Any interest in a cargo pod?

[whee]

Does anyone have any interest in a cargo pod for their 4-place BH? It could probably be setup for use on the model 5 as well. Fitting the Patrol is probably a stretch but not an impossibility.

This is a project I would like to get done for my airplane and put into use this summer. I have reached out to a composites company to see about getting a mold made and a proper layup for the pod determined. I am confident that the cost will exceed what I'm willing to spend for a single pod for my airplane but is may be a possibility if other builders are interested.

[Luke68]

What are your plans for attaching it and how big of a pain will it be to take on and off?

[whee]

What are your plans for attaching it and how big of a pain will it be to take on and off?

It will attach the same way Cub pods are attached; welded tabs or adel style clamps on the longerons with stainless straps slinging under the pod. The guys I've talked to say their cub pods take about 10 minutes to remove and a bit more to install.

[Luke68]

Have any idea on cost?

[whee]

Not sure at this point. All the experimental Cub pods I've looked at are $3000 USD give or take a couple hundred depending on the pod. That's my current ballpark at the moment.

[Luke68]

I’ll probably have to wait a bit, hoping to buy a panel in the next few months so I better reserve some funds for that.

[Battson]

I am interested, however shipping to NZ would be the trick. I would think we get a group order together and put them in a shipping container when one of the next kits comes over - there is a lot to come to NZ!

I cant make a pod stack up unless you are hauling light weight gear and have 5/6 seats filled. I find myself in that situation now, so it them becomes a question of the exact CG figure and the price.

The crux of this question is CG and price.

With my children on board, right now I have a spare 50kg (110lbs) spare load at the rear seat station. It hit the CG limit first, with useful load to spare.

So assuming the pod weighs 20lbs or thereabouts, that leaves 90lbs or 40kg to put into the pod. Not heaps, but enough that it would be very helpful.

[whee]

I could just fill a container with pods...and my household goods....

CG concerns is what has prevented me from moving forward for the past 2 years. My current plan will place the majority of the pod space below the feet of the middle passengers. This seems pretty good to me. Now I need to make sure the weight of the pod itself does not compromise the empty CG of the airplane. I do not think it will because I'm being told the pod can be built to weigh 10-15lbs and still strong enough to support 300lbs.

[Hewko]

I am interested at this point if it will work on a 5, once more info and price is available I can confirm.

[Bcone1381]

Are you building or buying? I built kayaks in the past using Skin on Frame design. I'm building my Patrol and have no interest in building a cargo pod right now. I only tell you this because I believe this design method may be suitable for a cargo pod. All joints are lashed with multiple wraps using a stretchy 50 lb tensile strength nylon cord . Joints have give on impact, no glue or screws are used....no cracks. Very robust and light weight.

A Frame could be lashed up in maybe maybe 16 hours, covered with aircraft fabric, If you so desire an outer shell could be then fabricated from your favorite cloth (Fiberglass, carbon fiber, or Kevlar) and epoxy. A 17 foot kayak made using this method is 28 pounds. I think an 8 foot pod would be less tan half that. Double cover the frame instead of a composite frame would also save some weight.

This is a bucket list item for me.
Screen Shot 2022-01-26 at 11.07.36 PM.png

[m.mooney]

I'm definitely interested but I've got a Patrol. I have a friend who builds pods for super cubs and carbon cubs. I've been harassing him for close to a year to find time to build me one. He's so busy that he's yet to give it any serious thought. If there's interest in this from other Patrol owners, I might be able to convince him that it's worthwhile. He's crawled all over my Patrol and thinks it is completely feasible with modification to his existing pod. This might work for the 4 place also. If Whee's inquiry doesn't work out and there is enough interest from Bearhawk owners, I'll do my best to pursuade him to take it on, Patrol, 4/5 place, who knows? His work is absolutely Top Shelf and I'm sure the price would reflect that. $3000 seems too low for what's required of a small production run. The pods are amazing and he's now building a combo fuel/cargo pod for cubs. Hopefully Whee's search is fruitful.

