum was too heavy, but everything else was right and I'm still using it! Well, after I modified the front end again.......it's just fiberglass.

[scard]

Originally Posted by DanH

https://www.danhorton.net/Articles/1...sinInfused.pdf

Not to hijack the thread, but, holy posted treasure trove Dr. Horton! I must have missed it, but when did you become so "internet savvy"? Thanks for getting affairs in order and getting your collection out for us public to sniff through.

[gmcjetpilot]

Originally Posted by BillL

A gallon of HTR, 4 yrds of 8oz, some pink foam and guts is all it takes. Then add micro, some body work, and cool paint. Anyone can do it. And . . free advice right here on VAF.

Ha ha ha ha...

Bill I tried to send PM but your inbox is full. Sent email. Hope you get it. Thanks

[Charles in SC]

Originally Posted by 6 Gun

Sam sends you the plans for the aluminum baffles real easy to make for the James plemums.
Bob

Maybe my engine setup was different but the baffle templates I got with mine were not much help. There were some big differences in what mine needed. YMMV.