[milehighpeter]

I have a Patrol and would also be interested in a Pod. I have one on my Super cub and never take it off.

[Light&Sweet]

I would be interested in a Patrol pod. Seems like the building phase would be the perfect time to consider a pod so mounting tabs and fuel plumbing could be accounted for.

[AKLawler]

I really want one for my Patrol. When you have 2 people plus camping gear it's hard to get everything in the baggage area. I'm going to talk to Randy at Carbon Concepts at some point this year and see what he can do.

[whee]

I'm definitely interested but I've got a Patrol. I have a friend who builds pods for super cubs and carbon cubs. I've been harassing him for close to a year to find time to build me one. He's so busy that he's yet to give it any serious thought. If there's interest in this from other Patrol owners, I might be able to convince him that it's worthwhile. He's crawled all over my Patrol and thinks it is completely feasible with modification to his existing pod. This might work for the 4 place also. If Whee's inquiry doesn't work out and there is enough interest from Bearhawk owners, I'll do my best to pursuade him to take it on, Patrol, 4/5 place, who knows? His work is absolutely Top Shelf and I'm sure the price would reflect that. $3000 seems too low for what's required of a small production run. The pods are amazing and he's now building a combo fuel/cargo pod for cubs. Hopefully Whee's search is fruitful.

Is your buddy Ted? His pods look great and I’m positive you could make one work on a Patrol. His price is is right at the $3k mark without the fuel pod. Unfortunately the dimensions aren’t great for a 4-place.

The PA-12 pod build the Alaska Bush Pods (Firmin Pods) is another option for the Patrol.

I’m not positive on the dimensions of the Patrol or the BH5 so I can’t say for sure but…

The 4-place tapers from 33” to 35” to 28” over a length of 78 inches.

The Patrol is 32” wide? The BH5 is 4” wider than the 4-place?

A 33” tapering to 28” x78” pod is what I think would be best for the 4-place.

The eAeroFab pod is 29” x 96” and the Firmin pod is 24”x 84”. Both pods taper to about 22” at the rear.

[m.mooney]

No, Eric Lewis (Lewaero Works on Facebook?). He builds the pods for cubcrafters and is one of the fab guys behind the Double Ender airplane, if you’re familiar. Aurora, Oregon (Pdx area). I think most of the pods that you list will work on a Patrol with modifications but Eric’s would be a custom fit of his “bubba pod” which is appealing.

[whee]

Eric’s Bubba pod looks pretty cool! Similar in size to the Firmin Jumbo pod. If I were flying a Patrol that would be a great option and it wouldn’t have to be shipped from AK.

[Wyo Johnson]

Whee,

Youtube "resin transfer molding"...it was invented for aerospace, but the boat guys jumped on it quicker than general aviation. Most of the heavy structure for wing skins, wing boxes and flight controls on Boeing and Airbus are built using some variant of transfer molding.

Basically you could build a "plug" out of 2" foam with a couple bulkhead made out of 1/8" or 1/4" masonite (double hard board). This would require some sanding and cussing, but would give you an Inner Mold Line (IML) form that you then could either epoxy paint or wrap in a "peel ply" to give it a surface that the composite cloth won't stick to. Forming the foam could be roughed out with a hotwire bow, which can be made from stuff at lowes/hardware store or you can buy them.

Transfer molding uses dry fabric in a vacuum bag with extra vacuum ports. Once the bag is pulling vacuum, the extra ports are used to suck in the resin. This allows for an aerospace type finish (depending on how good your plug is) with no starvation or "extra" resin like with wet layup/vacuum bagging. The more resin you get out up to starvation the stronger the part.

I have experience with Cessna Caravan Pods and they have bulkheads in them that create "bays" so that cargo can't shift in flight and jack with your CG. Each bay has an access door with cam locks.

Bulkheads for the pod could be made in a similar fashion and then bonded in with structural epoxy (think toothpaste on steroids) made my 3M or CB etc.

The hardest part of this is not the composites...it would be sizing and mounting. I'm willing to help with AutoCad support and could build you a basic lofting with templates for the bulkhead and body shapes. Those shapes could be printed out and glued to the masonite and foam as a template that you could hotwire and/or sand to. 3M makes a great spray adhesive in a can or you can use resin, but its messy and sometimes are to sand.

I would think you would want this to start aft of the gear struts and end close to the rear cargo bulkhead. Mounting scheme would have to be tested but you could make some "test articles" and pull test them...just thinking out loud.

Andy

[AKKen07]

Hey Whee, give Randy at carbon concepts a call. He has made BH pods and will be happy to chat with you. He almost talked me into one but I made my plane non compatible with a couple of extra fuel drains underneath. I like talking with Randy - always has good ideas.

[whee]

Thanks Ken. I texted with Randy about a year ago after seeing a video of his pod on a Maule. It’s made for a wide body Super Cub, so about 29” wide, and trimmed to fit the belly of a Maule or BH. If I recall correctly your drains are below the door posts. The BH is 35” wide at that point so I would think his pod would work on your plane.

[AKKen07]

My drains are below door posts but inboard on the lower stringers. No go I’m afraid.

[whee]

Whee,

Youtube "resin transfer molding"...it was invented for aerospace, but the boat guys jumped on it quicker than general aviation. Most of the heavy structure for wing skins, wing boxes and flight controls on Boeing and Airbus are built using some variant of transfer molding.

Basically you could build a "plug" out of 2" foam with a couple bulkhead made out of 1/8" or 1/4" masonite (double hard board). This would require some sanding and cussing, but would give you an Inner Mold Line (IML) form that you then could either epoxy paint or wrap in a "peel ply" to give it a surface that the composite cloth won't stick to. Forming the foam could be roughed out with a hotwire bow, which can be made from stuff at lowes/hardware store or you can buy them.

Transfer molding uses dry fabric in a vacuum bag with extra vacuum ports. Once the bag is pulling vacuum, the extra ports are used to suck in the resin. This allows for an aerospace type finish (depending on how good your plug is) with no starvation or "extra" resin like with wet layup/vacuum bagging. The more resin you get out up to starvation the stronger the part.

I have experience with Cessna Caravan Pods and they have bulkheads in them that create "bays" so that cargo can't shift in flight and jack with your CG. Each bay has an access door with cam locks.

Bulkheads for the pod could be made in a similar fashion and then bonded in with structural epoxy (think toothpaste on steroids) made my 3M or CB etc.

The hardest part of this is not the composites...it would be sizing and mounting. I'm willing to help with AutoCad support and could build you a basic lofting with templates for the bulkhead and body shapes. Those shapes could be printed out and glued to the masonite and foam as a template that you could hotwire and/or sand to. 3M makes a great spray adhesive in a can or you can use resin, but its messy and sometimes are to sand.

I would think you would want this to start aft of the gear struts and end close to the rear cargo bulkhead. Mounting scheme would have to be tested but you could make some "test articles" and pull test them...just thinking out loud.

Andy

It is so interesting how ones perspective changes things. To me the sizing and mounting are easy; composites are the challenge. With a layup plan and a little instruction I could do it but developing the plan is something I haven't a clue about. If I can hand someone a plug and have them return to me a mold and a layup plan for a affordable amount of money I think it would be worth while.

Bulkheads make sense in something big like a Caravan pod but none of the regular GA pods I've seen have them. The Cessna 185 pod is pretty huge, 35" x18" x 108", and even it does not have bulkheads. Plus they would prevent you from loading long items like skis, oars, and kayak paddles.

Andy, If you have the knowledge to develop a layup plan and can help me source the materials and tools then I'm game for some sort of collaboration. Same goes for others that have knowledge in composites.

[Wyo Johnson]

Whee, happy to help...I think if you're smart enough to build a Bearhawk from scratch, you're smart enough to build a carbon or fiberglass "blister"

The bulkhead thing is a tradeoff...throw a couple bulkheads in and your rigidity goes up and you can make the "hull" thinner lowering your weight of the unit. The bulkheads can have a hole in them...think frame on an aircraft, they are just there to add rigidity to the pod so you can lower the skin plys on the outer hull (saving weight). Long stuff still can fit but short fat items can be contained betwen with the bulkheads with a simple bungee net. The bulkheads also will make "zones" that allow you to keep stuff in the zone (cargo shift)...there's a ugly video of a 747 freighter coming out of Bagdad that the load shifted and it was a bad day (I was involved on the Boeing side and knew the pilot on a personal side). Load shifts can kill you. Russ Erb's article about the wind shear he got caught in comes to mind...

The other idea is to use stringers...easy to do as you can use pultruded rod (fishing pole rod) and strips dry and infuse them in the vacuum bag.

I'm not a stress guy so mounting would still be a guess, but sounds like you have experience with other pods, and if it "ain't broke don't fix it".

I can help getting you to speed on the composites. The only tooling you need is a good vacuum pump which can be purchased from and Airconditioning shop or built from a compressor off a refrigerator (seriously). The rest of the "composite" tooling you can get at the hardware store.

The plug or mold you could start on as soon as you lock down the size and shape. Look up Rock West, ACP composites or VectorPly for fabric (100's of choices).

PM me and I'll kick you a phone and we can compare notes.

Andy

[svyolo]

I made a extended cargo tube for light stuff. I used an 8" round pressed cardboard concrete former as a male mold. I layer of heavy CF, and some scraps of kevlar on the bottom/outside as kind of a safety backup. I used 2 external formers of CF/kevlar at the front and middle which also mount to the fuselage tubing. Rear former is inside/rear of the tube. The formers really stiffen up the tube. I think the 8" tube (42 or 44" long) weighs 22 oz. I will probably put a 5 lb limit placard on it, but I am pretty sure double that would be ok for long items.

[svyolo]

I know it is somewhat common on some aircraft type to have tip tanks. If you needed more space, I wonder if you could use the outboard wing panel for light stuff like clothes. Or make "cargo tips".

[Wyo Johnson]

composites are really a "dark science" but one thing to remember is the more resin you get out of the fabric (up to starvation) the stronger the part becomes for a given weight.

A good example is the corvette. From the beginning until the 2000's they were "wet layup" using chopped fibers "shot" into a mold with lots of resin (like a boat). They are heavy and crack all the time. Finally they started using vacuum bagging and "pressing" all the resin out of the fabric that is extra...lowering the weight dramatically and making the part stiffer. The current vettes use a resin transfer system where they put dry fabric into a rigid mold and then pressure inject the resin into the mold.

So the next question would be "how do I get all the excess resin out of the fabric"....vacuum bagging and using 15-21" of vacuum. Every inch of vacuum is 14.7 psi of pressure on the bag. 21" of vacuum is 308.7 pounds per square inch pressing on the bag...that is a lot of force which if you're using wet layup and have a layer in the bag so soak up the excess resin...you can make an aerospace quality part in your garage.

Your tool has to be rigid enough to handle the vacuum pressure...

Whee has really got me thinking (while I'm sitting in stupid meetings at work) about the different approaches to this...Firmin pods are one example that I stumbled into...simply strapped to the belly and the mounts would be like a float or landing gear mount.

These seem to be limited to light weight and/or soft items as there is a trade off for weight to rigidity...but you could carry rifles, spare tire(s) or a mountain bike if you designed it right.

Another design consideration is you would have to think about the mounting so it would interfere with the float mounts (if you were or in the future wanted to be so equipped). Also how do you weld on the attach points on a covered aircraft...no impossible but a little bit of work.

Seems something to be interesting in scratch building as a pod for a "wide cub" or a C180/185 run from $2500 and up...you can buy a lot of foam, sand paper, resin and cloth and still pay yourself pretty well for all the cussing in the shop...

[Russellmn]

Instead of welding mounts on a completed fuselage, how about bending steel to wrap around the tubes with both ends poking through the fabric to be your mounting tabs? Then there's no welding involved, just a little cut in the fabric for the tab to exit.